THE DYSON’S SPHERE
What good was this idea? This is also discussed by today's astronomers and scientists. Here is a modern summary:
1 - Who get their energy from the resources of their home planet. (Young Civilizations)
2 - Who traps the energy of their star (or other stars). (civilizations a few million years old)
3 -Those who are already able to bring an entire star city under their yoke. (civilizations up to 100 million years old)
Why do advanced aliens need so much energy? Sci-fi-minded astronomers pondering on the subject have accepted the simplified extrapolation of today’s economists about what the structure of the upcoming world economy will look like. The predicted future requires ever-faster development, ever-higher levels of production, and higher consumption. The increasing consumption will need more and more energy, they think, but they are very wrong. The future will not be characterized by over-consumption and not by a wild pace of production, but by sensible self-regulation, sophisticated high-level technology, and a return of energy consumption to a near-natural level. Besides, aliens must have already found obvious ways to produce energy. A fraction of our energy use will be enough for the population of a planet. They will not need the energies of the central star at all.
Is the Dyson sphere technically feasible? First, take into consideration that a great deal of material is necessary to form such a sphere. The radius of the spherical shell in the figure is 1.5 * 1011 meters, i.e. 150 million kilometers. The recorded wall thickness is desperately economical, 3 meters, which certainly can’t create such a huge sphere, but let’s count on it now. The surface of the sphere is 4/3 R2p, which in our case is 9.4 * 1022 square meters. This must be multiplied by the wall thickness and the density of the Earth. Then 1.5 * 1026 kilograms are obtained. This means a mass of 260 pieces of earth, as the mass of the Earth is known to be 6 * 1024 kilograms. Maybe there isn't that much Earth insight. It would be at least as much of a problem to bring together so many planets, crush them, and then glue them together in the form of a huge spherical shell.
Does the spherical shell stay together? It certainly won't stay together! A narrow strip would remain together if we were to provide a speed of 30 km / s, i.e. the orbital speed of the Earth. The problem with the entire spherical surface is that the circumferential velocity decreases as it moves towards the pole since the spherical shell rotates as a single solid body. The lower velocity gives less centrifugal force, less resistance to the attraction of the central star, and not all the force is acting against the star, but only its component parallels the plane of rotation. The top of the sphere therefore collapses, so the sphere falls onto the star except for the said ring. At the level of childhood, sci-fi lives the believer in the Dyson Sphere who does not foresee the collapse of the sphere. Astronomers and mathematicians could foresee the catastrophe of a crash, but there are many of them who, out of love of comfort or hatred of math, do not think through the above. (Unfortunately, mathematicians don't like to count either, they avoid it if possible. Most of all, they like to invent new scientific principles, but it's as rare as the white raven.)
To study the rings of Saturn, the Royal Academy of England issued a competition, which was eventually won by a little Scottish boy, James Clark Maxwell. He wrote a nice dissertation, was also clever, and won the competition in front of many English academics and astronomers (1859 Adams Prize). His claim was that the ring of Saturn could not be made of a single solid piece.
Let's see why! Take a circular narrow strip in the middle of the wide Saturn ring. By choosing the orbital velocity corresponding to this band, the centrifugal force just balances the gravitational pull of the planet.
Now let’s go a few tens of thousands of miles in and select a narrow ring there as well. In the case of a solid body, the rotational speed and the centrifugal force will be less in proportion to the reduced radius. At the same time, the gravitational pull will be greater as it is closer to the central planet. With a simple calculation, we could get the amount of extra attraction per unit mass. No matter how strong the steel ring is, the extra force will be so great that it will tear the ring apart. Continuing the line of thought outwards, we get that the outer lane is about to fly outward and the steel material breaks here as well. This is because in this outer band the centrifugal force increases while the gravitational pull decreases. The only possible solution to the problem is that the material of the rings already consists of small pieces that can move independently of each other or circulate at the required speed. In fact, the ring is made up of fine dust, small and large ice crystals, and pebbles. Little Maxwell also came up with this solution and won with this theory. The ring, and with it the Dyson sphere, cannot be made of a single connected material, because then it breaks into pieces. This is such a simple and interesting end result that it should be taught in schools. We didn’t study that in my time, although there was an astronomy chapter in our elementary school physics book. We just didn't get there. The same thing happened in high school, and I’m afraid it happens that way today.
Can we do some tricks to help the sphere? Put plenty of air inside, just enough to have a pressure of 1 ground atmosphere (1 bar) at the pole. This means a force of 100,000 newtons per square meter. (I'm afraid this won't be enough.) The 3-star-thick, 1-square-foot earth column would be attracted by the central star with a force of 4.5 million Newtons according to the F = mMG / R2 formula. However, the pressure of 100,000 newtons inside the equator is too much because it would upset the equilibrium there. The idea would materialize in two places, just above and below the equatorial plane. We could calculate the distance - but we avoid that carefully. There is also a big problem with the inserted air. As much as it is, the star in the middle would swallow it all the time and eventually absorb it all.
Extraterrestrials would obviously live on the planet Venus there with their own Venus atmosphere and solar radiation equal to earthly conditions. Since the inside of the outer sphere would also radiate to them, they would have to lower the radiant power of the central star. If you think about it, it's not an easy task, it's not infinitely easy. This is impossible!
Why do scientists feed us sci-fi follies? F. Dyson is because he is a great scientist as well as an American, so he can. But quite a few astronomers and mathematicians have embraced the idea and now believe it sincerely. They do not count on instinctive authority out of respect, and out of love of comfort. There really are research teams that search for Dyson spheres with infrared binoculars or an automatic surveillance system and sincerely hope for success. They may even receive central funding for these research projects.
Is Dyson's idea good for something? He invented an exciting reality-mimicking sci-fi that would greatly increase interest in the question of the possible existence of astronomy and extraterrestrials. But sci-fi shouldn’t be mixed into astronomy because it’s a very exciting topic anyway. Surely many intelligent astronomers have noticed the errors listed above, but they have not spoken. Partly because it is not recommended to go against the opinion of the so-called scientific community. Also, because this idea is able to serve the more open thinking of humanity
Date: December 2021