CRASH COURSE VIDEOS ERTH 101
A neutron star has more mass than the sun, but is packed into an object only 1000 miles wide. 1 mile wide. 10000 miles wide. 10 miles wide. 100 miles wide.
10 miles wide
The Milky Way Galaxy is a spiral galaxy with a disk shape whose dimensions are 100,000 light years across and 100,000 light years thick 50,000 light years across and 100,000 light years thick 100,000 light years across and 50,000 light years thick 100,000 light years across and several thousand light years thick 100,000 light years across and 10 light years thick
100,000 light years across and several thousand light years thick
For a short while, astronomers were unsure of the source of regular radio pulses from space and gave them the name LGMs. What does LGM stand for? Light Generated Minutia Little Green Men Lower Generation Manifestation Light Guided Missiles Laser Green Medallions
Little Green Men
The astronomer named Vesto Slipher who according to Phil has the "uncontested, coolest name for an astronomer", began in 1912 abserving the spectra of spiral galaxies and by 1917 had observed 25 of them. What was the remarkable discovery that he made? The astronomer named Vesto Slipher who according to Phil has the "uncontested, coolest name for an astronomer", began in 1912 abserving the spectra of spiral galaxies and by 1917 had observed 25 of them. What was the remarkable discovery that he made?
The galaxies were highly red shifted indicating the galaxies were rapidly moving away from our galaxy.
Optical Double Stars are two or more stars that appear next to each other in the sky. Which of the following statements is true about them? They are never binary stars. They could be close together in space, but more carfeul observation is needed to determine if they are. They are never close together in space. They are temporarily bound together with a gravitational force. They are always close together in space.
They could be close together in space, but more carfeul observation is needed to determine if they are.
When galaxies collide, what is the most likely outcome? One will be ripped apart by tidal forces and the other will become more compact They will eventually merge to form a single galaxy The smaller galasy will grow while the larger galaxy will shrink until they have approximately the same mass The galaxies will orbit each other for several billion years before separating and continuing on their original paths The stars and the gas clouds can pass of one galaxy can pass right through the stars and dust clouds of the other galaxy so no collision is likely to occur
They will eventually merge to form a single galaxy
All of the following are types of galaxies except Elliptical Spiral Irregular Peculiar Toroidal
Toroidal
The brightest star in the night sky, Sirius, has a very faint companion star that can be seen with a telescope. Which of the following telescopes can see the binary actually appear as brighter than Sirius? Ultraviolet telescope Radio telescope Visible light telescope Microwave telescope X-ray telescope
X-ray telescope
On August 17, 2017 the LIGO detectors in the US and the Virgo detector in Italy detected a disturbance in spacetime called a gravitational wave. a seismic wave beneath the Martian surface. a seismic wave on the lunar surface. a seismic wave on the Martian surface.
a disturbance in spacetime called a gravitational wave.
One of the primary reasons that kilonvoae have not ever been seen is that they fade very quickly in only a few years. a few hours. a few days. a few minutes. a few months.
a few days.
The Tarantula Nebula is forming so many stars that astronomers think it may be forming a globular cluster a new galaxy a supermassive black hole an open cluster
a globular cluster
A star with a mass of about 8 solar masses will be able to fuse carbon in the core never be able to fuse helium collapse under the intense force of gravity until it forms a grey dwarf use all of its fuel in about 10 million years and then explode
be able to fuse carbon in the core
Two huge, looping streams of stars circling the Milky Way are probably part of the Sagittarius and Canis Majoris galaxies pulling material out of the Milky Way being eaten by the Milky Way passing by like a comet past our solar system were ripped apart by the Andromeda Galaxy before orbiting the Milky Way and will merge to form a "moon" or daughter galaxy around the Milky Way
being eaten by the Milky Way
In March 2011, a star which wandered in too close to a black hole was completely unaffected by the black hole swallowed up in one quick gulp flung out of its ogalaxy into intergalactic space pulled apart to make two smaller stars which now orbit the black hole completely ripped apart and briefly flared to be as bright as a trillion suns
completely ripped apart and briefly flared to be as bright as a trillion suns
When the Las Cumbres Observatory (LCO) began looking for the kilonova, they had preprogrammed galaxies to look at. Which galaxy was the kilovova located in? third! first! second! fourth! fifth!
fifth
At the exact same time that LIGO and Virgo had their detections, NASA's Fermi satellite detected sound waves. gamma rays. radio waves. a neutrino pulse.
gamma rays
Measuring the Doppler shift of radio waves emitted in a narrow band by young star-forming regions allowed us to "see" that the Milky Way is very dusty is made of metal-rich stars has spiral arms is collapsing is expanding
has spiral arms
After the main life of the sun, where it fuses hydrogen in the core, it will become a red dwarf blue giant red gient green dwarf
red gient
A kilonova is 1000 times as powerful as a nova and is a cataclysmic explosion from the merger of two red giant stars. two white dwarfs. two black holes. one white dwarf and one red giant. two neutron stars.
two neutron stars.
