Simply put, the speed of light limit is the conclusion of Einstein's special theory of relativity .
Friends who understand the special theory of relativity should all know that the special theory of relativity is based on two assumptions. These two assumptions are: the principle of constant speed of light and the special principle of relativity. What does
mean?
The first one is the principle of constant speed of light, which means that the speed of light remains unchanged in any inertial reference system and is the speed of light.
Article 2, the principle of special relativity, the laws of physics are the same in any inertial reference system.
All conclusions and formulas derived from the special theory of relativity are derived from the above two assumptions, including mass-energy equation , ruler shrinkage effect, clock slowness effect, mass increase effect, etc.
For example, mass increase effect tells us that the mass of an object will increase as the speed increases. When the object's speed is infinitely close to the speed of light, its mass will become infinite. To accelerate further, infinite energy is required, not even the energy of the entire universe, which is obviously impossible.
Therefore, it can be seen that the limit of the speed of light is the conclusion drawn from the special theory of relativity. As long as special relativity is correct then the speed of light limit is correct. Since the special theory of relativity is based on two assumptions, as long as those two assumptions are correct, the special theory of relativity is correct.
So, why are the above two assumptions correct?
To put it simply, the so-called "hypothesis" is actually a rule summarized by predecessors through a large number of observations and experimental analysis. To put it bluntly, it is an axiom. It does not require proof or proof, and no one can finally prove it.
is like "the shortest straight line between two points". This is an axiom. It is a rule that people summarize through observation. It is very consistent with people's daily life experience. It does not require proof, no proof, and it is impossible to prove it ultimately.
Because there are countless ways to connect two points, if you really want to prove "the shortest straight line between two points", you have to prove countless ways to connect one by one. Obviously this is impossible.
In other words, any scientific theory is essentially a hypothesis, but it is by no means a random hypothesis, but a hypothesis based on a large number of observation experiments. This hypothesis is then continuously verified, and a scientific theory is derived in the process of falsification.
Let’s take the “principle of constant speed of light” as an example. It does not conform to our daily life cognition. That is because we live in a low-speed world. In a high-speed world, it is very consistent with our life cognition. For example, “ Michelson-Morley Experiment " proves this. There are also mathematical formulas that also support the "principle of constant speed of light." The following figure is the expression formula of the speed of light:
From the formula, it can be seen that the speed of light does not require any reference system. It is only related to the magnetic permeability and dielectric constant of vacuum.
and " special principle of relativity ", the laws of physics are the same in any inertial reference system. The most obvious example is that the earth can be regarded as an inertial reference frame, and a train traveling in a straight line at a constant speed is also an inertial reference frame. When you sit on a train that is moving in a straight line at a constant speed, the feeling is no different from what you feel on the ground. The two are equivalent!
