All of the following observations are real. Which one does not support the model in which active galactic nuclei are powered by accretion disks around massive black holes?

The most luminous active galactic nuclei have huge redshifts. More test answers on https://studyhippo.com/mastering-astronomy-chapter-21-galaxy-evolution/

(14) Why do sunspots appear dark in pictures of the Sun? A) They are too cold to emit any visible light. B) They actually are fairly bright but appear dark against the even brighter background of the surrounding Sun. C) They are holes in the solar surface through which we can see to deeper, darker layers of the Sun. D) They are tiny black holes, absorbing all light that hits them. E) They emit light in other wavelengths that we can’t see.

B. They actually are fairly bright but appear dark against the even brighter background of the surrounding Sun. More test answers on https://studyhippo.com/astronomy-final-ch-14/

Many nearby galaxies (a) will become black holes; (b) contain quasars; (e) have radio lobes; (d) were more active in the past.

d) were more active in the past More test answers on https://studyhippo.com/chapter-25-33748/

All of the following observations are real. Which one does not support the theory that active galactic nuclei are powered by accretion disks around massive black holes? 1. X-ray emission from active galactic nuclei can vary significantly in times as short as a few days. 2. Spectra of active galactic nuclei show that clouds of gas are orbiting a central object at very high speed. 3. The most luminous active galactic nuclei have huge redshifts. 4. The total luminosity of an active galactic nucleus can be as high as about 10 billion times that of the Sun.

3. The most luminous active galactic nuclei have huge redshifts. More test answers on https://studyhippo.com/astronomy-chapter-21-concept-quiz/

Black holes are formed from the collapse of ____ stars, and _____ be directly viewed through telescopes.

very large, cannot More test answers on https://studyhippo.com/earth-science-test-1/

White dwarfs are so called because ANSWER: they are the opposite of black holes. it amplifies the contrast with red giants. they are both very hot and very small. they are the end-products of small, low-mass stars. they are supported by electron degeneracy pressure.

they are both very hot and very small. More test answers on https://studyhippo.com/assignment-08-chapter-18-the-bizarre-stellar-graveyard-39295/

Black holes, images of x-Rays

The Chandra X-Ray Observatory is used to study _____ _____ and produces More test answers on https://studyhippo.com/science-studying-the-sun/

White dwarfs are so called because A) they are both very hot and very small. B) they are the end-products of small, low-mass stars. C) they are the opposite of black holes. D) it amplifies the contrast with red giants. E) they are supported by electron degeneracy pressure

A) they are both very hot and very small. More test answers on https://studyhippo.com/astr-102-chapter-18-the-bizarre-stellar-graveyard-35656/

Tides are influenced by the gravitational forces of black holes.

F More test answers on https://studyhippo.com/oceanography-chapter-11-efsc/

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Eng 3 Unit 5 Test Review: Harold Incandenza, Death by Black Hole, Fast Food Nation – Flashcards 20 terms

Jamie Hutchinson

20 terms

Preview

Eng 3 Unit 5 Test Review: Harold Incandenza, Death by Black Hole, Fast Food Nation – Flashcards

question

That's the gory moment when your body snaps into two segments, breaking apart at your midsection. Upon falling further, the difference in gravity continues to grow, and each of your two body segments snaps into two segments. Shortly thereafter, those segments each snap into two segments of their own, and so forth, and so forth, bifurcating your body into an ever-increasing number of parts: 1, 2, 4, 8, 16, 32, 64, 128, etc. After you've been ripped into shreds of organic molecules, the molecules themselves begin to feel the continually growing tidal forces. Eventually, they too snap apart, creating a stream of their constituent atoms. And then, of course, the atoms themselves snap apart, leaving an unrecognizable parade of particles that, minutes earlier, had been you. Which statement best describes how the author conveys the message that humans are no match for the power of a black hole?

answer

Tyson stresses humanity's relative insignificance in the universe, while Collins stresses man's perceived importance

question

Read the excerpt from Neil deGrasse Tyson's "Death by Black Hole." That's the gory moment when your body snaps into two segments, breaking apart at your midsection. Upon falling further, the difference in gravity continues to grow, and each of your two body segments snaps into two segments. Shortly thereafter, those segments each snap into two segments of their own, and so forth, and so forth, bifurcating your body into an ever-increasing number of parts: 1, 2, 4, 8, 16, 32, 64, 128, etc. After you've been ripped into shreds of organic molecules, the molecules themselves begin to feel the continually growing tidal forces. Eventually, they too snap apart, creating a stream of their constituent atoms. And then, of course, the atoms themselves snap apart, leaving an unrecognizable parade of particles that, minutes earlier, had been you. Which statement best describes how the author conveys the message that humans are no match for the power of a black hole?

answer

He personalizes the experience for the reader and uses vivid imagery to create a clear mental picture.

question

Read the excerpt from Fast Food Nation. Up and down Academy Boulevard, along South Nevada, Circle Drive, and Woodman Road, teenagers like Elisa run the fast food restaurants of Colorado Springs. Fast food kitchens often seem like a scene from Bugsy Malone, a film in which all the actors are children pretending to be adults. No other industry in the United States has a workforce so dominated by adolescents. How does Schlosser effectively build his argument in this excerpt?

answer

He uses analogical evidence to help the reader visualize his point about the workers

question

Read the excerpt from Neil deGrasse Tyson's "Death by Black Hole." If you stumbled upon a black hole and found yourself falling feet-first toward its center, then as you got closer, the black hole's force of gravity would grow astronomically. Curiously, you would not feel this force at all because, like anything in free fall, you are weightless. What you do feel, however, is something far more sinister. While you fall, the black hole's force of gravity at your two feet, they being closer to the black hole's center, accelerates them faster than does the weaker force of gravity at your head. Read the excerpt from Billy Collins's "Man Listening to Disc." the only true point of view, is full of the hope that he, the hub of the cosmos with his hair blown sideways, will eventually make it all the way downtown. Which choice best describes the differing views Tyson and Collins present of humanity?

answer

Tyson presents humans as powerless against the forces of nature, while Collins presents an individual creating his own destiny.

question

Read the following excerpt from Levitt and Dubner's Freakonomics. There is a tale, "The Ring of Gyges," that Feldman sometimes tells his economist friends. It comes from Plato's Republic. A student named Glaucon offered the story in response to a lesson by Socrates—who, like Adam Smith, argued that people are generally good even without enforcement. Glaucon, like Feldman's economist friends, disagreed. He told of a shepherd named Gyges who stumbled upon a secret cavern with a corpse inside that wore a ring. When Gyges put on the ring, he found that it made him invisible. With no one able to monitor his behavior, Gyges proceeded to do woeful things—seduce the queen, murder the king, and so on. Glaucon's story posed a moral question: could any man resist the temptation of evil if he knew his acts could not be witnessed? Glaucon seemed to think the answer was no. But Paul Feldman sides with Socrates and Adam Smith—for he knows the answer, at least 87 percent of the time, is yes. Feldman reaches the conclusion that most people are honest without receiving an incentive by

answer

studying his individual experiences and arriving at a broad generalization.

question

Read this statement from an argumentative speech. Students with inconsistent bedtime routines are less successful in school than their peers. What is most needed to strengthen this statement?

answer

facts and statistics

question

Read the following excerpt from Levitt and Dubner's Freakonomics. The bagel data also reflect how much personal mood seems to affect honesty. Weather, for instance, is a major factor. Unseasonably pleasant weather inspires people to pay at a higher rate. Unseasonably cold weather, meanwhile, makes people cheat prolifically; so do heavy rain and wind. Worst are the holidays. The week of Christmas produces a 2 percent drop in payment rates—again, a 15 percent increase in theft, an effect on the same magnitude, in reverse, as that of 9/11. Thanksgiving is nearly as bad; the week of Valentine's Day is also lousy, as is the week straddling April 15. There are, however, a few good holidays: the weeks that include the Fourth of July, Labor Day, and Columbus Day. The difference in the two sets of holidays? The low-cheating holidays represent little more than an extra day off from work. The high-cheating holidays are fraught with miscellaneous anxieties and the high expectations of loved ones. Which of the following best summarizes the main idea of this paragraph?

answer

Different emotional states affect people's honesty.

question

Which excerpt from Infinite Jest best illustrates an objective narrative voice?

answer

'You are Harold Incandenza, eighteen, date of secondary-school graduation approximately one month from now, attending the Enfield Tennis Academy. . . .

question

Read this excerpt from Extremely Loud and Incredibly Close. She said, "Ron is a great person," which was an answer to a question I didn't ask. So I asked again. "True or false: you are in love with Ron." She put her hand with the ring on it in her hair and said, "Oskar, Ron is my friend." Which of these statements best describes the ambiguity in this excerpt?

answer

It is unclear whether the ring is from Ron or from Oskar's dad.

question

Read the excerpt from Fast Food Nation. English is now the second language of at least one-sixth of the nation's restaurant workers, and about one-third of that group speaks no English at all. The proportion of fast food workers who cannot speak English is even higher. Which type of evidence does the author use in this excerpt?

answer

statistical

question

Which of the following excerpts from Fast Food Nation best provides evidence that fast food restaurants are designed for using unskilled labor?

answer

The ovens at Pizza Hut and at Domino's also use conveyer belts to ensure standardized cooking times.

question

Read this excerpt from Extremely Loud and Incredibly Close. I stood on all of that and it worked for a second. But then I had the tips of my fingers on the vase, and the tragedies started to wobble, and the tuxedo was incredibly distracting, and the next thing was that everything was on the floor, including me, and including the vase, which had shattered. "I didn't do it!" I hollered, but they didn't even hear me, because they were playing music too loud and cracking up too much. How does the narration shape Oskar's characterization in this excerpt?

answer

It shows his youth and inexperience

question

Read the following excerpt from Levitt and Dubner's Freakonomics. In the real world, Feldman learned to settle for less than 95 percent. He came to consider a company "honest" if its payment rate was above 90 percent. He considered a rate between 80 and 90 percent "annoying but tolerable." If a company habitually paid below 80 percent, Feldman might post a hectoring note, like this one: The cost of bagels has gone up dramatically since the beginning of the year. Unfortunately, the number of bagels that disappear without being paid for has also gone up. Don't let that continue. I don't imagine that you would teach your children to cheat, so why do it yourselves? The excerpt serves as which type of support for the authors' argument?

