How black holes could delete the universe - new explainer video


#1

Originally published at: http://boingboing.net/2017/08/24/how-black-holes-could-delete-t.html


#2

#3

I for one welcome our crushing singularity of oblivion.


#4

It’s about time the Universe took out the garbage.


#5

Could they start with Trump? Please?


#6

Which is the bigger void?


#7

Pet Peeve:

“If you were to fall into a black hole, nothing bad would happen to you until well after you crossed it’s outer border, the event horizon”.

“… so there’s no way of really telling what goes on inside black holes…”

If you allow yourself to assume contradictory things, you can assert anything. And if you basic your logic on speculation, you can end up anywhere. This video (and many like it) say a great many things that are, and likely will remain, pure speculation. Speculation is fine, but until you can confirm by experiment, it’s not science.

This sort of thing need a big disclaimer up front: This is a model, based on what we know. We have no actual experimental verification of most of it, and might never. Additionally, a ton of the things being discussed (like “information”, and what we “can” do) don’t match the normal definitions - In theory, information is never lost, because you can trace backwards from the charred paper in the example - but in practice, you sure as hell cannot.

Anyway - fine video, lacks rigor.


#8

It’s ten minutes long and aimed at the lay public. Kurzgesagt does a much better job than the vast majority of popular science content outlets. I would like to see them offer a further reading section in their video descriptions.


#9

I have never understood this idea that information can’t be destroyed. Why not? Chaos theory would seem to say the exact opposite - that information is lost when it is randomized, and this is irreversable. You can’t unshuffle a deck of cards, unless you start out with a list of the order of the cards, so you’re forced to input all of the missing information. Maxwell’s demon can’t work for free.

But I’ll admit I have an engineer’s definition of information, and I’ve never really understood quantum theory. Can anybody explain this in a way a monkey like me can understand?


#10

The short answer is that the value of a quantum state’s wave function at a given point in spacetime determines it’s value at every point. Basically, QM requires that the universe have a memory of its past states. As the entropy of a system increases, that memory can become increasingly “hidden”, but it can no more be destroyed than energy can, and in fact information and energy are equivalent for many purposes in physics. In a very real sense, the wave functions describing all the elementary particles in your scrambled deck of cards encodes their past states. If you had enough time, energy and computation, you could in theory figure out how it was ordered.


#11

But if you had enough energy, wouldn’t you vaporize the cards? I think that’s the whole point of the Uncertainty Principle. Also, sensitive dependence on initial conditions means the energy input increases very fast over small amounts of time, and noise very quickly overwhelms signal. A milliwatt of signal buried in a kilowatt of noise is still there, in theory, but extracting it is not only impractical, it is impossible.

Also, thanks.


#12

I’m not doing a great job of explaining this. I mostly just relied on the math in college and it’s one reason I’m not as good at teaching as I’d like to be. But here are some resources that might help a bit.


#13

Yea, that stuff makes my brain hurt.


#14

It’ll have to come out. (He said, both adding and removing information at the same time.)


#15

This topic was automatically closed after 5 days. New replies are no longer allowed.