Neutron stars are one of the
most extreme things in the universe. They’re like giant atom cores. Kilometers in diameter,
unbelievably dense and violent. But how can something
like this even exist? The life of a star is dominated
by two forces being in balance. Its own gravity and the radiation
pressure of its fusion reaction. In the core of stars, hydrogen
is fused into helium. Eventually, the hydrogen
in the core is exhausted. If the star is massive enough,
helium is now fused into carbon. The cores of these massive
stars become layered like onions, as heavier and heavier atomic
nuclei build up at the center. Carbon is fused into neon, which leads
to oxygen, which leads to silicon. Eventually, the fusion reaction hits iron,
which cannot fuse into another element. When the fusion stops, the
radiation pressure drops rapidly. The star is no longer in balance, and if its core mass exceeds
about 1.4 solar masses, a catastrophic collapse takes place. The outer part of the core reaches
velocities of up to 70,000 km/s, as it collapses towards
the center of the star. Now, only the fundamental
forces inside an atom are left to fight the
gravitational collapse. The quantum-mechanical repulsion
of electrons is overcome, and electrons and protons
fuse into neutrons packed as densely as an atomic nucleus. The outer layers of the star
are catapulted into space in a violent supernova explosion. So, now we have a neutron star! Its mass is between 1 and 3 Suns, but compressed to an object
about 25 kilometers wide! And 500,000 times the mass
of Earth, in this tiny ball that’s roughly the diameter of Manhattan. It’s so dense that one cubic
centimeter of neutron star contains the same mass as an
iron cube 700 meters across. That’s roughly 1 billion tons,
as massive as Mount Everest, in a space the size of a sugar cube. Neutron star gravity
is pretty impressive too! If you were to drop an object from
1 meter over the surface, it would hit the star in one microsecond
and accelerate up to 7.2 million km/h. The surface is superflat, with
irregularities of 5 millimeters maximum, with a superthin atmosphere of hot plasma. The surface temperature
is about 1 million kelvin, compared to 5,800 kelvin for our Sun. Let’s look inside the neutron star! The crust is extremely hard
and is most likely made of an iron atom nuclei lattice with a sea
of electrons flowing through them. The closer we get to the core, the more
neutrons and the fewer protons we see until there’s just an incredibly dense
soup of indistinguishable neutrons. The cores of neutron stars
are very, very weird. We are not sure what their properties are,
but our closest guess is superfluid neutron degenerate matter or some kind of ultradense quark
matter called quark-gluon plasma. That does not make any sense
in the traditional way and can only exist in such an
ultraextreme environment. In many ways, a neutron star
is similar to a giant atom core. The most important difference is that atom
cores are held together by strong interaction
and neutron stars by gravity. As if all this wasn’t extreme enough, let’s take a look at
a few other properties. Neutron stars spin very, very fast,
young ones several times per second. And if there’s a poor star nearby
to feed the neutron star, it can rotate up to several
hundred times per second. Like the object PSRJ1748-2446ad. It spins at approximately
252 million km/h. This is so fast that the star has
a rather strange shape. We call these objects pulsars, because
they emit a strong radio signal. And the magnetic field of a neutron star is roughly 8 trillion times stronger
than the magnetic field of Earth. So strong that atoms get bent
when they enter its influence. Okay, I think we got the point across. Neutron stars are some
of the most extreme, but also some of the
coolest objects in the universe. Hopefully, we will one day send spaceships
to learn more about them and take some neat pictures! But we shouldn’t get too close! Subtitles by the Amara.org community
You guys didn't mention that Neutron Stars can experience starquakes
It sounds like an awful sci-fi movie, but the whole concept of it blows my mind. Neutron stars are like a physics problem on a test taken to the extreme.
One small error in the video. In mentioning pulsars and their radio emissions, it was depicted as going out everywhere. In actuality, the pulse is leakage from the magnetic poles. Since most often the magnetic poles don't line up with the rotational poles, you will have the off center pulse sweeping certain parts of the sky, and if someone (like Earth) is in that direction, we see the pulse of radiation.
Thanks for sharing! This channel seems to have a lot of great videos
Neutron stars are awesome. If anyone's interested, Dragon's Egg is a sci-fi novel about life evolving on a neutron star, pretty interesting concept.
Such amazing stuff. It really amazes me we can figure out all of this stuff without even having been there.
They didn't even mention some of the crazy general relativity type effects neutron stars have. Like how the really compact ones can support (unstable) orbitals for photons, and the spin causes Frame-dragging.
Read a couple of articles on them now and they seem so interesting yet quite rare. Is this true? How many have we observed in the milky way. Do scientists think beatulguies will become a neutron star when it goes supernova?
For the Doctor Who fans out there they like to hide little TARDISs (tardi?) throughout their videos.
For how colorful the video is, it sure is grim.
Poor bird and space shuttle.