The Black Hole Entropy Enigma

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Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Luke Maroldi
Assistant Editing and Sound Design by Mike Petrow

Black Holes should have no entropy, but they in fact hold most of the entropy in the universe. Let’s figure this out.

If black holes exist – which, apparently, they do – they contradict other theories in physics as sacred as general relativity. They cause all sorts of problems with quantum theory, which we’ve talked about and will review in a sec. But they also present an apparent conflict with the notion of entropy and the second law of thermodynamics. It was while pondering that conflict that Jacob Bekenstein realized an incredible connection between black holes and thermodynamics. His insight launched an entire new way of thinking about the universe in terms of information theory, and ultimately led to the holographic principle. Which I promise we’re getting to and we’re almost there. We just need to understand string theory first and to understand that, you’re going need to know about why Black Holes contain most of the universe’s entropy.

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سلطان الخليفي

[wabznasm]

"Let's figure this out" nah mate you go on ahead, I'll wait here and nod if I hear a word I know.

[michaelriley]

Anytime I'm feeling too smart, I come here to be humbled.

[Mritunes]

I know this proably won't be read, but I want to thank you guys for putting these videos out. Physics is one of my favorite subjects and has inspired me to study physics in college. So thank you guys for the great videos, and keep them coming
. :)

[painzockt]

Quantum information is stored in the balls.

[michaelblacktree]

So that's where the holographic universe theory came from. Thanks for explaining.

So many other YouTube channels feel like they're sucking IQ points out of my brain. I come to PBS Space Time to get them back. 👍

[VA-phml]

2nd law of thermodynamics, do not talk about thermodynamics.

[guanche]

Holy shit.. I had a "Holy Shit" moment seeing how the holographic principle could make sense.. Thanks for going in (casual-conceptual) depth!

[robertcaracuda]

Great video, as always.
You made this channel something amazing and unique.
Lots of love, keep the great work up.

[dWHOHWb]

Oh, was just about to go to sleep

It can wait

[AlexDesise]

I consider myself to be a somewhat intelligent person. I'm not a genius nor am I dull but every time I try to attempt to follow these videos I get lost after about 20 seconds. I feel like a total moron but would still like to thank the PBS team for these videos. They are highly informational and what pieces I can comprehend are very well explained and produced.

[JoshuaHillerup]

Wait, can you go back and explain how you can reduce the mass and radius of a black hole without reducing the surface area?

[jamesaltonfilms]

Who is the designer of all the typesetting, animations and colour sequences? They're absolutely stunning!

[DoryenChin]

The whole idea that black holes can only have mass spin and charge makes them sound a lot like quantum particles

[epocfeal]

The definitions of entropy had been hammered into my brain for the last 2 episodes and then a lot of things were just casually thrown out at the end leaving me with one big "wait... What?"

[cyanideghost]

I really love your videos, always look forward to watching them, thank you and everyone involved in making it happen.

[MrSpikegee]

The idea that even black holes cannot destroy information is comforting. It helps me to know that my loving mother will always exist, encoded in the universe particles and fields quantum states.

[garavonhoiwkenzoiber]

I UNDERSTAND quantum mechanics...
but " 'T Hooft. "
that's where I draw the line buddy!

[mantisproductions]

Fucking love this channel. Thank you for existing, everyone who is a part of making this channel

[alessandrocapurso]

if we see spacetime not in 3D space + 1D time, but as a 4D Hypersphere quantised on Plank Units, with 2D "Real plane" Space (kind of holographic hypersphere surface expanding that bends according to mass) and 2D Imaginary plane of time, it all seems to make sense, from quantum to relativity... We can consider, as "axes" of time, an Absolute Time of "evolution of the universe" (iT, a kind of tick as the Plank Time perpendicular to the Real plane) and a local time of "quantum blurriness" as e^(it), that we perceive as third spacial dimension developing linearly e^(it)... then a universe of possibilities could start evolving... considering elementary forces particles as vibration "shifted in time" relatively to the surface (maybe the famous string theory extra dimensions :) even the "un-existence" of magnet mono-poles or quark mass could be explained and black holes and dark matter figured out... The local time maybe could also be called free will ;-)

[llcn]

I love the new aesthetic of your graphics!

Keep up the good work. This is one of my favourite channels on YouTube.