The wife said, "More than one car. I have seen hundreds of retrograde SB vehicles. "
Einstein is a bit like this stupid wife. When everyone thought he should abide by an accepted rule, he found a whole new world from a different angle.
Physicists are trying to put a coordinate system for light and put the speed of light into the basket of classical mechanics. When the frame of reference of the speed of light could not be explained in any way, they collectively fell into confusion.
At this moment, Einstein stood up. He said: you always look at the light and don't like it. Have you considered the feeling of light?
Einstein's paper on relativity is entitled "On electrodynamics of moving objects". In this paper, Einstein asserted that-
The laws of physics are the same in all uniform linear motion or stationary coordinate systems.
This sentence is called "the principle of relativity", which is one of the two basic premises of relativity.
What do you mean? Is actually an extension of Galileo's theory of relativity. Galileo said that "mechanics" has no difference in all coordinate systems of uniform linear motion and static motion. Einstein said that not only mechanics, but also all physical laws-including electrodynamics-have no difference between uniform linear motion and static coordinate system.
What does Einstein's theory of relativity add to Galileo's theory of relativity?
When you do a static or uniform linear motion mechanical experiment, such as throwing a small ball on it, it will fall back to the ground indiscriminately-this is Galileo's theory of relativity.
You do an electrodynamics experiment, such as testing the speed of light, when you are at rest or moving in a straight line at a constant speed. Einstein said that the laws of physics are the same in all uniform linear motion or stationary coordinate systems-that is, when you do electrodynamics experiments to test the speed of light, the experimental results should be the same as those at rest.
Then the speed of light measured by you in the state of uniform linear motion should be the same as that measured in the static state, which is c = 299792458 m/s.
For example, speaking human words—
Your car is parked in the parking lot. Turn on the light. The light from the headlights will travel forward at the speed of light C.
When you are driving on the road, assuming that your car is fast enough to reach (c- 1) m/s, what do you see when you turn on the lights? Before 1 s, the light is only farther than your car 1 m, and the front is dark; The second 1 sec, the light is 2 meters in front of your car, and the front is dark. ...
Einstein said, no, it's not like that! Even if you fly forward at a speed only slower than the speed of light 1 meter, the light you see still travels forward at the speed of light C.
The constant speed of light is the second basic premise of Einstein's theory of relativity.
How come... Isn't this obvious counter-common sense? Shouldn't the velocities in different coordinate systems be superimposed? Shouldn't the speed of light be (C- my speed) m/s for me when I chase the light?
Einstein said, no, not only light, but also your view of time and space.
A few years ago, the city Council of Monza, Italy put forward a motion: it is forbidden to keep goldfish in curved fish tanks. The person in charge of the proposal explained that because goldfish will see the distorted scenery through the curved fish tank-this is cruel to goldfish.
You see, foreign parliamentarians seem to be no more reliable than our NPC and CPPCC representatives and parliamentarians.
Let's not talk about members and proposals. Let's consider a scenario:
Assuming that these fish are intelligent, one of them put forward a set of "goldfish physics" based on his own observation of the outside world of the fish tank-
For example, wherever a person goes, he will become fat, and wherever he goes, he will become thinner. What is the range of change? What is the curvature of a beam of light shining from the window to the fish tank in the morning? At dusk, the fish tank shines through another window. What is the curvature?
These laws, after constant observation by other goldfish, are completely correct and very accurate, so they are regarded as classics to explain the world.
After a while, another goldfish appeared. After observation and thinking, it is concluded that the size of people outside the fish tank has not changed, but has spread in a straight line without bending. The classic "Goldfish Physics" only applies to the fish tank coordinate system.
All the other goldfish opened their mouths in surprise. This new theory is too counterintuitive, too counterintuitive. You don't say!
You must have thought of the second goldfish. Its name is Einstein.
(Wan Weigang's Notes on Elite Day Class)