When we stand on a blue water balloon and look up at the bright stars in the night sky, have you ever wondered that the universe is so big that there will be other civilizations besides us?
Scientists have long given their guesses about this goosebump-inducing question. Have you ever wondered how far their technological level would have been if aliens really existed? Imagine that maybe there is a kind of intelligent life on a planet that we can't imagine. They don't need to eat, drink, they don't need to breathe, they don't even have a solid form! Do you believe it?
It may sound like science fiction, but in reality, this idea is not a fiction. As early as 1964, a Russian scientist named Nikolai Kardashev proposed the concept of "cosmic civilization level". To put it simply, he believes that the intelligent civilizations in the universe can be roughly divided into three levels:
A first-class civilization capable of controlling the energy of the planet. That's where we humans are now, we can use fossil fuels, hydropower, nuclear power, wind power, and so on the planet, but we are still some way from mastering fusion technology. Do you believe it? Not long ago, there was a report that a certain young man in China secretly built a nuclear reactor at home, and as a result, he was directly invited to drink tea for a few years?
Level 2 civilizations are able to harness the energy of entire stars. Well, you see, in comparison, our little universe is probably just a "mosquito blood". The sun alone releases 38.46 billion trillion watts of energy every second, adding up all the energy we use, which is the 3 before the decimal point. Therefore, if we want to become a second-level civilization, we are far from qualified.
The third-level civilization can control the energy of the entire galaxy. But for us, I'm afraid it's more like a fantasy. Take the recent Andromeda Galaxy, for example, there are trillions of stars in it!
Some might argue that this classification seems to be general and lacks scientific basis. But don't worry, in 1973, the astrophysicist Carl Sagan added a mathematical formula to the "civilization level", describing it with the "civilization index".
According to this formula, if the average total power of a civilization is 10 to the 16th power, then it is a first-level civilization, 26 watts is a second-level civilization, and 36 watts is the height of a third-level civilization. And the average total power of our human beings is only about 0.2 times that of 10 to the 13th power, which is equivalent to a 0.73-level civilization, which is still far from a first-level civilization.
You see, when it comes to first-level civilizations, at least the technology of controlled nuclear fusion must be mastered. Nuclear fusion uses the gravitational pull between atomic nuclei, and as long as the nuclei are compressed to a dense enough size, they will automatically "fuse" together and release a huge amount of energy. It sounds simple, but to be "manageable" comes with overcoming a lot of hurdles.
In order to achieve this goal, the whole world is now stepping up its efforts. For example, the famous International Thermonuclear Experimental Reactor (ITER) project will involve 35 countries and the total cost will reach hundreds of billions of dollars. It is expected that by 2035, this scientific device will be able to bring us humans into the ranks of first-class civilizations.
Well, even if we can advance to a first-level civilization, what can we do? Be as comfortable as a god? No! To become a second-level civilization, we need to use the extremely outrageous imagination of the "Dyson sphere"!
What is a Dyson sphere? Simply put, it is to wrap a star around one or more giant artificial structures and harness its energy. Think about it, how many materials would be needed to build such a giant project with a radius of millions of kilometers! According to calculations, even the combined mass of the planets in the solar system is only 0.14% of that of the sun. Are you aware by now how unrealistic it is to become a second-tier civilization?
However, we must not choke on food. Scientists have already had a bold idea in their minds: mass and energy transfer!
You can think of this principle as that energy and mass can be converted into each other. The familiar mass-energy equation E=mc^2 actually hides such a truth: as long as the energy is large enough, it can be condensed into matter, and conversely, matter can be converted into energy.
In other words, as long as there is a strong enough mass-energy transfer technology, the second-level civilization can continuously convert the huge amount of energy of the star into matter, which can be used to build the Dyson sphere, and at the same time, the remaining energy will become antimatter, which will become the ultimate energy source.
Have you ever heard of the concept of antimatter, which is arguably the ultimate energy source in science fiction. Because once the annihilation reaction of ordinary matter and antimatter occurs, the energy release efficiency will reach 100%, which is far better than the poor nuclear fusion.
To explain simply, everything we see with our naked eyes, including the Earth, the Sun, and the entire universe, is made up of the most basic particles, such as protons, neutrons, and electrons. Antimatter is composed of corresponding antiparticles, such as antiprotons, antineutrons, and positrons. When ordinary matter and antimatter meet, they are instantly annihilated and completely converted into energy. One part of antimatter can produce twice its mass.
Sounds mysterious, right? In fact, we can find traces of antimatter all around us. For example, common bananas contain trace amounts of the radioactive isotope potassium-40. When potassium-40 undergoes β decay, it releases positrons, which are the antiparticles of electrons.
