Why do some people say that aliens may have been here a long time ago, but there are no humans on Ea

Whether there are aliens and alien civilizations in the universe has always been one of the secrets that people exploreAlthough there are many reasons for the existence of aliens, no one has seen aliens so far, and recently many people have said that aliens may have been there a long time ago, but there are no humans on Earth yet, which is indeed possible.

First of all, we have all seen the appearance of aliens in the plot of the movie, they are all advanced civilizations, and the scientific and technological theories and scientific knowledge mastered are not comparable to our human beings, and even the spaceship used when landing on the earth, it can be seen that the technology level of aliens is definitely much higher than that of humans, and according to this idea,It is very likely that alien technology came to Earth many years ago, even before the birth of humans.

At this point, we can think about it, our human beings' current science and technology can be said to be the pinnacle, all kinds of travel tools, scientists also have a lot, but there are still many places on the earth that we can't explain, such as what is the principle and what is the role of the stone placement of the stone henge, and who proposed the design of the Egyptian pyramids, who came up with the design plan, and the mysterious disappearance of the earth, etc., these are all things that we can't explain now. And a lot of years have passed so farThese are enough to suspect that it is very likely that the traces left by aliens who once came to the earth, otherwise such a high level of civilization traces at that time would not have been possible for human beings at that time.

Therefore, the alien technological civilization at that time was already much more powerful than our current human beings, butIt can be that if you encounter the devastating factors of force majeure in the universe and have to flee to other planets, after all, the cosmic catastrophe cannot be escaped by all living beings, and then aliens came to Earth, and at that time human beings had not evolved at all, so there was a statement at the beginning.

There should be such a reason, after all, human beings have not discovered aliens until now, but it is not excluded that there are alien creatures higher than humans, so this situation should be some.

Because someone discovered UFO in the first place, and through some discoveries, we don't have it on Earth now. Hence the belief that aliens have already come from our earth.

Because they have found traces of aliens in some parts of the earth, but there is no sign of human existence around.

Because in many ancient murals, the existence of aliens is clearly recorded, so some people say that they have actually come to the earth a long time ago.

Hypothesis; Aliens once came to Earth, when there was no living life on Earth, oxygen was deadly to aliens, and Earth had no energy source that aliens looked at. Therefore, the earth is not suitable for aliens to live, there is no energy that can be used, or there is no equipment that cannot extract energy at that time, and the earth has deadly poisonous gas, so they choose to leave and wait for the technology to come.

Hypothesis 2; Aliens came to Earth in the age of dinosaurs, oxygen was fatal to aliens, and missiles launched in space when aliens were gone, resulting in the extinction of dinosaurs around the world, radiation mutation, and microbial evolution.

Have aliens really come to our Earth? Do aliens really exist?

According to mainstream scientific findings, aliens have never visited Earth. Despite the whimsical nature of many fictional works and the confusion of many so-called eyewitnesses with their imaginations, there is no credible scientific evidence that aliens ever visited Earth.