According to Phil, the only way we know how to get accurate stellar masses is when they are incredibly dim when they have iron absorption lines when they are incredibly bright when they have hydrogen absorption lines when they are in a binary system
when they are in a binary system
The most bizarre binary system that Phil knows about is 4U 1820-30 which orbit each other with a period of only 685 seconds (11.4 minutes) and is composed of a neutron star and a red supergiant blue supergiant red giant white dwarf yellow dwarf
white dwarf
According to Phil, when compared to lower mass stars, higher mass stars go out with a whisper with an explosion with a bang with a whimper silently
with a bang
A spiral galaxy can grow by making more stars supernovae converting hydrogen into heavier elements absorbing smaller galaxies fling some stars awy from the center and some stars toward the center of the galaxy
absorbing smaller galaxies
According to Phil, our solar system is located near the center of the Milky Way at the outer rim of the Milky Way about 1/2 of the way from the center to the edge of the Milk Way about 3/4 of the way from the center to the edge of the Milk Way about 1/4 of the way from the center to the edge of the Milk Way
about 1/2 of the way from the center to the edge of the Milk Way
The density of neutron stars matter, neutronium, is about 400 million metric tons per cubic inch. Phil tells us this is like squishing _________________ into one single six-sided die. all of the water on Earth all of the automobiles on the entire Earth all of the automobiles in North America all of the people on Earth all of the automobiles in China
all of the automobiles in North America
The reason a low mass star can live so long is that it fuses its hydrogen fuel more quickly the fusion takes place throughout the star it fuses hydrogen fuel slowly and the region outside the core is convective so the fuel can make it back to the core where it will eventually be used it gets new fuel from neighboring stars it does not mix very well so it only uses a small fraction of its mass
it fuses hydrogen fuel slowly and the region outside the core is convective so the fuel can make it back to the core where it will eventually be used
What happens when a white dwarf steals enough mass from its companion to exceed 1.4 solar masses? it fuses nearly all of its carbon at once and becomes a supernova. It will collapse and form a black hole. it releases a large amount of energy called a nova and then can collect more mass. It will become a red giant. It will split into two smaller stars, about 0.7 solar masses each.
it fuses nearly all of its carbon at once and becomes a supernova.
About how far can we see before intstellar dust begins to block our view of the stars? 25 light years 550 light years 1000 light years 50,000 light years 100 light years
1000 light years
If we reverse the expansion of the universe and ask when all of the material in the universe was in the same location, the age of the universe can be determined. According to Phil the current, best estimate for the age of the universe is (the value has been updated slightly since the video was recorded but is close to this value) 4.76 Billion years 10.21 Billion years 13.82 Billion years 46.75 Billion years 11.05 Billion Years
13.82 Billion years
How far away was the kilonova event? 1.3 ly from Earth. 130 trillion ly from Earth. 130 ly from Earth 130 million ly from Earth. 130 billion ly from Earth.
130 million ly from Earth.
