Warped Ambitions?

by Clifford Johnson     Department: Physics & Chemistry

Just spotted this in the Guardian:

Next Thursday, the British Interplanetary Society is bringing together physicists for a conference entitled Faster than Light: Breaking the Interstellar Distance Barrier. "The main purpose is to raise awareness of this obscure field of research within general relativity and quantum field theory and attract new and particularly young researchers to work on the technical problems," said organiser Kelvin Long.

Wow! I had no idea there was such a meeting. Did anyone reading go?! What is the British Interplanetary Society? From their site I found this quote:

"From Imagination to Reality" The British Interplanetary Society serves both space flight professionals and those with a general interest in space flight and astronautics. The Society has a worldwide membership, and is actively devoted to supporting forward looking policies and visionary thinking towards the advancement of space flight through its publications, symposia, meetings and other events. It is the world's longest established organization devoted to the promotion of astronautics both nationally and internationally.

Sadly, I can't find anything on the site about this warp drive meeting. In particular, I'd love to know what papers were presented, and what questions were asked - wouldn't you? If you know of a website with such information, do let us know.

The article goes on:

Although the subject is firmly in the realm of exotic physics, he said previously controversial ideas often find their way into the mainstream eventually. "Historically, black holes and worm holes were not taken seriously. Now, dozens of papers are published every year on these topics. It is desirable for warp field theory to receive similar attention, if we are to realistically appraise its potential," he said.

Ok. I'd better say something contentful here. In lumping black holes and worm holes together in this way, he should be careful. While they are both solutions of Einstein's equations that we might wonder if Nature used, it was always clear that black holes can be formed by ordinary stuff that we knew existed, even before we were able to gather evidence for their actual existence. What is that ordinary stuff? Why, regular garden variety matter, of course. Also, it was/is not too hard to imagine the kind of conditions that could encourage the matter to form black holes. Worm holes, on the other hand (short cuts to distant places or times), have a bit more going against them. To make traversable ones requires forms of matter/energy that we've never encountered before (and so far has no compelling reason to exist) - it is considered exotic since it violates a certain condition known as the (averaged) null energy condition. We don't know how to make and manipulate stuff like that, or whether it can be employed to support a worm hole.

The means for how to put this unknown exotic stuff to good use in supporting a wormhole (what mechanisms would give rise to them in nature? How could you make them even in principle?) does not really suggest itself at all, and this is in contrast to the situation for black holes, where collapse of ordinary matter is quite readily arranged (relatively speaking). (By coincidence, I've recently done some commentary on this very topic for an upcoming television program, so you'll hear more about this if you catch it in the coming month or so.) The same is true for the phenomenon known as "warp drive" (familiar from Star Trek). You can engineer the solution representing the spacetime "bubble" that does it, but the equations require the same unknown, exotic, (and unmotivated?) stuff to source it. (Do a search for discussions of Miguel Alcubierre's paper that presented such a solution in 1994. See (at least) the opening paragraphs of a nice blog post by Aaron Bergman, here. There's a Wikipedia article here, that as of the time of writing does not seem unreasonable, and has some useful references.)

Nevertheless, there's no harm in playing with the ideas - who knows what may come of it? Maybe nature has figured out a way...or at least cooperate with us to help us find a way one day... Right now it is hugely speculative as a technological reality, and so I'm amused because I'd not expected to see a whole conference about it, and I'd love to know what the discussions were like. How advanced are the discussions toward the spaceflight goal? Were they focusing on searching for the required exotic stuff? Discussing containment chambers and other other engineering hurdles to overcome? Arguing over the warp scale: how does warp 2 compare to warp 3? is the scale linear? logarithmic? exponential? why? And so forth. All good fun.

-cvj

(This article is cross-posted on Asymptotia.)

Tags: black holes, science fiction, space travel, star trek, warp drive

TrackBack URL for this entry: http://www.pbs.org/mt4/mt-tb.cgi/151

+ Add Comment