Time Travel

Albert Einstein wasn't able to get the details right. He understood that in this universe you could approach the speed of light but could not exceed the speed of light. Now that there is a vague understanding of quantum theory, we've identified eleven dimensions of space, only four of which (height, width, depth and time) operate above the Planck Length.

All this notwithstanding, if you plan to travel back in time, you should take precautions. 

(cautionary note) Just because a comet is hurdling toward earth, don't drink poison punch so your "spirit" can join with the Mother Ship following in the comet's tail. There likely is no mother ship and all you'll end up doing is providing work for grave diggers.

If you hope that traveling to the future will somehow improve your lot in life, you may be wrong. It might suck a whole lot more than it does here and now.