Speeding Light

Document Sample
Speeding Light Powered By Docstoc
					                                              Speeding Light
                                                 July 20, 2000

     RAY SUAREZ: Maybe you can accept that superman is faster than a speeding bullet, but few would
believe anything could travel faster than light. An experiment by scientists at the NEC research lab in
Princeton, New Jersey, suggests new thinking might be in order-- maybe. The results are in today's issue of
the journal "nature," and with us to explain is science educator and author bill Nye. He is the former host
of the PBS program, "Bill Nye, The Science Guy." Well, why don't we begin by maybe explaining how
these researchers got light to go faster than light. What did they do?
     BILL NYE: Well, they put a pulse of electromagnetic radiation, they put a beam of light, a laser light
into one end of a tube just a few centimeters long, just that long with a gas in it made of metal, the metal
cesium, and they measured the pulse going in, and they compared it with a pulse apparently coming out.
And the pulse coming out comes out faster than it should, about 300 times faster than it should by what
you would expect, acknowledging the speed of light as the speed limit of the universe.
    RAY SUAREZ: So are we in a situation where, in fact, the light was coming out one end faster than it
was going in the front end, or leaving before it really entered the jar?
    BILL NYE: That's the way it looks. The jar... It's a fancy-schmancy cell, a fancy-schmancy gas tube.
Anyway, apparently that's so. Now, I'll say for my part they're sending in a wave, they're sending in a pulse
that is, if you will, curved. It has a bump, it's a blob. And what they get out is another bump, another blob.
What I am interested to see, what I would love to see is to send in a single photon or just a few photons, a
few quanta of light and see if you get out the same quanta of light at the same speed -- because I'm
wondering, you cannot help but wonder if it's an experiment. Now, these things, these so- called
superluminal experiments, superluminal would be above light. Superman's above man. Superluminal:
Above light, above the speed of light. These things have been going on for a couple of years, but this one is
especially compelling. It looks like it's really happening.
    RAY SUAREZ: Well, I think it was Einstein who cemented the notion that, to have an effect, you
have to have a cause. And you can't have an effect before you have a cause. Do we have to take a look or at
least put an asterisk on the laws of physics now?
      BILL NYE: Well, this is what everyone's wondering. This is the fascinating, remarkable thing. Is it
happening faster than the speed of light? That is to say, are you creating an effect at one end of the cesium
gas and then 300 times faster than the speed of light you're getting the same effect at the other end, or are
you creating some other different thing in this gas that's really not exceeding the speed of light in energy,
but exceeding the speed of light in what we would call the wave domain. In other words, when you
acknowledge that light is a wave, you get not only the measure rate that the wave is propagating, but you
also measure the up and down, or the amplitude of the wave.
     And the example of this that I give people is when you have a radar, let's say... what are you, you are
in "the perfect storm," you're on a ship at sea, and if you see that movie, the radar is going around on the
bridge above the pilot house, and that radar is going through its microwave energy, same microwave --
same style of energy as in your microwave oven, is going through a metal tube. It's really not going
through a wire at the very end. It's going through a tube, and so because the wave is bouncing in that tube,
there is in a mathematical sense, a very real mathematical sense, a part of the wave that's going faster than
the speed of light. But the energy that comes out of the tube is still going the speed of light. And I'm
wondering -- I cannot help but wonder if this effect that we're all discussing today isn't a result of that same
type of thing. Or is it really, is it really a new part of physics, a new remarkable thing that will change the
course of history?
     RAY SUAREZ: Well, how do we find that out?
     BILL NYE: Well, the big thing in science, Ray, we want to see if we can repeat it. We want to see if
we can get another lab to do the same experiment and get the same results. And I especially would like to
see it go one more step and get the same... or similar results with smaller pieces of energy, because when
you have a big... big. It's tiny. When you have a blob-shaped wave going in and you get out a similar
blob-shaped wave, you're not sure, at least I'm not sure, that we're seeing the same energy propagating at
the same speed, because this gas is held in an excited state. It's revved up by a couple of other beams of
laser light. And I can't help but wonder if that energized gas has another wave or wave domain effect that
we're not measuring and is really an artifact of this experiment. But I suspect not. I think these people are
on to something new.
     RAY SUAREZ: Well, here we are -- we're talking about speeding up the speed of light. We were
taught in school that it was the fastest thing there is. Just recently some other researchers slowed down
light. And I'm wondering if this opens the door to some new things. Does it mean that time is something
different from what we thought it is?
     BILL NYE: Oh, wouldn't that be great? Wouldn't that be something?
     RAY SUAREZ: We can manipulate things, move things around that we weren't able to.
     BILL NYE: That would be something. But let me just say a couple of things about that for everybody
to think about. When you're wearing a pair of eyeglasses or you look through binoculars or microscope,
you are changing the speed of light. I'm not trying to shock anybody, but light when it goes through glass
or water or even air is slowed down by that medium, by that stuff. The glass makes the light slow down,
and when it slows down, it changes direction. And the analogy I love to give people is imagine a marching
band going across a field, and the field is muddy on one side. Well, the marching band would slow down
and the light wave, the wave of marching band would curve because they all keep an eye on each other to
make sure they're marching together. Well, that's what happens with waves of light. But in this experiment,
somehow instead of the medium slowing the wave down, the medium, that is the cesium gas, seems to be
speeding it up.
     There's another thing to think about, and I'm not saying that this is what's going on, but I want you to
think about this. Apparently the universe is expanding faster than people anticipated. That is to say, at
extreme distances in the universe, gravity seems to have, seems to have a repulsive effect or it goes away
in a way that's not fully understood by making these long-distance observations from this tiny speck of a
planet on which we all live. But it may be related to this. That is, the spaciousness of space, the... the fabric
of space may somehow have a lot more to it than we heretofore expected. And I wouldn't be shocked, I
would not be galvanized to discover that this experiment is alluding to do that. And in the same way, I
wouldn't be shocked to discover that this experiment is just an artifact of a measurement, like they forgot to
use a three-pronged plug in one of their measuring devices. But this is a very reputable institution doing
very reputable work, and it seems to be explained by this remarkable wave domain, in other words, by
looking at light strictly as waves, you get this effect. And yes, it could change everything, Ray, yes.
     RAY SUAREZ: The always galvanizing Bill Nye, thanks a lot.
     BILL NYE: Thank you, sir.

Shared By: