Introduce Einstein s energy in a language that junior high school students can understand

1.The hydrogen bomb is powerful. In the nuclear variant, m in e=mc2 is not the mass of the atom, but the mass loss, which is large in the hydrogen bomb and has a large energy.

Losing money, just like you spend money on something, spend money and get something. Spend more money and buy more things, while some people may have a lot of money, but if he doesn't spend or is good, he will get very little. The key to the energy released by nuclear transformation is not the size of the mass, but the mass loss, which is large and the energy is large.

Note that when you subdivide a thing, it's not a loss of quality, but a loss when you make it disappear. For example, if you have a way to make something the size of an apple disappear, it will be able to unleash a lot of power. Indifferently, this is not easy to do.

2.The unit of energy is j, joules. 1 kWh is 3600 000J.

Albert Einstein was born in Germany, the first language he knew was German, and some of the important ** of his stupid filial piety bridge were written in German, and he was a genius who used German, second only to his scientific genius. Later, he moved to the United States in the 30s and gradually learned English, but he was not very proficient until he was old. So he should only know two languages, German and English.

Still waters run deep.

Dedicated. Chew one's cod.

Quick thinking. Optimistic and cheerful.

Walk vigorously. Indifferent and self-controlled.

Ambition is a thousand miles. World-renowned.

World-famous. Assiduous.

As much as it is ...

Approachable and pleasant.

Dumbfounded.

Stir. Simple-minded.

The limbs are well developed. Indifferent.

I don't know what political science is in the second year of junior high school now?。。 As I understand it, this passage is to say that man is not an individual who exists independently, but a member of society. At that time (think about it, it's been 12 years, hehe) there was a story about Robinson Crusoe in my first year of junior high school politics textbook, and even if Robinson is an isolated island, he has to rely on what human civilization has created to survive, so people can't survive without society.

This is the meaning of the first half of the sentence, "My spiritual and material life depend on the labor of others"; Of course, noting the "spiritual life and material life", we can extract that the civilization created by the labor of human society includes two kinds of civilization: spiritual civilization and material civilization (I don't know if you need this); The second half of the sentence is based on the value judgment of the first half of the sentence: since "my spiritual life and material life depend on the labor of others", then I should "repay what I have received and what I still receive with the same weight", that is, the principle that people must repay society.

Thank the Lord for your blessings.

Thank the Lord for giving me food.

Look at the world with gratitude.

In other words, due to the progress of science and technology, people used technology to fight each other and finally destroy the world. Think about the atomic bombs that bombed everywhere, and what happened to the world in the end? It must be in ruins.

Humanity had to start from scratch, and when it came time to fight again, all that was left was stones and sticks.

Einstein's words actually meant:

I don't know how the Third World War will be fought, but I know that the Fourth World War will be fought with sticks and stones.

The meaning of this sentence is:

The vicious development of the arms race has led to the regression of human civilization.

by。Fortunate.

Einstein's discovery: e=mc2, thus entering the era of atomic energy applications. The energy of atomic energy is huge, and theoretically the shoes you wear on your feet are enough to destroy the earth if all of them are converted into energy.

Nuclear energy is used in nuclear energy, which not only breaks the external force, but also has strong radiation and is destructive. When a reporter asked Einstein if there would be a world war, he said: I don't know if the third world war will happen, but I know that the fourth world war will definitely not happen.

Observing the one-dimensional world, that is, the world of lines, a point moving on a line and cannot be detached, then this line is his universe. If this line is not a straight line, but a closed circle, then when moving at this point**, there will be the feeling that my universe is a line with limited production but no boundary.

Observe the two-dimensional world, the world of faces, and if the surface is spherical, the surface will be a surface with a finite area but no boundary.

By analogy, our three-dimensional world is, as Albert Einstein said, finite in volume and without boundaries.

I think the important thing for you now (after all, it's only the first year of junior high school) is not to know what the principle or conclusion of special relativity is, but to understand that special relativity is studying a very old question, that is, "Do observers moving at different speeds observe the same physical phenomena?" If so, how are they related? ”。

Before the advent of special relativity, this question had an extremely simple answer (the kind you intuitively think of now) that it was not seriously studied. But Albert Einstein came to the novel conclusion: "Strictly speaking, our intuition is wrong".

Here are 2 examples:

1. If a car is moving at a speed of 60 kilometers per hour relative to you, the speed you observe is 60 kilometers per hour; I, as another observer, are traveling at a speed of 20 kilometers per hour (the same direction as the car) relative to you, so does it seem to me that the speed of the car is 40 kilometers per hour? The answer to "physics before special relativity" is "yes", but special relativity tells us "no".

2. You have a ruler in your hand, of course it is still relative to you, and you can measure its length to 1 meter; Now I'm another observer, I'm moving at 20 kilometers per hour relative to you, I'm also measuring the length of the ruler, is my measurement 1 meter? Special relativity tells us "no".

Why can't the speed of light be superimposed? "Is it asking why the speed of light does not change in different inertial frames?

This is not a question answered by the special theory of relativity, but a corollary given by classical electrodynamics. The equation for electromagnetic waves can be obtained using the Maxwell equation (in a vacuum), where the velocity of the electromagnetic wave (light is an electromagnetic wave) is directly obtained. But the Maxwell equation holds in any inertial frame, so this indicates that the velocity of the electromagnetic wave is not relative to a specific inertial frame, but is an absolute constant.

Everything in the world is relative, not absolute. Einstein's theory of relativity is like taking a train alone for an hour and it will feel like a long time, and it is the same as a person of the opposite sex you like will feel very short if you take a train for three hours

Explain it in a brief history of time.

Take advantage of the relativity of motion and rest.

How can there be as many as 15 kinds of the three upstairs? But he should be able to speak English, French, and German. Considering that he has been in Switzerland for a long time, it is possible that he will also have some Italian and Latin Romance.