Is it possible to surpass the speed of light?

If there is no speed faster than the speed of light on the earth, I mean at present, before, I read books. The book says that if you exceed the speed of light, you can reach time and space, and you can reach absolute zero. Theoretically, it goes like this:

The accumulation principle of velocity is based on the classical physical theory, which is not applicable to the movement of light.

According to the relativistic velocity addition formula:

v =(v 1+-V2)/( 1+-v 1 * V2/C)

V 1 is the speed a, V2 is the speed b, and c is the speed of light. If V 1=V2=C, you can get V=C by substituting it into the formula.

In V 1 and V2, as long as one is equal to the speed of light, the result is always V=C regardless of the speed of the other.

In a word, the fastest speed in the world is the speed of light, and there is nothing faster than the speed of light.

But to be honest, at this time, I always feel that nothing is impossible. Just like aliens, they say that there is no air and water on other planets in the banking system, but they don't have to rely on water and air to survive like humans. I think the words on the first floor are simple, but they still make sense. What is impossible? Who can know what happened after 1000, 10000?

No, you can't, because when the speed is close to the speed of light, time will stand still (according to the theory of relativity), and finding something faster than the speed of light is even more terrible. Think for yourself, at least the current technology can't reach it.

Those are eyes. The reason is simple: it took 40 billion years to get to the present, and with astronomical telescopes, you can run to the place where flowers have been running for 40 billion years in a flash. Speaking of which, someone has to ask, how can we see without light? That's a good question Can we find something faster than light to replace light? The answer is yes, it is something unique to us. If scientists study this aspect, I believe there should be a great breakthrough in 50 years. The idea of transcending time and developing the human brain is not a dream, it is the only best way to understand the universe or everything in the world.

Cosmic repulsion wave-something faster than the speed of light

Cosmic repulsion wave-something faster than the speed of light

I believe that most amateur astrophysicists or cosmologists must know the story of Einstein's search for gravitational waves. As for whether this wave is detected on the moon, it seems that there is no following. However, when I was studying the repulsive wave, the twin brother of gravitational waves, I was surprised to find that no matter what method I use, all the material conditions may not be able to detect these two waves, because both their wavelengths and their wave velocities are a kind of limit, a kind of superphysical limit.

I don't want to waste my breath here to discuss that gravitational waves and repulsive waves are common sense of twins. Obviously, with our current scientific and technological capabilities, it is much easier to find repulsive waves in atoms than gravitational waves in the center of the universe, but this requires us to make some bolder assumptions to build such a research platform (but please forgive me for keeping the assumptions about the most basic particles secret and not making them public).

Let's discuss the wavelength of repulsive wave first. I think the repulsion between atoms is a wave that balances gravity (the reason is confidential). Because repulsion wave comes from inside the atom, it will definitely have a great influence on the structure of the atom. Therefore, in order to prevent the phenomenon of large and small atomic size, that is, to ensure that the trajectory of the next layer of atoms is balanced, the wavelength of repulsion wave should be in an order of magnitude with the particles of the next layer of atoms. We know that the particles in the lower layer of an atom are protons and neutrons, and their lower layers are quarks and neutrinos respectively. In quantum mechanics, there seems to be no saying that repulsive waves affect the motion of protons and neutrons, so the wavelength of repulsive waves may be an order of magnitude with quarks. Considering that there are as many as six kinds of quarks and neutrinos, I don't think there could have been such a complicated form before the Big Bang. Their lower layer should be composed of relatively simple elementary particles, so the most elementary particles are smaller than quarks. Therefore, if the repulsive wave still does not affect the motion form of quarks, its wavelength is likely to be smaller than quarks, so the wavelength of repulsive wave may be between 0.0 1fm and 10fm (1fm = 10 minus15th power meter). (The above things about wave mechanics are omitted)

