Could Black Holes Be Portals to Other Universes?

David Shiga writes "Astronomers have identified many objects out there that they think are black holes. But could they be portals to other universes called wormholes, instead? According to a new study by a pair of physicists, we wouldn't be able to tell the difference. They have discovered that wormholes with the right shape would look identical to black holes from the outside. But while a trip into a black hole would mean certain death, a wormhole might spit you out into a parallel universe with its own stars and planets. Exotic effects from quantum physics might produce wormholes naturally from collapsing stars, one of the physicist says, and they might even be produced in future particle accelerator experiments."

Comments

easy to test...

[pedantic bore]

... just send some probes through what seem to be black holes, and then see if any of them come back.

Oh, wait, there's another small problem to address first -- all the known black holes are a bajillion miles away. Maybe we should work on answering the question of how to get there before we start to obsess about what's on the other side. Or perhaps the multiverse is just teasing us, saying "Hey, there's a portal here to another universe -- want to see what's on the other side? Too bad you won't know for a few thousand years! Psych!"

Re:easy to test...

[aled]

all the known black holes are a bajillion miles away.

No problem, just find a wormhole to go there.

No need to get there

[Anonymous Coward]

Just look in the universe for places where material appears out of nowhere (if wormholes exist, some wormholes should have traffic from other universes to ours.)

Re:what would happen on the other side?

[radarsat1]

An additional question comes to mind: If black holes have an event horizon beyond which no matter can return, and there is a wormhole with a black hole on each side, then if you went into the black hole and try to get out the other side, you'd find that you're behind the other black hole's event horizon and are unable to escape. So... you'd be in a tunnel from which there is no escape. So... you'd stick in a wormhole... which doesn't seem all that different from a black hole... what was the point of this thought experiment again?

Perhaps wormholes just don't exist then.

I think the thing that differentiates worm holes from black holes is that they DON'T shrink to a singularity, but instead attach to a hole on the other side of the universe through a tunnel that has a finite radius. So they're not the same thing... the difference between having a singularity and NOT having a singularity is pretty staggering. Is the point of the article just trying to say that wormholes have an event horizon?

If this were true...

[AbsoluteXyro]

If this were true... Shouldn't we see some black holes spitting out extradimensional spaghetti noodles?

No event horizon

[suv4x4]

The article claims, that unlike a black hole, a "wormhole" (in the sense they explain it) has no event horizon. If it has no event horizon, it means light can escape it.

So it wouldn't look like a black hole AT ALL. I call bullshit on the whole article.

Re:No event horizon

[Ambitwistor]

So it wouldn't look like a black hole AT ALL. I call bullshit on the whole article. I think you may want to take a more informed look at their claims before making such strong statements.

The authors propose a wormhole constructed such that light takes so long to escape from its mouth, it's effectively indistinguishable from a black hole, because nobody can realistically wait long enough to see anything come out of it.

They write,

An immediate consequence of the metric (2.1) is that time in the throat is extremely slow from the point of view of a distant observer. Indeed, they are related by lambda, [...] The throat thus mimics what happens at the event horizon of a black hole where time is "frozen" [we recall that the old name (especially in Russia) for a black hole was a "frozen star"]. The only difference from an actual horizon is that time does not completely stop in the throat: if an observer makes observations during a time of order GM/lambda he or she will resolve the processes happening in the throat and thus be able to distinguish a wormhole from a black hole. Reciprocally, this preliminary remark suggests that if an observer only looks at a wormhole during a finite time he or she might not be able to distinguish it from a black hole. We shall see below, in several examples, that this is indeed the case, even for phenomena that are usually considered as characteristically linked to the presence of an horizon (such as no-hair properties, or dissipative properties). However, we shall see that the observing time span needed to distinguish a wormhole from a black hole is not GM/lambda, as suggested by the above naive argument, but rather GM/ln(1/lambda).

Re:Universal gravity

[radarsat1]

Once can say that the expansion of the universe is due to the expansion of space, which means that the distances between spatial points change with time.

Which is actually something that's been bothering me since I thought of it: I feel like there's a tendency in cosmology to forget that time is also a dimension, and that the big bang is an expansion not of SPACE, but of SPACE-TIME. So if space and time is expanding, how can it be something that is taking time? How can time be expanding along a timeline? It's a recursive definition. Circular logic.

I have yet to hear a good explanation of this. I get the feeling, in all these many multi-dimensional theories of our universe, that it's a mistake to think about "time" as being somehow distinct and "special" as a dimension. But who knows, I've got nothing to base that on, it's just a hunch. All the theories I've seen have been things like, "3 large space, 6 small space, 1 time", or "5 space dimensions, 1 time". I've never seen a theory of physics that unites these two critical concepts of dimensionality. On the other hand, maybe there really is a difference between them, so it's not necessary. But in that case, does time play some special role in the big bang?

Re:Logical contradiction

[illegalcortex]

You're not just splitting hairs, you're assuming that a word is simply a collection of roots (Latin or otherwise) and it has a fixed and unchanging meaning derived from them.

That's really not the case with language. It's ESPECIALLY not the case with scientific language.

You might also notice that what you posted isn't the definition of universe, it's a definition of universe. Another from the same page: a world or sphere in which something exists or prevails. This is much more applicable to our usage of universe to mean the current cosmology we understand.

I know it makes some people who crave order and stability mad, but language is created, molded, abused and transformed by the speakers and writers with little remorse for whose feelings may be hurt.

More like:

[Cadallin]

From the Somebody-started-reading-50's-pulp-sci-fi Dept.

Christ, how is THIS news? People have been speculating about this kind of thing since the theorization of Black Holes. Carl Sagan talks about in one of the more trippy, pot induced segments of 1980's Cosmos!

I think I'm getting too damn old. The entire internet is looking like a dupe to me.

Re:No

[Anonymous Coward]

I have to agree here. I'm bored of all this 'black holes have super duper effects on space and time and logic' they are just really large mass. Same with wormholes.

Space is nothing, it's not a fabric you can rip into. it would be cool if you could but its just not logical. just because theres a load of mass in a small area?

Uh oh - that worhs both ways..

[cheros]

If a black hole could port stuff from our Universe elsewhere there's really no argument to stop the reverse being true either.

This would, however, mean that the laws about preserving mass, energy etc. must have a bigger scope, or those holes could cause quite a bit of an imbalance. Or maybe there's always an opposite flow somewhere else, a bit like communicating vessels but in multiple dimensions..

Meanwhile, back in the real world, I got a parking ticket :-/

Re:Logical contradiction

[Anonymous Coward]

Actually his statements about the evolution of language are correct, and you are misunderstanding the definition of the term 'evolution' in this context.

First, ask any linguist whether the definitions of words are immutably set based on prior etymology, or even original use?
For example, when is the last time you accessed anything?
Originally (IIRC) access was something you had [I have access to the database.], Not something you did [Bob accessed the client database to find billing info.], but common usage changed the definition of the word.
You don't have to LIKE it, but that is reality. Your opinion is at odds with the way language works.

Further, comments about one language being more highly 'evolved' than another are largely nonsensical, since this implies progress toward a goal. This is not the case. In this context, evolve simply means 'change'. So when we say "language evolves", that just means that "language changes" based on its environment and history (or at least the environment and history of its speakers).