Of course, humanity's ability to make antimatter is very limited. Let's put it this way, since the 60s of the last century, when humans first created antimatter, the total amount of antimatter produced is only equivalent to a dozen nanograms. You know, 1 nanogram = 0.000000001 gram, which is simply too little.
But for the second-level civilization with advanced technology, let me continue to tell you about it:
For a technologically advanced second-level civilization, creating antimatter may be as simple as eating and drinking. They have in their hands a powerful mass-energy transfer technology that can efficiently convert the huge amount of energy of stars into antimatter fuel. With this ultimate energy source, it is easy to maintain the entire civilization system.
Do you think, if we humans also master this magical skill, how great it would be? With a twist of the finger, with a bang, the energy will turn into matter, and the extra energy can also be turned into antimatter fuel, perfect! In the eyes of the second-level civilization, nuclear fusion is as simple as we look at lighters, right?
But then again, for those of us who are petty and make trouble, we haven't even stepped into the door of the first-level civilization to talk about the second-level civilization, which is a bit too advanced. You know, nuclear fusion has been a long-cherished wish for generations, and we all regard it as a "perpetual motion machine" in the energy world.
What is the magic of nuclear fusion that makes us so hungry? It has to start with the roots of nature.
As we all know, the universe works by four basic forces: strong, weak, electromagnetic, and gravitational. The reason why stars exist is because the nucleons in their bodies attract each other and are compressed to the limit by strong gravity, with temperatures as high as hundreds of millions of degrees.
It is not easy to replicate this miracle on Earth. Because in order for the nuclei to "spontaneously combust" and fuse, the Coulombic repulsion between them must be overcome, which requires extremely high temperatures and densities. The problem is that such extreme conditions simply cannot exist on Earth, so we humans can only manage to "artificial" them.
It's like if we want to survive in the desert, we have to build houses, extract water, and grow crops. Controlled fusion requires the construction of high-tech devices that heat and pressurize the nuclei until they fuse on their own.
It can be seen that the reason why nuclear fusion technology is valuable is not because the theory is doubtful, but because the operation is too difficult. It's like mountaineering, although the principle is very simple, but how can it be so easy to climb the peak of 8,000 meters? Even though scientists have been working on it for decades, controlled nuclear fusion is still far away in the hands of humans.
Fortunately, our scientists have not given up on their dreams. In the last century alone, a variety of experiments have been given birth to controlled nuclear fusion schemes, such as magnetic confinement fusion, inertial confinement fusion, etc. To put it simply, the former uses a strong magnetic field to restrain the movement of high-temperature plasma, while the latter uses a laser or cannon to heat the shell to quickly compress the fuel on its inside.
The two schemes are still advancing simultaneously, but there are still many obstacles to inertial confinement fusion, and it seems that magnetic confinement fusion is more promising. That's why scientists around the globe are now concentrating on magnetic confinement fusion.
Take the International Thermonuclear Experimental Reactor (ITER) project, for example, which is a very large tokamak facility. A tokamak is a device that uses a magnetic field to confine a plasma, and it was chosen because of its longer confinement time and lower requirements for surrounding devices than other options. As long as the plasma is heated to more than 100 million degrees Celsius and confined long enough, artificial stellar nuclear fusion can be achieved.
It sounds simple, but it's a huge undertaking to do. With a length of 30 meters and a height of 30 meters, a weight of 23,000 tons and an estimated total cost of 20 billion euros, the ITER plant is one of the largest scientific installations in the world. In 2025, representatives of 35 countries will be on hand to witness the great breakthrough moment of this energy technology.
Of course, in the final analysis, even if there is a breakthrough in controlled nuclear fusion, it will only bring the future of a first-class civilization. To truly evolve into a second-level civilization and build a super device like the Dyson Sphere, I'm afraid there are more obstacles waiting for us.
However, I believe that if there is a dream, there must be a way out. Perhaps, in the future, there will be a new technological revolution that will make it easier to convert mass and energy and make antimatter easier, and then we will not only be able to conquer the stars, but we may also become a super civilization in the galaxy!
Of course, this is just a layman's imagination. Regarding the law of the development of cosmic civilization, we have to listen to what scientists have to say. But you can be like me, cherish the present, work hard, live well, but don't give up the beautiful yearning for the future! Let us look forward to the day when our scientists can open up new fields of energy and let human civilization continue to evolve to a higher level!
Disclaimer: The information in this article comes from the Internet, which is not guaranteed to be completely correct and is for reference only.