If you could magnify an atom to be 100 meters across (the size of a football field), then the nucleus would be about the size of a football a grain of sand a baseball a basketball a marble
a marble
All of the following are layers within the sun EXCEPT core radiative zone conduction zone convection zone
conduction zone
According to Einstein's theory of general relativity, the force that we perceive to be gravity is really just the warping of the fabric of spacetime. The presence of mass causes this fabric to be warped and the larger the mass, the more it warps spacetime. The strange thing is that time will not pass the same for people in different gravitational fields, according to an outside observer. The greater the warping of spacetime (the stronger the gravitational field) does not matter; clocks will always tick in the same way the faster the clocks will appear to tick the slower the clocks will appear to tick
the slower the clocks will appear to tick
This scientist was the first to declare that the universe was NOT static and unchanging, but either expanding or contracting. Albert Einstein George Lemaitre Vesto Slipher Annie Cannon Stephen Hawking
George Lemaitre
When light escapes from a black hole, it appears to lose energy. This is known as Gravitational blueshift conservation of energy Doppler blueshift Gravitational redshift Doppler redshift
Gravitational redshift
The region surrounding the Milky Way out to about 100,000 light years is made up of old, stable red dwarf stars and NO star-forming regions is called the halo the stellar graveyard the stellar nursery the hat the bowl
the halo
A magnetar has incredibly powerful magnetic fields. as much as a quadrillion times the magnetic field strength of our sun. Occasionally these will have star quakes, like earthquakes that can release energy in a flare a trillion times stronger than a typical solar flare. The amount of energy released in one of these events is the same as the sun releases in 250,000 years 2.5 Million years 1,000 years 250 years 50 year
250,000 years
The escape velocity of the Earth is about 11 km/s. The sun has an escape velocity of 600 km/s. A neutron star can have an escape velocity of 150,000 km/s. What is the escape velocity at the event horizon of a black hole? 450,000 km/s (1.5x the speed of light) 150,000 km/s 300,000 km/s (the speed of light) 600,000 km/s (2x the speed of light) 200,000 km/s
300,000 km/s (the speed of light)
At the center of the Milky Way Galaxy is a supermassive black hole with a mass of 2.5 Million Solar Masses 2.2 Million Solar Masses 2.75 Million Solar Masses 10 Million Solar Masses 4.0 Million Solar Masses
4.0 Million Solar Masses
It wont happen on its own, but in order to form a black hole with a star the mass of our sun, it would need to be compressed to a diameter of only 6 km 20 km 60 km 100 km 50 km
6 km
A "low mass star" has a mass less than **(1 solar mass = mass of our Sun)** 0.5 solar masses 0.33 solar masses 1 solar mass 5 solar masses 8 solar masses
8 solar masses
According to Wikipedia - Stellar Nucleosynthesis (Links to an external site.), all of the following are produced in a kilonova explosion EXCEPT Platinum (Pt) Uranium (U) Aluminum (Al) Silver (Ag) Gold (Au)
Aluminum (Al)
What will happen to the Earth when the sun becomes a black hole? It will be sucked in because of the sun's increased gravitational field It will continue to orbit the black hole at its current radius it will drift away from the sun due to the weakening of the gravitational field it will get a little closer because the light from the sun will no longer be pushing on it Bad question. The sun will never be able to form a black hole
Bad question. The sun will never be able to form a black hole
Pulsating stars, that change their brightness with a regular period are known as ____________. They were important for determining the distance to galaxies because their period is related to their luminosity (L). pulsars neutron stars Cepheid variables. novae supernovae
Cepheid variables.
The study of the large scale structure of the universe is called: grand astrology cycadian astronomy cosmology cosmetology bangology
Cosmology
Which one of the following types of binaries would best be studied by watching the light curve of the system (the total light from the system). Eclipsing binary. Spectroscopic binary. Visual binary.
Eclipsing binary.
These galaxies are characterized by a lack of gas and dust and are primarily made of older stars. They range in size from a few thousand light years across to vastly larger than the Milky Way. Spiral Elliptical Irregular Peculiar Toroidal
Elliptical
According to Phil, where is the center of the universe? The supermassive black hole at the center of the Milky Way galaxy The Virgo supercluster of galaxies The center of mass of the Local Group of galaxies Every point in the universe looks like the center, so no point is actually the center of the universe The center is approximately 35,000,000 LY from us in the direction of the constellation Cameleopardis.
Every point in the universe looks like the center, so no point is actually the center of the universe
When ancient people looked up at the Milky Way, they saw a glow that looks like a nebula. Which of the following astronomers looked with a telescope and descovered that the Milky Way is made of countless stars, so close together that they could not be seen as separate with the naked eye. Galileo Galilee Christian Huygens Edwin Hubble Edmond Halley William Herschel
Galileo Galilee
In 1920, the Great Debate was an argument about whether the the Milky Way was the entire universe, or if the Milky Way was one of many similar type of objects. Who was the astronomer who argued that the Milky Way was all there is? Harlow Shapley Heber Curtis Edwin Hubble Annie Cannon Subrahmanyan Chandrasekhar
Harlow Shapley
What makes the Las Cumbres Observatory better than most ground based telescopes? The cameras are sensitive to both infrared and x-ray light. They have the highest resolution cameras in the world. The telescope is four times the size of the Keck observatory. The telescope is at the top of La Cumbre peak. It is a network of telescopes around the globe that always has at least one telescope in the dark.
