Has anyone built a time machine before?

Of course... nothing more than complex musings in my head.

Not sure what you mean on this, but this may help

 

If I had a time machine I'd go back and buy a Marathon bar, bring it back to now, and ring up Mars complaining bitterly abut 20 year old stock being sold as new

 

They would probably answer by saying that as the Marathon bar changed name to Stickers in 1990 then it must be older than 20 years

 

A bit like the Fermi Paradox for aliens, if time travel is possible in the future then where are all the time travellers?

Some people think this guy might be one. Commonly called "The Time-Travelling Hipster", captured in this photo from 1941

 

I'd kill Courtney Love before she got the chance to murder Kurt. Then we wouldn't have Nickelback wannabes, the Foo Fighters headlining Glasto.

 

I like the Foo Fighters so I'm glad she killed him