Are interstellar travel real?

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

The author of the article tells in detail about four promising technologies that give people the opportunity to reach any place in the Universe during one human life. For comparison: using modern technology, the path to another star system will take about 100 thousand years.

Ever since man first looked into the night sky, we have dreamed of visiting other worlds and seeing the Universe. And although our chemical-fueled rockets have already reached many planets, moons and other bodies in the solar system, the spacecraft that was farthest from Earth, Voyager 1, covered only 22.3 billion kilometers. This is only 0.056% of the distance to the nearest known star system. Using modern technology, the path to another star system will take about 100 thousand years.

However, there is no need to act as we have always done. The efficiency of sending vehicles with a large payload mass, even with humans on board, over unprecedented distances in the universe can be greatly improved if the right technology is used. More specifically, there are four promising technologies that can get us to the stars in much less time. Here they are.

one). Nuclear technology. So far in human history, all spacecraft launched into space have one thing in common: a chemical-fueled engine. Yes, rocket fuel is a special blend of chemicals designed to provide maximum thrust. The phrase "chemicals" is important here. The reactions that give energy to the engine are based on the redistribution of bonds between atoms.

This fundamentally limits our actions! The overwhelming majority of the mass of an atom falls on its nucleus - 99, 95%. When a chemical reaction begins, the electrons revolving around the atoms are redistributed and usually release as energy about 0, 0001% of the total mass of the atoms participating in the reaction, according to Einstein's famous equation: E = mc2. This means that for every kilogram of fuel that is loaded into the rocket, during the reaction, you receive energy equivalent to about 1 milligram.

However, if nuclear-fueled rockets are used, the situation will be drastically different. Rather than relying on changes in the configuration of electrons and how atoms bond with each other, you can release a relatively huge amount of energy by influencing how the nuclei of atoms are connected to each other. When you fission a uranium atom by bombarding it with neutrons, it emits a lot more energy than any chemical reaction. 1 kilogram of uranium-235 can release an amount of energy equivalent to 911 milligrams of mass, which is almost a thousand times more efficient than chemical fuel.

We could make engines even more efficient if we mastered nuclear fusion. For example, a system of inertial controlled thermonuclear fusion, with the help of which it would be possible to synthesize hydrogen into helium, such a chain reaction occurs on the Sun. The synthesis of 1 kilogram of hydrogen fuel into helium will convert 7.5 kilograms of mass into pure energy, which is almost 10 thousand times more efficient than chemical fuel.

The idea is to get the same acceleration for a rocket for a much longer period of time: hundreds or even thousands of times longer than now, which would allow them to develop hundreds or thousands of times faster than conventional rockets today. Such a method would reduce the time of interstellar flight to hundreds or even tens of years. This is a promising technology that we will be able to use by 2100, depending on the pace and direction of science development.

2). A beam of cosmic lasers. This idea is at the heart of the Breakthrough Starshot project, which gained prominence a few years ago. Over the years, the concept has not lost its attractiveness. While a conventional rocket carries fuel with it and spends it on acceleration, the key idea of this technology is a beam of powerful lasers that will give the spacecraft the necessary impulse. In other words, the source of acceleration will be decoupled from the ship itself.

This concept is both exciting and revolutionary in many ways. Laser technologies are developing successfully and are becoming not only more powerful, but also highly collimated. So, if we create a sail-like material that reflects a high enough percentage of laser light, we can use a laser shot to make the spaceship develop colossal speeds. The "starship" weighing ~ 1 gram is expected to reach a speed of ~ 20% of the speed of light, which will allow it to fly to the nearest star, Proxima Centauri, in just 22 years.

Of course, for this we will have to create a huge beam of lasers (about 100 km2), and this needs to be done in space, although this is more of a cost problem than technology or science. However, there are a number of challenges that need to be overcome in order to be able to carry out such a project. Among them:

• an unsupported sail will rotate, some kind of (not yet developed) stabilizing mechanism is required;
• the inability to brake when the destination point is reached, since there is no fuel on board;
• even if it turns out to scale the device for transporting people, a person will not be able to survive with a huge acceleration - a significant difference in speed in a short period of time.

Perhaps someday technologies will be able to take us to the stars, but there is still no successful method for a person to reach a speed equal to ~ 20% of the speed of light.

3). Antimatter fuel. If we still want to carry fuel with us, we can make it the most efficient possible: it will be based on the annihilation of particles and antiparticles. Unlike chemical or nuclear fuel, where only a fraction of the mass on board is converted into energy, particle-antiparticle annihilation uses 100% of the mass of both particles and antiparticles. The ability to convert all fuel into pulse energy is the highest level of fuel efficiency.

Difficulties arise in the application of this method in practice in three main areas. Specifically:

• creation of stable neutral antimatter;
• the ability to isolate it from ordinary matter and precisely control it;
• produce antimatter in large enough quantities for interstellar flight.

Fortunately, the first two issues are already being worked on.

At the European Organization for Nuclear Research (CERN), where the Large Hadron Collider is located, there is a huge complex known as the "antimatter factory". There, six independent teams of scientists are investigating the properties of antimatter. They take antiprotons and slow them down, forcing the positron to bind to them. This is how antiatoms or neutral antimatter are created.

They isolate these antiatoms in a container with varying electric and magnetic fields that hold them in place, away from the walls of a container made of matter. By now, mid-2020, they have successfully isolated and stable several antiatoms for an hour at a time. Over the next few years, scientists will be able to control the movement of antimatter within the gravitational field.

This technology will not be available to us in the near future, but it may turn out that our fastest way of interstellar travel is an antimatter rocket.

4). Starship on dark matter. This option certainly relies on the assumption that any particle responsible for dark matter behaves like a boson and is its own antiparticle. In theory, dark matter, which is its own antiparticle, has a small, but not zero, chance to annihilate with any other particle of dark matter that collides with it. We can potentially use the energy released as a result of the collision.

There is possible evidence for this. As a result of observations, it has been established that the Milky Way and other galaxies have an inexplicable excess of gamma radiation coming from their centers, where the concentration of dark energy should be the highest. There is always the possibility that there is a simple astrophysical explanation for this, for example, pulsars. However, it is possible that this dark matter is still annihilating with itself in the center of the galaxy and thus gives us an incredible idea - a starship on dark matter.

The advantage of this method is that dark matter exists literally everywhere in the galaxy. This means we don't have to carry fuel with us on the trip. Instead, the dark energy reactor can simply do the following:

• take any dark matter that is nearby;
• accelerate its annihilation or allow it to annihilate naturally;
• redirect the received energy to gain momentum in any desired direction.

A human could control the size and power of the reactor to achieve the desired results.

Without the need to carry fuel on board, many of the problems of propulsion-driven space travel will disappear. Instead, we will be able to achieve the cherished dream of any journey - unlimited constant acceleration. This will give us the most unthinkable ability - the ability to reach any place in the Universe during one human life.

If we limit ourselves to existing rocket technologies, then we will need at least tens of thousands of years to travel from Earth to the nearest star system. However, significant advances in engine technology are close at hand, and will reduce travel times to one human life. If we can cope with the use of nuclear fuel, cosmic laser beams, antimatter or even dark matter, we will fulfill our own dream and become a space civilization without the use of disruptive technologies such as warp drives.

There are many potential ways to turn science-based ideas into feasible, real-world next-generation engine technologies. It is quite possible that by the end of the century the spaceship, which has not yet been invented, will take the place of New Horizons, Pioneer and Voyager as the most distant man-made objects from Earth. Science is already ready. It remains for us to look beyond our current technology and make this dream come true.