what does “preservation of information” mean?

191 views

I recently watched a video that explained how, previously, the opinion was that falling into a black-hole meant one would be stretched and torn. Never to recover.

But a newer, more sophisticated, understanding is that there is a “preservation of information”, to the effect that were an advanced race to collect all the materials from a blackhole and somehow analyse them you could, in theory, be brought back.

This was referred to as a “preservation of information.” What on earth is “information”? I can’t seem to find any literature on this because I don’t really even know what I’m searching for.

Here’s a link to the video: https://www.youtube.com/shorts/4Wac52-NYNI

In: 1

2 Answers

Anonymous 0 Comments

This is the [Black Hole Information paradox](https://en.wikipedia.org/wiki/Black_hole_information_paradox), if you wanted to do some more reading

‘Information’ here means ‘anything you could measure about something’. Height, length, width, mass, electric charge, velocity, rotation, brightness, etc, etc, etc.

Think about the sun. It’s a giant ball of fusion, that’s emitting all sorts of radiation all the time. That radiation is ‘information’, which we can measure, and use to figure stuff out about the sun, like what it’s made of (mostly hydrogen, bit of helium, and a tiny bit of other). If you fell into the sun, we could (very theoretically) measure the tiniest change in that ‘other’, so ‘information’ about you is ‘preserved’.

According to the theory of relativity, nothing can come out of a black hole. If you fall into one, you’re never coming out, nor is any ‘information’ about you (see the [No-hair theorem](https://en.wikipedia.org/wiki/No-hair_theorem)). So, under our traditional understanding, the information about you is destroyed.

Now, why we’re moving away from the traditional understanding is waaaay beyond ELI5, but those wiki articles should be a good entry point if you wanted to dive in

You are viewing 1 out of 2 answers, click here to view all answers.