How to See Faster-Than-Light Motion

When I was a teenager, I was – in full swing, I know – deeply cheesy. During a science fiction agreement, I bought a button that said: “186,282 miles / second: not just a good idea, it is the law.”

He made fun of a highway speed limit slogan from time; The speed listed is the speed of light (forgive me, it was as well before I became personally metric). The joke is that the speed of light is really a cosmic law; To the best of our understanding, nothing can travel faster than light.

Generations of Star Trek Notwithstanding, this restriction is not only an engineering limit, like the way in which the speed of sound was not unsurpassable for planes (the expression “sound barrier” was popular in science fiction films when I was a child). The speed of light is the ultimate physical speed limit, a parameter woven in the fabric of the universe itself. The rules governing the way in which space behaves, the way in which time behaves, does not rely on anything of the possibility of going from point A to point B faster than a photon. This is the law.

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You can therefore imagine the perplexity of astronomers in 1901 when they saw equipment in the space move faster than light –apparently.

That year, a star in the constellation of Perseus brilliantly in sight; Astronomers have nicknamed him GK Persei. Ironically called Nova – Short for Nova Stella, or Nouvelle Star – this is actually what happens when a dead white dwarf star accumulates enough account on its surface that the material merges catastrophically. This creates an extremely powerful explosion that explodes the material at very high speeds.

Nova has become very brilliant and was observed by many astronomers at the time. One, the German researcher Jacobus Kapteyn, noticed that the star was surrounded by brilliant materials that seemed to be expanding. Measuring this expansion, he found that he was moving faster than light!

It was still a few years before Albert Einstein published his special theory of relativity, which established that nothing can travel faster than light. But even, at the time, such a rapid movement was unknown. Kapteyn quickly realized that it could be an illusion, however. He was right. And in fact, the much better telescopes and cameras today see an apparently superluminal movement. But how?

The simplest analogy is a large part of the schoolchildren will include: if you take a pair of open scissors and close them, the point where the two blades meet seem to move very quickly. Its speed depends on the angle between the blades and the speed at which you close them. Think about it this way: if the blades are almost parallel, this point can move incredibly quickly in the lengths of the blades as they close. If the blades are exactly parallel, the point will move infinitely quickly! It is certainly faster than light speed.

The solution to this paradox lies in the fact that the point where we see the blades crossing is not physical thing; It’s just a location in space. Nothing moves physically faster than light; It seems that it is.

What astronomers saw during these first years of the 20th century was a light echo: the light of the Nova reflected by the intermediate interstellar dust. As I described in a column earlier The Universe, it looks very much like a sound echo in that there is a delay between seeing the event and seeing the echo. The volume of space that we can see illuminated is, strangely, in the shape of a paraboloid, a raging shape, with the central axis passing through the Earth’s view line, the enlightening object and the summit of the opposite side of the object. Over time, this paraboloid widens, lighting the material when it passes.

Imagine a gas streamer that is almost but not quite parallel to the surface of this paraboloid. The part of this streamer closer to the Nova is turned on first, but the more distant part is illustrated fairly quickly after – similar to that of almost parallel scissors. The wave of light that we see illuminating the streamer will move over its length very quickly, and if the geometry is just like this, we will see it seems to be lit by a wave of light in moving faster that light. The closer the streamer, the parallel to the surface of the paraboloid, the faster the wave seems.

As I noted in this previous column, the material of fantastic shape around the V838 monocetis star was lit by the light echo of the star. This effect also imitated faster than light trips.

There is also another way of obtaining an apparent superluminal movement, and once again the geometry and the finished speed of the light are the keys.

In the late 1960s, astronomers began to make high resolution observations of remote galaxies called Quasars. Powered by the material falling into supermassive black holes, these objects can explode gas spots far from the galaxy at speeds approaching those of light.

If the material is more or less towards the earth, we obtain a funny illusion. Let’s say that a blob is suddenly exploded. A year later, the light he expressed when she formed was a light year far from the black hole. But the blob itself is hot on its heels, moving only a little slower and always emitted light. Due to this movement, the light he emits a year later could be detected by us only a few weeks after the initial burst of light; It is as if we see the events unfolding their real speed several times, looking at accelerated images with considerably compressed time. If the angle is just correct, we see that Blob was moving away from the sky of the black hole much more quickly than its real movement through space, and it might seem to travel several times the speed of light.

This type of movement is common in galaxies with supermassive central black holes, such as that of the Elliptical Galaxy M87 nearby. Astronomers have measured the movement in the ejecta of M87 as fast as six times the speed of light, and everything is illusory.

In a way, it’s a shame. I hope that superluminal trips in space are really possible; There are many astronomical phenomena that I would like to see in person. For this reason, it sometimes seems that the cosmos laughs at us seeming to violate the law.

But by studying this phenomenon, we can know more about the equipment surrounding energy events and black holes, the way it behaves and, in some cases, the way it was created. If we go to the anthropomorphy of the cosmos, we can say that he does not tease us – that helps us to learn. And as we have discovered, the universe does not violate the law as much as, well, well, warping he.