Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
time dilation of 10 years at 0.4c
time dilation of 10 years at 0.4c
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random
