What is Dyson's sphere? Does Dyson's sphere exist or not?

It's hard to say when a person first thought about whether he is alone in the universe. But you can determine the time when the search for an answer to this question passed from the pages of science fiction novels to science - the middle of the last century, the beginning of the space age. As the development of interplanetary space began to appear more and more ideas about extraterrestrial civilizations. On the pages of science fiction intergalactic wars were played out, and astrophysicists and astronomers tried to understand whether life is possible in the vicinity of distant stars. If so, how to detect it? Among the latest ideas belongs the theory of Freeman Dyson. The sphere of huge dimensions, allowing to accumulate the energy of the star, is what, in his opinion, is worth searching in the vast outer space to find aliens.

Freeman John Dyson

An American scientist of English descent was born in 1923. Today 92-year-old Dyson, whose sphere of interests covers quantum physics, astrophysics, low-energy physics, is known as one of the creators of quantum electrodynamics. It is hardly more glory to him brought the concept, which the scientist borrowed from Olaf Stapledon, a science fiction writer, author of the book "The Creator of the Stars." The theory, dubbed the "Dyson sphere," suggests that highly developed civilizations can build a huge structure around the star in order to maximize its energy. Having found such a construction, scientists will be able to detect extraterrestrial intelligence.

Concept

A highly developed civilization, hypothetically existing in outer space, will sooner or later face the exhaustion of energy resources - this is Dyson's assumption. A sphere with a radius of one astronomical unit with a star in the center can solve this problem. The impressive design allows full use of star energy and, if necessary, becomes home to its creators.

Options

The thickness of the sphere, according to Dyson's calculations, should be quite small. For the construction of such a structure you need material that by mass approximates to Jupiter. Today, such a project looks like a very bold fantasy. However, it is impossible to exclude the possibility that after hundreds or thousands of years, humanity will be able to make it real, and now in the vast expanses of space, the construction of such a structure is being handled by an extraterrestrial civilization that surpasses us in terms of development.

A star with a Dyson sphere obeys the same physical laws as planetary systems. Therefore, the structure must rotate: the force of centrifugal rotation balances the power of gravity of the light and does not allow the object to collapse and fall on it.

Signs of a developed civilization

According to Dyson's idea, the sphere can become a kind of beacon, marking the presence of extraterrestrial intelligence. However how to find it? According to theoretical calculations, such a design must constantly emit light. For the human eye, it is elusive. The radiation should lie in the infrared part of the spectrum. The existing equipment is able to detect such sources, moreover, they have already found a lot.

A distinctive feature of the Dyson sphere should be an atypical spectral distribution. The design search, theoretically described by the physicist, is being carried out within the framework of the SETI program aimed at detecting the presence of extraterrestrial intelligence in space. The main hopes for the fulfillment of this difficult task are placed on the telescope "Spitzer".

Arguments against

Since the advent of the theory, Dyson has repeatedly been rethought and rechecked. As a result, a well-founded opinion emerged that such an object can not exist, no matter how advanced the civilization and whatever characteristics the star possesses. The sphere of Dyson, revolving around the star, acquires the maximum speed in the equatorial region. At the poles the design remains fixed, which will inevitably lead to its collapse. This is the main argument against the theory of the American scientist.

The researchers of the issue also note that the sphere spatially restricts the development of civilization and generates several significant socio-cultural problems, eclipsing the benefit from its creation.

Alternative options

Nevertheless, in the scientific world, the theoretical development of Dyson did not sink into oblivion. Several variants of design modifications have been described, which take into account the main criticisms. The first of them is a ring of small width, as significant in diameter as the sphere. You can meet such an object on the pages of the novel "The World-Ring" by Larry Niven.

The second option is a design that resembles a top. The curved thickenings in the vicinity of the poles are open. This version of the sphere is characterized by the same weight at any point on the inside.

The Soviet physicist G.I. Pokrovsky. In his model, the design consists of a set of rings that form something like a shell. This version of the sphere was called "Pokrovsky shell".

The structure of Criswell is another modification of the proposed Dyson astrokonstruktsii. Its feature is the fractal surface, which allows maximizing the area that receives the radiation from the star.

The search for the hypothetical Dyson sphere

Theoretical development of the American physicist for more than fifty years. However, they began to seriously think about finding structures similar to the sphere, only in the 2000s, when the development of technology allowed to glance into the remote corners of the cosmos. Analysis of information from telescopes showed that several hundred thousand are suitable for the role of giant artificial structures. However, the features of each candidate with different probability are explained by more prosaic reasons, among which are comet swarms, hydrogen clouds and so on.

One of the last contenders for the star, surrounded by the sphere of Dyson, was the star in the constellation Cygnus. In astronomical catalogs it is designated as KIC 8462852.

Discovered Dyson sphere ?!

In the autumn of last year, on the pages of the media, one could notice a headline reporting the discovery of the location of an extraterrestrial civilization. The star, near which live unknown to us intelligent creatures, was called KIC 8462852. The peculiarities of the luminary became known thanks to the telescope "Kepler".

In the fall of 2015, the results of a study of its strange luminosity were published. Approximately once every 800 days, the radiation of the star decreases by 15-20%. The decline lasts from several days to several months. This behavior is not inherent in the known classes of luminaries and can not be explained by the passage of the planet along the disk, since in this case the reduction of radiation would always be the same in time. Jason Wright, a scientist from the University of Pennsylvania, suggested that the cause of this anomaly - the sphere of Dyson. KIC 8462852, thus, became the main candidate for the search for extraterrestrial intelligence.

Other explanations

Wright repeatedly noted that this is only one of the versions, and the most unlikely. However, thanks to the media, the news of a possible discovery of Dyson's sphere has flown around the world. Meanwhile, there are other explanations for the strange radiation of the star. Researchers from the University of Yale, led by Tabete Boyadzhian suggest that the luminary is surrounded by a swarm of comets. Perhaps KIC 8462852 seized them several thousand years ago at a time when another stellar system was passing by. Tabeta notes that this explanation is only slightly more likely than Dyson's sphere. The meeting of two star systems is a very rare event, and the volume of the captured swarm of comets must be huge. Nevertheless, this theory has so far gained the largest number of supporters in the scientific world.

Take a closer look at the white dwarfs

And scientists from Turkey joined the search for Dyson's sphere. Recently they published a study according to which white dwarfs should look for such a structure . Relatively small and cold objects of space represent the final stage of the evolution of luminaries, like the Sun. In their vicinity, erecting a sphere requires less effort and material than around more massive stars. According to the calculations of scientists, the thickness of the structure near the white dwarf would not exceed 1 meter. For its erection, it would take material, approximately equal to the Moon.

Perhaps, after some time, scientists will come to the conclusion that Dyson's sphere is an unnecessary or too complex structure. However, while the search for a hypothetical design continues. One can say with confidence that such ideas will arise in the future, since mankind will not stop trying to find brothers in mind in space.