Physical Inquiries

Originally posted by Arbitrageur
The snake observation example is another one. He gives an excellent illustration of a problem, looking at a snake crawl by a slit and not seeing the whole thing. But instead of coming to the conclusion I do, which is these are separate observations which we must assemble to form a picture of what we are looking at, he comes to the opposite conclusion: that they are NOT separate observations. What he means to say is we are looking at the same snake, I think, but it seems like he confuses it being the same snake with being the same observation, they are not the same observation but different observations of the same thing which is totally different to me. But he's speaking as a philosopher, and not as a scientist, so I have to give him some latitude and try to figure out what he means, and stop focusing on what he actually says, which doesn't always make good sense to me. When I focus on his meaning and intent instead, it's easier to listen to.

I'd rather read some good books by Carl Sagan.

Ha – yes, I'd much rather listen to Carl Sagan too!

I thought the snake was an interesting example though. I don't think calling them "separate observations" deals with the problem he's referring to, which is that we receive, through our senses, a stream of information that we interpret as events, and we infer some kind of causality into that. If event B regularly happens after event A, we tend to interpret that as a cause. This is part of human nature.

I don't agree with him when he seems to be using this as a way of saying there isn't really any causality, though, that does seem a bit silly. Some events consistently happen after each other, such as a football match starting after a football fan turns on the tv, or night following daylight, but the second event isn't caused by the first. The snake example is a bit like this. The fact that some things don't cause others doesn't mean you can dismiss causality.

Also the fact that some things have arbitrary definitions doesn't mean you can't make useful definitions of them and then use those definitions to say very precise and very profound things about the world. Who cares if you can define an event in all sorts of ways? Just choose one that you can work with, and work with it.

But I quite like his way of getting people thinking.

(So long as people do actually think, that is)

I have lost track of where I was talking about information escaping from a black hole(whether through HR or whatever), and thought I would add this article to this thread:

Cosmologists Discover How Black Holes Can Leak

Originally posted by beebs
Cosmologists Discover How Black Holes Can Leak

Interesting, but I don't see what they call a problem as a problem:

That could help solve an old problem. One of the big puzzles in black hole physics is what happens to information once it enters a black hole. The conventional view is that information cannot be destroyed and so must be recovered somehow.

I never said the information is destroyed once it enters the black hole ( I don't know if it is or not).

All I said is the information about what's inside the black hole can't be retrieved from outside the black hole.

One possibility is, that just inside the event horizon, the information might not be destroyed yet such that an observer just inside the event horizon could still observe information about what is entering the black hole. So in this case the information isn't destroyed, it's just a matter of where the information can be accessed.

But at some point I expect the atomic structure to collapse.

In any case, I've been reading these highly speculative theories by string theorists (or more recently m-theorists) for many years and while they are interesting, none of them ever seem to have a shred of evidence to back them up, so I have no way to judge if they might be real concepts, or complete fantasy.

You can do things mathematically, that may not be possible in the real world (like taking the square root of negative 1 for example). As far as I can tell these theories are purely in the mathematical realm until there's any evidence to the contrary.

I even needed to see evidence of black holes before I was convinced, but now that I've seen massive stars orbiting what looks like an empty point in space, I find the evidence persuasive that there's a mass there the stars are orbiting and the reason we can't detect any emissions from it is that it's a black hole.

Similarly, I need to see evidence these m-theories are real before I can tell if they are a fairy tale or reality. Right now I don't know which is true and I don't think anyone else really knows either unless they've seen evidence I haven't.