Isn’t an event horizon just a question of being dense enough to bend light past the point of no escape?
A hollow planet supporting a detached core with enough density to have an event horizon seems kinda ridiculous… If even light can’t escape it, I don’t see some rocky ‘shell’ withstanding that much gravity. Any hollow section would have collapsed well before reaching the point of the planet’s densest point forming an event horizon.
What matters is the total mass of the black hole, not its density. If you replaced Earth’s core with a black hole of the same mass, the gravity you’d feel at the surface (or beneath the surface) would be the same. You’d only notice a difference if you were in the hollow region formed by removing the core.
The way I see it, the real problem with a planet like Earth is that because the inside is so hot, the inner parts are too soft to support their own weight, and the crust is probably too fragile to support its own weight. That’s not a problem, though, in an asteroid or a planet that’s solid all the way through.
Depending on the mass of the black hole, the “shell” doesn’t need to be a shell it could be effectively completely solid with an atom sized black hole at the centre.
PBH’s as discussed in this article have pretty wild mass ranges, so anything is possible. It’s entirely possible to have black holes so small they can’t easily absorb new matter as they’re smaller than protons. Tiny black holes only have large surface gravity, nothing noteworthy at a distance.
After more than a century of speculation, data seem to confirm that Betelgeuse (the brightest star in the Orion constellation, shown here) has a much smaller star as an orbital companion.
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Two independent studies found evidence of a star about the same mass as the sun, orbiting Betelgeuse about once every 2,100 days.
You got it wrong - the poster above is not trying to prove the astronomical phenomenon through a show, the poster is saying that the show itself (called Big Bang) is real. It’s simply a joke.
You can use a pinhole to project an image of the sun onto a sheet of paper but not directly as glasses. Look up a ‘pinhole projector’ you can make a pretty good one with an Amazon box.
I can’t see it anyway from my part of the world :( I was just curious because it doesn’t seem like it would be safe, but it was literally taught to me in elementary school.
Are you so deeply entrenched in modern technology that you cannot fathom that a human could comprehend and map future astronomical patterns?
Humans have been doing this since early records of humankind on earth. Loooooong before computers existed. Computers have only been around the last few decades.
IANAP, but isn’t universal expansion understood to be accelerating? How would “weakening forces of nature” account for that? Assuming this energy could be “lost” (breaking an even longer standing and well tested principle of physics), that loss wouldn’t accelerate anything. At best the speed would remain neutral.
The tired light theory is an alternative explanation to the red shift of distant light that says it’s not because distant objects are all moving away from us but instead that the light somehow loses energy as it travels, which lowers its frequency.
There was another alternate theory that suggested everything was shrinking instead of the universe expanding (thus wavelengths seem longer by the time they get to us).
Personally, I’m more “open to the idea” than “sold” for the idea of the universe’s accelerated expansion. I like theories that eliminate the need for dark matter or energy, especially given that the current ones requiring them assume that they make up 95% of everything. It just seems more likely that we don’t understand things as well as we do than to assume we’re right about everything we think but just need to add 19 times what’s already here to balance it all out.
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