The velocity of repulsive waves. If you want to solve this speed, you must have a premise, otherwise you can't solve it. We have to assume that the theory of relativity holds in any morphological space, especially the mass-energy equation-I want to mention Hawking's statement that all physical laws are invalid in black holes, but conversely, how can you think of black holes without the theory of relativity? Repulsion wave is an energy wave released by elementary particles, which needs to consume the mass of elementary particles. The question is what proportion of elementary particles are involved in releasing this energy. Obviously, it is not all elementary particles. Otherwise, in the future, all substances will disappear into the universe because they become repulsive waves, which does not conform to the BIGBANG principle. At first, I assumed that this ratio was 1: 1, but I soon found that this ratio could not constitute the condition of BIGBANG, and it must be less than this ratio, even far less than this ratio, that is to say, the matter that produces repulsive waves is only a small part of the total matter. Through the relativistic mass-energy equation, we can know that once this ratio is less than 1: 1, the speed of repulsive waves is already greater than the speed of light. Knowing this condition, the speed of solving repulsive waves will have a certain appearance. But at present, science and technology still know very little about the most basic particles, so it is difficult to find out the proportional relationship between substances in the nucleus, which is full of infinite values or values with large intervals, and has little value. So I turned to cosmology to find a way out, and soon found a reference parameter among a series of cosmic parameters. Excluding some absurd calculation results, I got a value closer to the expected value-2505 light years/second, slightly larger than the square of the speed of light. This value is obviously quite huge. Admittedly, there may be some inappropriate selection of units in the calculation process, but the result is more in line with some of my assumptions about BIGBANG-this special space energy plays a role in determining the fate of the universe without affecting the structure of the universe, and the universe also needs such energy to create miracles. I think, if we stay in the thinking space with the fastest speed of light, the aliens coming to the earth will laugh at us like this: "Sample, do you want to come to my house at the speed of light?" Wait until a species on earth has a civilization. "

The remaining frequencies and amplitudes no longer seem to interest readers enough. Interested friends can do their own calculations. Let's go back to the beginning of the question. Now that we have roughly understood the basic properties of repulsive waves, gravitational waves, as one of the twins, may also have the same properties. It seems that it is possible to detect it with the improvement of detection technology in the future, but how to distinguish it will lead to such a conclusion. But it's not that simple. In fact, I published an article in this forum, entitled "Is Time and Space Machine Possible? A possible experiment of dinosaur extinction puts forward the mechanism of synchronous vibration between microscopic substances. What I want to explain here is that the mechanism of synchronous vibration is caused by repulsive waves, which in turn affects the possibility of people trying to detect twins. The synchronous vibration of matter is like two trains at the same speed and direction. Who can tell who is moving and who is still? First, it is absorbed by the black hole, releasing energy.

And 1L said something would escape.

That's just released energy.

The speed of light is not equal to the escape speed.

Of course, it all depends on speed.

If you can search the light cone, you will probably understand.

You can also go through the last equation of Lorentz transformation and know why C is the fastest.

People are interested in superluminal, which generally refers to superluminal transmission of energy or information. According to the special theory of relativity, superluminal travel and superluminal communication in this sense are generally impossible. At present, most of the debates about superluminal are that some things can indeed travel faster than the speed of light, but they cannot be used to transmit energy or information. However, the existing theory does not completely rule out the possibility of superluminal in the true sense.

Let's discuss the first case first: it's not superluminal in the real sense.

1。 The speed of light in Cherenkov response medium is smaller than that in vacuum. The propagation speed of particles in the medium may exceed the speed of light. In this case, radiation will occur, and this is cherenkov effect. This is not superluminal in the true sense, but superluminal in the true sense refers to exceeding the speed of light in a vacuum.

2。 The third observer, if A moves eastward at a speed relative to C 0.6c and B moves westward at a speed relative to C0.6c. For C, the distance between A and B increases at a speed of 1.2c, and this "speed"-the speed of two moving objects relative to the third observer-can exceed the speed of light. But the relative motion speed of two objects will not exceed the speed of light. In this example, in the coordinate system of A, the speed of B is 0.88c. In the coordinate system of B, the speed of A is also 0.88c.

