Relativity

What experiment can be done to decipher between 'at rest RF' and the 'constant velocity RF'?

None - both have no acceleration and therefore have the same value of zero.

What problem existed between Newton's laws and the speed of light?

The speed of light is not relative.

A clock aboard a high speed is slow. If the rocket reverses its direction, does the clock run fast or slow?

Slow because direction doesn't affect time.

What is space-time?

The 4 dimensional fabric we live in. When space or time is affected, so is the other.

If you are moving at 1/2 c, and fire a photon at c, how fast does an observer on the ground see the photon moving at?

c because the 2nd postulate (speed of light is constant in all frames).

Under what condition will you and a special friend share space-time?

When you're in the same RF.

If you were moving in a ship at a large speed close to the speed of light, what would you notice about your pulse and clocks on board the ship?

Nothing

Cite 2 pieces of evidence that support time dilation.

Atomic clocks and muons

According to Einstein, what is it that 2 observers will always agree on, regardless of their motion?

speed of light

What speed must your rocket ship have such that a beam of light will have a relative velocity of 0.4c as it passes you from behind?

This can't happen

Is simultaneity absolute or relative?

Relative - everything is relative except c.

When you gaze upon your mirror, are you looking into the past?

Yes - everything is in the past.

When we speak of time dilation, does time really slow down for moving objects, or does it just appear that way?

It actually slows down.

Explain how a parent could biologically outlive their child using space travel.

The parent travels fast in space, causing their time to go much slower than the child's time on Earth.

Could you travel into the past (meaning, go back before something happened)? The future?

You can only travel into the future.

As you move at very high speeds, what happens to the space that you travel in?

Space and the length of an object being measured contract (get smaller).

What would the Earth look like as you move past it at high speeds moving along the equator?

The width would contract but the height would remain the same.

According to an Earth observer, muons shouldn't be able to reach ground level due to their short lifespan (2.2 x 10^6 s), however, since they are moving at 0.99c, they can survive because of time dilation. But, an observer who rides with the muon still registers the original lifespan, not an extended one. What does this observers say about the fact that the muon can reach the ground?

Space is contracted.

What is the main difference between special relativity and general relativity?

General theory looks at acceleration while special relativity focuses on constant and at rest velocity

In a spaceship accelerating at 'g', far from the gravity of Earth, how does the motion of a dropped ball compare with dropping one on Earth?

Same result

Exactly what is equivalent in the principle of equivalence?

Any effect that occurs with acceleration must be true with gravity.

What did Einstein predict about starlight passing by the sun?

It's bent by the sun's gravity.

What event proved Einstein correct in regards to his prediction about starlight?

A solar eclipse

Why must the sun be eclipsed to measure the deflection of starlight passing near the sun?

To photograph stars near the sun since the sun is too bright to do so during daylight.

What is the effect of strong gravitation on time?

Time is slow

Which runs slower, a clock on the Empire State building or a clock on the sidewalk outside the building?

The clock on the sidwalk

Would a clock run faster or slower if it was on the moon rather than the earth?

Faster

Describe the 2 effects of time dilation that would be present for a clock aboard a fast moving satellite, high above the earth.

Time is slow due to speed and fast due to less gravity - overall it is fast.

What effect does mass have on space-time?

It distorts space and time in the vicinity.

Define gravity according to Einstein.

The warp in space-time.

List at least 3 experimental tests of GR with a brief description of the tests.

Gravitational lensing - light travels curved paths around massive objects using gravity as a lens to see something otherwise invisible

Mercury's orbit - Mercury's precession faster because its curvature of space time is closer to the sun

Gravitational redshift - time dilation causes a shift in frequency when light leaves a region of larger gravity into a region of smaller gravity (time gets faster).

What is spaghettification?

When a person enters a black hole, the gravity on their head is so much less than the gravity on their feet that this difference rips them apart.

How do black holes form?

A large star exhausts its nuclear fuel and the star collapses into a singularity, creating an immense bending of space-time.

What is meant by the event horizon?

The distance from the singularity to a perimeter.

Define singularity.

A point of infinite density

Describe time effects from black hole from RF of Earth look back at black hole vs near black hole looking at Earth.

Earth RF sees black hole's time as so slow that if a person crossed into it the Earth RF would never see it.

From the black hole, the Earth's time is moving so fast it's as if it happens in a flash.

Briefly, explain the LIGO experiment... how did it measure gravitational waves?

A laser light was sent down 2 mile perpendicular arms. The laser light bounces off of mirrors at the end of each arm. The waves these lasers cause creates a slight shift in space-time and therefore slightly squeeze and stretch the arms.