Dyson sphere, a super plasma fusion entanglement annihilation tunneling quantum hoe, a good helper for farmland, really?

Freeman Dyson, Yang Zhenning's best friend, passed away.

About this physicist, of course, what you know best about him is the hair dryer (×) dyson sphere (√), which is a sci-fi concept he put forward in 1960. He believes that a fairly advanced civilization will build a sphere around its own star and transform all the energy radiated by the star into the driving force for the development of civilization.

Then why did I give it such a loud name? Of course, it is because dyson sphere is essentially a product of lack of imagination, just like the joke that "the emperor hoes farmland with gold". How can such a high-level alien civilization create such a sand sculpture? It's like a person who has the ability to make people forget, but only uses it to jump the queue to buy tickets.

Absorb all the energy of the sun.

Let's talk about the birth of this idea. Almost all the energy of the earth comes from the sun, and only 1 reaches the earth. If we can wrap the sun, the energy will increase by 2.2 billion times. Isn't it beautiful?

But how to use so much energy? It doesn't matter. Look at our human civilization. With the explosion of technology, energy demand is also exploding. Therefore, we can boldly predict that the demand of advanced civilization for energy will also explode. The so-called man is bold and prolific, and our inexhaustible energy can certainly be spent by aliens.

Where can I find the materials?

Ok, now let's see what's unreasonable about dyson sphere.

According to the development speed of human civilization, if there are no abnormal natural disasters, 1000 years later will enter the advanced civilization appropriately, so suppose that human beings will build a Dyson sphere in the future, so what is the difficulty?

The first nature is the material. 99.86% of the mass of the solar system belongs to the sun itself. We can't touch or move this big fireball. One force drops ten times, and ten forces hey hey; We don't want to take materials from the sun. We have no choice but to use all the planets, satellites, dwarf planets and asteroids in the solar system.

How many do all these low-temperature objects add up to? 2.8x 10^27kg。 It looks quite big. Let's calculate how much materials dyson sphere needs. To calculate materials, you must first know the area. Fortunately, Dyson's sphere is round and does not need integration. Let's use the formula of spherical area 4 л r 2.

So what is the radius of dyson sphere? We assume that the temperature limit of this equipment is the same as that of electronic products working in extreme environment, which is about 400℃, which is exactly the surface temperature of Mercury, so we set its radius as the apohelion of Mercury's orbit, 698 16900000 meters. It can be calculated that the area of this sphere is 6. 125× 10 22 square meters, so each square meter can be divided into 45 tons of substances. So it looks good?

But don't forget, we haven't analyzed the composition of elements yet! The mass distribution of the solar system is also extremely uneven. A Jupiter is 140% of the sum of the masses of the other seven planets. So what elements are the most powerful planet Jupiter made of?

75% hydrogen and 24% helium and others. ...

Why bother? The proportion of other elements is less than 1%!

Let's look at the proportions of the other three big planets:

Saturn: 75% hydrogen and 24% helium and other Uranus: 83% hydrogen and 65,438+05% helium and other Neptune: the proportion of elements is unknown, presumably between gas planets and rocky planets. What about the mass of the Earth, Mars, Mercury and Venus? Add up to1154 of Jupiter. ...

Well, it seems that the solid element is less than 1%, and the metal element is even less. It is estimated that it is only 1/300 of the total mass, and the mass distributed per square meter is less than 150kg.

What is this concept? Suppose these metals are all iron, and the thickness is only 2 cm.

What is this concept? You know, this is a ball with a radius of 69,865,438+06,900,000 meters, with a gap of 3 trillion times, which is equivalent to wrapping the whole earth with a durex. ...

This intensity ... I don't think so ... I guess any solar wind will blow you away.

To build such a sphere, all eight planets need to be dismantled (Pluto, don't laugh, you can't run away! ), you know a giant planet like Jupiter, its core is as high as 40 million atmospheres, the middle layer is diamond rain, and the inner layer is hydrogen turned into metal. How much energy does it take to dismantle it? Do you still have the energy to do other things that smell bad? Why do you have to be obsessed with the sand sculpture of dismantling planets and stars?

Even if we really try our best to be dyson sphere, who will use this energy? You know that energy itself is worthless, but the negative entropy contained in it is valuable. If you absorb 2.2 billion times the energy of the sun, you will emit 2.2 billion times the heat. Will you put all this energy into the earth? The earth will be evaporated in an instant! Sorry, I forgot that the earth was torn down when dyson sphere was just built.

So this is a typical sci-fi setting of begging with a golden bowl. What about Dyson sphere? Low-level civilization can't do it, and advanced civilization disdains to do it. Can you imagine a civilization with the level of industrial revolution making jet boosters and installing them on Guan Gong's broadsword instead of inventing a gun?

Getting energy from stars may be the only way for advanced civilization, but it is obviously not practical to wrap it in a ball.

Finally, seriously. I miss Mr. Freeman Dyson and thank him for his contribution to the progress of physics, as well as dyson sphere, who brought us countless interesting fantasies.