1) yes

2) action at a distance

3) heaviness (Greeks), force (Newton), distortion of spacetime (Einstein), entropy

4) gravity and acceleration are equivalent

5) no force implies constant velocity, Force equals mass times acceleration, for any force there is an equal and opposite reaction force.

6) Entropy is a measure of the amount of disorder of a system. It is a measure of number of times a system can be rearranged before that change can be noticed.

7) Laws of physics are the same for everyone, and the speed of light is the same in any reference frame

8) the wavelegth is shifted towards the blue; the speed is unchanged

9) that planets orbit on elliptical orbits

10) the decrease in the period of orbiting pulsars

11) a straight path is defined by weightlessness

12) Having particles separated into their individual systems has a lower entropy than having all particles in one system. If the universe is to then evolve towards high entropy, then systems want to come together to make this happen.

13) clocks are running slower if you have a veloticy, so you sitting there are ageing faster.

14) Neptune was discovered since there was a gravitational disturbance measured to the orbit of Uranus.

15) 0:point. 1:line. 2:plane. 3:cube/sphere. 4:adding time

16) We think GR breaks down since inside of a black hole, the calculations show that all mass goes into a central point of infinite density. Anything that goes to infinity is suspicion that an assumption is wrong. We can test the breakdown of GR best by studying material as it orbits a black hole, since that has the highest density.

17) If the gravitational pull is 16x less then it is 4x further away (i.e., a=4). With P^2=a^3, then P^2=4^3=64. Or P=8 years.

18) If GPB measured that the distance travelled was a inch longer then it still would have measured a distortion of spacetime. But the distortion would be curved outward, which is saddle-shaped or pringle potato chip shape.

19) He measured the length of an eclipse when the Earth was moving towards Jupiter and when it was moving away. Due the light travel time from Jupiter to the Earth, the Earth moves a little bit closer or further in that time. This causes a change in the eclipse time, which is due to the speed of light.

20) In Special Relativity, a simple thought experiment by reflecting a laser off the top of a moving object will show that time goes slower in the moving frame. In General Relativity, one can use pulses of light in an accelerated reference frame to demonstrate time dilation.

1) too little

2) proper motion of stars

3) exploding massive star or colliding neutron stars

4) gamma-rays

5) Earth's atmosphere blocks them

6) isotropic: the air, temperature, radio waves, dark matter. Non-isotropic: people, chalkboard, many things....

7) SMBH are far away (since they are in the centers of galaxies), but because of their mass they have a large effect on stars that we can easily measure. Stellar mass BHs are within our galaxy, and some are very nearby by which means that we can also measure their effect. IMBH are not very nearby and they are relatively small, so we cannot yet easily measure their effect.

8) velocity and distance from center

9) Seeing rapid variations in brightness implies that the object has to be smaller than the light travel time across it. If the object were larger, then the light from one side would get blended with the light from the other side, and we wouldn't see variations. For quasars, the variations are short (weeks), which means the actual size is small.

10) nuclear burning, electron degneracy pressure, neutron degneracy pressure, nothing

11) Quasars, which are actively feeding black holes, peaked in the universe before the time when star formation peaked. We also see quasars as some of the earliest objects in the universe, when galaxies did not have time to form yet. Thus, there is some evidence that black holes came first.

12) The rate of the spin tells us about the feeding rate of a black hole. If spinning maximally, the black hole eats large amount of material at a time, as opposed to a gentle stream. It also provides some information on the accretion disk model.

13) Most of the light around a black hole is coming from the accretion disk. The reason is because that is where the density is the highest and the particle interaction rate is therefore the largest. When the particles collide, they produce light.

14) The black hole could have been ejected from a nearby massive galaxy. Then it would either run into a nearby small galaxy or hold on to nucleus of stars.

15) For the Milky Way black hole we are able to measure the highest density for any other reported black hole. With such a high density, we are unable to come with any physical model to explain it other than it being a black hole. So, it is by process of elimination.

16) It means that there is no preferred direction on the sky where GRBs are located. I.e., they are distributed everywhere on the sky. Possible orgins for this are anything that is distributed spherical around us: cosmological, the Oort cloud, the Milky Way halo.

17) Heisenberg Uncertainty Principle states that in a short amount of time (small uncertainty), the uncertainty on the energy increase. Thus, you might be able to have huge energy fluctuations in small time intervals. Since energy is equated with mass, then the energy fluctuations can lead to mass fluctuations. This then causes the creation of a pair of particles (they come in 2 since you have to conserve charge and spin). This is what we call virtual particles.

