Earth Era

The definition of conventional propulsion is actually very simple, that is, propulsion that can be widely used on a large scale. ◎, just like the propulsion method used by the Xinghai spacecraft to heat the working medium with a fusion engine and then eject it.

Corresponding to the conventional propulsion method is the unconventional propulsion method. Most of this advancement method is still in the envisioning stage, and there are many whimsical methods. For example, a nuclear bomb is thrown every second to explode behind the spacecraft, and the radiation pressure of the nuclear bomb is used to propel the spacecraft forward. This propulsion method has one thing in common, that is, they are only required in very special environments, and they are not capable of large-scale interstellar transportation needs.

For long-distance interstellar voyages, the only option is conventional propulsion. The reason is very simple, because in the future, a large spaceship that may carry hundreds of thousands of people or even millions of people will need to continuously throw nuclear bombs to propel it forward. This kind of thing is unimaginable for anyone.

In the field of interstellar navigation, it is not feasible to take a slanted sword. The honest development of basic technology and the development of conventional propulsion is the only feasible way.

But... Chu Hai now tells Wei Feng that some scientists have theoretically proved that the upper limit of the speed of conventional propulsion is 4,500 kilometers per second. While the theory has not yet gained general acceptance, it has some supporters.

This made Wei Feng's heart flutter once again.

"The scientist demonstrated this issue from the aspects of material technology, specific impulse, the ratio between the mass of fuel and working medium and the total mass of the spacecraft, the voyage distance, and the basic theory. His conclusion is that to conduct long-distance interstellar voyages, If we can't break through the basic theory. The upper limit of the speed we can achieve by conventional means is 4,500 kilometers per second. If a ship's speed exceeds this upper limit, then it will slow down because there is not enough fuel. .Therefore, it has become a cosmic island that can never stop drifting in the universe. All people living in this isolated island will be trapped here because of the exhaustion of fuel." Chu Hai wrote in the letter.

"A scientist pointed out that there is a loophole in this theory, and the scientist retorted that if the speed of a spacecraft depends only on these factors, then people can build a very large spacecraft, such as a length of ten kilometer, a giant spaceship with a width and height of one kilometer, and then pile up fuel in 100% of the spaceship. Only 10% of the space is used as a living area, even so, the spaceship of this spaceship is It can still provide at least 10,000 people to survive for thousands of years, and the fuel is enough to accelerate the spacecraft to 40% of the speed of light, which is 120,000 kilometers per second. The fuel consumption of the giant spacecraft After the light, we don't have to slow down the whole ship, we just separate the manned area from the ship, and then only slow down for the manned area, because the manned area has only a small mass compared to the whole ship. Slowing down the manned area also requires a limited amount of fuel, which would break the 'regular propulsion speed cap'."

"In this way. We will be able to send 10,000 people from the solar system to the Nanmen two galaxies in just eleven years."

see here. Wei Feng frowned slightly. Wei Feng didn't know whether the conclusion that "the upper limit of the conventional propulsion speed is 4,500 kilometers per second" is correct or wrong, but Wei Feng knew that this method used to refute the above conclusion must be wrong. It also has huge loopholes.

First of all, ignoring the material and structural technology required to build such a huge spaceship, and assuming that people can build such a huge spaceship, but even so, can this method be widely and widely used? No, it still won't work, because this method is still an "unconventional propulsion method", and it is obviously unacceptable in terms of cost to abandon such a huge spacecraft for every interstellar voyage. In other words, there is no essential difference between this navigation method and the navigation method of throwing nuclear bombs, and neither of them is capable of meeting the needs of large-scale interstellar navigation.

Sure enough, just as Wei Feng thought, Chu Hai wrote down the rebuttal words of the scientist who proposed the theory, and those words were basically the same as Wei Feng's thoughts.

In this letter, Chu Hai went on to describe some of the other scientists' refutations to this conclusion, but without exception, all of those refutations could not be used for large-scale interstellar navigation. According to Chu Hai, although the "upper limit" theory has not been recognized by most people, at least until now, no one has been able to refute it forcefully.

