The Most Dangerous Stuff In The Universe - Strange Matter
Neutron stars are the densest things that are not black holes. In the cores of neutrons stars, we might find the most dangerous substance in existence: strange matter. A neutron star is what remains after a very massive star explodes in a supernova and collapses under its own gravity with such a strong inward force that it squeezes nuclei and particles together violently.
Electrons are pushed into protons and converted into neutrons. All the empty space in atoms is suddenly completely filled with particles that don't want to be close to each other but have no choice. The atoms then desperately push back against gravity. If gravity wins, they will become a black hole. If they win, they will become a neutron star. This makes neutron stars like giant atomic nuclei, the size of a city but holding the mass of our sun.
All electrons, protons, and neutrons consist of quarks. Inside a neutron star core, protons and neutrons could melt into a sort of bath of quarks due to extreme pressure. If the pressure is great enough, some of the quarks may be converted into strange quarks. Strange quarks could have bizarre nuclear properties and make up strange matter. Strange matter might be the ideal state of matter, perfectly dense, stable, and indestructible and could be more stable than any matter in the universe.
Strange matter could even exist without the extreme pressure found in a neutron star. If this is the case, it could be very infectious. Protons and neutrons that come into contact with strange matter could also become strange matter. All of this strange matter is inside a neutron star except when neutron stars collide with other neutron stars or black holes. When a neutron star collides with another neutron star or black hole, it spews out tremendous amounts of its inside which might include little droplets of strange matter called strangelets.
Strangelets could be as dense as the core of a neutron star and could be very small, maybe even subatomic. These strangelets would then drift through the galaxy for millions or billions of years until they meet a star or a planet by chance.
If one were to strike the earth, it would immediately start converting it into strange matter, and ultimately, all of the atoms making up the earth would be converted into strange matter. Earth would then become a hot clump of strange matter, the size of an asteroid. If a strangelet strikes the sun, it would collapse into a strange star, eating through it like fire through a dry forest. This would not change the sun's mass much but would become way less bright and could freeze the earth to death.
Like a tiny virus, we would have no way to see a strangelet coming. Some theories even suggest that strangelets are more than common, outnumbering all stars in the galaxy and could be the dark matter that we suspect holds galaxies together. However, we must also keep in mind that all of this is hypothetical and could not be true. Scientists are still looking for evidence of strange matter.