It is a network of telescopes around the globe that always has at least one telescope in the dark.
When the hydrogen in our sun's core runs out, it will begin to collapse and heat up. What will happen in the shell around the core as a result? It will get hot enough to fuse helium It will get hot enough to fuse hydrogen It will contract as well and heat up more It will turn to liquid under the extreme pressures
It will get hot enough to fuse hydrogen
The Greek word Galaxius means Broad river Huge river Milky Clean Humongous
Milky
What is the universe expanding into? Nothing, it is creating spacetime as it expands Another universe The superuniverse The ether, which actually pervades all of spacetime as well A black hole
Nothing, it is creating spacetime as it expands
Mizar and Alcor (also called the horse and rider) have been known since ancient times. Which of the following statements is NOT true about them. They are found in the Big Dipper. One of the stars will be exploding (supernova) soon. They are a multiple star system with a total of six stars orbiting each other. They are held together with a force of gravity. They were once used as a vision test.
One of the stars will be exploding (supernova) soon.
Our sun is thought to be on a small projection from one of the major arms of the Milky Way Galaxy, called the Persueus Arm Outer Arm Sagittarius Arm Orion Arm Norma Arm
Orion Arm
When multiple star systems are first formed, they may not be fully stable, causing one or more stars to eventually be ejected. Only the stable arrangements survive for a long period of time. Which of the following stars does Phil say "might have" had a companion but we will never really know Arcturus Polaris Our sun Rigel Betelgeuse
Our sun
These galaxies have odd or distorted shapes and are all due to collisions between galaxies that are still occuring. Spiral Elliptical Peculiar Irregular Toroidal
Peculiar
If a pair of binary stars are so close together that we cannot see them as separate even with the largest telescope, then we can use spectroscopy to determine that two or more stars are present. Spectroscopic binaries rely on which of the following principles to distinguish the two stars. Take a photo of it and use digital zoom until we can finally see them as separate. The Doppler effect. One of the stars will be moving away and its light red-shifted, while one will be moving toward us and its light will be blue-shifted. The light of the dimmer star is blue-shifted when it is behind the brighter star and red-shifted when it is in front of the brighter star. The Doppler effect. Both of the stars will be red-shifted or blue-shifted depending on how the Earth is moving. The light of the brighter star is dimmed when the other star passes in front of it.
The Doppler effect. One of the stars will be moving away and its light red-shifted, while one will be moving toward us and its light will be blue-shifted.
When the sun is a red giant, what will happen to the Earth? The Earth will freeze because the surface of the sun is cooler. The Earth may move to a larger radius because the sun will exert a weaker force of gravity, and will freeze because it is colder further out in the solar system. The Earth will fall into the sun because the force of gravity will increase. The Earth may move out to a larger radius because the sun will exert a weaker force of gravity, but will become a molten ball much like when it was formed. The Earth will very likely be ejected from the solar system, along with the matter being expelled by the sun.
The Earth may move out to a larger radius because the sun will exert a weaker force of gravity, but will become a molten ball much like when it was formed.
If we study the light curve, we can see that the dips in brightness are not always the same "depth". What is the cause for a deeper dip? The hotter star passes in front of the cooler star. The cooler star passes in front of the hotter star. The stars vary in brightness and the deeper dip corresponds to a decrease in the overall brightness of the system. The larger star is hotter and is passing in front of the cooler, smaller star. The larger star is cooler and is passing behind the smaller hotter star.
The cooler star passes in front of the hotter star.
A star with a mass between 8 and 20 solar masses will undergo nuclear fusion in the core all the way up to iron (Fe) before exploding in a supernova explosion. If the remaining core mass is more than 1.4 solar masses and less than 2.8 solar masses then this incredibly dense object will form. a black hole a proton star a neutron star a white dwarf an electron star
a neutron star
A neutron star packs a mass of more than our sun into the size of the state of Arizona the planet Earth a basketball the North American Continent a small city
a small city
A really low mass red dwarf can live as long as a billion years 5 billion years 10 billion years 100 billion years a trillion years
a trillion years
As we observe more and more distant objects, the time the light takes to get to us is longer and longer. This means that we are seeing the object as it appeared in the past. The astronomical term for this is past time future time cosmological time lookback time red shift time
lookback time
Most of the globular clusters in the Milky Way are found in the galactic disk the galactic bar or bulge the galactic halo a ring around the edge of the Milky Way the Andromeda Galaxy
the galactic halo
The new field of "multi-messenger astronomy" refers to the idea that we get information from both light and cosmic rays. light and gravitational waves. ultraviolet and infrared light. sound and gravitationaly waves. sound and light.
light and gravitational waves.