18) If the black hole is too small in mass then as material falls on to it, it will only produce a small amount of energy in terms of winds and jets. The small energy (because the black hole is small) is not enough to halt the material from falling in. Thus, it would naturally start to grow quickly.

19) When a gas cloud falls inward, the first thing it will do is speed up due to conservation of angular momentum (so the disk will be fast spinning). The second thing that happens is that the particles begin to interact with each other. This interaction causes them to get in an order configuration. The only stable configuration in the end is when the particles do not collide on their orbits, and this is a thin disk.

20) The two observations that Einstein used are the precession of Mercury and the bending of starlight by the Sun. For Mercury, the elliptical orbit would take it closer and then further away from the Sun. As it got closer, spacetime was curved more, and it would appear to travel a little further than if it were not curved. This additional movement causes it to precess. For the Sun, it was predicted that a star behind the Sun would appear in a different place than if the Sun were not in the path, since the Sun warps spacetime. This star movement was measured during an eclipse of the Sun, since you cannot see the stars when the Sun is up.

1) WIMPS or neutralino or higgsino or many others

2) the bonds in our body are stronger than the dark energy pull

3) temperature decreasing or entropy or increasing wavelength of photons

4) It showed that the universe was significantly larger than we thought.

5) dark matter origin would have an isotropic distribution and the pulsar origin would not.

6) Everything starting at time equal zero, infinite density, and need for inflation

7) V=H0xD: V is velocity and we measure that by taking a spectrum with a spectrograph and getting the redshift. D is distance, which we get from seeing how bright something is (taking an image) and knowing how bright it is supposed to be through a calibration. H0 comes from plotting V and D against each other and seeing what the relationship is.

8) The horizon problem is that opposite sides of the universe are effectively at the same temperature, yet they are separated by too large a distance for information to have traveled between them. Inflation solves this by making the universe a lot smaller in the past, so these sides could have come into equilibrium.

9) Nothing - time and space came into existence at the moment of the Big Bang. Thus, nothing was beforehand. Or...there has always been a sea of fluctuating space and time, called the multiverse, and our universe is one large fluctuation among the infinte ones.

10) When normal matter collides, it slows it velocity, and thus falls into the center of a galaxy. When dark matter particles collide, they annihilate each other and just make light. Thus, the dark matter will not fall in towards the center.

11) If inflation did not come to an end, then all matter would be spread very thin and galaxies would never form. Thus, we wouldn't exist to ask the question.

12) gravitational lensing, rotation curve of galaxies, galaxy velocities in a cluster, X-rays from a cluster, Bullet Cluster, gamma-rays in FERMI, positron excess, direct hit causing a vibration, direct hit exciting an electron, direct hit causing a shower of particles, oscillations of hit events caused by different flow, others...

13) 0th is a point; 1st is a line; 2nd is a plane; 3rd is a cube; 4th is a timeline; 5th is all possible timelines

14) There are some objects we see now that are moving away from us at faster than the speed of light. The reason for this is that we are seeing those objects a long time ago (due to finite speed of light) when the universe was a lot smaller - that is why we can see them.

15) Since the early universe, the expansion rate has been slowing down due to the mutual gravitational pull of everything in the universe. Thus, the rate was higher in the past. In the future, dark energy has taken over and the expansion rate will be getting faster.

16) Given the considered size of the universe at that time, Einstein thought it should have collapsed due to gravity. Since that didn't happen, he included a term that would perfectly balance gravity. It is a blunder since Einstein missed the opportunity to discover that the Universe is expanding from theoretical considerations. He basically missed that his model of the cosmological constant placed the universe in an unstable configuration.

17) dark energy: cosmological constant (or virtual particles), a new particle, or misunderstanding of gravity, or a Hubble Bubble. dark matter: a new particle or a misunderstanding of gravity. inflation: strong force pulling out of GUT force, or inflaton rolling down hill, or colliding branes or Higgs Field turning on.

18) DAMA sees a yearly modulation in their recoil rate of the nuclei in their experiment. They attribute this modulation since the orbit of the Earth sometimes is moving against the dark matter flow (and hence has increased rate) and sometimes going with it (giving a lower rate of interaction).

19) The Heisenberg Uncertainty Principle leads to fluctuations in spacetime. These manifest as energy fluctuations which lead to over and under dense regions. These would normally average out, but during inflation these regions were greatly separated and got frooze into bumps in the matter distribution (and hence CMB).

20) CDMS uses vibrations from direct dark matter hits to measure the dark matter. The amplitude and duration of the vibration tell us about the mass of the dark matter particle. The frquency at which this vibrations occur tell us about the number density of the dark matter.