Superluminal motion is an expression used to describe events that occur or appear to occur faster than light, in the most vulgar terms. Many people objected at this point and said, ” Nothing can move faster than light!”he may say, but the situations mentioned here neither violate Einstein’s special relativity nor are they stuck in any other law of physics.
What Is Superluminal Motion (Faster Than Light)?
Superluminal motion (superluminal motion) appears in several different titles in the literature. It’s important to first make a distinction between them, then focus on what each of them is. The first point to be understood is that what is wanted to be given by the phrase “the speed of light cannot be exceeded” is “the speed of light in space”. The speed of light measured in different environments (for example, in water) is significantly lower than this value. In such a medium, another particle can pass through the speed of light in that medium, and when this happens, Cherenkov radiation occurs. This is an event that is common in nuclear reactors and forms the basic working principle of underwater neutrino detectors (water Cherenkov detector).
Although this situation does not seem as impressive as the rapid movement of light itself, some special and non-perceptual events occur in the environments in which this occurs . Before going into detail, it is useful to consider other situations of rapid light movement.
“Things That Go Faster Than The Speed Of Light”
This situation does not violate any laws, because in fact the laser point is not a physical object and does not carry information. The phrase “information” here is important and in a nutshell says: it is not possible to communicate faster than the speed of light using a number of fraudulent methods. What we interpret as a laser point is actually different photons hitting a different point of that surface at every moment. We interpret it as a” wandering spot, ” but there is nothing actually wandering.
Many people would not be satisfied at this point. There is no doubt that there is no sense of satisfaction that transcends the speed of light itself with a physical object (for example, a spacecraft). But it should be emphasized not to look at Science in such a utilitarian way. Otherwise, we may fall for attempts that may end up wrong, such as questioning why all scientists are astronomers, not biologists, when diseases are present.
Of course, this discovery has important consequences, for this we must expand the event from the example of “laser point” to a more general situation. And what could these be? Could it be our Shadow? Well, maybe because it’s not really a physical object. Only regions where light falls less (or does not fall at all) create a contrast with the falling regions, so we perceive it as a shadow, define it. If we build a suitable device, we can take our shadow too far and move it faster than light. Again, it is worth underlining that the concept of motion that we are talking about here is slightly different perceptually from the motion of a particle. Because nothing really changes his position. It’s just an optical effect.
Some” things ” can also move faster than the speed of light in space, and there are no laws of physics that prevent it. For example, a laser point. If we take a laser pointer in our hand and rotate our wrist and move the laser on the wall, we see the movement of a “point”. Here, the angle of rotation of the wrist is constant and completes its movement in a certain time. So much so that if we move the wall far enough, the laser point will scan a longer distance in the same time, so the speed of the point will increase. If we move the wall far enough, as a result of the scanning movement we make with our hand, the speed of this laser point on the wall is equal to the speed of light in space. Beyond that, it passes this speed.
Laser point and shadow… as the samples multiply, what kind of situation we’re actually trying to talk about helps us start to have a concept in our minds. But two examples are hardly enough in most cases to reach a generalization. Sometimes there is nothing to do because there are no more examples, but there is another example that we can touch on: the echo of light.
Echo Of Light
A light echo is an effect caused by the propagation of light from a distant object, as a result of light reflected from the environment it illuminates around it, reaching the Observer at different times (with delay). In a nutshell, because we see two points that actually light up at the same time due to distance differences, we perceive them at different speeds because we see them at different times. The condition is an optical phenomenon and may appear to be faster than light, although nothing exceeds the speed of light in such observations.
In astronomy, such observations have been made and are still being made. According to the observation, the actually measured value is that movement occurs at speeds that can reach up to 10 times the speed of light. Of course, no physicist in his mind immediately thinks that the speed of light can be exceeded after such an observation. Either an observational error is sought or another explanation. At this point, the explanation that clarifies the subject is the light echo, and in fact it has a fairly simple explanation.
The most widely known example is V838 Monocerotis. It is actually a changing star, and it underwent an “explosion” – like event in 2002. The observed event is a nebula structure that expands outward after a flare. But when measured, it was found that this expansion expands by 4-7 light years in just one month, which is significantly higher than the speed of light.
The first thing that comes to mind is that it’s a supernova explosion that throws material out, but we know that no physical object can reach these speeds. At the same time, we can tell that this is not a supernova explosion, but from the spectral identity that supernovae show us. Later, it seems that the changing star showed an instantaneous increase in brightness after a number of astrophysical processes (perhaps after a merger). Just like the explosion of a flash, this sudden increase progressed by illuminating material that had already existed around it, but could not be seen because there was not enough light. In other words, there is no nebula that spreads faster than light, on the contrary, the nebula has been there before, but this is the first time it has been illuminated by this wave of light.
This progression of the light wave causes the light echo to form exactly what we are looking for. Light emitted from a single point illuminates the surrounding material globally. Every point on the surface of this imaginary sphere is illuminated at the same time. But one side of the sphere is closer to us, while the other points are farther away. Therefore, light reaches us earlier than at nearby points. And when we see the far end, the nearby part has made a lot of progress. For this reason, the speed measured at close ends is perceived as faster than the speed of light.
Intuitively understanding this situation from sentences, I think, is an escape by heart. For this reason, although you think you may have understood the simple geometric proof of this, I suggest you examine the following advanced reading title.
Superluminal motion (faster than light motion) can be recovered in three subheadings:
- A state in which light moves slowly from its speed in space, but faster than its speed in the environment in which it is located (Cherenkov radiation occurs).
- Indeed, a movement occurs faster than the speed of light in space, but it is not a physical object (laser point, shadow, etc.) because it differs from the classical concept of movement.
- Especially at speeds close to the speed of light (relativistic speeds), movement appears/measures faster than light depending on the observer (but in fact it does not).
Note: it is worth noting that here we list only events that have been observed so far and whose accuracy is known by superluminal movement (faster than light). In addition, although there are theoretical issues such as tachyons and warp drive, we exclude these issues from this article.