Question

is it possible to build a time machine?

Answer 1

No but we used are brain so that is possible

Answer 2

No. Not in the very near future, at least.

By the laws of relativity, if you are traveling at the speed of light, time passes slowly for you relative to others. THAT, my dear friend, is not you moving into the past. Its just you going slowly into the future.
Time can twist and bend, but it cannot run backwards. That's the beauty of physics.

Mark me best! Cheers