answer

an example

question

ead the excerpt from Infinite Jest. 'You are Harold Incandenza, eighteen, date of secondary-school graduation approximately one month from now, attending the Enfield Tennis Academy, Enfield, Massachusetts, a boarding school, where you reside.' His reading glasses are rectangular, court-shaped, the sidelines at top and bottom. 'You are, according to Coach White and Dean [unintelligible], a regionally, nationally, and continentally ranked junior tennis player, a potential O.N.A.N.C.A.A. athlete of substantial promise, recruited by Coach White via correspondence with Dr. Tavis here commencing . . . February of this year.' The top page is removed and brought around neatly to the bottom of the sheaf, at intervals. 'You have been in residence at the Enfield Tennis Academy since age seven.' Based on this excerpt, which of the following statements is implicit?

answer

The university interview process is quite lengthy

question

Read this excerpt from Extremely Loud and Incredibly Close. I knew I could never let Mom hear the messages, because protecting her is one of my most important raisons d'être, so what I did was I took Dad's emergency money from on top of his dresser, and I went to the Radio Shack on Amsterdam. It was on a TV there that I saw that the first building had fallen. I bought the exact same phone and ran home and recorded our greeting from the first phone onto it. I wrapped up the old phone in the scarf that Grandma was never able to finish because of my privacy, and I put that in a grocery bag, and I put that in a box, and I put that in another box, and I put that under a bunch of stuff in my closet, like my jewelry workbench and albums of foreign currencies. Which word best describes the tone of this excerpt?

answer

methodical

question

Having a counterclaim in an argumentative essay allows the author of the essay to

answer

address any opposition to his or her claim.

question

Read the excerpt from David Foster Wallace's Infinite Jest. I am seated in an office, surrounded by heads and bodies. My posture is consciously congruent to the shape of my hard chair. This is a cold room in University Administration, wood-walled, Remington-hung, double-windowed against the November heat, insulated from Administrative sounds by the reception area outside, at which Uncle Charles, Mr. deLint and I were lately received. What is the setting in this excerpt?

answer

at a university office

question

Read the excerpts from The Namesake. Excerpt 1: But Gogol doesn't want a new name. He can't understand why he has to answer to anything else. "Why do I have to have a new name?" he asks his parents, tears springing to his eyes. It would be one thing if his parents were to call him Nikhil, too. But they tell him that the new name will be used only by the teachers and children at school. Excerpt 2: Mrs. Lapidus studies the registration form. She has not had to go through this confusion with the other two Indian children. She opens up the folder and examines the immunization record, the birth certificate. "There seems to be some confusion, Mr. Ganguli," she says. "According to these documents, your son's legal name is Gogol." Which statement best tells how the internal and external conflicts in each excerpt are the same?

answer

Neither Gogol nor Mrs. Lapidus understands the cultural schooling traditions experienced by Gogol's parents.

question

answer

It is unclear whether the ring is from Ron or from Oskar's dad

question

answer

Different emotional states affect people's honesty.

STUDY

AP Environmental Science Black Holes Environmental Science Nonrenewable Natural Resources Peer Review Process Scientific Method

Env. Bio – Ch. 1 – Flashcards 44 terms

Matilda Campbell

44 terms

Preview

Env. Bio – Ch. 1 – Flashcards

question

How many citizens of Haiti does it take to equal the ecological footprint of the average citizen of the United States?

answer

Twelve citizens of Haiti equal the ecological footprint of the average U.S. citizen.

question

Nearly 50% of the land on our planet is currently used for agriculture, with very little more agriculturally usable land available. If everyone on the planet had an ecological footprint the size of the average citizen of the United States, then ________.

answer

we would need at least two more planet Earths to feed and support everyone.

question

The U.S. average footprint is ________ times larger than the world average footprint.

answer

2.7

question

The global average footprint per person has increased from 2.2 to 2.7 hectares since 2008 including the footprints of many developing nations, such as India and China. This means that ________.

answer

our collective lifestyle is even more unsustainable than before

question

The variable that is manipulated.

answer

Independent variable.

question

A scientific field of study.

answer

Ecology.

question

Information expressed with numbers

answer

Quantitative data.

question

Expectations of experimental outcome.

answer

Prediction.

question

Widely accepted, well test explanation of one or more cause and effect relationships.

answer

Theory.

question

Type of discipline describing environmental science.

answer

Interdisciplinary science.

question

A paradigm ____.

answer

is a dominant view in science.

question

Global population is projected to be about ________ in 2050.

answer

7 billion

question

The scientific method is a process that involves ________.

answer

testing hypothesis that are built on observations.

question

To determine your specific impacts on the environment, you can ________.

answer

calculate your ecological footprint.

question

A hypothesis is ________.

answer

a statement that explains an observed phenomenon or answers a question.

question

Sachiko and Fred are having a discussion about the scientific method. Sachiko makes the comment that every time she sees people carrying open umbrellas, she also sees car accidents. This is a(n) ________.

answer

observation.

question

An experiment ____.

answer

is an activity designed to test the validity of a hypothesis.

question

In a manipulative experiment ________.

answer

researchers manipulate the independent variable.

question

An environmental scientist is least likely to be involved with which of the following?

answer

Studying X-ray emissions for evidence of black holes.

question

Which of the following terms best describes the practice of environmental science?

answer

Integrative and interdisciplinary.

question

In general, natural resources ________.

answer

should be used efficiently and conserved.

question

Solutions to environmental problems ________.

answer

must be designed with sustainable goals.

question

Ruben has a new puppy named Paddington and wants to feed him the best possible food. He decides on an experiment where he will feed Paddington the very best canned food plus a dietary supplement of vitamins recommended by a veterinarian. Which of the following best describes Ruben's project?

answer

This is not an experiment-there are no controls or replicates.

question

The process by which several researchers review another researcher's manuscript prior to publication to ensure research quality is referred to as ________.

answer

peer review.

question

Geothermal energy, wind energy, and solar radiation are all examples of ________.

answer

renewable environmental resources.

question

Which of the following best embodies the qualities of a scientific theory?

answer

Students who study for their environmental science exams will perform better on those exams than those who do not.

question

Ecosystems are ____.

answer

are economically valuable services provided by natural systems

question

The concept of sustainable development includes ________.

answer

the needs of future generations

question

You have read about the mistakes made on Easter Island. On Tikopia, another small island, the people acted in other ways. When they realized that the pigs they had imported were damaging the environment, they killed them all. They had to have permission from a chief to fish, which prevented overfishing. They also practiced contraception. These actions all indicate that ________.

answer

they truly practiced sustainability.

question

Sustainability _____.

answer

involves using resources without compromising future availability.

question

Pesticides use ______.

answer

may be a necessary part of modern technological agriculture

question

In a controlled experiment, ____.

answer

the researcher controls for the effects of all variables except one

question

Qualitative data ____.

answer

can be acquired in the detailed examination of personal interviews or observations.

question

A pharmaceutical company wishes to study a possible new headache medicine. They are doing human trials with 1000 volunteers who experience frequent headaches. The researchers will need to ________.

answer

control for the type of headache - stress, migraine, or other causes.

question

A study's results are deemed worthy of acceptance into the body of scientific knowledge if they are published in journals which ________.

answer

use the peer review process.

question

Pablo and Johanna have to do a yearlong study for their biology course. After some discussion, they decide to try comparing their dogs and the diet that they feed them to test their hypothesis that the local veterinarian's special dog food mix will enhance growth and development. Each student adopts a puppy from the local pound. Pablo plans to feed his shepherd-mix dog the special diet, while Johanna plans to use generic dry kibble from the supermarket for her bulldog. The independent variable in this study will be ________.

answer

the type of food the dogs receive.

question

One dependent variable in this study will be ________.

answer

how much the dogs grow

question

When they write up their initial proposal, the instructor will probably ________.

answer

tell them they have some serious problems with the proposal, but it is fixable if they are willing to take care of more dogs.

question

Pablo and Johanna have too many ________.

answer

variables that they didn't control and not enough replicates.

question

After meeting with their instructor, Pablo and Johanna know that they need to change their experimental design. They contact a local puppy farm and arrange to do their study with 3-month-old litters of pups from four Irish setters, for a total of 24 puppies consisting of 12 females and 12 males. In order to have two groups of puppies (control and experimental), Pablo and Johanna should ________.

answer

for several months, weighing and measuring the pups every week

question

If the puppies in the experimental group gain, on average, 3 pounds more than those in the control group over a 4-month period and seem healthier and more energetic, then ________.

answer

there is a high probability that the veterinary diet is better than kibble for puppies.

question

Why is it important to understand our interactions with the environment? What will studying environmental science enable you to do?

answer

we depend on environment for air, water. food, and other necessities. More understanding will give us knowledge on the changes and problems of our natural environment and how an individual can positively play their environmental role on earth.

question

Differentiate between environmental science and environmentalism. Define each term and explain how they are similar and how they differ.

answer

Environmental science is the actual study of the environment and our interactions. It's somebody who studies the environment in a scientific manner. Environmentalism science is the concept on how humans prevent environmental problems. they are concerned with the protection and preservation of the natural environment Both have same topic however participate in different roles. An environmental scientist conduct research to subside, identify, and eliminate hazards that affect people, wildlife, and their environments Environmentalism is more concerned with the protection and preservation of the natural environment.

question

Compare and contrast the types of knowledge gained and the research methods of natural and social sciences when considering environmental problems. Why do both types of disciplines need to be a part of environmental science?

answer

The natural sciences are made up of disciplines that study the physical and biological facets of the natural world and their interactions with each other. These disciplines rely on all types of studies that generate mainly quantitative data, allowing scientists to acquire and interpret information about the natural world. The social sciences are made up of disciplines that study human attitudes, behaviors, and interactions. The scientists in these disciplines mainly collect qualitative data using a variety of research techniques that are similar to natural scientists. Studies that examine how cultures perceive an environmental concept may be used to implement environmental policy. Because environmental problems involve accurate assessment of the scope of the problem by which policy that affects humans is devised, both types of sciences are needed to be a part of environmental science.

