【Random Talks on Physics】Gas molecules are in constant thermal motion

Brownian motion – can the universe not be said to be composed of molecules? Isn’t it composed of particles such as atoms, photons, neutrons, as well as dark matter and dark energy?

Molecules are composed of atoms. Atoms are made up of a nucleus and electrons outside the nucleus. The nucleus consists of protons and neutrons

It’s not rigorous enough. A nucleus may consist only of protons (H11 protium)

　Absolute zero is the lowest temperature in thermodynamics, but it is only a theoretical lower limit. The unit of the thermodynamic temperature scale is Kelvin (K), and absolute zero is the zero point defined by the Kelvin temperature scale (also known as the Rankine scale, denoted as K). 0 K is approximately equal to minus 273.15 degrees Celsius on the Celsius scale, which is also 0 Kelvin. At this temperature, the molecules of a substance have no kinetic energy, but their potential energy is not zero; therefore, the internal energy of the substance is not zero at this point. The temperature of a substance depends on the kinetic energy of its internal particles such as atoms and molecules. According to the Maxwell-Boltzmann distribution, the greater the kinetic energy of the particles, the higher the temperature of the substance. Theoretically, when a particle’s kinetic energy reaches the minimum level permitted by quantum mechanics, the material attains absolute zero temperature, and it cannot go any lower. However, absolute zero is the lowest temperature that cannot be reached; the temperatures in nature can only be approached infinitely closely. If it is reached, then all things will reach the lowest form of motion. Because any space necessarily contains energy and heat, which are constantly converting into one another without disappearing. Therefore, absolute zero does not exist, unless that space has no energy or heat from the very beginning. At absolute zero, atoms and molecules possess the minimum energy permitted by quantum theory. 　　Absolute zero is obtained by extrapolation, based on the laws governing ideal gases (namely, the ideal gas law, pV=mRT/M=mrT, where r=R/M). Using this method, when the temperature drops to -273.15°C, the volume of the gas will decrease to zero. From the perspective of molecular kinetic theory, since the average translational kinetic energy of ideal gas molecules is determined by the temperature T, absolute zero can also be described as the \"temperature at which ideal gas molecules cease to move.\" Both of the above statements are merely idealistic reasoning. In fact, all real gases exhibit distinct quantum properties at temperatures approaching -273.15°C, at which point the gas has already turned into a liquid or solid state. In short, the motion of gas molecules no longer follows the thermodynamic statistical laws of classical physics. Through numerous experiments and theoretical derivations adjusted using quantum mechanics, it has been shown that at temperatures approaching absolute zero, the kinetic energy of molecules tends to a constant value; this extreme value is known as zero-point energy. This shows that at absolute zero, the energy of molecules is not zero, but rather has a very small value. The reason is that all particles are in the lowest possible energy state, that is, all particles are in their ground state.

......Baidu has the answer.......

I’ve learned that gas molecules are in constant thermal motion, and the energy for this motion comes from a heat source. The temperature in nature can only approach absolute zero infinitely closely. Absolute zero does not exist; even at absolute zero, the energy of molecules is not zero, but rather has a very small value.

According to the black hole principle, even without absolute zero, molecules would not move; are black holes only suitable for photons?