Open the door of low-temperature world

[Use a small spoon to hold Helium II. There is a drop of Helium II at the bottom of the spoon. The liquid in the spoon will flow out automatically until the liquid in the spoon flows out]




[Put a cup into liquid helium II, the cup surface is higher than the liquid level, and the liquid helium II outside will automatically flow into the cup]




[Helium Knife Fountain, insert a capillary tube into liquid helium II, irradiate liquid helium with light, and it will spray out like a fountain. The stronger the light is, the higher it will spray, and it can reach several centimeters. Light energy is directly converted into mechanical energy]

[At the temperature of liquid helium, place a magnet on a lead ring. The magnet will float on the ring like weightlessness, keeping a certain distance from the lead ring, which is called the "Meissner effect"]




[When the temperature drops below 4.2K, the resistance of mercury will change to 0, which is the legendary "superconductivity". Later, people found that some substances will also have superconductivity at a higher temperature, which led to the development of superconductivity science in the 20th century]





[Young Bose insisted on the truth, Einstein did not put on the airs of academic hegemony, and the spirit of single-mindedly discussing scientific research was respected]


Is there a sense of deja vu: the "macro atom" in Liu Cixin's "Ball Lightning"? In fact, it is not so mysterious. In reality, there is really "macro atom".



[Is the mysterious "spherical lightning" also a "Bose-Einstein condensate"?]




[Japan showed the superconducting maglev train, which is scheduled to open in 2027, and China should also keep up!]





The world of high temperature is too complicated, not like the world order of ultra-low temperature. The study of the ultra-low temperature world is more close to the origin of the world. That must be the simplest beauty!