STUDY

Astronomy Black Holes Main Sequence Star Supermassive Black Hole

Mastering Astronomy Chapters: 9-13 – Flashcards 293 terms

Adam Howard

293 terms

Preview

Mastering Astronomy Chapters: 9-13 – Flashcards

question

Where does an object on an elliptical orbit experience the greatest acceleration?

answer

where spacetime has the most curvature

question

Imagine that the Sun could be turned into a black hole without changing its mass. How would Earth's orbit change?

answer

Earth's orbit would not change.

question

Imagine that the Sun gained mass without changing its radius. How would the structure of spacetime change at the distance of Earth's orbit?

answer

Spacetime would become more curved at Earth's orbit.

question

From the viewpoint of an observer in the orbiting rocket, what happens to time on the other rocket as it falls toward the event horizon of the black hole?

answer

Time runs increasingly slower as the rocket approaches the black hole.

question

As the falling rocket plunges toward the event horizon, an observer in the orbiting rocket would see that the falling rocket __________.

answer

slows down as it approaches the event horizon, and never actually crosses the event horizon

question

From Part B, you know that from afar we'll never see the in-falling rocket cross the event horizon, yet it will still eventually disappear from view. Why?

answer

Its light will become so redshifted that it will be undetectable.

question

If you were inside the rocket that falls toward the event horizon, you would notice your own clock to be running __________.

answer

at a constant, normal rate as you approach the event horizon

question

If you were inside the rocket that falls toward the event horizon, from your own viewpoint you would __________.

answer

accelerate as you fall and cross the event horizon completely unhindered

question

All millisecond pulsars are now, or once were, members of binary-star systems.

answer

True

question

The fact that gamma-ray bursts are so distant means that they must be very energetic events.

answer

True

question

All things, except light, are attracted by gravity.

answer

False

question

According to general relativity, space is warped, or curved, by matter.

answer

True

question

Although visible light cannot escape from a black hole, high-energy radiation, like gamma rays, can escape.

answer

False

question

A neutron star is about the same size as

answer

A U.S. city

question

Thousands of black holes have now been identified in our Galaxy.

answer

False

question

The most rapidly "blinking" pulsars are those that

answer

spin fastest

question

The X-ray emission from a neutron star in a binary system comes mainly from

answer

heated material in an accretion disk around the neutron star.

question

Gamma-ray bursts are observed to occur

answer

approximately uniformly over the entire sky.

question

If the Sun were magically to turn into a black hole of the same mass,

answer

Earth's orbit would remain unchanged.

question

The best place to search for black holes is in a region of space that

answer

has strong X-ray emission.

question

In a neutron star, the core is

answer

made of compressed neutrons in contact with each other.

question

Two important properties of young neutron stars are

answer

extremely rapid rotation and a strong magnetic field.

question

An object more massive than the Sun, but roughly the size of a city, is a

answer

neutron star

question

The mass range for neutron stars is

answer

1.4 to 3 solar masses

question

Neutron stars have

answer

very strong bi-polar magnetic fields.

question

In the Lighthouse Model,

answer

if the beam sweeps across us, we will detect a pulse of radiation.

question

Neutron stars do not have

answer

rotation periods comparable to the Sun's.

question

The supernova of 1054 AD produced:

answer

a pulsar with a period of 33 milliseconds, visible optically.

question

Three terrestrial-sized planets in orbits of a fraction of an AU have been found near

answer

a millisecond pulsar.

question

Almost half of all known millisecond pulsars are found in what type of object?

answer

globular clusters

question

X-ray bursters occur in binary star systems. The two types of stars that must be present to make up such an object are:

answer

a main sequence or giant star and a neutron star in a mass transfer binary.

question

Pulsars have a measured mass of

answer

about 1.4 solar masses.

question

You would expect millisecond pulsars to be

answer

part of a binary system.

question

A proposed explanation for gamma-ray bursters is A-coalescence of a neutron star binary. B-hypernova-making black holes and bi-polar jets. C-collisions between two white dwarfs. Both A and B are possible. All three are possible.

answer

Both A and B are possible.

question

What would happen if more mass was added to a 1.4 solar mass neutron star?

answer

It could eventually become a black hole, via a hypernova explosion.

question

A hypernova creates

answer

A black hole

question

The densely packed neutrons of a neutron star cannot balance the inward pull of gravity if the total mass is

answer

greater than Schwartzschild's limit of 3 solar masses.

question

The Schwartzschild radius for a 12 solar mass star is

answer

36 km

question

What explanation does general relativity provide for gravity?

answer

Gravity is the result of curved spacetime.

question

An observer on a planet sees a spaceship approaching at 0.5c. A beam of light projected by the ship would be measured by this observer to travel at

answer

question

As a spaceship's velocity gets closer to the speed of light

answer

its length will decrease and its clock will run more slowly.

question

If light from a distant star passes close to a massive body, the light beam will

answer

bend towards the star due to gravity.

question

What can we detect from matter that has crossed an event horizon?

answer

Nothing

question

As a spaceship nears an event horizon, a clock on the spaceship will be observed

answer

to run slowly

question

If the Sun were replaced by a one solar mass black hole

answer

we would still orbit it in a period of one year.

question

What is Cygnus X-1?

answer

the leading candidate for an observable black hole binary system

question

A method for identifying a black hole is to

answer

look for their effects on nearby companions.

question

The largest known black holes

answer

lie in the cores of the most massive galaxies.

question

Any main sequence star over 25 solar masses will probably retain enough matter in its core after its type II supernova to make a black hole.

answer

True

question

The Schwarzschild radius of a black hole is about 3 km per solar mass; it is amazingly linear over a wide range of masses.

answer

True

question

Special relativity says that c, the speed of light, is the maximum velocity for both matter and energy in our universe.

answer

True

question

Who discovered the first four pulsars?

answer

Jocelyn Bell

question

In a neutron star, the protons and electrons are fused together, leaving only neutrons.

answer

True

question

A neutron star is what remains after a Type II supernova explosion has destroyed the rest of the star.

answer

True

question

In a neutron star, the electrons in the core are all in contact with each other.

answer

False

question

The "pulse" from a pulsar is due to the rapidly expanding and contracting outer shell of the star.

answer

False

question

Pulsars are created in a Type I supernova.

answer

False

question

The pulses from a pulsar are most likely coming from localized areas near the magnetic poles.

answer

True

question

While most pulsars slow down over time, millisecond pulsars spin faster due to the mass transfer from a close companion.

answer

True

question

An X-ray burster is similar to a nova.

answer

True

question

Gamma-ray bursts are all found to be within our galaxy.

answer

False

question

Gamma-ray bursters seem scattered randomly over the entire sky.

answer

True

question

All the gamma-ray bursters measured to date have distances of millions or even billions of light years.

answer

True

question

All Type II supernovae produce neutrons stars when they collapse.

answer

False

question

Both space and time are warped near the strong gravitational fields of neutron stars and black holes.

answer

True

question

No communication is possible across an event horizon.

answer

True

question

The presently known laws of physics clearly describe the conditions inside a black hole's event horizon.

answer

False

question

The radius of a white dwarf is determined by a balance between the inward force of gravity and the outward push of _________

answer

electron degeneracy pressure

question

A(n) __________ occurs when hydrogen fusion ignites on the surface of a white dwarf in a binary system.

answer

nova

question

A(n) _________ occurs when fusion creates iron in the core of a star.

answer

massive star supernova

question

A white dwarf in a close binary system will explode as a supernova if it gains enough mass to exceed the ________.

answer

white dwarf limit (1.4 solar masses)

question

A(n) _______ consists of hot, swirling gas captured by a white dwarf (or neutron star or black hole) from a binary companion star.

answer

accretion disk

question

A(n) ________ can occur only in a binary system, and all such events are thought to have the same luminosity.

answer

white dwarf supernova

question

All of the single red-dwarf stars that ever formed are still on the main sequence today.

answer

True

question

The Sun will get brighter as it begins to run out of fuel in its core.

answer

True

question

A planetary nebula is the disk of matter around a star that will eventually form a planetary system.

answer

False

question

The various stages of stellar evolution predicted by theory can best be tested by observations of stars in clusters.

answer

True

question

A nova is a sudden outburst of light coming from an old main-sequence star.

answer

False

question

It takes less and less time to fuse heavier and heavier elements inside a high-mass star.

answer

True

question

In a core-collapse supernova, the outer part of the core rebounds from the inner, high-density core, destroying the entire outer part of the star.

answer

True

question

Because of stellar nucleosynthesis, the spectra of old stars show more heavy elements than those of young stars.

answer

False

question

A white dwarf is supported by the pressure of tightly packed

answer

electrons

question

A star like the Sun will end up as a

answer

White Dwarf

question

A white dwarf can dramatically increase in brightness only if it

answer

Has another star nearby

question

Nuclear fusion in the Sun will

answer

create elements up to and including oxygen.

question

Most of the carbon in our bodies originated in

answer

the core of a red-giant star.

question

If the evolutionary track in Overlay 3, showing a Sun-like star, were instead illustrating a significantly more massive star, its starting point (stage 7) would be

answer

up and to the left

question

A star (no matter what its mass) spends most of its life:

answer

As a main sequence star

question

When a star's inward gravity and outward pressure are balanced, the star is said to be

answer

in hydrostatic equilibrium.

question

What temperature is needed to fuse helium into carbon?

answer

100 million K

question

A star is on the horizontal branch of the H-R diagram. Which statement is true?

answer

It is burning both hydrogen and helium.

question

During the hydrogen shell burning phase

answer

the star grows more luminous.

question

A solar mass star will evolve off the main sequence when

answer

it builds up a core of inert helium.

question

A surface explosion on a white dwarf, caused by falling matter from the atmosphere of its binary companion, creates what kind of object?

answer

Nova

question

Virtually all the carbon-rich dust in the plane of the galaxy originated in

answer

Low mass stars

question

An iron core cannot support a star because

answer

iron cannot fuse with other nuclei to produce energy.

question

A 20 solar mass star will stay on the main sequence for 10 million years, yet its iron core can exist for only a

answer

day

question

As a star's evolution approaches the Type II supernova, we find A.) helium to carbon fusion takes at least 100 million K to start. B.) the heavier the element, the higher the temperature to fuse it. C.) photo disintegration of iron nuclei begins at 10 billion K to ignite the supernova. D.) the heavier the element, the less time it takes to make it. E.) All of the above

answer

All of the above

question

As a 4-10 solar mass star leaves the main sequence on its way to becoming a red supergiant, its luminosity

answer

remains roughly constant.

question

Which of the following best describes the evolutionary track of the most massive stars?

answer

Horizontal right

question

If it gains sufficient mass, a white dwarf can become a

answer

type I supernova.

question

For a white dwarf to explode entirely as a Type I supernova, it's mass must be

answer

1.4 solar masses, the Chandrasekhar Limit

question

The heaviest nuclei of all are formed

answer

in the core collapse that set the stage of Type II supernovae.

question

The Chandrasekhar limit is

answer

the upper mass limit for a white dwarf.

question

Where was supernova 1987a located?

answer

in our companion galaxy, the Large Magellanic Cloud

question

Which of these events is not possible?

answer

white dwarfs and companion stars producing recurrent Type I supernova events

question

Which of these does not depend on a close binary system to occur?

answer

a Type II supernova

question

What can you conclude about a Type I supernova?

answer

It was originally a low-mass star.

question

A recurrent nova could eventually build up to a

answer

Type I supernova

question

The brightest stars of a young open cluster will be

answer

massive blue main sequence stars.

question

Noting the turnoff mass in a star cluster allows you to determine its

answer

age

question

Compared to a cluster containing type O and B stars, a cluster with only type F and cooler stars will be

answer

older

question

Which stars in globular clusters are believed to be examples of mergers?

