Neutron stars have a density of up to 100 trillion tons per cubic meter

Neutron stars are extremely dense planets in the universe. Even according to the most conservative estimates, the density of neutron stars can be as high as 100 trillion tons per cubic meter. I have to say that such a density is unimaginable. Why is there such a high density? Let's start by looking at how empty atoms are.

Take the hydrogen atom as an example. The hydrogen atom is the simplest in the universe. It has only one electron. Its nucleus is a proton. The radius of a hydrogen atom in the ground state is about 0.528 x 10^(-10) meters, and the proton radius of the electron is about 0.84 x 10^(-15) meters. As for the radius of the electron, we have not yet determined the value, but, certainly, the order of magnitude of the electron radius will not be greater than 10^(-18) meters.

That is to say, the total radius of a hydrogen atom is about 62,857 times that of its nucleus. If the radius of the nucleus of a hydrogen atom is enlarged to the size of a football, then the radius of the hydrogen atom will be about 7 kilometers after the same scaling. An electron is a speck of dust with a radius of about 0.1 mm.

Yes, the inside of an atom is so empty. For substances on Earth, atoms are not tightly close together. For example, the average atomic spacing in solid substances is usually between 10^(-9) meters and 10^(-10) meters. The average atomic spacing in the gaseous matter is larger than that in solid matter. If we compress all the atomic spacing in the earth's matter and the space inside the atoms, the radius of the earth will be reduced to about 11 meters, and the earth in this state will be reduced to about 11 meters. The density is the density of the neutron star.

So we can simply understand that the reason why neutron stars have such a high density is actually that the materials that makeup neutron stars are in a highly compressed state, so why are there such dense planets in the universe? The answer is gravitational collapse.

Since gravity is a long-range force, and there is only an "attractive force" but no "repulsive force", gravity can be superimposed infinitely. For various planets in the universe, the gravitational force generated by them will not only "attract" nearby matter, but will also cause its gravitational collapse.

If a planet wants to exist stably, it must have a mechanism to resist gravitational collapse. In theory, "8% of the mass of the sun" is a critical value. If the mass of the planet is lower than this critical value, then The electromagnetic force between matter alone can resist gravitational collapse. If the mass of the planet is greater than or equal to this critical value, the electromagnetic force cannot withstand it.

The mass of all stars in the universe is greater than or equal to 8% of the mass of the sun. They rely on the nuclear fusion reaction of their cores to resist their collapse. However, the "nuclear fuel" of stars is limited after all, and when the "nuclear fuel" is exhausted After that, the star will inevitably continue to collapse.

For less massive stars, their cores can resist gravitational collapse by the "degenerate pressure" between electrons, and eventually evolve into a white dwarf.

But if the star is massive enough, the "degenerate pressure" between the electrons can't resist gravitational collapse, in which case the core of the star will continue to collapse, and under the enormous pressure, the electrons will be squeezed into the nucleus, and combine with the protons in it to form neutrons, these neutrons and the original neutrons in the nucleus will be closer together, resulting in "neutron degenerate pressure".

Generally speaking, when a star evolves to this point, a powerful supernova explosion will occur. After that, if its remnant core can resist gravitational collapse using "neutron degeneracy pressure", it will evolve into an extremely dense On such a planet, all the microscopic particles are close together, and their density can be at least as high as 100 trillion tons/cubic meter, because most of the microscopic particles that make up this kind of planet are neutrons, so people call it a neutron star.

Some people may ask, after a supernova explosion of a star, what will happen if the mass of its remnant core is so great that the "neutron degeneracy pressure" cannot resist gravitational collapse?

Such a situation exists. According to modern physics, neutrons are composed of quarks, and there is also a "degenerate pressure" between quarks, so reasonable speculation is that if the "neutron degeneracy pressure" also If the gravitational collapse cannot be resisted, then the neutrons will be "crushed", and then the "quark degeneracy pressure" will take on the responsibility of "withstanding the gravitational collapse".

If the "quark degeneracy pressure" can withstand gravitational collapse, then the remnant core of the star will evolve into a more dense star than a neutron star, which we can call a quark star.

If it can't be resisted, then in the framework of modern physics there will no longer be a force that can resist gravitational collapse, in which case the remnant core of the star will become an infinite volume due to the unstoppable gravitational collapse. Small, infinitely dense "singularity", and this "singularity" will bend the nearby space-time to the extreme, forming a completely closed space-time, thus evolving into the most formidable existence in the universe - a black hole.

It is worth mentioning that since scientists have not yet determined whether there are quark stars in the universe, we usually think that neutron stars are the most compact celestial bodies in the universe after black holes.

Well, today we will talk about it here first, welcome everyone to pay attention to us, and see you next time.