In the amazing world of physics, the impossible, although not immediately, but still becomes possible. And lately, scientists have managed to achieve really super impossible things. Science is progressing. Only one pasta monster knows what else awaits us in its most secret bowels. Today we will analyze a dozen of unreal things, states and objects that have become possible thanks to modern physics.
Incredibly low temperatures
In the past, scientists have been unable to cool objects below the so-called "quantum limit" threshold. To cool something to such a state, it is necessary to use a laser with very slowly moving atoms and suppress the heat-generating vibrations they generate.
However, physicists have found the right solution. They created an ultra-tiny aluminum vibrating drum and were able to cool it down to 360 µK, which is 10,000 times the temperature in the very depths of space.
The diameter of the drum is only 20 micrometers (the diameter of a human hair is 40-50 micrometers). It was possible to cool it down to such ultra-low temperatures thanks to a new technology of the so-called "squeezed light", in which all particles have the same direction. This eliminates heat generating vibrations in the laser. Even though the drum has been cooled to the lowest possible temperature, it is not the coldest type of matter. This title belongs to the Bose - Einstein condensate. Even so, achievement plays an important role. Since one day a similar method and technology may find their application to create ultrafast electronics, as well as help in understanding the strange behavior of materials in the quantum world, approaching in their properties to physical limits.
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The brightest light
The light of the Sun is blindingly bright. Now imagine the light of a billion suns. It was he who was recently created by physicists in the laboratory, in fact, having created the brightest artificial light on Earth, which, moreover, behaves in a very unpredictable way. It changes the appearance of objects. However, this is not available to human vision, so it remains to take physicists at their word.
Molecular black hole
A group of physicists recently created something that behaves like a black hole. To do this, they took the world's most powerful X-ray laser Linac Coherent Light Source (LCLS) and used it to collide molecules of iodomethane and iodobenzene. Initially, the laser pulse was expected to knock out most of the electrons from the orbit of iodine atoms, leaving a vacuum in their place. In experiments with weaker lasers, this void, as a rule, was immediately filled with electrons from the outermost boundaries of the atomic orbit. When the LCLS laser hit, the expected process actually started, but then a truly amazing phenomenon followed. Having received such a level of excitement, the iodine atom began to literally devour electrons from nearby hydrogen and carbon atoms. From the outside, it seemed like a tiny black hole inside the molecule.
Subsequent laser pulses knocked out the attracted electrons, but the void pulled in more and more. The cycle was repeated until the entire molecule exploded. Interestingly, the atom of the iodine molecule was the only one that showed such behavior. Since it is on average larger than others, it is able to absorb a huge amount of X-ray energy and lose its original electrons. This loss leaves the atom with a sufficiently strong positive charge, with which it attracts electrons from other, smaller atoms.
Metallic hydrogen
It has been called the "Holy Grail of High Pressure Physics", but until recently no one was able to succeed in obtaining it. The possibility of converting hydrogen to metal was first announced in 1935. Physicists of the time suggested that such a transformation could be brought about by very strong pressure. The problem was that the technologies of that time could not create such pressure.
In 2017, the American team of physicists decided to return to the old idea, but took a different approach. The experiment was carried out inside a special device called a diamond vise. The pressure generated by this vise is produced by two synthetic diamonds located on both sides of the press. Thanks to this device, an incredible pressure was achieved: more than 71.7 million psi. Even at the center of the earth, the pressure is lower.
Computer chip with brain cells
Breathing life into electronics, light could one day replace electricity. Physicists realized the amazing potential of light decades ago, when it became clear that light waves could travel parallel to each other and thus perform many simultaneous tasks. Our electronics relies on transistors to open and close the paths for electricity to travel. This scheme imposes many restrictions. However, recently scientists have created an amazing invention - a computer chip that mimics the work of the human brain. Thanks to the use of interacting beams of light that work like neurons in a living brain, this chip is able to really "think" very quickly.
Previously, scientists could also create simple artificial neural networks, but such equipment took several laboratory tables. It was considered impossible to create something with the same efficiency, but at a much smaller size. And yet it succeeded. The silicon-based chip is only a few millimeters in size. And he conducts computational operations using 16 integrated neurons. It happens like this. A laser light is supplied to the chip, which is divided into several beams, each of which contains a signal number or information that varies in brightness level. The output intensity of the lasers provides the answer to a numerical problem or any information for which a solution was required.