answer

blue stragglers

question

What made supernova 1987a so useful to study? A. We saw direct evidence of nickel to iron decay in its light curve. B. Its progenitor had been observed previously. C. In the Large Magellanic Cloud, we already knew its distance. D. It occurred after new telescopes, such as Hubble, could observe it very closely. E. All of these are correct.

answer

All of these are correct.

question

While more massive than most of its neighbors, the Sun is still technically a low mass star.

answer

true

question

A massive star can fuse only up to the element silicon in its core.

answer

False

question

Because they all involve formation of iron in cores of massive stars, all type II supernovae are equally luminous.

answer

False

question

Because they all involve the detonation of a carbon-rich white dwarf at Chandrasekhar's limit, all type I supernovae are equally luminous.

answer

True

question

Novae are more closely related to type II than to type I supernovae.

answer

False

question

A carbon-detonation supernova starts out as a white dwarf in a close binary system.

answer

True

question

Most of the energy released during a supernova is emitted as neutrinos.

answer

True

question

Which of these is true of planetary nebulae?

answer

They are ejected envelopes surrounding a highly evolved low-mass star.

question

Compared to our Sun, a typical white dwarf has

answer

about the same mass and a million times higher density.

question

Which of these evolutionary paths is the fate of our Sun?

answer

Planetary Nebula

question

Black dwarfs are

answer

not found yet; the oldest, coldest white dwarf in the Galaxy has not cooled enough yet.

question

About 90% of the star's total life is spent on the main sequence.

answer

True

question

Paradoxically, while the core of the red giant is contracting and heating up, its radiation pressure causes its photosphere to swell up and cool off.

answer

True

question

A star may undergo two or more red giant expansion stages.

answer

True

question

A star system may undergo two or more nova outbursts.

answer

True

question

Our Sun will eventually become a nova.

answer

False

question

Today the majority of the mass of the universe is already in the form of black dwarfs, the solution to the "dark matter" problem.

answer

False

question

White dwarfs were once the cores of stars that produced planetary nebulae.

answer

True

question

It is the formation of iron in an evolved giant's core that triggers the Type II supernova event.

answer

True

question

In the cores of the most massive stars, the electrons and protons fuse together and form neutrons.

answer

False

question

Elements heavier than iron are formed mainly in supernovae.

answer

True

question

Supergiants are burning different fuels in several shells around the core.

answer

True

question

A star system can become a Type I supernova several times.

answer

False

question

Neutrinos can move faster than c, the speed of light, as was discovered in SN1987A in 1987.

answer

False

question

The spectra of the oldest stars show the most heavy elements.

answer

False

question

As a clump of interstellar gas contracts to become a main-sequence star, its changing position on the H-R diagram tells us __________.

answer

how its outward appearance is changing

question

Watch the red dot representing the protostar in the animation. After it reaches its highest point on the diagram, how do the protostar's surface temperature and luminosity change as it approaches the main sequence?

answer

Its surface temperature increases, but its luminosity decreases.

question

When does a newly forming star have the greatest luminosity?

answer

when it is a shrinking protostar with no internal fusion

question

When a newly forming star is at its greatest luminosity, what is its energy source?

answer

gravitational contraction

question

How do the properties of long-lived stars compare to those of short-lived stars?

answer

Long-lived stars begin their lives with less mass and a smaller amount of hydrogen fuel. Long-lived stars are less luminous during their main-sequence lives.

question

A main-sequence star twice as massive as the Sun would last __________.

answer

much less than half as long as the Sun

question

If stars A and B are both main-sequence stars and star A has a greater fusion rate than star B, which of the following statements hold(s)?

answer

Star A must be more luminous than star B. Star A must be more massive than star B.

question

The formation of the first high-mass stars in a collapsing cloud tends to inhibit further star formation within that cloud.

answer

True

question

A protostar that will eventually turn into a star like the Sun is significantly

answer

More luminous

question

Interstellar matter is quite evenly distributed throughout the Milky Way Galaxy.

answer

False

question

Twenty-one-centimeter radiation observations can be used to probe the interiors of molecular clouds.

answer

False

question

More massive stars form more rapidly.

answer

True

question

Brown dwarfs take a long time to form, but will eventually become visible as stars on the lower main sequence.

answer

False

question

Most stars form as members of groups or clusters.

answer

True

question

A dark interstellar globule is about the same size as

answer

The Oort Cloud

question

Of the following telescopes, the one best suited to observing dark dust clouds is

answer

A radio telescope

question

Interstellar gas is composed of

answer

90% hydrogen, 9% helium by weight.

question

What effect does even thin clouds of dust have on light passing through them?

answer

It dims and reddens the light of all more distant stars.

question

Which statement about the dark nebulae is true?

answer

They can be penetrated only with longer wavelengths such as radio and infrared.

question

Some regions along the plane of the Milky Way appear dark because

answer

stars in that region are hidden by dark dust particles.

question

Due to absorption of shorter wavelengths by interstellar dust clouds, distant stars appear

answer

redder

question

Which statement is true about the interstellar medium?

answer

We know more about the gas than the dust.

question

The spectra of interstellar gas clouds show that they have the same basic composition as

answer

Stars

question

Emission nebulae like M42 occur only near stars that emit large amounts of

answer

Ultraviolet Radiation

question

What is the primary visible color of an emission nebula?

answer

red due to ionized hydrogen atoms

question

The density of interstellar dust is very low, yet it still blocks starlight because

answer

the dust particles are about the same size as the light waves they absorb.

question

The gas density in an emission nebula is typically about how many particles per cc?

answer

Hundred

question

What two things are needed to create an emission nebulae?

answer

hot stars and interstellar gas, particularly hydrogen

question

A large gas cloud in the interstellar medium that contains several type O and B stars would appear to us as

answer

an emission nebula.

question

Which of these is not a consequence of dust in the interstellar medium?

answer

red light from the emission nebulae

question

Why are dark dust clouds largely misnamed?

answer

They contain much more gas than dust.

question

Complex molecules in the interstellar medium are found

answer

primarily in the dense dust clouds.

question

Interstellar dust clouds are best observed at what wavelength?

answer

Radio and infrared

question

When an electron in H changes its spin from the same to the opposite direction as the proton, it

answer

emits a radio wave photon.

question

A newly formed protostar will radiate primarily at which wavelength?

answer

infrared

question

During a protostar's T Tauri phase, it

answer

may develop very strong winds.

question

Which statement about the stages of starbirth is false?

answer

nuclear reactions begin in the core by stage 4.

question

On an H-R diagram, a protostar would be

answer

above and to the right of the main sequence.

question

A cloud fragment too small to collapse into a main sequence star becomes a

answer

Brown dwarf

question

How long does it take an M class star to reach the main sequence, compared to a solar type star?

answer

about twenty times longer

question

All globular clusters in our Milky Way are about how old?

answer

Around ten billion years old

question

What are the characteristics of an open cluster of stars?

answer

a few hundred, mainly main sequence stars

question

Which is characteristic of globular star clusters?

answer

old age and hundreds of thousands of stars, only about 30 ly wide

question

Most stars in our part of the Galaxy are formed

answer

in open clusters of a few dozen.

question

There is as much mass in the voids between the stars as in the stars themselves.

answer

True

question

Interstellar matter is distributed very evenly through the galaxy.

answer

False

question

The gas in the interstellar medium consists of mostly heavy elements.

answer

False

question

Molecular clouds are much warmer than typical interstellar gas clouds.

answer

False

question

Dark nebulae are opaque to all wavelengths of electromagnetic radiation.

answer

False

question

The 21 cm line of hydrogen is strongly absorbed by interstellar dust.

answer

False

question

What information does 21-cm radiation provide about the gas clouds?

answer

their motion; their distribution; their density; their temperature

question

Light from distant stars that must pass through dust arrives bluer than when it left its star.

answer

False

question

The predominant color of emission nebula is blue.

answer

False

question

Emission nebulae get their red color from the red supergiants forming in them.

answer

False

question

Dark dust clouds are optically invisible, but give off radio energy.

answer

True

question

Dark dust clouds are cooler than their surroundings.

answer

True

question

Globular clusters are typically much older than open clusters.

answer

True

question

Globular clusters contain mostly blue stars.

answer

False

question

Compared to a main-sequence star with a short lifetime, a main-sequence star with a long lifetime is __________.

answer

less luminous, cooler, smaller, and less massive

question

Compared to a high-luminosity main-sequence star, stars in the upper right of the H-R diagram are

answer

Cooler and larger in radius

question

Compared to a low-luminosity main-sequence star, stars in the lower left of the H-R diagram are

answer

Hotter and smaller in radius

question

Red giants are very bright because they are extremely hot.

answer

False

question

Star A appears brighter than star B, as seen from Earth. Therefore, star A must be closer to Earth than star B.

answer

False

question

The radius of a star can be indirectly determined if the star's distance and luminosity are known.

answer

False

question

Astronomers can distinguish between main-sequence and giant stars purely by spectroscopic means.

answer

True

question

In a spectroscopic binary, the orbital motion of the component stars appears as variations in the overall apparent brightness of the system.

answer

False

question

From a distance of 1 parsec, the angular size of Earth's orbit would be

answer

2 arc seconds

question

Compared with a star of absolute magnitude -2 at a distance of 100 pc, a star of absolute magnitude 5 at a distance of 10 pc will appear

answer

Fainter

question

Stars of spectral class M do not show strong lines of hydrogen in their spectra because

answer

their surfaces are so cool that most hydrogen is in the ground state.

question

Cool stars can be very luminous if they are very

answer

Large

question

The mass of a star may be determined

answer

by studying its orbit around a binary companion.

question

If a star has a parallax of 0.05", then its distance in light years is about:

answer

65 light years

question

Which statement about stellar motion is incorrect?

answer

Like parallax, proper motion is measured over intervals of exactly six months.

question

What physical property of a star does the spectral type measure?

answer

Temperature

question

The star's color index is a quick way of determining its:

answer

Temperature

question

On the H-R diagram, the Sun lies

answer

about the middle of the main sequence.

question

On the H-R diagram, white dwarfs lie Sirius B and Procyon B lie

answer

at lower left

question

On the H-R diagram, red supergiants like Betelguese lie

answer

at top right

question

Which type of binary can have their sizes measured directly by photometry?

answer

eclipsing

question

In what range of masses are most stars found?

answer

0.1 to 2 solar masses

question

The nearest star to our Sun, Alpha Centauri, is still over a parsec distant.

answer

True

question

A type B9 star is hotter than a type A0.

answer

True

question

The vast majority of stars near us would fall to the bottom right on the H-R diagram.

