Is the speed of light unsurpassable and does the FTL phenomenon really exist?

When it comes to the speed of light, we should first think of Albert Einstein and his theory of relativity, one of the greatest achievements of physics in the early 20th century. Relativity fundamentally changed the old concepts of time, space, and motion and established a new space-time.

First, let's understand the context in which Einstein's theory of relativity arose. In the 18th century, Newton's classical mechanics was still the generally accepted law of physics, but at that time people did not realize the limitations of classical mechanics (only applicable to the macroscopic world and low-speed states). With the rise of electromagnetism, scientists began to systematically study electromagnetic phenomena and explore the underlying causes of these electromagnetic phenomena. Scientist James Maxwell (James maxwell) based on the particle painting of matter to derive the micro Maxwell equations, successfully explained the various electromagnetic phenomena at that time, and through the equations predicted some electromagnetic phenomena. Because of this, Maxwell is also known as the founder of electromagnetism.

What does our discussion of relativity have to do with electromagnetism? The first time I saw this, I was able to find out that Maxwell's system of equations had changed after the Galilean transformation in classical mechanics, i.e., it did not conform to the principle of relativity.

The approximate meaning is that the physical laws of one coordinate system, with appropriate coordinate transformations, can be applied to all coordinate systems. As mentioned before, Maxwell's system of equations has been successfully confirmed by a large number of experiments, so there is no doubt about the correctness of Maxwell's system of equations. Then the question arises whether the Galilean transformation of classical mechanics has limitations or the principle of relativity. Initially, scientists pointed their fingers at the principle of relativity, and after abandoning it, they proposed the "Ether Hypothesis", which deduced that the speed of light has different values for different reference systems. However, the Feso and Michelson-Morley experiments soon showed that the speed of light is independent of the motion of the frame of reference.

The "Ether Hypothesis" was broken. It also proved the correctness of the principle of relativity. In other words, the Galilean transformation has limitations. This is when Lorentz proposed the Lorentz transformation. From then on, the contradiction between Maxwell's system of equations and the principle of relativity was finally resolved.

In 1905, Einstein published a paper entitled "On the Electrodynamics of Moving Bodies", which initially introduced the concept of special relativity, including two basic principles. All other conclusions about special relativity were pushed down based on these two basic assumptions.

Assumption 1. In general, the theory of the constant speed of light is that the speed of light will always be 299792458m/s in any frame of reference and the speed of light will not be superimposed by the motion of the frame of reference. Basic assumption two. Principle of Special Relativity The following is a famous conclusion derived from special relativity.1. The speed of light is the upper limit of motion and information transfer of all objects in the universe. It is also the speed of particles (photons) without rest mass in the vacuum and the corresponding field rise and fall (gravitational waves, electromagnetic waves).2. The famous mass-energy equivalence formula E = MC.

From the formula, we can find that the rest mass of an object is proportional to its velocity. When an object moves at the speed of light, its mass also becomes infinite. In other words, any matter with a non-zero rest mass cannot reach the speed of light, because if it were to reach the speed of light, it would need infinite energy to propel it forward, and infinite capacity does not exist, so it cannot reach the speed of light. Seeing this, we should have some idea about the speed of light, that is, the speed of light is limited by objects with mass. Under what circumstances can the speed of light be exceeded? The answer is simple: as long as there is no transfer of energy or information involved. What are the FTL phenomena in the universe? The accelerated expansion of the universe The expansion of the universe comes from the big bang theory, the big bang naturally said 13.8 billion years ago, a mass, heat, infinite density, and infinitely small volume of the singularity occurred in a thermal explosion, and the universe was born.

The vast majority of galaxies in the universe are far away from the Milky Way, not because of the motion of these galaxies themselves, but because of the expansion of space between them, causing them to be far apart. George Lemaitre, the astronomer who first discovered the expansion of the universe, observed that the spectra of most galaxies were redshifted and then came up with the famous Hubble's law V = HD, which is the expansion rate of the universe. h is measured in kilometers per second per megapascal, which means that every millionth of a second between Earth and the target galaxy, the galaxy's velocity increases by the value of the Hubble constant.

The Hubble constant plays an important role in the calculations of the universe. It is one of the most direct tools for quantifying the evolution of the universe. It can also calculate the absolute size, magnitude, and age of the universe. So how should its value be measured? There are two ways. One is to use cosmic microwave background radiation. The principle is to use these tiny fluctuations in the radiation to calculate the value of the Hubble constant. The background radiation produced 300,000 years after the Big Bang, is a kind of electromagnetic radiation that fills the universe. Cosmic background radiation is isotropic, black-body, and anisotropic microwave radiation from the cosmic space background. According to the Big Bang theory, the universe comes from an extremely hot state, and the background radiation will gradually cool as the universe expands, but the original blackbody shape of the energy spectrum of the background radiation is preserved. Microwave background refers to the thermal radiation left behind during the Big Bang (CMB for short, or legacy radiation), filling the entire universe, which can be called the oldest light in the universe.

The other is by observing father-making variable stars and la supernovae. The principle is to measure our distance from quasars and intermediate galaxies, and then compare this distance to the redshift of the object to see how much of the object's light has been stretched.

Redshift is a phenomenon in which the wavelength of electromagnetic radiation increases and the frequency decreases. In the visible band, the spectral lines of the spectrum will move a certain distance to the red end, and vice versa, there will be a blue shift, corresponding to shorter wavelengths and increased frequencies.

Scientists calculated the value of the Hubble constant by observing the phenomena of 3K microwave background radiation and redshift of the universe discovered in 1965. The current Hubble constant observed by scientists is H = 67.80 ± 0.77km/s/MPC, which means that the recessional velocity of the two galaxies increases by 67.80km/s for every 1 million seconds difference. in this measurement, not only the speed of the expansion of the universe but also the conclusion that the expansion of the universe is accelerating. The age of the universe that we get from the cosmic microwave background is 13.8 billion years old. With the observable diameter of the universe reaching 93 billion light years, we can also know the conclusion that the expansion of the universe is faster than the speed of light. So does the expansion of the universe faster than the speed of light contradict Einstein's theory of relativity? Of course not, because the expansion of the universe is the expansion of space itself and does not involve information transfer. Quantum entanglement is in quantum mechanics. When several particles interact with each other, the properties of each particle become the overall properties. This property is called quantum entanglement. Let's take a simple example: Suppose a particle with zero spin decays, called two particles with opposite directions, and then the spin of one of the particles is measured. If the spin is up, then the other particle must be down.

What is even more incredible is that this phenomenon is not limited by distance. Even if two particles are placed at the two ends of 93 billion light years, quantum entanglement can still be observed. Scientists also propose that quantum entanglement is at least 10,000 times faster than the speed of light. But scientists still do not understand the basic mechanism of quantum entanglement. So let's discuss that quantum entanglement does not violate Einstein's theory of relativity because it cannot transmit information.

Einstein's theory of relativity indirectly gave birth to the physical discipline of quantum mechanics, and also established a new mathematical model for studying the high-speed motion of the microscopic world. This shows the status of relativity in physics. The conclusion that the speed of light is unsurpassable is a conclusion reached by special relativity, with certain preconditions. -- People have always believed that the speed of light is unsurpassable. However, FTL phenomena have been discovered one by one. Most people do not properly understand the theorem that the speed of light is unsurpassable, leading to a logical error. Our exploration of the universe is still far away, and more FTL phenomena may be discovered in the future, but there will certainly be no information transmission in them.