3 ms·
Black holes in general are much smaller than people think. The event horizon of a 10 solar mass black hole is only something like 12 km across. That’s basically
by wayoutthere 5y ago
Black holes in general are much smaller than people think. The event horizon of a 10 solar mass black hole is only something like 12 km across. That’s basically the head of a pin at space scale.
Supermassive black holes are on a whole different level however.
- lrem 5y agoThe most mind-boggling bit is the inverse relation between mass and density. Quoting[1]: > A black hole of 387 million solar masses would have the average density of water and would be comparable to a giant water balloon extending from the sun almost to Jupiter. [1]: https://arxiv.org/abs/1312.0340 https://arxiv.org/abs/1312.0340
- piyh 5y agoA sphere of water extending to the orbit of Jupiter is a LOT of water.
- sneak 5y agoAverage density. What would the density be within the orbit of Mercury?
- lrem 5y agoBy nature of black holes: we don't know. For us it is pretty much a mass removed from this universe. For all we know, it has the average density everywhere. But the currently prevalent theory posits the density of the volume of the black hole is actually zero, with all the mass in a single point (singularity).
- sneak 5y agoInteresting! Thank you for explaining.
- tejtm 5y agoIf the event horizon of a 5-earth BH hole is several inches across as the paper states then doubling the mass/volume of said sphere would less than double the radius methinks ... maybe the figure is 12cm?