The "hardest" matter in the universe is 10 billion times harder than steel!

There's one dish in the universe that's impossible to bite, even with good teeth, and it's called "nuclear pasta."

How tough is the nuclear pasta? It's 10 billion times harder than steel, and it's made by a neutron star.

So how does a neutron star come from, and why is it so hard?

To understand this hard dish, we have to start with an explosion.

The origin of neutron stars

Stars are common objects in the universe, so what are neutron stars?

The birth of a neutron star starts with the death of a massive star.

Stars don't shine forever, and they have a lifetime limit. Just as human lifespans vary from person to person, stars' lifetimes vary depending on their mass.

Our sun, for example, is a G-type star, known as a yellow dwarf, with a lifespan of about 10 billion years.

But M - or K-type stars about half the mass of our sun, known as red dwarfs, can live anywhere from 20 to 50 billion years.

The states of stars can be divided into birth, growth, stability, aging and death. The stable period is the longest, so it is also called the main-sequence star. Our Sun is in the stable main-sequence star period.

When a star reaches its old age, it expands and becomes a red giant. The more massive ones are called red supergiants.

When the expansion reaches its limit, the star will eventually die. Every star has its own way of dying, depending on its mass.

A star less than eight SUNS in mass ends itself in a more gentle form, in the form of a collapse, a once-hot fireball that ends up with a cold, white-glowing tombstone called a White Dwarf.

Stars that are more than eight SUNS in mass, the way they learn about themselves, they end up with an explosion, an explosion called a supernova.

The supernova explosion returns the star's outer material back to the nebula, preparing the next star to be born.

The cores of massive stars become either black holes or neutron stars.

In general, the more massive you are, the more likely you are to become a black hole, so the biggest difference between a neutron star and a black hole is whose precursors are more massive.

That makes neutron stars second only to black holes in density.

Light bends as it passes near a neutron star because the gravitational pull of the star changes the path of light in a straight line.

Neutron stars don't have as much mass as black holes, and their gravity isn't strong enough to swallow up light.

It's the second densest in the universe, with a mass of 100 billion to 100 trillion grams per cubic centimeter, and it gets harder as you go further into the core.

The core of a neutron star is made up entirely of neutrons and has a density of 1,000 trillion grams per cubic centimeter. Why are neutron stars so dense?

The hardness of a neutron star

Neutron stars are very small, with a diameter of 10 to 20 kilometers, which is a concentrated "little steel cannon".

Imagine a neutron star colliding with Earth, which is much less dense than a neutron star. How would it survive?

Which brings us to the main component of neutron stars, a mysterious particle called the neutron.

Neutrons are the key to the diversity of elements, so let's just say that without them, we'd have half as many atoms to work with.

The neutron is one of the most important parts of an atom. It has mass, but it has no charge. It sits in the nucleus with protons.

Because it has no charge, the proton will not repel it and will even allow multiple neutrons to stay in the nucleus with it.

Thus, the same element can have different modes of neutrons, known as isotopes. The emergence of isotopes has enriched our understanding of elements and expanded atomic technology.

The principle of nuclear fission, for example, uses isotopes of heavy atoms, such as uranium-234, uranium-235 and uranium-238.

When particles collide with each other, they emit neutrons, which are the main source of radiation.

Therefore, a neutron star is a body filled with radiation.

Astronomers believe that the neutron star is divided into two parts, the outer shell and the inner core, especially the inner core, are the densest parts of the object, and the neutrons here even form a "fluid".

This gives birth to a dish at the core of neutron stars -- nuclear pasta.

Nuclear pasta is not real pasta, but a hypothesis that astronomers have drawn to better explain the inner structure of neutron stars.

Scientists think the neutrons in a neutron star's core are grouped together like dough.

Such a structure gives the neutron star great toughness, allowing it to withstand all the collisions in the universe.

It is no exaggeration to say that apart from black holes destroying neutron stars, ordinary astronomical phenomena, such as gamma rays and high-energy particle beams, cannot do anything about neutron stars.

If it's still hard to imagine how hard a neutron star really is, compare it to steel, a hard substance found on Earth, which is 10 billion times harder.

No wonder the inner core pasta of neutron stars is one of the most difficult dishes in the universe.

And this hard dish, it sends out pulses of propaganda for itself. Neutrons are the cause of radiation, and neutron stars composed of neutrons are naturally a huge source of radiation.

Neutron stars that emit pulses of radiation are called pulsars.

However, some neutron stars are unable to produce pulses, this is because different neutron stars produce different radiation energy, electromagnetic waves have different frequencies, not every electromagnetic wave can produce pulses.

Therefore, most of the neutron stars discovered by humans are pulsars.

Discover neutron stars

In theory, neutron stars can be seen by telescopes because of the visible light in the electromagnetic waves they produce.

But it is radio telescopes that have found the most neutron stars.

In other words, instead of seeing a neutron star, one hears a neutron star.

Because neutron stars emit only a small fraction of the electromagnetic waves that are visible, while stars in the universe emit most of the electromagnetic waves that are visible.

The star's light obscures the neutron star, so telescopes don't see many of them.

Pulsars, however, emit pulses that are easy for radio telescopes to detect by picking up pulses in space. Pulsars are a type of neutron star.

The world's most efficient pulsar discovery is China's FAST Sky telescope, which is also the world's largest aperture radio telescope.

From commissioning to 2022. The number of pulsars discovered by FAST Eye has reached more than 660, which is of great significance for the study of neutron stars.

Unfortunately, our understanding of neutron stars does not fully penetrate the core, and the true structure of the nuclear pasta is not known, which is currently limited to hypothetical models.

If we are lucky enough to find the real version of this "hard dish", it will push the whole universe "menu" update.

Study the significance of neutron stars

Scientists also hope to find four neutron structures inside neutron stars, a structure known as "element zero" that Miguel Marc of Lyon, France, came across during an experiment.

This is the only time in human history, and scientists have tried many ways since then, but have not been able to get a structure like the four-neutron.

Some scientists believe that it is nonsense to think of forming atoms without protons, and that four neutrons may never exist.

But Miguel Mark was convinced that the quadron structure must exist, but that it would upend our understanding of atoms.

Maybe it's in a neutron star, or maybe the nuclear pasta is a kind of four-neutron.

If humans want to know the true identity of nuclear pasta, they have to really "taste" it.

But getting close to a neutron star is a very dangerous business. It's not as all-consuming as a black hole, but its gravitational pull is strong enough to tear apart anything that comes close.

If it could be applied, it would be a perfect gravitational slingshot.

Voyager 1 and Voyager 2 used the gravitational pull of Jupiter and Saturn to add their speed to the third cosmic velocity.

If we could use a neutron star as a gravitational slingshot, we might be able to speed up to the fourth universe speed, so that we could one day leave the galaxy.