Hi dehammer,

DA Morgan answered you correctly so I will not expand on it.

You must stop thinking that when you observe time dilation it is really happening within the framework moving relative to you. Neither does the increase in mass you see of a body moving relative to you manifest within the framework moving with that body. Similar for length contraction.

This argument is even applicable in Galileo's relativity. The kinetic energy you measure for a body moving relative to you is NOT present within the reference frame moving with that body.

http://www.cathodixx.com