Endless Void: Background [ideas and discussion]

[dragonlord]

Tachyons are hypothetical particles that move faster than the speed of light. The point being that the exact restriction imposed by special relativity is that it is impossible to accelerate to the speed of light, it is not (theoretically) impossible for a particle to be moving faster than the speed of light from the outset, however such particles would have all sorts of wierd properties like travelling backwards through time.

The quantum entanglement idea is one that comes up fairly often as a possible means of faster-than-light communications, I'm not sure whether it would actually work but it's slightly more based in real physics.

Also, yes there have been some real practical implementations of teleportation on a small scale, I think one group might even have teleported a (very) small quantity of a liquid (easier as the precise location/arrangement of the atoms isn't that important), as to how 'fast' it is though, I don't know.

[Peter]

I'm not actually too familiar with quantum entanglement - I don't really see engineers ever being able to exploit the phenomenon reliably in telecommunications, however.

Saying that, I'm going to change my mind about tachyon communication (and the even better tachyon flow analysis). It still amounts to messing with the past, and I suspect that metaphysics might have something to say about that, even if the laws of physics are on holiday.

A really big problem faced by science-fiction telecommunications actually comes from security. A society capable of building these faster-than-light military spacecraft might not also be capable of building matter replicators, but they could certainly manage an implementation of quantum computing that could render any mathematical key exchange system utterly useless.

There is a way around this, but it involves polarised light, fibre-optic cables, and anyone with the ability to attempt an interception would still be able to prevent the signal being transmitted.

There are forms of cryptography that resist brute force attacks, but all of them fall into the key-exchange problem.

The other form of secure communication you can get through physics is 'laser comms' which work if you know exactly where the friendly ship is, there is nothing in the way, and the friendly ship knows that it is going to receive a signal.

Even then, anyone who wants to read a communication can - and as comms mostly pass through portals, there are plenty of relays and choke points for such a signal to be intercepted.

BTW, another good reason not to use antimatter in drive systems is the problem of containment. Deuterium tanks don't really mind if you burn a hole through them. Antimatter coils happily oblige by degenerating into an assortment of short-lived particles and radiation that are quite happy to fatally murder half the crew.

[Peter]

OK, so we have yet another U-turn on the reactors and propulsion used in the setting.

The latest plan is to use what is essentially a realistic form of cold fusion, where fuel is 'augmented' using particular forms of dark matter in order to make fusion possible at much lower temperatures.

The idea here is that usable dark matter exists in one or both of the following forms:

• Something that can attach itself to electrons, increasing their mass.
  
• Something that experiences the SNF but exerts an attractive force comparable to electromagnetism on other, similar masses.
  

You'd have to look up cold fusion on Wikipedia for more information on how these might help.*

The reason for the change this time is that while dark matter could potentially be an absolutely incredible propellant, I don't think there is really any GPE change that could cause it to radiate energy, and even if there was, it would still .

* Simplified explanation:

Increasing the mass of the electrons attached to D and T nuclei decreases the atomic radius, allowing the nuclei to approach more closely than would normally be possible at a given temperature.

The end result is a form of 'cold fusion' that would work, but makes use of prodigious quantities of unobtanium.

If I understand correctly, a fusion drive could theoretically be about as good as it gets in terms of propulsion, providing plenty of thrust for take-off and landing as well as a high exhaust velocity (which gives more deltaV for a particular ratio of propellant to payload).

Antimatter drives are actually low-thrust - they can work in space, but are useless in an atmosphere. They are also not particularly clean, and the antimatter is so hard to get hold of that it may be a waste of time.

It's not as bad as laser drives, however. While a laser would make an incredible drive system for a 1000 tonne spacecraft, it would have some minor power consumption issues.

It also looks like using it for 'blast off' would leave a crater about 232 km deep.

[Adam]

This sounds pretty good too.

[Peter]

There does seem to be one further advantage to using photon drive, however - an impressively small mass expenditure rate at around 60 g/s for the hypothetical 1000 tonne spacecraft. Admittedly, this mass is being converted into energy rather than being sprayed out of the back of the spacecraft like a hose, but it's still quite interesting.

Photon drives are apparently about as good as it gets in terms of minimising mass ratio.

Oh, and thanks to the way radiators would be armoured, the game also features sparkling spaceships.

I'm not sure how to get them drinking people's blood though.

;D

[Peter]

How would dark matter 'atmospheres' sound? As in, a place where dark matter is dense enough that craft can gather it for use as remass at the same rate as remass is expended.

It provides at least some measure of "not a weapon of mass destruction" drive technology to spacecraft in the right place at the right time, and something comparable to a 'space jet' engine would also perform a lot better than most rocket engines.

This also justifies smaller 'battle arenas' (most fights would take place inside dark matter clusters where the spacecraft perform best) and slightly more cinematic depictions of spacecraft.

Presumably, these dark matter clusters would also effectively be the areas where 'portals' can be found (more accurately, created).

Spacecraft would still probably include torch-class 'carriers', but people would be pretty reluctant to blow those up, because without them there is no way out of the cluster and into another system (or planet).

Because portal clusters can support craft analogous to 'jets', we now have our small destroyers and patrol craft, used to neutralise attacks from such things as portal-capable R-bombs.