Why Would I Want to Travel That Fast?
The universe is an almost impossibly vast place. The universe is so vast that even light itself take hundreds and thousands of years to travel across it. For us people light is seemingly instant in everything it does, which gives perspective on just how fast light is, and how incomprehensibly large the universe is.
Now we see the problem. The universe in its vastness is full of mystery, treasure, and wonders beyond compare (think whole planets made of diamond), but being so large it seems it's all out of reach. A space vehicle would need to be able to travel at unfathomable speeds to make any destination reachable in a human lifetime. The trouble is that the speed of light is the universe's great speed limit; nothing travels faster, no exception.
Are You Sure It's Impossible?
Why is faster than light travel impossible? Skip this paragraph if you don't care. and just want the fun stuff! If you're still here, here's a super fast break-down. Einstein's theory of relativity states that the faster you go, the more mass you have; somehow you get heavier. The more mass, the harder it is to go faster. It takes more and more energy to go faster until it requires an infinite amount of energy. It would take an infinite amount of energy just to match the speed of light, and we need to go much faster than that to get anywhere interesting.
If it takes light forever to get anywhere interesting, how can an intrepid explorer from Earth ever hope to see anything interesting? Faster than light travel is what's needed but it's clearly impossible; how do we accomplish something that's fundamentally impossible?
Very simply really, we cheat.
Cheat The Universe...Hm, Go On
So how do we cheat the laws of physics? Lucky for us, Einstein answered that for us as well. You see there's another part of relativity that says that the faster you go, the slower time passes for you. What?! Yes it seems that if you're going really really fast, a day for you would pass so slowly that a week would have gone by for everyone else. To you everything is normal, but really you're trapped in a real life slow motion.
The fact that time can slow down means that it can also be sped up. This is the key. Imagine that we could speed time up a million times inside a bottle. That means that a million years in the bottle would pass in the time for one of our years. Turn that into a billion times and you could re-evolve the human species in just one year.
So how does this apply to space travel? First we need to make a much larger bottle, one that can fit a space vehicle inside. Next we turn up the speed of time inside that bottle so that it's passing at a much higher rate of speed compared to that outside. The vehicle will be traveling at a comfortable sub-light speed inside the bottle; since time is passing so much faster inside the bottle than out, the outside effect will be that the bottle is traveling faster than in. Now just crank up that speed inside the bottle by like a billion times and boom, we can sail anywhere we want in the universe in a matter of hours! Voila!
Hold On A Second!
Alright, yes there is a gotcha. We crank up the speed of time, and now you're a billion years old. I really doubt that a pile of ancient dust that used to be your body, is going to be jazzed about its recent arrival at an interstellar destination. We need a way to keep the benefits of super speed, while protecting the crew from hyper aging. No problem, we just need another time bottle. Put a normal speed time bottle inside the hyper speed space vehicle bottle; the crew live in the normal speed bottle, and the vehicle in the fast one.
Cheating has never felt so good.
Build It to Last
The obvious gotcha here is that while the crew and people at home may reap the excitement and benefit of timely interstellar travel, the space vehicle will be required to endure literally billions of years of slogging through the universe. Billions of years of exposure to space radiation and debris, all the while maintaining the time bubble, engine thrust, and computers without running out of energy or wearing out. The irony is that that part may prove more difficult than the impossible feat of traveling faster than light.
Ok and yes there's the other big gotcha of how to manipulate the flow of time in the first place. The good news on that one is that Einstein's theory have so far been proven correct, even if we don't yet understand the forces that cause it. That means that the answer is out there, we just need some motivation to go after it.
Motivation for All Readers
If interstellar travel isn't enough of a motivator for you to invest in time manipulation research, just think about the boon to food industry if they had the ability to effectively freeze time. How about if you had a personal fast time bubble, you would be able to run around town just like the Flash. I'm pretty sure there's more so if you're still not convinced, give it a think. I'm pretty sure manipulating the flow of time, means there's some fun for everyone.