3。 Shadows and light spots shake your hand under the light, and you will find that shadows are faster than your hands. The ratio of the speed of shadow and hand shaking is equal to the ratio of their distance to the lamp. If you shake the flashlight at the moon, it is easy to make the light spot falling on the moon move faster than the speed of light. Unfortunately, information cannot travel faster than light in this way.

4。 When a rigid body touches one end of a stick, will the vibration immediately spread to the other end? Doesn't this provide a superluminal communication method? Unfortunately, the ideal rigid body does not exist. Vibration propagates in a rod at the speed of sound, which is ultimately the result of electromagnetic action and cannot exceed the speed of light. An interesting question is, when you hold the upper end of a stick vertically and suddenly release it, does the upper end of the stick start falling first or the lower end of the stick start falling first? The answer is the upper end. )

5。 Phase Velocity The phase velocity of light in a medium can exceed the speed of light in a vacuum in some frequency bands. Phase velocity refers to the "propagation velocity" corresponding to the phase lag of a continuous sine wave (assuming that the signal propagates for a long time and reaches a stable state) after propagating in a medium for a certain distance. Obviously, a simple sine wave cannot convey information. In order to transmit information, it is necessary to modulate the slowly varying wave packet on the sine wave. The propagation speed of this wave packet is called group velocity, which is less than the speed of light. (Translator's Note: Sommerfeld and Brillouin's research on pulse propagation in the medium proves that the propagation speed of a signal with an initial time of [zero before a certain moment] in the medium cannot exceed the speed of light. )

6。 Superluminal galaxies The apparent speed of galaxies moving towards us may exceed the speed of light. This is an illusion, because the time reduction from the galaxy to us is not corrected (? )。

7。 Relativistic rocket man saw the rocket moving away at a speed of 0.8c on the earth, and the clock on the rocket became slower than that on the earth, which was 0.6 times that on the earth. If you divide the distance traveled by the rocket by the time spent on the rocket, you will get the "speed" of 4/3 C. Therefore, the people on the rocket are moving at a speed "equivalent to" superluminal speed. For people on the rocket, time has not slowed down, but the distance between galaxies has shrunk to 0.6 times, so they also feel that they are moving at a speed equivalent to 4/3 C. The problem here is that the number obtained by dividing the distance in one coordinate system by the time in another coordinate system is not the real speed.

8。 The speed of gravity propagation Some people think that gravity travels faster than the speed of light. In fact, gravity travels at the speed of light.

9。 EPR Paradox 1935 Einstein, Podolski and Rosen published a thought experiment to show the incompleteness of quantum mechanics. They believe that there is an obvious distance effect when measuring two separated particles in an entangled state. Ebhard proved that it is impossible to use this effect to transmit any information, so superluminal communication does not exist. But the EPR paradox is still controversial.

10。 In quantum field theory, the force of virtual particles is transmitted through virtual particles. Because of Heisenberg's uncertainty, these virtual particles can travel faster than light, but virtual particles are only mathematical symbols, and faster than light travel or communication still does not exist.

1 1。 Quantum tunneling Quantum tunneling is the effect of particles escaping from a barrier higher than their own energy, which is impossible in classical physics. Calculate the time for particles to pass through the tunnel, and you will find that the speed of particles exceeds the speed of light. (Reference: T.E. Hartman, J. APPL. PHYS.33,3427 (1962)) A group of physicists made an experiment of superluminal communication by using quantum tunneling effect: they claimed that Mozart's 40th symphony passed through a width of1/kloc-0 at a speed of 4.7c Most physicists believe that because of Heisenberg's uncertainty, it is impossible to use this quantum effect to transmit information faster than light. If this effect holds, it is possible to use similar devices to transmit information to the past in a high-speed moving coordinate system.

Ref:W. Heitmann and G. Nimtz, Phys A 196,154 (1994); A. Enders and G. Nimtz, phys Rev E48,632 (1993) Tao Zhexuan thinks that the above experiment is not convincing. It takes less than 0.4 nanosecond for the signal to travel through the distance of 1 1.4cm at the speed of light, but the acoustic signal of 1000 nanosecond can be predicted by simple extrapolation. Therefore, it is necessary to carry out experiments on superluminal communication or high-frequency random signals at a longer distance.

