Friday, May 26, 2006

Light Breaks The Rules

Okay, this really threw me. I read a relatively short article (as papers on physics go), at World Science, about experiments to manipulate light and make it behave in unexpected ways--unexpected at least to me, and I found the concepts rather challenging. Physicists, not sharing my confusion, and looking beyond normal expectations, have figured out ways to make light break the rules. Einstein said nothing could go faster than light in a vacuum (in the neighborhood of 190, 000 miles per second.) According to World Science, "If something broke that limit, then some observers could see it reach its destination before it left, violating a universal law of causality." However, scientists in recent years have already managed to defy Einstein, and make light speed up and slow down. This seems miraculous enough in itself, but I suppose the wacky experiment I read about as the article continued is the next inevitable phase.

What it said was that now they could make light travel backwards. Huh? How does that happen? My first thought was something along the lines of them causing light to reverse directions, kind of like a ping pong ball, and I wondered what the big deal was, but from the explanation and illustrations the article provides, what they're really talking about is a light impulse that goes forward and backward at the same time through a tube, like a clone that forms at the other end and races the light back to its source. Equally amazing is the fact that when it travels backwards, "the backward-moving pulse of light travels faster than light." So, the backward light wave, as it moves through the tube, comes out at one end before the forward light wave comes out at the other. Okay, light travels backwards faster than light. Sure it does, and if I jump out of mud puddle backwards my shoes are suddenly going to be clean, too. (The comparison is a bit non sequitur, but I'm just trying to convey a little of my confusion.) It reminds me of the Harry Mudd episode of Star Trek where the android Norman gets all confused because they tell him that everything Harry says is a lie, but then Harry says, "Now listen to me Norman. I am lying." Norman eventually starts babbling, and smoke comes out his ears. Well, smoke didn't come out my ears, but I had to work pretty hard to grasp any of this.

You might wonder what the point would be to changing the speed of light. I have a very limited physics brain, but I can think of a couple of reasons (and if I can think of even one lame reason, you know the Smart People can come up with lots of really good ones.) One would be related to space travel. There are such vast distances involved in exploring even our tiny little solar system. The possibility of travelling to other star systems is pretty inconceivable, even at the speed of light. However, what if we (and I use the term we extremely loosely here) could figure out how to make things go faster than the speed of light, starting with light itself? Wouldn't that make the vast distances a little more conquerable?

The second reason I came up with for trying to change the way light operates is related to the first, not limited to space travel, but still connected to it in a way. If scientists can learn how to defy one physical law, it stands to reason that they might be able to defy others, or at least alter their impact considerably. It's not really that humans could change physical laws, but by delving deeper and deeper into what's really happening, we come to understand how to work within those laws in new ways. As our understanding grows about the way things really work, we are able to do things that could not even be imagined centuries, or even decades ago. Who in the nineteenth century could have imagined cell phones? We take them for granted. What else is possible that we barely imagine in science fiction? Could they learn how to overcome gravity? The practical applications to that one are staggering, both for space travel and Earth-based travel. What would the shipping rates be for moving a large item that weighs nothing? Building space stations and lunar colonies gets a whole lot more feasible when you're not having to fight gravity the whole way out of our atmosphere. We could just chuck loads into space, without all those dangerous and costly rockets, or fascinating but complicated space pier schemes. Even moving something here on Earth would be easier. How about a piano moving company that employs only 90 lb. girls?

I could go off from here onto the whole concept of "beaming" things from place to place, since we're talking about out-there schemes for scientists to defy physical laws as they currently understand them. (Note that I did not use the word we, mistakenly implying that I understand them.) What will save you from more ventures into the realm of Star Trek is the fact that I'm having enough trouble grasping the topic at hand.

Fortunately, linked to the article, they have these handy dandy little animated demonstrations of what it means to have light speed up, slow down, and go into reverse. They're kind of like a "Physics for Dummies" teaching aid. Once I watched those, things got somewhat clearer, so I read the article again and it made more sense. However, I will not try to explain any of it to you. It would only hurt my head, and probably try your patience, but if you want a bit of an adventure, read the article, and then come back and tell me in the comments how slow I am, and how you grasped it all in the first paragraph. It actually is interesting, I think. Of course, that could be because it's 1:30 am, and at this point my mental processes are going backwards. I wonder what Einstein would say about that?

Hat tip: Armchair Anarchist at Futurismic--I think. (It's late.)


  1. Wow. I haven't even read the article yet....but I can see the possiblities. When you get down to it, physics is such a very cool subject. My head hurts too,when I try to see the factual, but the conceptual? I love that. I guess it is because with the factual....there is no limit to what my empty head realizes it DOESN'T know or understand. But the conceptual? Anyone can stake a claim to creativity and possiblity. Imagination is your only real limit. And if you have a smidgeon of scientific facts to sprinkle loosely throughout? There is nothing but positive, open, limitless space to explore. Figuratively and literally. :):)

    Anyhow, if light can travel backwards, in the manner I so far understand it......matter is the next logical step,then time travel truly will become a reality as well. What a time we live in. Did you see Michael Crichton's "Timeline"? Very possible implications when you apply it to this light issue. :):)

  2. I wrote a long, and extremely brilliant, response to your comment Colleen, full of insights into the complications and paradoxes involved in time travel, and why I do not believe that it is feasible, but the dog ate my homework. Actually Blogger failed to publish my comments, and they are lost forever, a great loss to mankind. I can't recreate it now. That shining moment has passed, but I can remember one small piece of it: I REALLY don't want to go back and relive the seventies.

  3. Not to say 'I told 'em so' (and it would still be premature at this point) but the minute folks started claiming that nothing could possibly go fast than light, I said 'Wanna make a bet?" It's simply futile for scientists to get dogmatic about such things. We've seen too many examples of smart people finding out ways to do things they all said were 'impossible'.

    I don't have to know anything about science to see that.