Wei Feng felt a little melancholy in his heart. If the "ceiling" theory turns out to be true, it promises a dire scenario. In the future it predicts, human civilization will be forever trapped in a small solar system, and will not be able to take the steps of interstellar navigation until its demise. At the same time, it will also indicate that the interstellar voyage that oneself is conducting at the moment is also meaningless. After all, interstellar voyage by means of long-term hibernation is also strictly an "unconventional voyage" method, which is also unable to Competent for large-scale interstellar navigation.

This is different from the moon landing missions of human civilization hundreds of years ago. That way of landing on the moon can send one person to the moon. With the development of technology, it will inevitably be able to send 10,000 or 100,000 people to the moon. In other words, this method has large-scale applications. development potential. Now, the hibernation method can send Wei Feng to another star system alone, but if the sailing speed cannot be improved, even after another 10,000 years, this method can still only send a few people to another star system. That is, there is no development potential for this way of sailing.

What human civilization needs is a safe, reliable and fast interstellar navigation method that can be applied on a large scale within a life cycle time. Even if this method cannot be applied on a large scale at this stage, at least it has to show the potential for large-scale application. For example, assuming that there is a spaceship at the moment, its speed can reach 50% of the speed of light, that is, 150,000 kilometers per second, then it will only take more than eight years for it to go back and forth between the two Nanmen Galaxy, even if it only Being able to take one person in this way also has potential, because it heralds the feasibility of large-scale interstellar voyages in the future. And whether it's throwing nuclear bombs, or super-giant spaceships, or the hibernation sailing that Wei Feng is using at the moment, none of these three methods have the potential for large-scale applications.

But now, the upper limit theory proposed by that scientist locks the speed of conventional propulsion at 4,500 kilometers per second. He claims that unless one can increase this speed by a factor of ten, or increase the average human lifespan by a factor of ten, any remaining attempts are doomed to fail on a large scale.

"Whether increasing the speed by ten times or increasing the average life expectancy of human beings by ten times, this is not possible for us at present." Chu Hai wrote, "The development of science and technology needs the support of basic theory, if our The basic theory cannot be broken through, and these two requirements are both extravagant expectations for us.”

"Science is our weapon of understanding the nature of the universe, and it follows a process of discovery, hypothesis, and demonstration. We must discover what is different in the universe from our theories, and then make assumptions about it, supplemented by more observations. And thinking, and finally come up with new theories, and then continue to repeat this process, our level of technology will be improved. But my friend, you know, now some scientists have put forward a new theory, which believes that we Our vision is limited within the solar system, that is, if we can’t get out of the solar system, we won’t be able to discover more of the peculiarities of this universe, and we won’t be able to better understand this universe, and our technology will naturally not be able to develop. "

"And if the "upper limit" theory is true, then it means that with our existing technology, it is impossible to go out of the solar system on a large scale. But if we cannot go out of the solar system, according to the above theory, our technology cannot be developed."

"Wei Feng, do you understand, this is a dead knot, a dead knot that cannot be opened."

Wei Feng temporarily looked away from the display screen, UU reading www.uukanshu. com fell into contemplation.

If this dead knot is simplified a little bit, that is to say, in order to obtain higher navigation speed, the premise is that people must go out of the solar system to obtain more knowledge. You can't get higher speed without more knowledge, you can't get out of the solar system. In order to get out of the solar system at a higher speed, the premise is indeed to have more knowledge and higher technology.

"Going out of the solar system" and "gaining more knowledge" are a pair of mutually presupposed events. This situation is like the key is locked in the lock. The key must be removed to open the lock, and the lock must be opened to remove the key.

It is this paradox that restricts the pace of human civilization to the solar system.

"So...through unconventional methods such as hibernation voyages, super-giant spacecraft, etc., let a small number of people go out of the solar system to acquire knowledge, and then use this knowledge to feed back the people trapped in the solar system, and finally improve the knowledge level of human civilization. To the point where it is enough to conduct interstellar voyages on a large scale, this may be regarded as a way to open the dead knot." Wei Feng thought, "Maybe the island project is an attempt by human civilization to open the dead knot." (To be continued... )