How do you build a time machine?

You go to clock/watch engineering school and learn to do clock/watch repair then you take what uou have learned and build your own.

I would tell your son that a time machine is a very interesting idea, but that nobody has ever made one, and nobody can even figure out how it would work. A time machine that can only travel into the future might be possible. A time machine that can travel forwards and backwards in time would create a lot of problems that we don't understand today, and perhaps he could help to figure out how that would work.

Don't forget to tell him that you expect at least a hi-five before he jumps into the future!

Very simple:

1. Get some money.

2. Go to a bar.

3. Buy a lot of drinks and down them very fast.

4. Black out.

5. Remember nothing of the night before the next day

And hey presto! You've effectively travelled through time!

Impossible.

I'm not sure if that is even feasible. That's a good question for Vsauce.

With great difficulty.

Grit, spit, and a whole lot of duct tape