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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.

Show Me The Derivation

For our derivation, we will consider two measurements. One taken by a rider with the clock (referred to as the mover for the mover) and the other measurement for the clock will be made by a stationary observer (referred to as the stationary for the mover).

Below is an animated giff that shows where the triangle (shown below this giff) comes from. It is a large giff, but steps through each leg of the triangle. If you understand the triangle, the pythagorean theorm gets us the incredible time dilation equation.

To be sure the entire animated giff has loaded, the last frame should be the triangle shown below.

 

Show me these light clocks again.

Then below show the construction for the derivation:

From the above right triangle, the pythagorean theorem and a little algebra gives us the equation:

What is t, to, v, and c?

Want to see it derived by someone else?

See this derived by Cara at Rice University.

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.