Billions of years ago, when we Big Bang took place, the Universe was filled with quarks and gluons, the building blocks of atoms, protons, and neutrons.
But since the Universe was still too dense and excited, these couldn't combine, instead forming a quark-gluon plasma.
What a quark-gluon plasma looks like when it's not being crushed by the weight of several Suns - Brookhaven National Laboratory
Much much much more recently, scientists were able to recreate this plasma by smashing heavy atoms together. Now, scientists are suggesting gigantic stars also form this material when they explode, which would explain why we see so many different types of supernovae.
Physics has so far been able to explain a lot about supernovae, like how much mass they need to explode, and why there are different types. Unfortunately, it doesn't fit with the stellar explosions of much larger stars. For blue supergiants for instance, which are many times the Sun's mass, they just don't go boom.
It's not so much that they don't explode, they're just much more subdued when the lights go out. The exploding giant stars form a black hole so quickly that the shockwave from the blast itself is swallowed up. So, why can't the existing model explain that?
Well, the new paper suggests that it's to do with the instant a star dies, where critical events happen in the a fraction of a second. When the star's fusion reactions aren't able to balance out its gravitational pull anymore, it's iron-rich core collapses in on itself, crushing the atoms into an extremely hot and dense state. Possibly hot and dense enough to create a quark-gluon plasma.
During a supernova, mass many times the amount of our Sun is compressed into incredible densities of over 2.6 ¡Á 1014 grams per cubic centimeter. So the team simulated a star similar to the Sun, but with 50 times its mass, exploding. Once the core collapses, some of it bounces outward in a shockwave as a neutron star is formed. Normally that's where things end.
But in the new model, the core of the neutron star changes from individual neutrons to a quark-gluon material. This causes it to shrink suddenly, and produces a second shock wave at nearly the speed of light, blowing apart the rest of the star. All of this happens in about 10 seconds, after which you have a neutron star composed of unbound quarks and gluons.
The new theory also serves to explain why the types of supernovae among giant stars vary. If the star was unstable and its outer layers were ejected before exploding, then that material is hit by the shockwave and creates an extremely bright event. If the star was largely intact when it went boom, the explosion would be comparatively dim. And, with just the right situation, the matter blasted away can collapse onto the neutron star fast enough to block both shockwaves and directly make a black hole.