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What sonic black holes say about real ones

quantamagazine.org

31–33 of 33 posts

Re: What sonic black holes say about real ones

#31
post #28

My current question about black holes is: It is usually reported that the electron is a dimensionless point, with no extent. But it has mass. Why is it not, then, a black hole? A black hole with the mass of an electron would have an event horizon, which is not a dimensionless point. If it is a black hole, how does the charge "get out" to affect the outside world? If a black hole were given a charge, e.g. by injecting…

> dimensionless point

According to QM. Electrons/positrons aren't a particle but much closer to a probability cloud.

Black holes are fundamentally modified space time. So much, much different than particles.

> A black hole with the mass of an electron would have an event horizon, which is not a dimensionless point. If it is a black hole, how does the charge "get out" to affect the outside world?

Charge is one of few properties that black holes preserve.

> If the electron and positron are both dimensionless points, yet somehow not black holes, how do their paths ever succeed in intersecting?

Same way two clouds interact. No black holes necessary. Analogy isn't perfect. Two interacting clouds don't obliterate instantly to produce different clouds.

Re: What sonic black holes say about real ones

#32
post #20
post #5

Is there a good word that describes the somewhat uncomfortable feeling one gets in their stomach when thinking about the magnitude and complexity of reality? Is humbled a feeling? I can't thinking of anything good in English, wondering if any other languages have this word (like how Saudade is in Portuguese)

terrible beauty

fearful symmetry

Re: What sonic black holes say about real ones

#33
post #28

My current question about black holes is: It is usually reported that the electron is a dimensionless point, with no extent. But it has mass. Why is it not, then, a black hole? A black hole with the mass of an electron would have an event horizon, which is not a dimensionless point. If it is a black hole, how does the charge "get out" to affect the outside world? If a black hole were given a charge, e.g. by injecting…

Think of a black hole as [edit] a region of [/edit] the entire universe curling 'up' to an edge. Nothing within the universe escapes the edge, but the curl of spacetime has a way of pulling additional matter-energy into it.
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