The text describes the life cycle of a star, from its creation to its death and transformation into a neutron star. Stars are formed when the mass of millions of billions of trillions of tons of hot plasma is pulled inwards by gravity, causing nuclei to fuse. This fusion process releases energy that pushes against gravity, maintaining the star's stability. However, when the hydrogen in the star is exhausted, it undergoes a series of nuclear reactions, fusing heavier and heavier elements. This process continues until iron is nuclear ash, at which point the fusion suddenly stops, and the core is crushed by the enormous weight of the star above it. This implosion creates a shock wave that explodes outwards, catapulting the rest of the star into space. This is what we call a supernova explosion, which outshines entire galaxies. What remains of the star is now a neutron star, its mass is around a million times the mass of the earth but compressed to an object about 25 kilometers wide. It's so dense that the mass of all living humans would fit into one cubic centimeter of neutron star matter. From the outside, a neutron star is unbelievably extreme, with gravity the strongest outside black holes. Its surfaces reach a million degrees Celsius compared to a measly 6000 degrees for our sun. The text also mentions that when neutron stars first collapse they begin to spin very fast, creating pulses because their magnetic field creates a beam of radio waves. These radio pulsars are the best known type of
1. Neutron stars are one of the most extreme and violent things in the universe.
2. They are giant atomic nuclei, only a few kilometers in diameter but as massive as stars.
3. They owe their existence to the death of something majestic.
4. Stars exist because of a fragile balance.
5. The mass of millions of billions of trillions of tons of hot plasma is being pulled inwards by gravity and squeezed together with so much force that nuclei fuse.
6. Hydrogen fuses into helium, releasing energy which pushes against gravity and tries to escape as long as this balance exists, stars are pretty stable.
7. Eventually, the hydrogen will be exhausted.
8. Medium stars like our sun go through a giant phase where they burn helium into carbon and oxygen before they eventually turn into white dwarfs.
9. But in stars many times the mass of our sun, things get interesting when the helium is exhausted.
10. For a moment, the balance of pressure and radiation tips and gravity winds squeeze the star tighter than before.
11. The core burns hotter and faster while the outer layers of the stars swell by hundreds of times fusing heavier and heavier elements.
12. Carbon burns to neon in centuries, neon to oxygen in a year, oxygen to silicon in months, and silicon to iron in a day.
13. And then death. Iron is nuclear ash, it has no energy to give and cannot be fused.
14. The fusion suddenly stops and the balance ends.
15. Without the outward pressure from fusion, the core is crushed by the enormous weight of the star above it.
16. What happens now is awesome and scary.
17. Particles like electrons and protons really don't want to be near each other, but the pressure of the collapsing star is so great that electrons and protons fuse into neutrons.
18. An iron ball the size of the earth is squeezed into a ball of pure nuclear matter the size of a city.
19. It's so dense that the mass of all living humans would fit into one cubic centimeter of neutron star matter.
20. That's roughly a billion tonnes in a space the size of a sugar cube.
21. From the outside, a neutron star is unbelievably extreme. Its gravity is the strongest outside black holes and if it were any denser, it would become one.
22. Light is bent around it meaning you can see the front and parts of the back.
23. Their surfaces reach a million degrees celsius compared to a measly 6000 degrees for our sun.
24. When neutron stars first collapse, they begin to spin very very fast like a ballerina pulling her arms in.
25. Neutron stars are celestial ballerinas spinning many times per second.
26. This creates pulses because their magnetic field creates a beam of radio waves which passes every time they spin.
27. These radio pulsars are the best known type of neutron star about 2 000 are known of in the milky way.
28. These magnetic fields are the strongest in the universe a quadrillion times stronger than earth's after they're born.
29. But the absolute best kind of neutron stars are friends with other neutron stars.
30. By radiating away energy as gravitational waves ripples and space time their orbits can decay and they can crash into and kill each other in a kill and over explosion that spews out a lot of their guards.
31. When they do, the conditions become so extreme that for a moment heavy nuclei are made again.
32. It's not fusion putting nuclei together this time but heavy neutron-rich matter falling apart and reassembling.
33. Only very recently we've learned that this is probably the origin of most of the heavy elements in the universe like gold, uranium, and platinum and dozens more.
34. So then our two neutron stars collapse and become a black hole dying yet again.
35. Not only do stars have to die to create elements, they have to die twice over millions of years these atoms will mix back into the galaxy but some of them end up in a cloud which gravity pulls together to form stars and planets.
36. Repeating the cycle.
37. Our solar system