Special Relativity Flashcards
What is the first principle of special relativity
The laws of physics are the same in all inertial reference frames.
How did early experiments determine the speed of light?
Flashing a lantern and when someone else sees it, they flash theirs back. Measure how long that took. Try at longer distances. Then astronomical objects were used, considering that delays in predictable positions of objects could be due to the light delays.
What is the second principle of special relativity?
The speed of light is the same for everyone
What are the consequences of special relativity
People closer to an event will see it happen sooner, meaning two observers might see the same events happening at different times. The faster the ship is going, the slower the person on the ship experiences time (think about triangle motion of photon in clock). Lengths contract for the moving observer, and moving masses are increased.
How d
What is Lorentz factor y (gamma)
Y = 1/(sqrt(1-(v^2)/(c^2)))
How does an increase in v impact the Lorentz factor
As v increases (approaches c), y increases. Therefore, as the velocity gets closer to the speed of light, the Lorentz factor increases.
How does time relate to the Lorentz factor (and therefore speed of the ship)
t’ = t/y. Where t is the time perceived by stationary observer, and t’ is time observed on board. Therefore, as speed increases, the time observed on the ship decreases relative to the stationary observer.
How does length relate to the Lorentz factor (and therefore speed of the ship)
l’ = l/y. Where l is the length perceived by stationary observer, and l’ is length observed on board. Therefore, as speed increases, the length observed on the ship decreases relative to the stationary observer.
How does mass relate to the Lorentz factor (and therefore speed of the ship)
m’ = my. Where m is the mass of the ship when stationary, and m’ is mass of the ship at motion. Therefore, as speed increases, the mass of the ship increases relative to the stationary observer. `
How does matter (gravity) impact light and space-time
Matter bends space-time, which is perceived as gravity, which can be seen to bend light.
How does a gravitational field impact time
Inside an accelerating frame (gravitational field), light is bent, of which stronger acceleration = stronger bending. Therefore time moves slower in higher gravity.
How was general relativity validated
In the cosmos, bending of light around stars is observed, showing that light bends in gravity.
