Wormholes Unstable (BBC)

An anonymous reader writes that "The BBC reports on recent theoretical physics research showing that wormholes may not be very useful for space or time travel. Wormholes with smooth or classical spacetimes appear to be unstable and fall apart quickly. Too bad for budding time travelers and space explorers!"

Comments

Oh No!

[Bob McCown]

A completely theoretical and as-yet-to-be-discovered phenominon is unstable, and unusable for transportation? Say it aint so!

Re:Oh No!

[borroff]

I can just see the dialog now:

Captain: I'll give you a ride on my space elevator if you show me your wormhole.

Green-skinned lady-of-casual-virtue: Well if it wasn't a nanotube, maybe you'd get somewhere! It takes exotic matter to keep my wormhole from collapsing.

Of course they're unstable.

[allanc]

That's why the artificially-created stable one near the Deep Space Nine station was so strategically valuable.

You know what's bullshit

[Adult film producer]

That they made jodie foster wear that goofy outfit when she travelled through the wormhole.. come on, I'd like to think todays audiences are mature enough to handle a little bit of nudity, seeing her hotly oiled up and sleek body slips through the cosmic threshold shouldn't dismay anyone.

I'm going with her on the next trip, in the raw baby!

This explains the low-attendance ...

[Kaemaril]

Well, no wonder the time-travel convention was a bust :)

Not true

[barcodez]

The one I was using tomorrow worked just fine, well, it did until it broke yesterday.

The Worm Turns

[Doc Ruby]

If wormholes allow time travel, their brevity is nearly irrelevant.

Re:Am I the only one...

[Danger Stevens]

males ages 9 through 120, who readily associate almost anything they encounter with their own genitals or breasts.

As a male, I admit I spend way too much time associating things with my breasts.

All you need is PART of the wormhole

[Vitriol Angst]

The wormhole doesn't have to be stable to be useful. You could create a wormhole around a ship, and allow it to break apart behind. You could also say that rockets are unstable, because they only have a stable stream of plasma for a few feet--yet they still move the rocket.

Of course, putting limits on things that are still fiction is kind of ironic.

Re:Hilarious?

[Danger Stevens]

Apparently everyone at slashdot thinks this is funny. Isn't this supposed to be BAD NEWS?

This isn't the cancellation of Star Trek, this is real space travel. And therefore less important.

That's old news!

[DancesWithBlowTorch]

I've been taught that Einstein-Rosen bridges ("Wormholes") are unstable in MSc lectures. This knowledge is at least five to ten years old. I can't find the appropriate paper at the moment, but if you try this summary of Black Hole Theory, for example, it will tell you on page 25 that Wormholes are not crossable. There are similar problems with time machines ("closed timelike curves") and other strange phenomena of Quantum Cosmology: They all sound so cool at the beginning, but the closer you look, the less interesting they get.

Re:"Negative Energy" a conceptual mistake?

[jd]

I'll answer this as best as I can.

The mass/energy equivalence is actually quite important, because really mass is energy - in the early Universe, energy was all there was. What we call matter "condensed" out of that. The two are not just comparable, therefore, they really are the same stuff. Thus, E=MC^2 is true for both positive and negative masses, because negative mass must be condensed from negative energy.

(I'm not sure if that's very clear.)

Anyways, a negative charge is NOT the same as negative energy. An electron has a positive mass and will therefore convert to a positive amount of energy, and likewise if you were to "fuse" that energy, you would get an electron with it's attendent negative charge but positive mass.

Nor is antimatter the same as negative matter. Antimatter and matter are largely the same stuff, but "rotated". (Matter has 720' symmetry, so if you "rotate" matter only 360', it becomes antimatter. This is covered in Professor Hawking's Brief History Of Time.)

Negative matter has negative mass. This means that it would have negative momentum, negative gravity and all sorts of other bizare characteristics. (To give you an example, a positive massed rocket that used negatively massed fuel would fire the engines in the direction it wished to go.)

Because the forces inside a negative mass are repulsive, negative mass is highly unstable, as all the forces are trying to blast it apart. What you would want is matter that is sufficiently distributed that the repulsive force (in this case, things like gravity) are weaker than what would be attractive forces (in this case, say, the strong nuclear force, which is normally repulsive, in positive matter).

It is very unclear as to whether you could have complex atoms with a negative mass, simply because gravity and the strong nuclear force are not equal and therefore there would be a high degree of asymmetry in what would be possible.

Negative mass or negative energy is required in a stable wormhole, because it forces the throat of the wormhole to stay open. Normally, a wormhole would collapse instantaneously, whenever any positive mass or energy tried to cross it, but the negative mass/energy prevents it from doing so. Provided there is enough.

Essentially, what you are doing is creating a region of space that has such an intense repulsive force that "normal" space cannot enter into that region.

Of course, this does beg an important question - is the force so great that NOTHING can enter? If so, then such wormholes may exist almost everywhere and we'd never know, as the normal Universe would wrap round it.