Impossible form of matter
There is a type of matter called "superfluid solid". And in fact, this matter is not as terrible as it might seem from the name. The fact is that this very bizarre form of matter has a crystalline structure characteristic of solids, but at the same time it is a liquid. This paradox remained unrealized for a long time. However, in 2016, two independent groups of scientists (American and Swiss) created matter, which can rightfully be attributed to the properties of a superfluid solid. Interestingly, both teams used different approaches in creating it.
The Swiss created the Bose-Einstein condensate (the coldest matter known) by cooling rubidium gas to extremely low temperatures. Then the condensate was placed in a two-chamber installation, in each chamber of which small mirrors directed at each other were installed. Laser beams were directed into the cameras, which triggered the transformation. The gas particles, in response to the laser action, built up the crystalline structure of the solid, but in general the matter retained its fluid property.
The Americans obtained a similar hybrid matter based on a condensate of sodium atoms, which was also strongly cooled and exposed to a laser. The latter were used to shift the density of atoms before the appearance of a crystalline structure in liquid form.
Negative mass fluid
In 2017, physicists created a really cool thing: a new form of matter that moves towards the force that repels it. While not really a boomerang, this matter has what you might call negative mass. With a positive mass, everything is clear: you give acceleration to some object, and it begins to move in the direction in which this acceleration was transmitted. However, scientists have created a fluid that works very differently than anything in the physical world. When pushed, it accelerates to the source of the acceleration being exerted.
And again the Bose - Einstein condensate came to the rescue in this matter, in the role of which were the rubidium atoms cooled to ultralow temperatures. Thus, scientists have obtained a superfluid liquid with a normal mass. Then they strongly compressed the atoms with lasers. Then, with the second set of lasers, they strongly excited the atoms, so much so that they changed their spins. When the atoms were freed from the laser grip, the reaction of an ordinary liquid would be the urge to move from the center of fixation, which in fact can be interpreted as pushing. However, the rubidium superfluid liquid, whose atoms were given sufficient acceleration, remained in place when released from the laser grip, thereby demonstrating a negative mass.
Time crystals
When Frank Wilczek, the Nobel laureate, first proposed the idea of time crystals, it sounded crazy. Especially in the part in which it was explained that these crystals can have motion, while remaining in a state of rest, that is, demonstrating the lowest level of energy of matter. It seemed impossible, since energy is required for movement, and the theory, in turn, said that there was practically no energy in such crystals. Wilczek believed that perpetual motion can be achieved by changing the ground state of the crystal atom from stationary to periodic. This went against the laws of physics known to us, but in 2017, 5 years after Wilczek proposed this, physicists found a way to do it. As a result, a crystal of time was created at Harvard University, where nitrogen impurities "rotated" in diamonds.
Bragg mirrors
The Bragg mirror is not highly reflective and consists of 1000-2000 atoms. But it is capable of reflecting light, which makes it useful wherever tiny mirrors are needed, such as in advanced electronics. The shape of such a mirror is also unusual. Its atoms are suspended in a vacuum and resemble a chain of beads. In 2011, a German group of scientists was able to create a Bragg mirror, which at that time had the highest level of reflection (about 80 percent). To do this, scientists have combined 10 million atoms in one lattice structure.
However, later, research teams from Denmark and France found a way to significantly reduce the number of atoms needed, while maintaining high reflective efficiency. Instead of tightly bundling around each other, the atoms were placed along a microscopic optical fiber. With the correct placement, the necessary conditions arise - the light wave is reflected directly back to its point of origin. When light is transmitted, some of the photons break out of the fiber and collide with atoms. The reflective efficiencies demonstrated by the Danish and French teams are very different and are around 10 and 75 percent respectively. However, in both cases, the light returns (that is, is reflected) to its point of origin.
In addition to promising advantages in the development of technologies, such mirrors can be useful in quantum devices, since atoms additionally use the light field to interact with each other.
2D magnet
Physicists have tried to create a two-dimensional magnet since the 1970s but have always failed. A true 2D magnet must retain its magnetic properties even when separated to a state where it becomes two-dimensional, or only one atom thick. Scientists even began to doubt that such a thing was possible at all.
However, in June 2017, physicists using chromium triiodide were finally able to create a two-dimensional magnet. The connection turned out to be very interesting from several sides at once. Its layered crystal structure is excellent for tapering, and, in addition, its electrons have the desired spin direction. These important properties allow chromium triiodide to retain its magnetic properties even after its crystal structure has been reduced to the thickness of the last atomic layers.
The world's first 2D magnet could be produced at a relatively high temperature of -228 degrees Celsius. Its magnetic properties cease to work at room temperature, as oxygen destroys it. However, experiments continue.
NIKOLAY KHIZHNYAK