Hey, for some odd reason i can't post a new thread, so i'll jsut post it here, seeing as this is the most related topic here. i found this formula for time dilation, and used it to see how much time dilation would occur if you went 90% the speed of light for 20 minutes and back. i came up with 51 minutes. my teacher came up with 51 years...who is right? T=T'/sqrt1-(velocity sq./speed of light sq) T=1200 seconds/sqrt1-(167400 m/secs/186000 m/secs) T=1200 seconds/sqrt 1-0.81 T=1200 seconds/sqrt 0.19 T=1200 seconds/ 0.4358898944 T=2952.988806 Subtract T from T' and you get time dilation=51.76629355 minutes (converted from seconds). Key: T=time measured by person who is stationary T'=time measured by person in motion V=velocity/speed C=speed of light (186000 m/secs) my teacher says the formula is flawed and it's really 51 years, not 51 minutes. who's right here?