Here’s the thing about building your own time machine:

If you plan on changing anything in the past to improve your present (or future),
you can’t build your own time machine to do it.

WHY?

Because making a change to your past… eliminates the reason why you wanted to create a time machine in the first place. It’s a paradox. You will never have created a time machine because you will not have had a need to create a time machine.

Still don’t get it?  Let me give you an example:

Let’s say that a year ago you entered a hot dog eating contest and before the big contest, you got hungry and ate a few pizzas, which made you fall 10 hot dogs short of a world record, losing to Joey Chestnut once again.

You decide to build a time machine so you can go back in time and warn the 2012 version of You not to eat the pizzas, so 2012-You can make room for those extra hot dogs and get the world record.

2013-You successfully invent a time machine, but every time you travel back to warn 2012-You not to eat the pizzas, you fail. The laws of time prevent you from changing the outcome because if you do, you will never have had a reason to build the time machine.

We could talk about parallel dimensions, Gallifreyan Astro-Physics, flux capacitors, Springfield Toaster Mechanics, how freaky that Butterfly Effect movie was, and how every possible outcome becomes it’s own reality, but for now let’s stick to the basics and just assume this:

If you have a reason to build your time machine other than observing time, you won’t be able to change anything.

(Well, not on purpose anyway. Accidents can happen.)

HOW DO YOU GET AROUND THIS?
You get around this by stealing someone else’s time machine. Preferably, it will be a time machine that was built by someone who had no desire to change anything in his own past, thus insuring that the time machine would have been built regardless.

HOW DO I FIND SOMEONE WITH A USEABLE TIME MACHINE?
Look for Universities that have lots of money for History and Science. Odds are pretty good that you’ll find some egghead professor or grad student who just thought it would be cool to invent a time machine so he could pop back to the Cretaceous period for a few minutes to see if Dinosaurs have feathers, then zip right back home in time to watch Shark Week on Discovery Channel.

OK. I FOUND AN EGGHEAD WITH A TIME MACHINE. NOW WHAT?
Become his ‘research assistant’ or ‘intern’. You’re bound to end up participating in one of his test runs, along with one of his pets, who he’s likely named after some famous scientist like Albert Einstein, H.G. Wells or Emmet Brown.

It’s best to let someone else make the first trip, just to make sure you’ll be able to return to your own time once you’ve scolded your pizza-eating past-self. You also want to make sure that you have easy access to a time-machine repair kit in case you blow out the flux capacitor or run out of plutonium… and don’t get too close to the radioactive stuff. There’s no point in tweaking your past if you’re not going to live to enjoy the future. Also, you might accidentally erase yourself from existence if you come in direct contact with your past-self, so wear gloves.

Once you’ve successfully changed the thingy that you wanted to change, it’s difficult to say what will happen when you return from the past. Most likely, your memories may have an overlap where you remember the past year’s events happening two different ways, one where you had your time travel adventure and the other where you skipped the pizza and broke a hot dog eating record, and then live happily ever after.

There is, however, a very slight possibility that when you return from the past, there will now be TWO of you. If this happens, you’re going to have to have a long talk with yourself on what to do next. It could be in your advantage to be in two places at once, but be prepared to ‘eliminate the paradox’ if necessary. The other you might not want to share your Cubs bobblehead collection.

So good luck. Be careful. Let us know how it goes. Try not to implode the universe.
Also, if you could pop forward a few years and write down a few winning lottery numbers…

—