Several sci-fi books posit that FTL travel can only be achieved when vessels are at hyperspace jump points or nodes. Two books off the top of my head that use this device are The Mote in God’s Eye and The Uplift Trilogy. Is there any science behind this idea, or is it purely a plot device?
Sua
Wormholes. A bit speculative though.
Not really, since we have no idea how the physics of FTL travel would actually work. When I read The Mote in God’s Eye and The Gripping Hand, however, the way the jump points were treated reminded me a lot of the real-life physics behind Lagrange points, in that they were particular points in space that could be calculated from the influence of nearby stars.
There’s not a lot of similarity, except that they are definite points in space. Lagrange points have nothing to do with black holes, wormholes, or FTL transportation. (They are, however, neat and interesting, and figure in quite a few science fiction stories)
John Wheeler published an article in Analog circa 1978 where he addressed the issue of travel via wormholes, and pointed out how it was not really workable by the science known then. I have to admit that I haven’t really looked into the matter since around that time, so I don’t know what the current thinking is, but my belief in the cussedness of Nature makes me suspect he’s still right, and you shouldn’t count on using hyoerspatial Jump Points generated by Black Holes to move around space with.
Niven and Pournelle actually worked with Dan Alderson to develop a plausible underpinning for the Alderson drive in The Mote in God’s Eye . I am not at home, so I can’t check, but I think it is in one of the newer printings of the book. It is an interesting essay on how they worked to make the details of the technology be plausible, if not actually possible.
The mathematics of general relativity allows for the possibility of worm holes, but it’s highly unlikely that any will ever be created or found.
For one thing their existence depends on the availability of exotic matter, (matter with a negative energy density), and the only presently known “source” of this “stuff” is the “stuff” found between Casimir plates.
Yes, those are scare quotes. (I think that’s you guys call them.)
Which still doesn’t have quite the right properties, even if we were able to manipulate it on a large scale.
But the jump points posited in Mote aren’t quite the same thing as wormholes. Anything which came to a wormhole would go through, but the jump points are only useable if you activate the special engines (however they work) when you’re right at that point.
Interesting. Is this something new or I have been mislead?
I’m also very much afraid that your statement, “doesn’t have quite the right properties”, could possibly drive me to a state of lethal distraction. Would you be so kind as to expand on this? I probably won’t understand it, but, nonetheless, I’d like to at least read the words. Thanks.
I need a scorecard to keep track of them, myself. The search terms to use are “Strong Energy Condition”, “Weak Energy Condition”, “Dominant Energy Condition”, and “Null Energy Condition”, among others. Some of them are violated between Casimir plates, and some are violated by quintessence, but not the one(s) which are needed to be violated for a wormhole.
(I’m not sure whether Hillman is a mathematician or a relativist but he’s one sharp cookie. A lot like some of our physicists and mathematicians.)
Question: What is exotic matter
Underlining mine.
Which seems to say what Chronos was saying.
But then he says:
Which seems to say that the negative energy “stuff” between Casimer plates could be used if a stupendous amount of energy were available. It’s all too confusing for me.
I had forgotten about the quantum inequalities; thanks for reminding me. Classically, all the matter that we know about (with the exception of the cosmological constant) obeys certain “energy conditions” at every point in space. A quantized field can violate these energy conditions arbitrarily badly at a given point; however, in the mid- to late 90’s it was shown that these energy conditions still had to hold when you averaged them over a certain region of space. So, roughly speaking, any magic that you did to create negative energy density somewhere would require a big pile of positive energy density somewhere else. (It’s actually more subtle than that—I’m making it sound like it’s just a consequence of conservation of energy—but I’m kind of rusty on the details.)