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  • So admittedly, we don't have a lot of concrete information about black holes.

  • We have a lot of ideas, but we've mostly been quite literally shooting in the dark

  • when it comes to figuring out what would happen if you went in one.

  • Now, some theoretical revelations open up a new line of thinking, and all I can say

  • is whooo boy here we go--black holes and string theory, time to rock'n'roll!

  • Let's review the pieces: black holes are objects in space that are seemingly infinitely

  • dense and swallow everything, including all kinds of radiation, including visible light.

  • Past their event horizon, or the point past which you can't escape their pull, they're

  • so dense they seem to warp gravity.

  • And theoretically, they have a point inside them called their gravitational singularity:

  • the point where that density coalesces into its infinite-ness and space and time as we

  • know them no longer exist.

  • Ok, casual.

  • Then we have string theory, which unifies our conflicting understandings of the quantum

  • world and gravity.

  • In the string theory, the particles we think make up the standard model of physics are

  • actually all just the same kind of string, vibrating at different resonances to give

  • each 'particle-like entity' its unique characteristics.

  • Black holes are also gravitational puzzles, so string theory seems like a natural fit

  • for helping us understand how they work.

  • Because that's the thing about black hole singularities, too.

  • The point at which time and space cease to exist has obviously never been physically

  • observed, it's just the point at which our math breaks down.

  • Which is also the point where we start to identify paradoxes presented by black holes,

  • and the many theories that set out to resolve those paradoxes...start to get a little wild.

  • We're still constrained by the math we DO have.

  • The way we primarily try to describe the physics of the world is through the laws of conservation,

  • things that can neither be created nor destroyed under the conventional laws of the observable

  • universe...like information.

  • In this context, information means quantum information--the characteristics of a particle

  • that make it what it is.

  • Its fingerprint, if you will.

  • And black holes, those tricky guys, present problems because they seem to subvert at least

  • one of these--the law of conservation of information.

  • Resulting in the information paradox, first put forward by Stephen Hawking.

  • See, black holes are supposed to swallow everything that gets too close because they're so dense,

  • but Hawking showed that they're also radiating energy.

  • This thermal radiation, which we now call Hawking radiation, means black holes could

  • eventually waste away to nothing, radiating out all the energy and matter that went into

  • them....but none of this matter would contain its original information, meaning all that

  • information is just gone forever, violating that law of conservation.

  • And this leads to many fun lines of inquiry.

  • Since black holes were discovered in 1916, physicists have been trying to figure out

  • what would happen if you went in one, like with your human body.

  • Y'know, 'cause they're quirky like that.

  • Theorists a few years back put forward a new idea that actually resulted in the identification

  • of another related paradox.

  • The prevailing idea has been the 'no drama' theory, where if you're an astronaut who

  • crosses the event horizon of a black hole, you wouldn't notice.

  • Until you reach the singularity, that is, and you are quite suddenly 'spaghettified'

  • by the impossibly intense gravitational pull.

  • Which sounds very pleasant indeed.

  • But then where did you go?

  • To try and rectify the information paradox, physicists have put forward a newer, more

  • dramatic theory about what happens to you--the firewall.

  • They argue that you, the astronaut, must be incinerated as you pass the event horizon

  • and that's how your information is conserved.

  • Cue the fuzzball.

  • By replacing the particles in a black hole with strings, you get a theoretical black

  • hole model called...a fuzzball.

  • Very scientific.

  • Instead of the membrane of an event horizon, past which you'd get pulled into a point

  • of infinite density, the fuzzball model has no event horizon, and no singularity.

  • It's...a fuzzy ball.

  • A tangled ball of strings that looks a little more like a planet than our current typical

  • imaginings of a black hole.

  • And those strings, vibrating with the possibilities of multiple dimensions, make up a hot, vibrating

  • extremely dense mass that would incinerate you on impact.

  • This is where the string theory fuzzball model of black holes and the relatively new firewall

  • paradox meet and may have common ground--some theorists think the firewall is the hot fuzzball.

  • And are very put out that it took the rest of the physics community so long to catch

  • up.

  • But here's the thing.

  • All of this is conjecture.

  • Big conversations are still happening in the physics community about how to think about

  • black holes and the many problems they pose.

  • String theory is still just a theory.

  • And the applications of string theory in this particular case are very general--in any of

  • these models, we still don't have any clear way that the information of that astronaut

  • entering a black hole is conserved and then recycled...but string theory is a fun--and

  • useful--voice in the loud symphony that is theoretical astrophysics.

  • While we're speaking, scientists are hard at work taking the first photo of a black

  • hole that would totally change the way we think about all of this.

  • So where's the photo, you ask?

  • We've got a video all about that here.

  • Don't forget to subscribe to seeker for all your black hole needs, and I'll see

  • you next time on Seeker.

So admittedly, we don't have a lot of concrete information about black holes.

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B2 中上級

ホーキング博士のブラックホールのパラドックスはファズボールで解決できるのか? (Can Hawking’s Black Hole Paradox Be Solved With Fuzzballs?)

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    林宜悉 に公開 2021 年 01 月 14 日
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