12。 Ghasemi effect When the distance between two uncharged conductor plates is very close, a very weak but measurable force will be generated between them, which is the Casimir effect. Casimir effect is caused by vacuum energy. Scharnhorst's calculation shows that the speed of photon moving laterally between two metal plates must be slightly higher than the speed of light (for a gap of one nanometer, this speed is higher than the speed of light 10-24). Under some cosmic conditions (such as near [cosmic string] [if it exists]), this effect will be much more significant. However, further theoretical research shows that it is impossible to use this effect for superluminal communication. Reference: K. scharnhorst, Physics Bulletin B236,354 (1990) S. Ben Menahem, Physics Bulletin B236, 133 (1990). Advanced learning). IAS SNS-AST-90-25 Barton & amp； Scharnhorst, Journal of Physics A26, 2037 (1993)

13。 Hubble's theory of cosmic expansion says that galaxies with a distance of d separate at HD speed. H is a constant independent of galaxies, called Hubble constant. Galaxies far enough away may separate from each other at a speed faster than the speed of light, but this is the separation speed relative to the third observer.

14。 The moon revolves around me at superluminal speed! When the moon is on the horizon, let's say that we circle at the speed of half a cycle per second. Because the moon is 385,000 kilometers away from us, the rotation speed of the moon's appearance to us is 1, 2 1, 000 kilometers per second, which is about four times the speed of light! This sounds ridiculous, because we are actually spinning, but we say that the moon revolves around us. But according to the general theory of relativity, any coordinate system, including rotating coordinate system, can be used. Isn't this the moon moving at superluminal speed?

The problem is that in general relativity, the speeds in different places cannot be directly compared. The speed of the moon can only be compared with other objects in its local inertial system. In fact, the concept of speed is not very useful in general relativity, and it is difficult to define what is "superluminal" in general relativity. In general relativity, even the "constant speed of light" needs to be explained. Einstein himself said on page 76 of the Theory of Relativity that the narrow and broad theories of "constant speed of light" are not always correct. In the absence of absolute definitions of time and distance, how to determine the speed is not so clear.

Nevertheless, modern physics believes that the speed of light in general relativity is still constant. When distance and time units are linked by the speed of light, the speed of light is constant and is defined as a self-evident axiom. In the previous example, the speed of the moon is still less than the speed of light, because at any moment, it is in the future light cone of the current position.

15。 Defining the definition of superluminal speed The specious examples listed in the first part illustrate the difficulty of defining superluminal speed. The "superluminal" of shadow and light spot is not true superluminal, so what is true superluminal? "World line" is an important concept in the theory of relativity, and we can give a clear definition of "superluminal" with the help of "World line".

What is the "world line"? We know that all objects are made of particles. If we can describe the position of particles at any moment, we describe the whole "history" of objects. Imagine a four-dimensional space, which consists of three-dimensional space and one-dimensional time. Because a particle can only be in a specific position at any time, its whole "history" is a continuous curve in this four-dimensional space, which is the "world line". The world line of an object is the set of the world lines of all the particles that make up it.

Not only the history of particles can form a world line, but also the history of some artificially defined "things", such as shadows and spots. Shadows can be defined by points on their boundaries. These points are not real particles, but their positions can be moved, so their "history" also constitutes.

World line.

A point in four-dimensional space-time represents an "event", that is, three spatial coordinates plus one time coordinate. Spatio-temporal distance can be defined as the distance between any two "events", that is, the square of the spatial distance between two events MINUS the square of the product of their time interval and the speed of light and then open the root sign. Special relativity proves that this space-time distance has nothing to do with the coordinate system, so it has physical significance.

Space-time distance can be divided into three categories: time-like distance: space interval is less than the product of time interval and light speed; Light-like distance: the space interval is equal to the product of time interval and light speed;