How aliens may contact us

  From weak radio signals to huge alien spacecraft bombing the White House, in the world of science fiction and movies, we always have no lack of imagination of alien life.
  Of course, some of the descriptions of all these sci-fi works are completely unreliable, but in real life, there are indeed many scientists who are spending a lot of time thinking about the ways in which intelligent alien life might get in touch with us. They proposed Some of the thoughts sounded more imaginative than Hollywood movies.
  From extraterrestrial superstructures to mining robots, the article lists some possibilities for contact with interstellar civilization that scientists have proposed.
  Super building
  , of course, signs of extraterrestrial civilizations do not have some kind of tiny target, they may also be a monster. Some scientists pointed out that if a huge alien structure is found, it is likely to be a “come here” signal sent by the aliens. In fact, scientists have been closely watching a star numbered KIC8462852 recently. In the past few years, the brightness of this star has been changing repeatedly. Some researchers believe that this change in brightness may indicate that there are huge structures around the star that periodically block the star’s light when it orbits the star. Of course, it is very obvious that you cannot rule out that this brightness change may also be caused by exoplanets or other possibilities.
  In December 2015, scientists discovered that no communication signals existed around this star. A researcher said that they did not find evidence that there are advanced intelligent life around the star sending interstellar signals to the earth.
  Robotic probes
  , of course, signal the existence of extraterrestrial civilizations is not necessarily in the form of electromagnetic waves appear, there may be a small unmanned alien spacecraft. That may be a probe sent by an alien civilization to explore the universe.
  In fact, the researchers pointed out that due to our low level of exploration of the solar system, if aliens have spacecraft deployed on the asteroid belt or on the surface of Mars, we might not find it. Such a detector can be very miniature, perhaps as large as a golf ball-who knows how high the technological level of an alien civilization is?
  Radio signals
  In a paper published in the journal Nature in 1959, physicist Philip Morris and others put forward an idea that scientists might be able to identify alien civilizations by listening to radio signals from the universe signal of. This can be done because the radio wave propagation in the universe is relatively low loss, and will not be absorbed by various celestial bodies or severely interfered. Therefore, they believe that if an alien civilization wants to communicate with the outside world, they might choose this method.
  For decades, the SETI (Search for Extraterrestrial Intelligent Life) program in California, USA has been engaged in this work, constantly monitoring the sounds from the universe. Of course, the premise of this plan is still to assume that aliens and ours think in the same way, but this idea is not necessarily tenable. Some scientists pointed out: “the aliens will not necessarily subscribe to” Nature “magazine.”
  Power station radiation
  , of course, we can not assume that all extraterrestrial civilizations want to look for in a similar huge and lonely universe. Therefore, there is also a possibility that they are like hermits, wanting to hide their tracks. If this is true, then they will not try to broadcast to the outside world, trying to reveal their position.
  However, theoretical physicist Freeman Dyson pointed out that even an alien hermit kingdom may develop a type of large-scale device called “Dyson Sphere” to obtain the energy of stars. Dyson himself pointed out that the Dyson sphere may not be a sphere, as long as it is a place where the extraterrestrial society produces energy on a large scale.
  A large amount of infrared radiation will appear in such places, which is inevitable when developing stellar resources. Currently, NASA’s Wide-angle Infrared Survey Probe (WISE) is searching for such signals in the universe.