: I was wondering if someone could tell me about the ageing process in space. I have heard that if a person goes into space and travels around the world fast enough that when they come back to earth that their kids may be older than them. Does anyone know what I am talking about?

This message attempts to explain the twin paradox without delving into any math. If you are interested in the math, check out a modern physics textbook : the equations are the time dilation equations for the special theory of relativity.

When an object travels at a significantly high speed, the time through which it travels begins to change. If this object can tell the time, such as a clock, an observer in another reference frame, not moving at the same velocity, would see the clock running slower. In the case that a person were travelling at a high speed, the people left behind in a slower moving frame would age faster than the person who is travelling quite rapidly. When the person who took the rapid flight returns to the ground, the traveller will have found that those who stayed on earth aged more then he/she did.

The twin paradox is that a twin could be sent to such a high speed that when the travelling twin returns - seeming to him after only a short time - his twin could have died of old age, while the traveller is still a young age.

Before this will make sense, you must release the idea of absolute time.

Yes, this has been shown to be correct. Notice, I did not say proven. The time dilation effects and the corresponding lorentz transformations that produce relativistic effects have been correct in predicting the results of certain experiments including clocks slowing down on fast flights, and the doppler shifting of light.

Don't die!

Mark Chapman

Astronomy-Physics undergraduate student at the University of Wisconsin-Madison

e-mail : machapma@students.wisc.edu

• Re: twin paradox - bouwe/">bouwe - May 7, 1998 - 12:01 UTC
• Re: twin paradox - robert_barbow/">robert barbow - June 10, 1998 - 21:40 UTC
• Re: twin paradox - Luciano_Medina/">Luciano Medina - August 28, 1998 - 08:50 UTC
  • I FOUND IT! Anyone interested, please check this page - Luciano_Medina/">Luciano Medina - August 28, 1998 - 10:57 UTC