Wednesday, December 16, 2009

Our rapidly accelerating universe

So there are these super smart guys sitting around looking at data collected by telescopes and getting paid good money for it. These smart guys have noticed that it looks like the galaxies that are furthest from the center of the universe are accelerating. This is contrary to what SHOULD be happening. Because these galaxies have lots of matter behind them (relatively) and there is no apparent pulling force in front of them they should be slowing down.

Now these super smart guys are often incapable of uttering the three words "I don't know" and so they immediately started brainstorming to figure out why this would be happening. They have, to my knowledge, come up with four theories. 1) Our galaxy is in it's own "time bubble" (and yes they used that term.) 2) There is "dark matter" that is causing the acceleration (dark matter being this invisible thing that they THINK they can detect with their telescopes.) 3) A strange alteration of space/time when energy levels become extreme (which is strange because I was just sitting here thinking of writing this exact blog entry when I came across this web site ) and 4) Giant space faeries with giant space brooms sweeping the path clean in front of the galaxies (OK I made that last part up.)

I have a more simple explanation. I think they look like they're speeding up because they're actually slowing down. I LOVE it when my brain comes up with these things. But here's the thing. We have to dive into the shallow kiddie pool end of Einstein's relativity theory (so don't be scared.)

First off, everything in the universe is moving. Nothing is actually still. We are on earth which is spinning and orbiting the sun which is orbiting the center of our galaxy which is hurtling through space. You get the idea.

Now, Einstein says that as we approach the speed of light time is altered. For simplicity we'll say that someone orbiting the earth VERY quickly might experience 1 day while everyone on earth might experience 10 years in that time.

This idea goes both ways. The astronaut would look down and see a year pass on earth in only 2.4 hours his time. At the same time, if someone on earth could see the astronaut's watch with a super powerful telescope they would see that it takes a whole year for his watch to advance 2 hours and 24 minutes.

So here is where I get my light bulb moment. This time relativity thing shows that something moving more quickly than you appears to YOU to be progressing more slowly through time. It also shows that something moving more slowly than YOU appears to be progressing more quickly through time.

So let's look at the most simple answer here. These very distant galaxies have been spinning through space for a very long time. They have the drag of gravity behind them. They are SLOWING DOWN but since everything flew out of the big bang at the same speed(don't take me for an evolutionist because of that term. It would take another whole blog post for me to explain how the big bang is not contrary to divine creation)our galaxy has not encountered as much friction or gravitational drag as these distant ones have and is, therefore, traveling more closely to its original speed at time of creation.

So we are moving more quickly than these galaxies which means that to OUR perspective they APPEAR to be progressing through time more quickly than us. Since speed is equal to distance/time and time is being perceived incorrectly by us they appear to be traveling more quickly than they are. And since they're slowing down more rapidly than we are that time difference is becoming more pronounced and therefore makes them appear to be speeding up.

Weird isn't it?

Next problem...if they're slowing down more rapidly than we are that means we're going to run into them eventually...I wonder what the braking distance is for a galaxy our size.

1 comment:

DM Dad said...

Okay, I'll tell you, I didn't understand that. But, that part about running into another galaxy scares me. Do you have time to fix it?