answer

True

question

A star's absolute magnitude is its apparent brightness as seen from

answer

33 light years distant

question

What can be said with certainty about a red star and a blue star?

answer

The blue star is hotter than the red star

question

The H-R diagram can plot

answer

temperature vs luminosity

question

On the H-R diagram, the bright blue stars that dominate the naked-eye sky lie

answer

at the top left.

question

A star near the lower right of the H-R diagram is likely to be

answer

red with low luminosity

question

Binary stars separated enough to be resolved in a telescope are called

answer

visual binaries

question

A parsec is about 3.3 light years.

answer

True

question

Less than 100 stars lie within 5 parsecs of the Sun.

answer

True

question

Our nearest stellar neighbor is a little less than 1 parsec away.

answer

False

question

A type B star is bluer than a type G star.

answer

True

question

Only A type stars show hydrogen lines in their spectra.

answer

False

question

White dwarfs lies on the lower left portion of the H-R diagram.

answer

True

question

Our Sun lies about the middle of the main sequence and the H-R diagram.

answer

True

question

Main sequence stars are fusing hydrogen into helium in their cores.

answer

True

question

The mass of a newly formed star will determine its position on the main sequence.

answer

True

question

Most stars are single stars like our own.

answer

False

question

In describing other stellar properties, almost everything is relative to our Sun.

answer

True

question

In which of the following layers of the Sun does nuclear fusion occur?

answer

Core

question

Which of the following layers of the Sun can be seen with some type of telescope? Consider all forms of light, but do not consider neutrinos or other particles.

answer

Corona, Photosphere, Chromosphere

question

Nuclear fusion of hydrogen into helium occurs in the ____

answer

Core

question

Energy moves through the sun's ______________ by means of the rising of hot gas and falling of cooler gas.

answer

Convection Zone

question

Nearly all the visible light we see from the Sun is emitted from the ___________.

answer

Photosphere

question

Most of the Sun's ultraviolet light is emitted from the narrow layer called the ____________ where temperature increases with altitude.

answer

Chromosphere

question

We can see the Sun's _________ most easily during total solar eclipses

answer

Corona

question

The ______________ is the layer of the Sun between its core and convection zone

answer

Radiation Zone

question

The most abundant element in the Sun is hydrogen.

answer

True

question

The density and temperature in the solar corona are much higher than in the photosphere.

answer

False

question

Sunspots appear dark because they are hotter than the surrounding gas of the photosphere.

answer

False

question

Flares are caused by magnetic disturbances in the lower atmosphere of the Sun.

answer

True

question

The proton-proton chain releases energy because mass is created in the process.

answer

False

question

Neutrinos have never been detected experimentally.

answer

False

question

Compared with Earth's diameter, the Sun's diameter is about

answer

100 times larger

question

The Sun spins on its axis roughly once each

answer

month

question

If astronomers lived on Venus instead of on Earth, the solar constant they measure would be

answer

Larger

question

A typical solar granule is about the size of

answer

Large U.S. State

question

The time between successive sunspot maxima is about

answer

Decade

question

The primary source of the Sun's energy is

answer

fusion of light nuclei to make heavier ones

question

From inside out, which is in the correct order for the structure of the Sun?

answer

radiative zone, convective zone, chromosphere

question

How long does the sunspot cycle last, on average?

answer

11 years

question

Visible sunspots lie in the

answer

granulation in the photosphere.

question

As the Sun rotates, an individual sunspot can be tracked across its face. From eastern to western limb, this takes about

answer

2 weeks

question

The most striking example of solar variability was the

answer

Maunder Minimum from 1645-1715.

question

Sunspots

answer

come in pairs, representing the north and south magnetic fields.

question

During a period of high solar activity, the corona

answer

Is more irregular

question

Sunspots are dark splotches on the Sun. Which statement is true?

answer

They are extremely hot, but cooler than the surrounding areas of the Sun.

question

Suppose a large flare is detected optically. How long until radio interference arrives?

answer

Simultaneously

question

While observing the Sun, you note a large number of sunspots. What can you conclude?

answer

There are likely to be an above average number of flares and prominences.

question

What natural barrier tries to prevent two protons from combining?

answer

electromagnetic repulsion

question

The critical temperature to initiate the proton-proton cycle in the cores of stars is:

answer

10 Million K

question

In the proton-proton cycle, the helium atom and neutrino have less mass than the original hydrogen. What happens to the "lost" mass?

answer

It's converted to energy

question

The primary source of the Sun's energy is

answer

the strong force fusing hydrogen into helium.

question

In the proton-proton cycle, the positron is

answer

An anti-electron

question

Which is the net result of the proton-proton chain?

answer

4 protons = 1 helium 4 + 2 neutrinos + gamma rays

question

The photosphere is about 100 times the diameter of the Earth, and large sunspots are larger than our whole planet.

answer

True

question

Granulation is the most obvious proof of solar convective energy transport.

answer

True

question

The solar corona is much cooler than the Sun's surface, hence we must wait for a total solar eclipse to glimpse it with the naked eye.

answer

False

question

What is the meaning of the solar constant?

answer

the amount of energy the Earth receives per unit area and unit time

question

The density of the Sun is most similar to which object?

answer

Jupiter

question

Which of these are not associated with the active Sun? aurora flares sunspots prominences granulation

answer

Granulation

question

The outward pressure of hot gas in the Sun

answer

is balanced by the inward gravitational pressure.

question

The Sun's radius is one astronomical unit by definition.

answer

False

question

The Sun's structure is uniform throughout its interior, with no evidence of different layers.

answer

False

question

The Sun's magnetic field is very weak compared to Earth's.

answer

False

question

Sunspots usually come in pairs, each a magnetic pole.

answer

True

question

The sunspot cycle averages about 11 months.

answer

False

question

Although sunspots are cooler areas in the photosphere, an increase in their number tells us the Sun is becoming more active.

answer

True

question

The solar corona is best studied using X-ray telescopes.

answer

True

question

The solar neutrinos observed on Earth come from the hot spots in the corona.

answer

False

question

The Sun produces energy by fusing hydrogen into helium.

answer

True

question

During the fusion process, mass is converted into energy.

answer

True

question

The Solar Neutrino Problem is that we observe more neutrinos than predicted.

answer

False

STUDY

Astronomy Black Holes Milky Way Galaxy Supermassive Black Hole

Astronomy ch 14 review – Flashcards 42 terms

Kenneth Miller

42 terms

Preview

Astronomy ch 14 review – Flashcards

question

The letters AGN stand for _____.

answer

an active galaxy nucleus

question

The energy from an AGN is produced by

answer

matter flowing into a supermassive black hole.

question

All ____ galaxies are spiral galaxies that have small luminous nuclei.

answer

Seyfert

question

In the double-exhaust model, the radio lobes of a radio galaxy are inflated by

answer

jets of excited gas flowing from the central galaxy

question

The hot spots in double-lobed radio source

answer

are where hot excited gas interacts with the intergalactic medium.

question

When discovered in the 1960's, a(n) ____ were found to emit large amounts of energy, but through visual and radio telescopes appeared to be a single point of light much like a star.

answer

quasar

question

The radio lobes that are on each side of some radio galaxies and jets from them produce mainly

answer

synchrotron radiation

question

The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that

answer

they are created by jets from the galaxy emitting where the material is halted

question

The central galaxy in a double-lobed radio source is usually

answer

a giant elliptical galaxy

question

The fact that the radio lobes radiate synchrotron radiation indicates that

answer

high speed electrons are spiraling through a magnetic field.

question

Centaurus A is a radio galaxy that has a visible galaxy at the center. This central elliptical galaxy of Centaurus A is encircled by a ring of gas and dust, different from most elliptical galaxies. The dust ring orbits about an axis that is perpendicular to the axis of rotation of the elliptical galaxy. What does this suggest about this central elliptical galaxy of Centaurus A?

answer

Centaurus A is probably the result of a merger of an elliptical galaxy and a spiral galaxy

question

If the red shifts of quasars arise from the expansion of the universe yet they have brighter magnitudes than galaxies with the same red shifts, the quasar must be

answer

emit a very large amount of energy per second

question

Soon after discovery, it was observed that quasars had a star like appearance which was blurred by Earth's atmospheric "seeing". Despite the blurring, it was realized that the intense energy emitting regions of quasars must be small because they

answer

fluctuate rapidly on time scales as short as a few hour

question

We suspect that quasars are the active centers of galaxies because

answer

"fuzz" around the central luminous regions produces spectra like a collection of normal stars.

question

The discovery of the gravitational lens effect for quasars

answer

shows that quasars are much further away than the distant galaxy that forms the gravitational lens.

question

_____ galaxies contain a supermassive black hole at their centers while active nuclei are present in _____of galaxies

answer

Most; a few percent

question

Galaxies may contain a supermassive black hole at their center but _____ an active nucleus because of _______ into the black hole

answer

show; mass inflow

question

Statistical evidence

answer

allows scientists to deduce general characteristics about a class of objects with similar properties.

question

What was the first evidence that quasars were different from astronomical objects before they were observed in visual wavelengths?

answer

Quasars emitted radio energy like active galaxies, but appeared to be point sources in radio wavelengths.

question

Evidence that supports quasars being the nuclei of very distant galaxies includes

answer

1) the existence of quasar fuzz. 2) the observation of a supernova near a quasar whose distance from its brightness is consistent with the large redshift. 3) gravitational lensing of some quasars by nearby galaxies. 4) all of the above.

question

According to the unified model of active galactic nuclei, a(n) ____ is in the center surrounded by _________with a Type 1 Seyfert or Type 2 Seyfert being seen depending on the viewing angle.

answer

a supermassive black hole; an accretion disk

question

According to the unified model of active galactic nuclei, a ____ is observed if our line of sight is parallel to the plane of the dense disk of an active galactic nucleus (the direct view of the nucleus is blocked by dust in the disk).

answer

Type 2 Seyfert (narow spectral emission lines; weaker x ray emission)

question

____ is (are) observed when light from a distant quasar travels past a massive galaxy between us and the quasar, and this light is focused to form two or more images of the same quasar.

answer

The gravitational lens effect

question

____ show(s) that some quasars are further away than distant galaxies and that space time is curved by massive objects.

answer

The gravitational lens effect

question

Seyfert galaxies

answer

1) are more common in close pairs of galaxies than in isolated systems. 2) emit more energy at X-ray, ultraviolet, infrared, or radio wavelengths than normal spiral galaxies. 4) 1 and 2.

question

Quasars are most common with red shifts

answer

of about 2

question

In the unified model of active galactic nuclei, the broad line region in an active galactic nucleus is

answer

composed of clouds of gas and stars moving at very high orbital velocities near a supermassive black hole

question

The unified model describes active galactic nuclei using

answer

a super massive black hole surrounded by an accretion disk and dense disk of gas.

