Monday, October 20, 2008

Just Passing Time

I'm forewarning you, today's entry is even weirder than usual.

I spent a good part of the day thinking about traveling faster than the speed of light. Einstein says that is not possible but I don't understand why. Here's my spaghetti thoughts on that subject:

When we see an object, we don't really see it per se, we see the light that is reflected from it. If there is no light, we can't see it. Therefore it stands to reason that we can see something only as soon as the time it takes for the light reflected from the object to reach our eyes.

Let's say that someone is going to travel to Alpha Centauri, which is 4 light years away from us; that is, it takes light traveling at the speed of light 4 years to get from there to earth, and vice versa. It's amazing to me that anyone was even able to figure out that light has a speed, rather than being instantaneous, and then how they were able to figure out how fast it goes. That must have been worth an "A" on the school science project.

Let's suppose we had a super duper telescope that was able to see the surface of the planet on Alpha Centauri where the aliens who abducted Betty and Barney Hill live, and they had the same kind of telescope and could see what was happening on earth.

What we would observe through our earth telescope would really be what happened four years ago on Alpha Centauri, since it takes light that long to reach us from there. We would really be viewing their "history."

Now let's suppose we launch a spaceship from earth to Alpha Centauri that is able to cruise at the speed of light. Every minute the astronaut aboard types "X" on their keyboard and sends the image back to earth. Therefore, these "X"'s should be received by earth at intervals of exactly one minute.

However, as the ship sails farther from earth, the intervals between X's increase because of the time it takes for light to travel from the ship back to earth after the X is typed. So would that make it appear that the astronaut is really typing the X's slower than one per minute? As the ship lands on the planet, it must seem like the X's have really slowed down because now it takes a whole four years for each one to reach earth (note: I don't mean time interval between each X is 4 years apart, I mean gradually it slows down to the point where now it takes each X four years to reach the earth).

But once the ship lands, the intervals between X's should now resume being exactly one minute apart as received by earth, only four years after they are typed by the astronaut.

Are you confused? I'll make it worse.

Now the astronaut takes off from the planet near Alpha Centauri and heads back to earth, again at the speed of light and still typing X's at one-minute intervals that are transmitted to earth.

Since the ship is speeding toward earth, it should seem as though the intervals begin to decrease because it no longer takes four years to travel back to earth; the time gets less and less. So it seems the X's are coming faster.

Now let's suppose that the ship is able to move at 10x the speed of light. That means that when the astronaut types an X, the ship actually moves toward earth at a faster rate than the X does. But the astronaut keeps typing the X's at one minute intervals.

So now there is a stream of X's heading toward earth at the speed of light but the astronaut is passing them up because the ship is moving faster than light. Eventually the ship will arrive on earth but the X's will not have all been received yet because they are moving slower than the ship.

You may be asking yourself, so what is the point??? I don't know. I'm just trying to figure out why they say it is not possible to exceed the speed of light, and how is it that all sorts of weird things begin happening once you begin to approach that speed. There is also something about how if you are a spaceman traveling into space at a rate of speed approaching the speed of light, that people back on earth will age much more rapidly than you would inside of your spaceship. Why is that so?

When I read the explanations in the books, I still can't understand it and wonder if the authors understand it themselves or are just repeating what they've read in another book just like people who write history textbooks do. Because if it really was something understandable, I would think they'd write it in a way that could be understood. But then again, you might be saying that about me and my blog.

I went and Googled "why can't you travel faster than the speed of light" and came up with some interesting links. Many of those links had comments from people saying that if you can travel faster than the speed of light, you can go into the future. My question is how can you go into the "future" when it hasn't happened yet? Maybe this is talking about if you are faster than the speed of light then you actually arrive at a place where you are looking into the past because the light, and consequently the images of whatever you are looking at, arrive after you do so it is as if you are in the future looking back at the past.

I'm still confused, as you can tell. All I know is in the future if there is interstellar communication, it will be dangerous to ask someone living in a distant galaxy if they could please tell you what time they have.

That first video of the Chambers Brothers - Michael Jones and I used to have lots of fun with the long version of the song, singing along and adding our own percussion to it.

And that second video - it's one of my favorite movies of all time. All those scenes bring back good memories of the movie.. but then the idea of having a memory - that's another interesting subject..

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