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Lesson 2: Time Dilation

Lesson 1: Relativity - What is it?

  1. Fermilab's Time Dilation Challenge.
  2. The Basics of Relativity (6 seconds)
  3. The Relativity Game - Challenge what you know!

Note: For Fermilab's Time Dilation Challenge and The Relativity Game, you need Shockwave. You may painlessly Download Shockwave here if you do not have it.

Lesson 2: Time Dilation

  1. The equation.
  2. Where does that come from?
  3. I still don't get it! Give me the basketball analogy.
  4. So what? There's an equation. How do I use the equation in the game?
  5. Practice Problems.
  6. Examples to aid your practice.

Lesson 3 : Relativistic Mass

  1. The equation.
  2. Where does that come from?
  3. I still don't get it! Give me the space pool analogy.
  4. So what? There's an equation. How do I use the equation in the game?
  5. Practice Problems.
  6. Examples to aid your practice.

Lesson 4 : Length Contraction

  1. The equation.
  2. Where does that come from?
  3. I still don't get it! Give me the pole and the barn analogy.
  4. So what? There's an equation. How do I use the equation in the game?
  5. Practice Problems.
  6. Examples to aid your practice.

Tell me more about these light clocks?

As seen by someone riding along with the constant velocity light clock, both the clock and the mover seem to be at rest. The light pulse would go 300,000,000 meters down in a time of one second and it would go the 300,000,000 meters up in another second and would not appear to move sideways at all.

As seen by a stationary observer, watching the mover and the clock fly by at say 150,000,000 m/s (50% c) the event would look very different.

The light pulse would travel down and to the right along the hypotenuse of the triangle formed by the light pulse traveling down 300,000,000 meters and right 150,000,000 meters.

This means that the stationary observer would see the light pulse travel more than 300,000,000 meters.

Question:

Can the stationary observer see the light pulse travel faster than c?

This means that the stationary observer would see the clock take 1.15 seconds to travel down, and another 1.15 seconds to travel back up. One tick and tock took 2.31 seconds!

The mover would say, "2.0 seconds took 2.0 seconds."

The stationary observer would say, "Mover, your clock that was supposed to time 2.00 seconds in your frame, took 2.31 seconds in mine!"

Question:

According to the stationary observer, did the mover's clock speed up or slow down?

Lesson 2: Time Dilation

  1. The equation.
  2. Where does that come from?
  3. I still don't get it! Give me the basketball analogy.
  4. So what? There's an equation. How do I use the equation in the game?
  5. Practice Problems.
  6. Examples to aid your practice.

 

 


© Brian Wegley, 1998
Comments and suggestions can be sent by e-mail to
Brian Wegley of Glenbrook South High School..
This page last updated on 7/23/98.