question

What is the major observational difference between a Seyfert galaxy and a normal spiral galaxy?

answer

The central region of a Seyfert galaxy is much brighter

question

How are astronomers able to determine that quasars are so small?

answer

They are variable over a short period of time.

question

How do astronomers know that the luminous regions of active nuclei of active galaxies are very small?

answer

The luminosity of the nuclei varies over short times

question

Why do astronomers believe supermassive black holes are the source of an AGN's energy?

answer

1) Such black holes have been found at the center of most galaxies both active and inactive. 2) Radio jets are seen from low mass black holes plus accretion disks inside our galaxy. 3) jets and accretion disks have been observed in active galaxies. 4) black holes can produce so much energy in such a small place. 5) all of the above.

question

Which kind of active galaxy has been observed at the greatest distances from us?

answer

Quasars

question

How does the study of quasars reveal information of the history of the universe

answer

Typical quasars are very distant so we can view how galaxy evolution occurred in the past.

question

The Milky Way galaxy is not a radio galaxy; it emits no radio radiation. T/F

answer

False

question

Double-lobed radio galaxies appear to be emitting jets of gas and radiation. T/F

answer

True

question

The radio radiation emitted by a radio lobe is mainly synchrotron radiation. T/F

answer

True

question

Seyfert galaxies are spiral galaxies with active cores. T/F

answer

True

question

Active galaxy radio lobes and jets contain magnetic fields. T/F

answer

True

question

The rapid fluctuations of quasars show that the energy emitting portions of these objects must be very small.T/F

answer

True

question

Quasar red shifts are usually larger than the red shifts of the visible galaxies. T/F

answer

True

question

Some quasars have fuzz around them that produce spectra similar to normal galaxies. T/F

answer

True

STUDY

Black Holes

CH 101 A Molecular Science (Exam Review) – Flashcards 58 terms

Claire Forth

58 terms

Preview

CH 101 A Molecular Science (Exam Review) – Flashcards

question

When two like charges interact, which combo gives it the highest energy?

small/large charge & close/far

answer

Large charges close together

question

When two particles move through a magnetic field, and one particle is refracted twice as far as the other, what two differences between the particles is possible?

answer

One may be twice the charge or twice the mass (this one will refract twice as much).

question

Which subatomic particles are responsible for the mass of an atom?

answer

Protons and neutrons

question

What transition combo is the absorption process that requires the most energy?
From a higher/lower n to a higher/lower n in a higher/lower level of n.

answer

From a lower n value to a higher n in a lower level of n.

Ex: n=1 → n=3

question

How would you describe the location cloumn of K on the periodic table?

answer

It is an alkali metal.

question

If element A has valence electrons at a higher level then B, then which has the higher ionization energy?

answer

Because A has a higher valence electon level, it has the higher ionization energy.

question

Which corner of the periodic table has the highest electronegativity?

answer

Top-right corner.

question

How would you find elements whose highest occupied orbital is the 4p orbital when in ground state?

answer

Find the p-block (rightmost block) and count down four rows. All the elements in this row and block have the highest occupied orbital of 4p.

question

How do you know an ionic compound from another compound?

answer

An ionic compound will be made of a metal and non-metal.

question

What orbital letters can hold how many pairs of electrons?

answer

s: 1 pairs
p: 3 pairs
d: 5 pairs

question

How do you figure out what the greatest mass is amongst elements given in moles, number of atoms, and mass?

answer

Convert the number of atoms into moles (divide by 6.02×10²³)
Convert the moles into grams (multiply by the elements' molar masses)

question

How do you compare the number of atoms in samples of atoms in grams, moles, and number of atoms.

answer

You can easily convert them to moles.
To convert grams to moles, divide by the elements' molar masses.
To convert number of atoms to moles divide by 6.02×10²³.

question

What corner of the periodic table has atoms with the largest radius and what charge increases atomic radii?

answer

Bottom-left corner. A negative charge increses the size of the radius.

question

How can you tell if a bond has more ionic character or covalent character?

answer

The greater the difference in electronegativity between the two atoms, the more ionic the character. The closer the electronegativities, the more covalent the character.

question

The n=1 level is higher for atoms in what corner of the periodic table?

answer

Top-right corner

question

When n=1 is high and a transition is made from n=2 → n=1, will the photon from that trasition be at high or low energy?

answer

It will be at low energy.

question

How do you find the number of valence electrons in a element's atom?

answer

Count on that elements row from left to right. The number of elements you counted is the number of valence electrons.

question

To find the number of atoms in a compound, what to you do?

answer

Take the number of "ingredients" (like 2 hydrogen and 1 oxygen for H₂O) and multiply it by the number of moles. Then you can convert moles to number of atoms (6.02;10²³)

question

If a atom is in a bond and has two attachments (either single, double, or triple bonds or lone pairs) what is it's bond angle?

answer

180°

question

If an atom is bonded and has three parts (either single, double, or triple bonds or lone pairs), what is the bond angle?

answer

120°

question

If an atom is bonded and has four parts (either single, double, or triple bonds or lone pairs), what is the bond angle?

answer

109°

question

If an atom is bonded and has two parts (either single, double, or triple bonds or lone pairs), what is the hybridization?

answer

question

If an atom is bonded and has three parts (either single, double, or triple bonds or lone pairs), what is the hybridization?

answer

sp²

question

If an atom is bonded and has four parts (either single, double, or triple bonds or lone pairs), what is the hybridization?

answer

sp³

question

What are the number of sigma and pi bonds in single, double, and triple bonds?

answer

single: 1σ
double: 1σ 1π
triple: 1σ 2π

question

How can a bond order can be found?

answer

Take the average of all possible bonds.

question

In sigma bonding, where is the electron density concentrated?

answer

The most density is concentrated between the two nuclei.

question

In pi bonding, where is the electron density concentrated?

answer

It is concentrated above/below the two nuclei.

question

Antibonding diagrams are shown how?

answer

With two similarly colored orbitals overlapping each other.

question

How does hydrogen bonding arise?

answer

Hydrogen bonding forces arise from the interaction of a hydrogen atom with a lone pair on a neighboring molecule.

question

Molecules with the highest boiling point have what kind of bonding?

answer

1: Hydrogen bonding
2: Dipolar bonding
3: Dispersion forces
(weight is also a factor)

question

The simple cubic cell has what coodination number and packing efficiency compared to the other cubic cells?

answer

Simple cubic has the smallest coordination number and the worst packing efficiency.

question

The body centered cubic cell has what coodination number and packing efficiency compared to the other cubic cells?

answer

Body centered cubic cells have the middle coordination number and the medium packing efficiency.

question

The face centered cubic cell has what coodination number and packing efficiency compared to the other cubic cells?

answer

The face centered cubic cell has the largest coordination number and the greatest packing efficiency.

question

What is the simple cubic cell's coordination number?

answer

question

What is the body centered cell's coordination number?

answer

question

What is the face centered cubic cell's coordination number?

answer

question

The less conductive a material, the larger or smaller the bandgap?

answer

The bandgap is larger in materials that do not conduct well.

question

Molecular solids tend to have what kind of boiling points?

answer

Molecular solids have relatively low, normal boiling points.

question

What is ;H?

answer

It is the change in enthalpy. Enthalpy is the sum of kinetic and potential energy.

question

What is ;S?

answer

It is the change in entropy. Entropy is the number of ways molecules can be arranged in a system.

question

If a weak bond is broken and a strong bond is formed, what is the most likely tempurature exchange?

answer

Exothermic

question

If a strong bond is broken and a weak one forms, what is most likely tempurature exchange?

answer

Endothermic

question

What is the equation for finding ;H from bond energies?

answer

;H
;
;(broken bond energies)
-
;(formed bond energies)

question

If ;H is positive, what was the heat transfer?

answer

Endothermic

question

If ;H is negative, what was the heat transfer?

answer

Exothermic

question

What is the equation for the Second Law of Thermodynamics concerning free energy?
(Used to calculate spontaneity)

answer

;
;G = ;H - T;;S
If ;G is negative, the reaction is spontaneous (and vice-versa).

question

What is the difference between ;G and ;G;?

answer

;G; is for specific amounts of reactant and product, ;G is for unspecified amounts.

question

If a reversible reaction's ΔG° is negative, then what is K in relation to 1 at equilibrium?

answer

K > 1

question

If a reversible reaction's K value is greater than 1, then what is true about the activation energy at equilibrium?

answer

The activation energy of the foreward reaction is less than that of the reverse reaction.

question

When you increase tempurature, what happens to the number of collisions in a system?

answer

It increases.

question

How does a catalyst help a reaction?

answer

It orients molecules porperly to speed up a reaction.

question

If you decrease the concentration of reactants, what will happen to the speed of the reaction?

answer

It will be slowed.

question

If a reaction has a high activation energy, then what can you conclude about the reaction rate?

answer

It has a very low reaction rate.

question

How do detergents work?

answer

They form a micelle with hydrocarbon tails pointing inwards.

question

What is Avagadro's Number?

answer

6.02 × 10²³

question

What is Coulomb's Law concerning force?

answer

F ; (q₁q₂)/r²

question

What is Coulomb's Law concerning energy?

answer

E ≈ (q₁q₂)/r

STUDY

Black Holes First Law Of Thermodynamics Know For Certain Second Law Of Thermodynamics Wild Animals World History World Literature

Summary: Adam and Eve – Flashcards 32 terms

Bettina Hugo

32 terms

Preview

Summary: Adam and Eve – Flashcards

question

In the beginning what was there?

answer

There was nothing except God

question

What did God create on day 1

answer

On the first day God created light/dark

question

What did God create on day 2

answer

On the second day God created the heavens and earth

question

What did God create on day 3

answer

On the third day God created the land. There were oceans, the dry land, the plants and trees

question

What did God create on day 4

answer

On the fourth day God created the moon and stars

question

What did God create on day 5

answer

On the fifth day God created the fish, sea creatures and birds

question

What did God create on day 6

answer

On the sixth day God created man and the wild animals

question

What did God do on day 7?

answer

On the seventh day God rested, which is why he commands us not to work on the Sabbath

question

What was the job given to Adam?

answer

Adam had to give names to all the animals

question

How did God create Adam?

answer

God created Adam from the dust on the ground

question

God gave a conscience - what does this mean?

answer

A conscience allowed Adam to tell right from ton

question

How did God create Eve?

answer

God created Eve from one of Adam's ribs

question

Where did Adam and Eve live?

answer

Adam and Eve lived in the Garden of Eden

question

What was the one rule that God gave to Adam and Eve?