With higher pressure, the nuclear fusion process occurs more frequently, releasing more energy. The lower the mass of a star, the shorter its life will be hotter its core will be longer its life will be more energy will be released by fusion in the core greater the pressure will be in the core
longer its life will be
The Big Bang must have been very hot, so hot that there would be a lot of visible light produced. Because of the expansion of the universe, this visible light has been red shifted to the ______________ range of the electromagnetic spectrum. Penzias and Wilson were awarded the Nobel prize in physics (1978) for their serendipitous discovery of this radiation in 1965. ultraviolet infrared red visible microwave x-ray
microwave
Which of the following elements were created in the Big Bang? only hydrogen (100% H) only helium (100% He) mostly hydrogen and helium (75% H and 25% He) all the elements were created in their current abundance in the Big Bang The Big Bang was so hot that even after 380,000 years no elements could be created
mostly hydrogen and helium (75% H and 25% He)
When a neutron star is formed, this force is strong enough to oppose the incredibly strong force of gravity trying to collapse it further. electron degeneracy pressure proton degeneracy pressure neutrino pressure neutron degeneracy pressure radiation pressure
neutron degeneracy pressure
If a supernova remnant core has a mass greater than 2.8 solar masses, then what force will be able to stop gravity from collapsing the core? nothing; it is not possible to stop gravity in this case electron degeneracy pressure radiation pressure neutrino degeneracy pressure neutron degeneracy pressure
nothing; it is not possible to stop gravity in this case
Inside the core of a star, 4 protons (Hydrogen nuclei) join together to make two helium nuclei four helium nuclei one helium nucleus one lithium nucleus
one helium nucleus
When the sun begins fusing helium in its core, the process is highly unstable and Phil says the sun will go through a series of orgasms reflexisms paroxysms unfortunate events
paroxysms
As a graduate student, Jocelyn Bell Burnell (and her advisor Antony Hewish who ultimately received a Nobel Prize for this work in 1974) is credited with the discovery of the first rapidly rotating neutron star, which she detected with a radio telescope array. The rapid rotation, together with the powerful magnetic field produces twin beams of energy whcih radiate away from the object. We call this a spinor pulsar hydrodynamic engine cosmic spinner rotator
pulsar
Conservation of momentum is a law of physics that says that if a star is rotating before it collapses, then when it collapses it will continue rotating at the same rate rotate faster after the collapse rotate slower after the collapse change its axis of rotation after the collapse stop rotating
rotate faster after the collapse
The Large Magellanic Cloud and Small Magellanic Cloud are considered _______________ of the Milky Way Galaxy. partner galaxies sibling galaxies sire galaxies daughter galazies satellite galaxies
satellite galaxies
If you were to fall feet first into a 10 solar mass black hole, the tidal forces would compress you into a tiny sphere spaghettify you squeeze you like a lemon flatten you like a piece of paper affect your head more than your feet
spaghettify you
A black hole with a mass between 3 solar masses and 12 (it could be more than this though) solar masses is considered to be a primordial black hole dwarf black hole stellar black hole Kerr black hole supermassive black hole
stellar black hole
At the core of nearly every galaxy is higher mass black hole. The first one that was conclusively observed is the one at the center of the Milky Way with a mass of more than 4 million solar masses. These black holes at the centers of glaxies are known as a primordial black hole supermassive black hole Kerr black hole dwarf black hole stellar black hole
supermassive black hole
Edwin Hubble and (partner) carefully studied the galaxies that had been studied by Slipher and concluded that the further away a galaxy was from us, the faster it was receding from us. the slower it was receding from us. the more likely it was to not be moving relative to us. the more likely it was to be made up of larger mass stars. the more likely it was to be made of younger, metal rich stars.
the faster it was receding from us.
What happens when protons and electrons are pushed together under extreme pressures? they merge and form a negatively charged neutron they merge and form a neutral neutron they form a positron electron pair plus two neutrinos they annihilate each other and release light energy they form a positively charged prion
they merge and form a neutral neutron
The sun will never be able to fuse carbon in the core, and the force of gravity will compress it into a small ball, only the size of the Earth called a red dwarf white dwarf brown dwarf neutron star
white dwarf
