Tuesday, February 22, 2011

Thoughts On The Feasibility Of Time Travel

I've recently thought about something that has completely ruined any chance I'll ever have of enjoying a movie that involves time travel. Not like Back to the Future was completely realistic to begin with, but still... suspension of disbelief has become extra difficult to suspend.

Consider this:
The Earth is spinning about its axis. Depending where on Earth you're at you are traveling pretty darn fast. If you are on the equator then you are traveling at about 1,000 miles per hour.

The Earth is also doing extremely fast laps around the sun. We're averaging about 67,000 miles per hour (sometimes faster, sometimes slower, thanks to elliptical orbits and whatnot).

That's fast.
But wait! There's more.

The sun itself, as well as the entire solar system, is part of the Milky Way galaxy, a spinning spiral-shaped collection of stars, gas, dust, and debris. We are orbiting the center of the galaxy at about 560,000 miles per hour.

The Milky Way is part of a galactic Local Group comprised of 30 or so galaxies. Our Local Group is hurtling through the universe at about 666,000 miles per hour.

These are just averages. If everything is moving in the same direction at the same time (like the way walking 5 mph forward inside a 30 mph school bus will put you at 35 mph) there is potential for speeds exceeding 1 million miles per hour. That is over 277 miles per second.

The point is we are always moving and we are always moving fast, even if we are just sitting on a couch pecking away at a laptop and thinking about time travel.

Speed is all relative, of course. When we see a guy on a bicycle fly by us we think he is going pretty fast... until a Ferrari passes that bike. Then a low-flying jumbo jet buzzes that Ferrari. Then a rocket-powered space shuttle buzzes that jumbo jet. Suddenly the bicycle doesn't seem to be going all that fast. Thanks, Einstein.

So when we're looking at the big picture, when we're looking at the whole stinking universe, we are absolutely flying through space. Something that travels several hundred thousand miles per hour, in a blink of an eye it is gone. In a blink of an eye we are gone.

With regard to time travel, if we are plotting points in space, something that is there one second will literally be a hundred miles away the very next second. If you're traveling back in time by one second... well, you're going to miss your landing pad. You might end up in the ocean. You might end up in a mountain. You might end up in Earth's outer atmosphere. You'll probably end up dead.

And going one-hundred years back in time... who knows where you'll end up. Somewhere in deep space. Burned instantly in a supernova if you're lucky.

It seems to me that not only do you need a machine to plot points in time, you also need a machine to plot points in space. Maybe the flux capacitor can do this. I don't know. They didn't get into it. It was just invented when Doc Brown hit his head on a toilet.

[I know physicists are trying (have succeeded?) to send photons back in time, but that is dealing with individual subatomic particles, not complicated masses of HUMAN. I'm not going to try to wrap my head around quantum physics anyway. It's pretty messed up. I DON'T GET IT.]

Going forward through time is different. You and I can do that by either closely orbiting a black hole (but stay away from that event horizon!) or by moving nearly as fast as light. No problem.

The speed of light, by the way, is over 670 million miles per hour, or over 186,000 miles per second. But Einstein recognized that time slows down for objects approaching that speed. That is, everything else appears sped up. It's not so much traveling into the future (which we're already doing just by being alive) as it is pressing life's Fast-Forward button.

So maybe traveling at the speed of light stops time? And bypassing it reverses time? I don't know. Apparently it's impossible and you'd be breaking several laws of physics if you succeeded.

I like the wormhole theories. Big tunnels in space and time. Go wherever you want whenever you want. Nice and clean. Your very own Stargate. Don't know how to make one. I'm sure the physicists are on it, accelerating particles, creating miniature black holes.

Anyway, in conclusion, it is easy to forget that Earth isn't the center of the universe. Our globe is a speck in the dust storm of existence, and we are but specks upon that speck.

We are tiny and insignificant.
Practical time travel is impractical.
Have a good night, everybody!

Through distant deeps and skies, behind infinity, below the face of Heaven, He stoops to create me. -- FIF


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