answer

Adam and Eve were told that they must not eat the fruit from the tree at the centre of the Garden of Eden

question

What was this tree?

answer

This tree is the Tree of Knowledge of Good and Evil - eating the fruit would teach them about evil

question

How did Adam and Eve disobey God?

answer

Adam and Eve disobeyed God by eating fruit from the tree forbidden to them

question

How did the serpent convince Eve to eat the fruit from the tree?

answer

The serpent told Eve that if she ate from the tree she would be just like God

question

Who convinced Adam to eat the fruit from the tree?

answer

Eve convinced Adam to eat the fruit

question

Would eating the fruit from the tree make Adam and Eve like God?

answer

Adam and Eve could never be just like God

question

What did it mean if Adam and Eve at the fruit from the tree?

answer

Eating the fruit from the tree meant that Adam in Eve had sinned - this was called the first mortal sin

question

Did Adam and Eve know that they had done something wrong?

answer

Adam and Eve knew immediately that they had done something wrong

question

The next time God visited Adam and Eve in the Garden, what did they do?

answer

The next time God visited, Adam and Eve hid from him

question

Who did Adam blame for their fall from grace?

answer

Adam blamed Eve

question

Who did Eve blame for their fall from grace?

answer

Eve blamed the serpent

question

Who was the serpent really?

answer

The serpent was really Lucifer, the devil, in disguise

question

Who was Lucifer?

answer

Lucifer had once been an angel in Heaven with God, but he became too angry and was banished from Heaven

question

How did Adam and Eve cover themselves?

answer

They covered themselves with fig leaves

question

What is another word for Lucifer?

answer

Lucifer is also called Satan

question

What did Satan want to make happen?

answer

Satan wanted all mankind to fail, if he couldn't be with God why should anyone else be

question

What happened to Adam and Eve after they ate the fruit of the Tree of Knowledge of Good and Evil?

answer

God made Adam and Eve leave the Garden of Eden as punishment for eating the fruit of the Tree of Knowledge of Good and Evil

question

What did it mean for Adam and Eve once they had to leave the Garden of Eden?

answer

After they left the Garden of Eden, Adam and Eve had to grow all of their own food, and work hard

question

What promise did God make to Adam?

answer

God promised Adam that one day he would send his son into the world (Jesus) and that he would put right all the damage that they had done

STUDY

Black Holes Supermassive Black Hole

Astronomy Final Chapter 13 Quiz HSU – Flashcards 25 terms

Dennis Jennings

25 terms

Preview

Astronomy Final Chapter 13 Quiz HSU – Flashcards

question

What useful purpose did RR Lyrae stars serve for Harlow Shapley in locating the galactic center?

answer

Their brightness variations allowed accurate distances to be measured.

question

What is the name given to a galaxy with a large nuclear bulge and tightly wound arms starting from a bar through the nuclear bulge?

answer

SBa.

question

Where is the Sun located in our galaxy?

answer

In or close to the Orion arm, which is between the Sagittarius and Perseus arms.

question

Who developed the classification system that divides galaxies into spiral, elliptical, and irregular and classifies spirals by the size of their nuclear region and the tightness of winding of their arms?

answer

Edwin Hubble

question

What name is given to a galaxy with a smooth distribution of brightness and a round shape?

answer

question

What is the Local Group?

answer

A cluster of about 30 galaxies of which the Milky Way is a member.

question

Which two parameters of star motion in a galaxy are represented by its rotation curve?

answer

Orbital speed as a function of star distance from the galactic center.

question

An astronomer studying a distant cluster of galaxies finds that several of the galaxies are spiral-shaped, with a large nuclear region and tightly wound arms. How should the astronomer classify these galaxies?

answer

question

Harlow Shapley first located the center of our Galaxy in 1917 by

answer

observing the distribution of globular clusters in the galactic halo.

question

The Magellanic Clouds seen from the southern hemisphere are examples of what type of objects?

answer

Irregular galaxies

question

A particular galaxy has a nuclear region of more or less uniform brightness from which long lanes of stars curve outward. What type of galaxy is this?

answer

Spiral

question

What is a barred spiral galaxy?

answer

A spiral galaxy with a straight bar instead of a nuclear bulge.

question

When distances were carefully measured from Earth to globular clusters above and below the Milky Way plane (where our view of them is not obscured by interstellar dust and gas), their distribution was found to be

answer

spherically symmetric about a point in the constellation Sagittarius and concentrated in that direction.

question

What is the galactic halo?

answer

A spherical distribution of stars and globular clusters centered on the nuclear bulge.

question

Who first discovered that the majority of galaxies are moving away from the Earth?

answer

Edwin Hubble

question

What method is used to determine the distances of very remote galaxies?

answer

Use of their spectral redshifts and the Hubble law

question

What name is given to a galaxy with a smooth distribution of brightness and a very elongated shape?

answer

E7.

question

The factor that misled Herschel into concluding that the stars of the Milky Way were distributed with the Sun at the center of the Galaxy was

answer

interstellar dust, which obscured the more distant stars and thereby localized his observations.

question

An astronomer studying a distant cluster of galaxies finds that several of the galaxies are spiral-shaped, with a nuclear region of moderate size and moderately wound arms. How should the astronomer classify these galaxies?

answer

Sb.

question

The Hubble law, representing observations of distant objects in the universe, relates which two parameters

answer

The distance to a distant object and the redshift of its light.

question

What is the Hubble classification for a spiral galaxy with a small nuclear region and loosely wound arms?

answer

question

The Milky Way Galaxy appears to have a spiral structure with

answer

four separate major arms.

question

The primary evidence for the expanding universe concept is

answer

the redshift of light from distant galaxies, which increases with distance of the galaxy from Earth.

question

In the 1780's, Sir William Herschel tried to measure the Sun's position in our Galaxy by

answer

counting the density of stars in different directions along the Milky Way

question

The dimensions of the disk of our Milky Way Galaxy are

answer

diameter 100,000 light-years; thickness 2,000 light-years.

STUDY

Astronomy Black Holes Milky Way Galaxy Space Science

Astronomy Unit 1 Test – Flashcards 50 terms

Daniel Jimmerson

50 terms

Preview

Astronomy Unit 1 Test – Flashcards

question

the study of the heavens, everything beyond the earth's atmosphere to the most distance reaches of the universe.

answer

Astronomy

question

Astronomy is a science, based solely on observations and facts. Science is about using facts to form, __________, testing those ideas, and devising accepted explanations for this knowledge.

answer

Hypothesis

question

What is the diameter of the earth in miles?

answer

8000 miles

question

What is the ratio of the earth's diameter to the moons?

answer

4 to 1

question

If the earth/moon distance is about 237,000 miles and the earth's circumference is 24,725 miles, what is the ratio of earth distance to earth circumference?

answer

10 to 1

question

How many times bigger is the diameter of the sun than the diameter of the earth?

answer

100 times

question

The name of these solar system bodies means "wanderer".

answer

Planets

question

We use the earth's distance from the sun as a good unit for measuring the scale of the solar system. What do we call this distance?

answer

Astronomical Unit

question

The_________is the name of the galaxy that our star(sun) and solar system area a part of.

answer

Milky Way

question

Distances in the galaxy are too big to be measured with AU, so we use the distance that light travels during the course of an entire year, which is a _______________.

answer

Light Year

question

Light travels at ____________ miles per second.

answer

186,000

question

Powers of ten notation is used so we don't have to write all the _____ in a number. The decimal goes behind the first digit and then you use "times ten to the nth power."

answer

Zeros

question

In scientific notation, 5.3297 x 10^5 is the number

answer

532,970

question

Just as stars are grouped into galaxies, galaxies are grouped into galaxy clusters. The ___________ is the cluster of galaxies the Milky Way belongs to.

answer

Local Groups

question

Galaxy clusters form an even greater assemblage of galaxies called superclusters. These superclusters make up the _________, the largest astronomical structure that we know of.

answer

Universe

question

The_________________ is the process of observing a phenomenon, proposing a hypothesis on the basis of the observations, and then testing the hypothesis.

answer

Scientific Method

question

(before 500BC)- this is a time in which man observed the motions of the sun, moon, and stars and learned to use their cyclical behavior to keep time and determine direction.

answer

Prehistoric

question

(1650 to present)- scientists began to search for the physical laws (the law of gravity, etc.) that govern the universe.

answer

Modern

question

(1400 to 1650)- in this period, scientists took a look at old ideas and found them to be inaccurate, so they devised new models that took into account all observations made over the centuries.

answer

Renaissance

question

(500 BC to 1400 AD)- during this period, scientists began to make measurements of the heavens and used geometry to construct models that account for the motion of heavenly bodies.

answer

Classical

question

______________, brought far away objects into focus.

answer

Telescope

question

in optics, electronics and computers, as well as mathematical advances like calculus, have shaped our view of astronomy today.

answer

Technological Advances

question

Knowledge of the cynical movements of heavenly bodies was crucial to early man because these movements could be used as ____________ and calendars

answer

Time Keepers

question

Celtics peoples built elaborate monuments, such as ___________ to mark the passage of the sun across the sky, indicating the beginning of the seasons.

answer

Stonehenge

question

Native Americans used the presence of ______________ in the sky to indicate tribal activity such as moving to a different hunting ground or planting crops.

answer

Constellations

question

M0st cultures view the stars as being affixed to a sphere surrounding the earth. This representation of the sky is known as the ___________________.

answer

Celestial Sphere

question

Patterns of stars on the celestial sphere are known as_________________.

answer

Constellations

question

If the celestial sphere was said to spin, then there are two areas that do not spin, the _________ __________. (We know these poles to be the axis on which the earth spins)

answer

Celestial Poles

question

There is a star positioned directly over the north pole (Polaris, the north star) that does not appear to move. It was very important to early travelers because it always marked the direction of true _____.

answer

North

question

Above the earth's equator is another useful sky marker, the ______________. It marks the boundary between northern and southern hemisphere constellations as well as giving us a reference for the earth's rotation.

answer

Celestial Equator

question

Annual motion is not cause by the rotation of the earth, but rather by the earth's ________ around the sun and is the reason for the seasons.

answer

Orbit

question

The earth's __________ is the spinning of the earth on its axis which causes day and night.

answer

Movement

question

The _________ is the path traced by the sun as it moves through the constellations . (This is not the same line as the celestial equator )

answer

Ecliptic

question

We call the two days that the sun rises due east the _________. There is one spring (vernal) and fall (autumnal) each year & the hours of sunlight and darkness on the earth at this time are equal.

answer

Equinoxes

question

The day in which the sun appears to move across the most northerly path is the summer __________.

answer

Solstice

question

The day in which the sun appears to move across the most southerly path is the __________ solstice.

