Gravastars are an alternate theory to black holes. The theory of a gravastar goes as such.
A star begins to implode on itself. However, instead of the core condensing into a singularity, forming a black hole, the center of the dying star is ground down to pure energy and wants to expand. These two forces meet, essentially making the immovable object meeting an unstoppable force scenario. These extreme pressures then form an extremely thin shell that is significantly stronger than is currently comprehensible.
This shell would be so thin that atoms would look enormous compared to it and it would be made from a substance completely unknown, and so cold, the coldness of space around would appear to radiate heat. The most amazing part, however, is the inside.
The force in the gravastar during its formation would make the inside of it almost like a mini- universe. In the gravastar would be the same energy or force that makes our universe constantly expanding. However, gravastars are completely empty, including of waves, meaning inside one there is no light, heat, or otherwise. The vacuum can be thought of like an ocean, and particles like waves; ripples can’t be put through it without other waves, but the fluid still exists without those waves, while also still having energy.
When the gravastar is formed, it is like it is pumped full of as much vacuum as physically possible. So much so that inside the gravastar is 1044 as much vacuum energy as everywhere else in the universe. Another model suggests that for gravastars to be able to exist they might be formed in pods, with layers of gravastars with energy between them.
It is hypothesized that the average gravastar would be about the size of London in diameter, but have the mass of ten suns. If you were to get caught in a gravastar, your body would be torn to shreds before you even touched the shell, and when you did your atoms would break down and dissolve completely and be converted into the vacuum energy inside, making the gravastar ever so slightly larger and ever so slightly more massive.
One possible way to figure out if black holes or gravastars exist, assuming only one of them does, would be to listen to the “sound” they produce when two collide. Black holes colliding would make a loud smacking sound that would cease quickly like a bass drum, while gravastars would make a loud noise that makes smaller rings of echoes like a gong.
“Black Hole’s Evil Twin – Gravastars Explained.” Performance by Steve Taylor, Youtube, Brilliant, 3 Dec. 2024, https://www.youtube.com/watch?v=BmUZ2wp1lM8&t=26s. Accessed 2 Jan. 2025.
Koberlein, Brian. “Gravastars Are an Alternative Theory to Black Holes. Here’s What They’d Look Like.” Universe Today, universe today, 19 Feb. 2024, www.universetoday.com/165795/gravastars-are-an-alternative-theory-to-black-holes-heres-what-theyd-look-like/.
