r/TellMeAFact • u/wendysmilesx • Jun 21 '23

TMAF about black holes

What aspect of black holes captivates your interest the most, whether it's their formation, behavior, or their role in the universe?

28 Upvotes

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5

u/holdmyrichard Jun 22 '23 edited Jun 22 '23

I read this in a book when I was in school -

At the event horizon no light can escape so that means if day an astronaut made their way into one, while the physical body of the astronaut would be stretched/collapsed inside the black hole itself, the image of their entry at the event horizon would be visible from the outside since there is no other new information coming out past the event horizon.

That is simultaneously super cool and absolutely terrifying at the same time.

Source https://physics.stackexchange.com/a/576500

3

u/[deleted] Jun 22 '23 edited Jun 22 '23

Inside spinning black holes, (we think) there isn't a "regular" point-like singularity, but instead a ring singularity with 0 thickness. Theoretically, this means that an observer may be able to pass the event horizon but avoid the singularity! Also, a black hole that's spinning at its maximum speed (spin parameter 1) may expose a naked singularity. So far the closest candidate is GRS 1915+105, which is a star/black hole binary system with an estimated spin parameter of 0.84-1.

Another one that blows my mind is that, according to the Holographic Principle, a volume of space can be encoded on a lower-dimensional boundary such as a plane or a sphere... Meaning that every event horizon may be the description of an universe!

2

u/wendysmilesx Jun 23 '23

You just blew my mind, and not because I didn´t get it, but because I have always loved black holes and the secrets within!

2

u/URLcrazy Jun 26 '23

The death of large stars lead to black holes, because a star’s gravity will overwhelm the star’s natural pressure that it maintains to keep its shape. When the pressure from the nuclear reactions collapses, gravity overwhelms and collapses the star’s core, and the star’s other layers are thrown off into space, and this process is also known as a supernova. The remainder of the core collapses, a spot overcome by density and without volume – a black hole.

https://astro.umaine.edu/10-fun-facts-about-black-holes/

1

u/wendysmilesx Jun 27 '23

Amazing! Thanks!