It seems that our world has been explored from top to bottom and science has found the answer to every question. But it is not (at all) so. There are still many mysterious things and phenomena that have no rational explanation.
We all know that cats always spin when they feel good. However, no one knows how to do it. There is no special organ in a cat's neck that makes these sounds. Scientists believe that cats use their vocal cords to produce the vibrant sounds we hear. During the research it was also found that the frequency of the sound emitted by them, helps to accelerate the regeneration and healing of lesions. Therefore, your cat can be an excellent doctor.
Species that appear out of nowhere.
For many years, scientists have been trying to unravel this mystery. It seems that many species of animals and plants on our planet have come out of nowhere. They had no ancestors from whom they could have evolved, and science cannot explain their arrival on Earth.
This is especially the case with amphibians: we do not know exactly at what stage the fish gave birth to amphibians. And the first terrestrial animals with very developed legs and heads appeared. Dozens of different species appeared at the same time. Then, after an alleged cataclysm that caused the extinction of the dinosaurs (about 65 million years ago), several groups of mammals appeared simultaneously.
Compass for cows.
You probably didn't think of that. In fact, no one thought about it until Google Earth appeared. This application made it possible to study thousands of photos of cows eating grass (don't ask why) and they discovered a strange fact. Almost 70% of cows turn their heads north or south when eating or drinking. This can be seen on all continents, regardless of geography, climate or any other factor.
What is dark matter made of?
Almost 27% of the universe is made of dark matter. It does not emit any electromagnetic radiation and does not interact with it. In other words, dark matter does not emit light and is therefore impossible to observe directly.
The first theories of dark matter were developed about 60 years ago. However, so far, scientists have failed to prove its existence.
How many planets are there in the solar system?
Since scientists have officially excluded Pluto from the group of planets, humans believe that there are only eight of them in our solar system. But this is not the case. Most of our solar system has not yet been explored. The space between Mercury and the Sun is very clear, and the space beyond Uranus is very dark.
Also, just beyond Pluto, at the edge of our solar system, is the Kuiper belt. It is made from frozen volatile compounds. Every day, scientists discover hundreds of thousands of objects the same size as Pluto and even larger.
They noticed a gap in the Kuiper belt. This indicates that there is another planet the size of Earth or Mars that attracts all the surrounding rocky bodies. Scientists will still have to write many books and do so much research to determine how many planets there are in the solar system.
Why are there right-handed and left-handed people?
Scientists have studied why most people use their right hand more often than their left. However, they have not yet been able to explain what mechanisms play a role in this.
Most people (70-90%) are considered right-handed, and the rest (5-30%) are left-handed. There is also an ambidextrous percentage: people who know how to use both hands perfectly. But scientists could not reach a unanimous conclusion.
Genes have been shown to play a role in determining whether a person will be left-handed or right-handed, but the "left gene" has not yet been detected. There is also evidence that the social circle also influences the dominant choice of hands. For example, teachers may sometimes try to get children to use their right hand instead of their left.
The disappearance of the Megafauna.
The megafauna includes all the species of large animals that have ever lived on Earth. They disappeared about 10,000 years ago, and scientists still haven't figured out why.
Some believe that the megafauna has disappeared due to climate change, but in reality there is little evidence to support it. Another theory is that these large animals began to run out of food. However, it is not so simple. Scientists have found mammoths in excellent condition in Alaska, still with undigested grass in their stomachs and even in their mouths. This shows that the animals died while eating: and all at the same time. Why did this happen? This remains a mystery.
Why do we dream when we sleep?
Some people believe that their dreams are just random images and impulses of the brain, while others are convinced that they have a deep meaning, which are the desires, problems and concerns of our subconscious. However, no one was able to establish a definitive answer.
Techniques such as hypnosis and lucid dreaming do not provide exact answers. The science dedicated to the study of dreams is called dreaming. Scientists agree that dreams symbolize something hidden in people's minds, but no one can say exactly what it is.
Sounds in interstellar space.
In 2006, while trying to study young stars, a group of scientists faced a problem: an inexplicable and mysterious noise that hindered the search. They still haven't figured out where that sound came from. Noise can't travel through space, but radio waves can, but where from? And who or what causes them? Scientists have just discovered that these waves do not belong to stars or other space formations or phenomena known to man.
Why do we have different blood groups?
Yes, science knows a lot about blood types, but there are still many unanswered questions. For example, we still don't know why they are different and why they are evolutionarily necessary.
Blood groups are different in blood cell antigens. These antigens cause the formation of antibodies that destroy foreign cells in the body. Scientists do not know why these antigens are different.
According to one theory, they have something to do with disease and the immune system. For example, it has been found that people with a third blood type can have almost absolute immunity to a form of malaria.