Interstellar. Science Behind the Scenes "- a book for those who are not satisfied with the film

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

Lifehacker publishes an excerpt from a book by Kip Thorne, an American theoretical physicist, author of the idea for the film Interstellar. A lot of modern physical theories and ideas are interwoven into the plot of the picture, the explanation of which for the most part turned out to be behind the scenes. Therefore, we are sure that the book will appeal to both film fans and those interested in physics.

Interstellar flight

At the first meeting, Professor Brand tells Cooper about the Lazarus expeditions to find a new home for humanity. Cooper replies: “There are no habitable planets in the solar system, and the nearest star is a thousand years away. This is, to put it mildly, pointless. So where did you send them, professor? Why this is pointless (if there is no wormhole at hand), it is clear if you think about how great the distances to the nearest stars are.

Distances to Nearest Stars

The closest (not counting the Sun) star in the system of which a planet suitable for life can be found is Tau Ceti. It is 11.9 light years from Earth; that is, traveling at the speed of light, it will be possible to reach it in 11, 9 years. Theoretically, there may be planets suitable for life, which are closer to us, but not by much.

To assess how far Tau Ceti is from us, let's use an analogy on a much smaller scale. Imagine that this is the distance from New York to Perth in Australia - about half the earth's circumference. The closest star to us (again, not counting the Sun) is Proxima Centauri, 4, 24 light years from Earth, but there is no evidence that there may be habitable planets next to it. If the distance to Tau Ceti is New York - Perth, then the distance to Proxima Centauri is New York - Berlin. A little closer than Tau Ceti! Of all the unmanned spacecraft launched by humans into interstellar space, Voyager 1, which is now 18 light-hours from Earth, reached the furthest. His journey lasted 37 years. If the distance to Tau Ceti is the distance from New York to Perth, then the distance from Earth to Voyager 1 is only three kilometers: as from the Empire State Building to the southern edge of Greenwich Village. This is much less than from New York to Perth.

It's even closer to Saturn from Earth - 200 meters, two blocks from the Empire State Building to Park Avenue. From the Earth to Mars - 20 meters, and from the Earth to the Moon (the greatest distance that people have traveled so far) - only seven centimeters! Compare seven centimeters with a half round the world trip! Now do you understand what leap must occur in technology so that humanity can conquer planets outside the solar system?

Flight speed in the XXI century

Voyager 1 (accelerated with gravitational slings around Jupiter and Saturn) is moving away from the solar system at a speed of 17 kilometers per second. In Interstellar, the Endurance spacecraft travels from Earth to Saturn in two years, at an average speed of about 20 kilometers per second. The highest speed attainable in the 21st century when using rocket engines in combination with gravitational slingshots will, in my opinion, be about 300 kilometers per second. If we travel to Proxima Centauri at 300 kilometers per second, the flight will take 5,000 years, and the flight to Tau Ceti will take 13,000 years. Something too long. To get to such a distance faster with the technologies of the XXI century, you need something like a wormhole.

Technologies of the distant future

Dodgy scientists and engineers have gone to great lengths to develop the principles of future technologies that would make near-light flight a reality. You will find enough information about such projects on the Internet. But I'm afraid it will take more than one hundred years before people will be able to bring them to life. However, in my opinion, they convince that for super-developed civilizations travel with speeds of one tenth the speed of light and higher is quite possible.

Here are three near-light travel options that I find particularly interesting *.

Thermonuclear fusion

Fusion is the most popular of these three options. Research and development work on the creation of power plants based on controlled thermonuclear fusion began in 1950, and these projects will not be crowned with full success until 2050. A century of research and development!

That says something about the scale of the complexity. Let thermonuclear power plants appear on Earth by 2050, but what can be said about space flights on thermonuclear thrust? Engines of the most successful designs will be able to provide speeds of about 100 kilometers per second, and by the end of this century, presumably up to 300 kilometers per second. However, for near-light speeds, a completely new principle of using thermonuclear reactions will be required. The possibilities of thermonuclear fusion can be assessed using simple calculations. When two atoms of deuterium (heavy hydrogen) fuse to form a helium atom, roughly 0.0064 of their mass (roughly rounding one percent) is converted into energy. If you convert it into kinetic energy (energy of motion) of a helium atom, then the atom will acquire a speed of one tenth of the speed of light **.

Therefore, if we can convert all the energy obtained from the fusion of nuclear fuel (deuterium) into the directional motion of the spacecraft, then we will reach a speed of about c / 10, and if we are smart, even a little higher. In 1968, Freeman Dyson, a remarkable physicist, described and investigated a primitive thermonuclear-powered spacecraft capable - in the hands of a sufficiently advanced civilization - to provide speeds of this order. Thermonuclear bombs ("hydrogen" bombs) explode immediately behind the hemispherical shock absorber, the diameter of which is 20 kilometers. The explosions push the ship forward, accelerating it, according to Dyson's most daring estimates, to one-thirtieth the speed of light. A more advanced design may be capable of more. In 1968, Dyson came to the conclusion that it would be possible to use an engine of this type no earlier than at the end of the XXII century, 150 years from now. I think this assessment is overly optimistic.

[…]

As attractive as all these technologies of the future may seem, the word “future” is key here. With 21st century technology, we are unable to reach other star systems in less than thousands of years. Our only ghostly hope for an interstellar flight is a wormhole, like in Interstellar, or some other extreme form of space-time curvature.