Dark Matter plagued science for 40 years: no knowledge of the composition of the universe's 96% billion

Sina technology news Beijing Time on May 18 news, according to the US Space Network reports, whenever night falls, looked up at the stars, people can not help but sigh the vast universe. But do you know that the total mass of all the stars, planets, and galaxies observed in the universe is less than 4% of the total mass of the universe. 96% of the universe is made up of mysterious things that scientists cannot see, detect, or even imagine.

These mysterious substances are called dark matter and dark energy. Although invisible, they impose gravity effects on the "visible Universe", which can be noticed. Dark matter and dark energy are hidden in the dark, without a trace.

In a speech at the New York City University in May 9, science writer Richard Panek said: "What are the major components of the universe? Who knows !" He went on to explain: "Now we know nothing about this, and we may never understand this problem ."

In his new book "The universe of 4%", panic reviewed the discovery of dark matter and dark energy for readers. This is an amazing scientific discovery process, and a fierce competition between scientists, hoping to reveal the road to exploration.

Dark Matter

Scientists first noticed that there may still be things that we could not see in the universe, that is, the things we could not see in the last century ~ May 1970s. Vera rubin, a young female astronomy from the geomagnetic system at Carnegie Al Research Institute in Washington, USA, was studying the movements of stars in different locations in the galaxy.

According to Newton's classical physics, stars on the outer edge of the galaxy have relatively slow motion, while stars close to the center are fast. But Lubin was shocked by the fact that the stars in different locations in these galaxy did not show any speed difference at all, they all seem to run around the center of the galaxy at the same speed.

Panick explained: "This means that the Galaxy should be torn apart and split. Because this is not in line with the gravity theory, it is completely unstable. Lu Bin decided that he must have made an error ."

However, repeated observations by other astronomers confirm that their observations are correct. Finally, after a large number of observations and computer simulations, astronomers have to accept the result that there must be a large amount of material that we don't see in these galaxies. This strange motion pattern can be explained only when we assume that the material we see occupies only a fraction of the total material of the galaxy. Confused scientists call these invisible mysterious things "dark matter ".

So where exactly is dark matter?

Despite the hard work of scientists over the past 40 years, they still have no idea what the essence of dark matter is.

A popular view is that dark matter is composed of a strange material particle that does not react to conventional substances, or even interact with light, and thus cannot be seen. However, it has the same quality as conventional substances, and thus has a gravitational impact on other substances around it, which is why it causes Stellar motion anomalies in the galaxy, and other unusual phenomena in the universe.

However, it is frustrating that long searches by physicists still cannot capture any trace of this singular particle, even specialized experiments designed based on its theoretical nature cannot be found.

Panick believes that this situation has severely affected a whole generation of scientists. He said: "I think the search for dark matter has given scientists a lot of frustration. When they were young, they entered this field with full confidence and told themselves, 'Okay, let me solve this thorny problem. 'But after 15 or 20 years, they still failed to make any progress. At this time, they will be very frustrated. They will say to themselves, 'I have put my entire scientific career into this job, however, I don't know whether I can make some new discoveries in this field in my life. '"

But there are still many passionate physicists with hope. They believe that our decades of work are bringing us closer to the truth, and the large LHC in Geneva, Switzerland, is expected to help us ultimately find the secret of dark matter.

Dark Energy

Dark energy is even more mysterious than dark matter. Its discovery is even later. In the foreseeable future, scientists are more likely to unlock its mysteries.

The story begins in the 1990 s. At that time, two top physicist groups were working on space expansion. Their purpose is to find out how fast the expansion of the universe is, so as to speculate its fate: whether the universe will expand forever. It will eventually contract to a point to form the so-called "big counterattack ".

To achieve this, scientists have used special methods to locate the superstars in all directions of the universe. Then they perform spectral measurements on these celestial targets to learn how quickly they are moving away from us.

We know that due to the limited speed of light, it takes millions or even billions of years for the light from distant celestial bodies to reach the Earth. Therefore, when we observe distant celestial bodies, we are actually looking back at time to see past time. Therefore, we are actually observing the difference in the expansion rate of the universe at different distances from the celestial bodies to us.

Scientists predict that they will observe two possible scenarios: the first is that the universe has been expanding at an approximate rate, and the second is that as the age of the universe increases, the expansion momentum gradually decreases, the expansion rate slows down.

However, the results of actual observations once again stunned them. Because what they see is totally unexpected: The universe is surging!

This fact cannot be explained by any knowledge of physics we know. According to the traditional concept of physics, the gravity of all things in the universe should slow the expansion of the universe, or even start to contract, just as we throw a ball, when it rises to a certain height, it will gradually slow down and fall down due to the gravity of the Earth.

Panick explained: "This means that there is a mysterious, cosmic scale of great force in anti-gravity. The scientific community was totally unable to accept this idea at the beginning, because it was so strange ."

Fierce competition

This time, scientists named this mysterious power "dark energy ". Even though the scientists themselves do not know what this mysterious force is and where it comes from? But it does seem to exist, and it can actually compete against the gravity of all material in the universe.

However, the full ignorance of this mysterious power cannot block the passion of scientists to uncover its mysteries.

"What I keep hearing is that although it is difficult to achieve achievements in this field and the future is unknown," panic told the US Space Network reporter. However, the scientists who are devoted to this field are still full of passion. They are all working hard and hope they can solve this mystery first. They are very excited by the great significance and profound impact of this issue ."

In general, dark energy occupies about 73% of the material and energy in the universe, and the remaining 23% is dark matter. Everything we can see, all the galaxy, all the stars and planets, and all the things we know are only 4% of the universe.

The two competing teams of scientists found this shocking fact almost at the same time. This competition continued, and both groups hated each other.

However, in the long history of science, the scientists of the two groups have used their work to make an indelible contribution.

"I think the discovery of dark matter will lead them to the Nobel Prize. This should be just a matter of time," panik said ." (Morning wind)