answer

Winter

question

Ancient Mayans built large pyramids to allow them a clear view of the planet _______ which they based their complex and accurate calendar on.

answer

Venus

question

The movement of planets can be confusing to those studying the night sky because the planets do not move across the sky in unison with the _________.

answer

Stars

question

The planets are always found in the _______ constellations, which are centered in a narrow band along the ecliptic.

answer

Zodiac

question

Planets normally move toward the ________ through the stars and can be seen night after night in nearly the same place, moving only slightly each night.

answer

East

question

Sometimes, because of a combination of the earth's orbit and other motions, a planet may appear to move from east to wear! We call this movement _____________ motion.

answer

Retrograde

question

The moon, like the stars appears to ______ in the east and set in the west.

answer

Rise

question

The moon also goes through _________ caused by sunlight hitting it as it orbits the earth.

answer

Phases

question

The phases of the moon always progress from __________.

answer

Right to Left

question

It takes the moon about a _______ to orbit the earth.

answer

Month

question

There are two kinds of eclipses. Which occurs when the moon passes through all or part of the earth's shadow?

answer

Lunar

question

Who was the mathematician who taught that the earth was round?

answer

Phythagoras

question

Two hundred years later, Aristotle argued that the earth was round because of the earth'a shadow cast during lunar eclipses and the fact that you see different groups of _________ as you move across the earth.

answer

Stars

question

A shift in a star's apparent position due to a change in position of the earth as it orbits the sun is called _________.

answer

Parallax

question

Ptolemy described retrograde movement of the planets with the term ______ or mini circle. This description was very complex and fancy, but it was wrong!

answer

Epicycle

STUDY

Black Holes Gravity Nobel Prize In Physics

Astrophysics for People in a Hurry – Flashcards 45 terms

Pedro Huang

45 terms

Preview

Astrophysics for People in a Hurry – Flashcards

question

Einstein's General Theory of Relativity

answer

The presence of matter and energy curves the fabric of space and time around it.

question

Molecules

answer

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

question

Atoms

answer

A unit of matter; the smallest unit of a chemical element.

question

Subatomic Particles

answer

A particle smaller than an atom (e.g., a neutron) or a cluster of such particles (e.g., an alpha particle).

question

Quantum Gravity

answer

Field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics

question

Planck Era

answer

Earliest stage of the Big Bang

question

Photons

answer

A particle representing a quantum of light or other electromagnetic radiation. A photon carries energy proportional to the radiation frequency but has zero rest mass.

question

Antimatter

answer

Molecules formed by atoms consisting of antiprotons, antineutrons, and positrons. Stable antimatter does not appear to exist in our universe.

question

Quarks

answer

Any of a number of subatomic particles carrying a fractional electric charge, postulated as building blocks of the hadrons. Quarks have not been directly observed, but theoretical predictions based on their existence have been confirmed experimentally.

question

Bosons

answer

A subatomic particle, such as a photon, that has zero or integral spin and follows the statistical description given by S. N. Bose and Einstein.

question

Leptons

answer

A subatomic particle, such as an electron, muon, or neutrino, that does not take part in the strong interaction.

question

Electrons

answer

A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

question

Antielectrons

answer

The antimatter counterpart of the electron.

question

Antiquarks

answer

The antiparticle of a quark.

question

Hadrons

answer

A subatomic particle of a type including the baryons and mesons that can take part in the strong interaction.

question

Light Year

answer

Unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km (nearly 6 trillion miles).

question

Kelvin

answer

The SI base unit of thermodynamic temperature, equal in magnitude to the degree Celsius.

question

Ozone Layer

answer

A layer in the earth's stratosphere at an altitude of about 6.2 miles (10 km) containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun.

question

Newton's Law of Gravity

answer

A particle attracts every other power particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

question

Dark Matter

answer

Nonluminous material that is postulated to exist in space and that could take any of several forms including weakly interacting particles

question

George Gamow

answer

A theoretical physicist and cosmologist. He was an early advocate and developer of Lemaître's Big Bang theory.

question

Ralph Alpher

answer

An American cosmologist, who carried out pioneering work in the early 1950s on the Big Bang model

question

Robert Herman

answer

A United States scientist, best known for his work with Ralph Alpher in 1948-50, on estimating the temperature of cosmic microwave background radiation from the Big Bang explosion.

question

Arno Penzias

answer

German-American astrophysicist who shared one-half of the 1978 Nobel Prize for Physics with Robert Woodrow Wilson for their discovery of a faint electromagnetic radiation throughout the universe.

question

Robert Dicke

answer

An American physicist who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity.

question

John C. Mather

answer

He showed that the cosmic microwave background radiation has a blackbody spectrum within 50 ppm

question

George F. Smoot

answer

an American astrophysicist, cosmologist, Nobel laureate. He won the Nobel Prize in Physics in 2006 for his work on the Cosmic Background Explorer with John C. Mather

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Dark Energy

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A theoretical repulsive force that counteracts gravity and causes the universe to expand at an accelerating rate.

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Cosmologist

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A branch of astronomy that involves the origin and evolution of the universe, from the Big Bang to today and on into the future.

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Milky Way

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The galaxy of which the sun and the solar system are a part and which contains the myriads of stars

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Magellanic Clouds

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Two irregular dwarf galaxies visible in the Southern Celestial Hemisphere

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Andromeda Nebula

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The brightest galaxy in the northern sky and one of the closest to our galaxy

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Supernovas

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A star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.

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Quasars

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A massive and extremely remote celestial object, emitting exceptionally large amounts of energy, and typically having a starlike image in a telescope. It has been suggested that quasars contain massive black holes and may represent a stage in the evolution of some galaxies.

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Issac Newton

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An English mathematician and physicist; remembered for developing the calculus and for his law of gravitation and his three laws of motion

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Albert Einstein

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A German who formulated the special theory of relativity and the general theory of relativity

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Fritz Zwicky

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Zwicky was the first to use the virial theorem to infer the existence of unseen dark matter

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Vera Rubin

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American astronomer who pioneered work on galaxy rotation rates

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Under-luminous

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Insufficiently luminous

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Nicolaus Copernicus

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Renaissance- and Reformation-era mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at the center of the universe

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Edwin P. Hubble

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He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology and is regarded as one of the most important astronomers of all time.

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Saul Perlmutter

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U.S. astrophysicist selected for the Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess for providing evidence that the expansion of the universe is accelerating.

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Nuclear Fission

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The splitting of the nuclei of atoms into two fragments of approximately equal mass, accompanied by conversion of part of the mass into energy: the principle of the atomic bomb

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Spectrometer

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An instrument used for measuring spectral wavelengths

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Coma Cluster

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Large cluster of galaxies that contains over 1,000 identified galaxies.

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Astronomy Black Holes Supermassive Black Hole

ASTRO WK 7 mastering astronomy chp 22 – Flashcards 32 terms

Brad Bledsoe

32 terms

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ASTRO WK 7 mastering astronomy chp 22 – Flashcards

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Which of the following is an important starting assumption in models of galaxy formation?

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Some regions in the universe start out denser than others.

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What happens when a particle of matter meets its corresponding antiparticle of antimatter?

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The combined mass of the two particles is completely transformed into energy (photons).

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What happens to gas as it freely expands?

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It gets less dense and cools.

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A "GUT" (grand unified theory) refers to theories that _________.

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unify the strong force with the electromagnetic and weak nuclear forces

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What do we mean by inflation?

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a sudden and extremely rapid expansion of the universe that occurred in a tiny fraction of a second during the universe's first second of existence

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When a proton and an antiproton collide, they

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convert into two photons.

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The charge of an antiproton is

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negative

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Although we can divide the history of the universe into many distinct "eras," sometimes it's useful just to have a broad perspective on what events occurred in the very early universe and what events occurred later. Listed following are events that occurred either before or after the first five minutes in the history of the universe. Match these events to the appropriate time period.

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Within the first five minutes *antielectrons (positrons) as common as electrons *temperature fell to 10^15K *strong force and electroweak force first became distinct *inflation occured Sometime after the first five minutes *galaxies formed *photos of cosmic microwave *stars formed *carbon nuclei formed by fusion

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During the history of the universe, what important event occurred about 0.001 seconds after the Big Bang?

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Most matter was annihilated by antimatter.

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Which of the following important events occurred earliest in the history of the universe?

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Space-time rapidly expanded during a brief period of inflation.

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During the history of the universe, what important event occurred about 380,000 years after the Big Bang?

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Light began to travel freely through the universe.

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Essentially all the hydrogen nuclei that will ever exist in our universe were created __________.

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by the time the universe was about 3 minutes old

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Compared to when the cosmic microwave background was first released, the radiation of the cosmic microwave background today is __________.

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fainter and has most of its photons at longer wavelengths

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Which statement about the cosmic microwave background is NOT true?

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It is the result of a mixture of radiation from many independent sources, such as stars and galaxies.

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In the past, the temperature of the universe was _____.

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hotter than it is today

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The Big Bang theory is supported by two major lines of evidence that alternative models have not successfully explained. What are they?

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(1) The theory predicts the existence of and the specific characteristics of the observed cosmic microwave background; (2) the theory correctly predicts the observed overall chemical composition of the primeval universe.

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What is the current temperature of the universe?

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a few K

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Which of the following does not provide strong evidence for the Big Bang theory?

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observations of the amount of hydrogen in the universe

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What is the earliest time from which we observe light in the universe?

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a few hundred thousand years after the Big Bang

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Which of the following observations cannot be explained by the Big Bang theory unless we assume that an episode of inflation occurred?

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the fact that the temperature of the cosmic microwave background is almost the same everywhere

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Which of the following statements can NOT be tested by science today?

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Prior to the Planck time, our universe emerged from another universe.

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Which of the following does inflation help to explain?

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the uniformity of the cosmic microwave background

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Which of the following does inflation help to explain?

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the origin of galaxies

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Which of these pieces of evidence supports the idea that inflation really happened?

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the apparently "flat" geometry of the universe

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Which of the following best explains why the night sky is dark?

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The universe is not infinite in space.

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Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. Use each word only once.

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CONTINUED

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A _____ predicts that the strong, weak, and electromagnetic forces should become indistinguishable at high temperatures

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grand unified theory

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The ______ is a single force that unifies the electromagnetic and weak forces.

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electroweak force

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______ was a dramatic expansion of the universe thought to have occurred when the universe was only a tiny fraction of a second old.

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inflation

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________ forces us to think about why the sky is dark at night.

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oblers' paradox

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Observations of the _____ provide a way to test our theory of the Big Bang.

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cosmic microwave background

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When a particle of ordinary matter meets its precise opposite particle of antimatter, the result is _______ with complete conversion of mass into energy.

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annihilation

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