Could We Find a Door To A Parallel Universe?

p1234 writes "Though no direct evidence for wormholes has been observed, this could be because they are disguised as black holes. Now Alexander Shatskiy of the Lebedev Physical Institute in Moscow, Russia, is suggesting a possible way to tell the two kinds of object apart. His idea assumes the existence of a bizarre substance called "phantom matter", which has been proposed to explain how wormholes might stay open. Phantom matter has negative energy and negative mass, so it creates a repulsive effect that prevents the wormhole closing. 'US expert Dr Lawrence Krauss, from Case Western Reserve University in Cleveland, Ohio, points out that the idea rests on untested assumptions. He told New Scientist magazine: "It is an interesting attempt to actually think of what a real signature for a wormhole would be, but it is more hypothetical than observational. Without any idea of what phantom matter is and its possible interactions with light, it is not clear one can provide a general argument."'"

Comments

No parrallel universe

[Anonymous Coward]

Only a parrallel part of the multiverse

Sqrt(Negative energy) = head hurts

[G4from128k]

IANAP, but most "energy" variables can be thought of as the square of some other physical properties (kinetic energy is related to velocity squared, electrical energy is related to voltage or current squared, etc.) So to get "negative energy", it would seem that we need imaginary (as in the number i = sqrt(-1) ) values of velocity, voltage, current, etc. So now my brain hurts (and the real physicists on slashdot can enjoy ripping me to shreds or educating me as is their wont)

Re:Sqrt(Negative energy) = head hurts

[jonnyfish]

Negative kinetic energy happens all the time in quantum mechanics. That's what tunneling is. In classical physics, the total energy is E=T+V, where T is the kinetic energy and V is the potential energy. In tunneling, a particle can pass through a "barrier" where V>E, so that the kinetic energy E-V is negative.

I still think the claims in the article are ridiculous though.

Re:Sqrt(Negative energy) = head hurts

[bheekling]

Imaginary numbers are used purely as a mathematical device, and do not point to anything tangible or real.

You could replace "i" everywhere with "sqrt(-1)" and everything would be the same. The fact that sqrt(-1) has no meaning in the physical world says nothing about using it to find a real answer; as long as the answer doesn't *contain* sqrt(-1). In fact, using imaginary numbers in calculations is very similar to using vectors.

The concept of negative energy OTOH, is not a mathematical device, and is *expected* to point to something "real".

However, the OP's claim that energy can be thought of as a square of some physical property and hence cannot be negative is purely deduction from example (hence with no basis), and does not contradict anything. Infact, a form of energy called potential energy is very often negative in calculations since it is a purely relative quantity.

Then again, I should mention that potential energy is also a mathematical device (with a vague physical counterpart), as are all other forms of "energy". *grin*

Re:Sqrt(Negative energy) = head hurts

[rasputin465]

IAAP, although not in this field (and actually I don't know anything about "phantom matter"). The idea of imaginary physical quantities isn't actually as forbidden as you might think. The best example I can think of are tachyons. Non-physicists invariably hear about these particles in sci-fi (I seem to recall multiple references to them in star trek), but actually a number of current theories predict their existence. They are particles that travel faster than the speed of light, which means that their rest mass is imaginary. You need not worry, however, because they never travel slower than the speed of light. One example, supersymmetery, predicts a number of particles whose mass^2 is positive at high energies (read: very soon after the big bang), but goes negative at lower energies; hence their rest mass is imaginary and are tachyons.

Less esoterically, in the realm of electronics, the electrical impedance of capacitors and inductors is imaginary. However, one could argue that this is just a mathematical trick to aid computations.

I might also note (and probably other commenters have too) that Lawrence Krauss, who's mentioned in the summary, is the author of the famous The Physics of Star Trek, which is a great read.

Re:Sqrt(Negative energy) = head hurts

[cathector]

imaginary numbers play fine at a surface level w/ lots of physics equations.

for example,
the reason we're often told an object can't travel at the speed of light is that it would then acquire infinite energy,
because the energy (momentum) of an object is proportional to 1 / [sqrt(1 - (velocity^2 / the speed of light^2))],
so if velocity == speed of light, then momentum would be proportional to 1/0, aka infinite.

however, notice that if an object is going *faster* than the speed of light,
the nasty divide-by-zero goes away, and you have a nice, happy, and imaginary value for the momentum.

Re:Does any of this matter really matter?

[knowsalot]

Just for the record, anti-matter is real, has mass, kinetic energy, et cetera, is affected by gravity, and is all around us. Lots of antimatter particles are created in nuclear reactions, and also naturally when radioactive elements decay. It's really not that weird. The only thing that is a little odd about it is that when antielectrons or antiprotons get together, they create (pairs of) photons. But on the other hand, a photon can create a matter-antimatter pair of particles also.

Dark matter, for the most part, is anything that is not a big ball of glowing hydrogen. The earth is not a big ball of glowing hydrogen, so much of what you know is ordinary "dark matter". The issue is that most of the mass of the universe *ought* to be concentrated in big balls of glowing hydrogen, yet galactic rotation rates and other observations predicated on the laws of physics as we know them imply that there is more out there than these big balls of glowing hydrogen. So what is the nature of all that non-hydrogen? That is a bit of a puzzle to physicists.

But "phantom matter" -- matter that is repelled by other matter (anti-gravity) --? That is just plain imaginary nonsense. Like asking what happens if you can travel faster than light, or if you can turn time around. In fact, all three of these concepts may in fact be the same idea in different aspects.

I'll be the first to admit that the laws of physics may not be the same everywhere (or everywhen) in the universe, but what exactly is even *meant* by a "connection to another universe"? If you can (even just theoretically) observe it, then it's within this universe, by definition, no?

Re:Sounds like science fiction

[tyme]

geek wrote:

It's like proving something exists buy using something that doesn't exist.

Actually, you can prove that one thing exists by using another that doesn't exist, it's called proof by contradiction and it's used all the time. The basic method is that you assume the existance of the oposite of what you are trying to prove and then show that the assumption leads to some logical contradiction.

Now, the guy in TFA is not making a proof by contradiction, but you certainly can prove the existance of a real thing using a thing that doesn't (and can't) exist.

I thought we already went through one

[Whatsmynickname]

when Ann Coulter endorses Hillary Clinton. If that isn't being transported to some parallel universe, I don't know what is...

Re:Sounds like science fiction

[maxwell demon]

Physics isn't just observation. If Kepler had only observed the planets, Kepler's laws wouldn't have ever materialized. All we would have would be large tables with planetary positions. We need theories in order to understand the data and make predictions which we then can, again, test again experimental data.
Experimental physics is about doing the observations, while theoretical physics is about developing the theories describing the results.

Re:If you can get there from here

[Brunonian]

Some theories propose a sort of multi-verse containing many universes with different physical laws and properties. If the physical laws governing wormholes in our universe (whatever those might be) were similar to those in another separate universe, and it allowed traversal but not "leakage" of properties, then yes it could be possible to travel to a completely different universe. Of course, you may explode into positrons when you get there.

I know that's alot of "if"s, but the whole thing is a thought experiment anyway.

IANAP btw (obviously)

reading material: http://en.wikipedia.org/wiki/Bubble_universe_theory

wormhole == balck hole

[ThirdPrize]

black hole == lots of matter going somewhere but we don't know where.
big bang == lots of matter coming from somewhere but we don't know where.

I like to think that for each black hole in our universe there is a big bang in another parallel universe. the multiverse would be in a constant state of flux as universes grew, and then when enough balck holes had appeared, were sucked out to make the raw material for new universes. these in turn eventually draining into others.