Vol 2 Chapter 575: Control one's own destiny

　　
　　 But thinking about it, Lei Tiantang still didn't really do that. On the one hand, he was afraid of getting his hands dirty, and on the other hand, he knew that these brain-destructive actions in a short period of time were not dangerous.
　　
　　 With so many radio signals emitted by human beings, has the position of the earth been exposed? The very real problem is that we want to be exposed, but our strength does not allow us to be exposed!
　　
　　 Even if it is only a hundred years or so, that the radio signal has only traveled a distance of one hundred light-years. Compared with the vast universe, one hundred light-years is too limited!
　　
　　 And this is only a purely theoretical analysis. In fact, the radio signals used by humans are difficult to fly so far. The signal strength will gradually become weaker during the propagation process, so that it is difficult to recognize it in the end!
　　
　　Think about what types of signals humans can detect and receive today. Basically, they are signals from abnormal activities of massive celestial bodies, which propagate outward in the form of high-energy cosmic rays!
　　
　　For example, when a supernova explodes, the energy produced at the moment of the explosion is more than the total energy of the sun in its lifetime. Even with such a high-energy signal, human beings only detect it!
　　
　　 Compared with cosmic energy, the energy of radio signals emitted by humans is too weak! Similarly, there are neutron star collisions, pulsars and more!
　　
　　 So, even if there is an alien civilization, it is difficult to receive the signal from human beings, because the signal is too weak, even if it is received, it is likely to be filtered out and will not attract the attention of the alien!
　　
　　 From the results of our human exploration using various detection methods, we can find possible habitable planets within 50 light-years of the sun and terrestrial planets in the habitable zone. There are currently about 10 known planets.
　　
　　 Within a radius of about 100 light-years, we can roughly think that the number is four times this. That is to say, there are about 40 planets where life may appear, plus the ones that have not been discovered, it should be less than 100.
　　
We know very little about these planets, but anyone with a bit of scientific common sense knows that the conditions for life on a planet are very harsh, especially for complex life. If life on our planet were not lucky, it might have been long before. It's over in several devastating disasters, let alone the birth of our humans!
　　
　　 Therefore, most of them are likely to have no life for various reasons. Even if the rest have life, the probability of developing intelligent life and even civilization is extremely low. Therefore, we are generally safe now.
　　
　　 "Haha! What do those people do! To be honest, I don't worry about the situation of the earth facing aliens in a short time, and I am not a fool who thinks the earth is the center of the universe!
　　
　　 The location of our earth is too far away, and the surrounding star systems are also scarce and pitiful. If several extraterrestrial life can be born in such a rare star system, then the universe will be too casual!
　　
　　 Such a situation has really happened, our earth will not be safe and stable, and the aisles have not been discovered by alien civilizations now! "Lei Tiantang said with a smile.
　　
　　 It is well known that we live in a spiral galaxy, the Milky Way, in fact the Milky Way is a barred spiral galaxy, which means that our galaxy may have two main spiral arms, plus a central bar, which astronomers know little about. But where is our solar system located in such a vast spiral arm structure?
　　
　　 The Milky Way is about 100,000 light-years wide. We are about 250,000 light-years from the center of the Milky Way. It seems that we are not located in the two main spiral arms of the Milky Way, but in a small spiral arm in the Milky Way. The spiral arm we are in is the Orion arm, also known as the Orion arm, which is located between the sagittarius arm and the perse arm of the Milky Way.
　　
　　 The Orion arm where we are located is 3,500 light years wide and about 10,000 light years long. Our sun, earth, and all other planets in the solar system are located in the Orion Arm. Our position is close to the inner edge of the spiral arm. , About half the length of the arm.
　　
　　 The Orion Arm also has an alias, sometimes called the Orion Swan Arm. It is named after Orion, which is one of the most prominent constellations in the northern hemisphere in winter and southern hemisphere in summer.
　　
　　 Some of the brightest stars in this constellation and the most famous celestial bodies Betelgeuse, Betelgeuse, Orion star belt and Orion Nebula are all neighbors of the sun and are also located in the arms of Orion. This is why we can observe so many bright objects in Orion.
　　
　　 The volume of the earth is only one-1.3 millionth of the sun, and our sun is just a very ordinary star in the Milky Way, and there are hundreds of billions of stars like the Sun in the Milky Way.
　　
　　 And the diameter of the Milky Way is hundreds of thousands of light years! For humans, the size of the Milky Way is unimaginable, but humans have discovered billions of extragalactic galaxies as large as the Milky Way!
　　
　　 "Yes! But even so, I am very upset about their behavior. What if there is an accident, such as a fleet of advanced civilization passing by our solar system?
　　
Originally, people might not pay attention to a small asteroid in such a remote rural area as we were sailing, but the signals emitted by these dead guys were received by them. Such things are of course in the long cosmic voyage. It is a very interesting thing!
　　
　　 At that time, how did we respond to these alien fleets of interest? Relying on those people kneeling on the ground and calling Dad for letting go? "Kuafu is still very upset with such things.
　　
　　"So this is why I am so desperately developing space technology~EbookFREE.me~ It’s not a good habit to wait and die. Since the boss, I have this opportunity, I should make good use of it.
　　
　　 Otherwise, if there is a doomsday scene, even if I can save some human beings, but the earth as home is gone, it will not really become a wandering civilization like the science fiction said!
　　
This is also one of the reasons why Tian Mingli and the others said that they would build a large scientific instrument such as the Hadron Collider. I did not hesitate to agree to it. Although high energy physics research cannot see the harvest in a short period of time, I am still optimistic about its future of.
　　
　　 Antimatter, dark matter, dark energy, and even the fur of space research can also be studied with such equipment, and these things can be used as energy or weapons!
　　
　　 Especially when it comes to weapons, I can say with certainty that the time for them to make weapons is much faster than the time for them to become energy sources. This is exactly what we have now for nuclear energy!
　　
　　 Think about it when we have mastered anti-matter bombs, dark matter bombs, or even space annihilation bombs, etc. The threat to us by ordinary aliens is very small! "Lei Tiantang said with a smile.