1. One of Albert Einstein’s Greatest Insights By Larry Kimbrough

2. Time is Relative One of Einstein’s greatest insight was realizing that time is relative. Time is relative means that time dependent upon another thing. Time speeds up or slows down depending on how fast one thing is moving relative to something else.

3. Time is Relative Albert Einstein believed that the closer we came to the traveling at the speed of light (186,000 miles per second) the more time would appear to slow down from the perspective of someone who was not moving. He called this slowing of time Time Dilation ( Δt ). Δt = Where v = speed of the object Δt p = proper time and c = speed of light

4. Could This Theory Be True ? In an experiment in 1971 scientists used atomic clocks, ( extremely accurate clocks that can measure in the billions of a second ) to test Einstein’s theory. One clock was set up on the ground, while another was sent around the world on a jet traveling at 600 mph. Both clocks showed exactly the same time. What do you think happened?

5. Einstein Was Right ! As Einstein predicted the clocks no longer showed the same time. The clock on the jet was behind by a few billionths of a second. Why such a small difference? Well, 600mph is only a small fraction of the speed of light ( 186,000mps).

6. Another Test of Einstein’s Theory In 1976 at the laboratory of the European Council for Nuclear Research (CERN) in Geneva, muons (unstable elementary particles with a lifetime of 0.0000022 seconds), injected into a large storage ring reached speeds of approximately 0.9994c. The scientists measured the moving muons lifetime to be 30 times as long as the stationary muons. Thus Einstein’s theory was proven to be true.

7. The Twin Paradox Einstein came up with an example to show the effect of time dilation that he called the “Twin Paradox”. There are a pair of twins, lets call one Speedo, and the other Goslo. They are 10 years old. Speedo’s parents send him to summer camp to the Alpha -3 star system, which is 25 light years away. Goslo did not want to go,so he stayed home. Speedo travels at 99.99c. The trip to the star and back took 50 years.

8. The Twin Paradox When Speedo returns to Earth he finds that Golso is 60 years old, and he has only aged 6 months. The trip lasted only 6 months for Speed, but 50 years passed on Earth. Time can slow down, but never will go backward. Check out this web-site. http://www.pbs.org/wgbh/nova/einstein/hotsciencetwin/in dex.html http://www.pbs.org/wgbh/nova/einstein/hotsciencetwin/in dex.html