Special Relativity, What The...

[JesseK]

Usually I can read enough of a concept to understand it, but Relativity itself is something that baffles me. Time slows down just because you're moving? I get that information from a single point appears to slow down as you move away from it. Yet here's what doesn't make sense to me:

Indeed, if you put an atomic clock in an airplane and fly it around the world, it will end up with a slightly different time than an identical clock that remained at the airport.

How can the time of flight for the clock on the plane be different from the time of flight for the clock on the ground, given that both went tick-tock for an identical length of time?

And doesn't this imply that photons may have an infinitesimally small lifetime if they were to stop moving?

Can anyone shed some light on this?

Article

Maybe I should just stick to software...

[Ether]

Originally Posted by JesseK

doesn't this imply that photons may have an infinitesimally small lifetime if they were to stop moving?

In a vacuum, photons are always moving at the speed of light.

[FrankJ]

Originally Posted by Ether

In a vacuum, photons are always moving at the speed of light.

A frictionless vacuum that is.

[Taylor]

Frictionless vacuums are best vacuums.
Speaking of infinitesimally short lifetimes...http://xkcd.com/669/

[Aren Siekmeier]

Originally Posted by JesseK

And doesn't this imply that photons may have an infinitesimally small lifetime if they were to stop moving?

As Ether pointed out, a photon can never "stop moving." However, if you were to "attach a clock" to the photon and watch the clock as the photon went by, you would see that the clock is frozen. In fact these two things are related by the theory.

[Bob Steele]

The constant is the speed of light... not the time. The time is relative.

[Ether]

Originally Posted by Bob Steele

The constant is the speed of light... not the time. The time is relative.

To whom were you responding?

[Michael Hill]

This class is very good at teaching special relativity: https://www.youtube.com/watch?v=BAurgxtOdxY

[Bob Steele]

Originally Posted by Ether

To whom were you responding?

JesseK

[Ether]

Originally Posted by Bob Steele

JesseK

OK.

It was a bit confusing, because your post is linked to compwiztobe's post#5, so it appeared that you were commenting on his post.

[GCentola]

http://www.testtubegames.com/velocityraptor.html

[Ether]

Someone zips by you at 90% of the speed of light. You say his watch is running slowly because he's going so fast...




...but from his perspective, you zipped by him at 90% of the speed of light. So he says your watch is running slowly.

[JesseK]

Originally Posted by Ether

Someone zips by you at 90% of the speed of light. You say his watch is running slowly because he's going so fast...




...but from his perspective, you zipped by him at 90% of the speed of light. So he says your watch is running slowly.

Say the time of flight was 1 hour according to the airport. What does the air traffic controller say? Do the planes have to make relativity-induced adjustments for landing upon approach? Did the pilots age more or less than one hour during the flight, relative to the air traffic controller who aged exactly one hour? Age is very perspective-based, which is the only reason I bring it up here.

The video helped a lot with defining the inertial frames of reference Michael, thanks for the link.

[Ether]

Originally Posted by JesseK

Did the pilots age more or less than one hour during the flight, relative to the air traffic controller who aged exactly one hour?

For a one-hour flight at 500 mph, the pilot would be about 1 nanosecond younger.