[Spaceships] Your preferences regarding plausible/playable Reactionless Drives

[sir_pudding]

Originally Posted by Anthony

Who says you have to understand QM to find it disturbing?

How do we know he was even aware of it? He mentions Einstein in published works I think three times. He doesn't mention Bohr once. I don't recall any discussions of QM in his letters. Am I misremembering?

[Anthony]

Originally Posted by sir_pudding

How do we know he was even aware of it? He mentions Einstein in published works I think three times. He doesn't mention Bohr once. I don't recall any discussions of QM in his letters. Am I misremembering?

Probably not, I haven't studied the subject. There are various creepy things that are aware of being observed and react, which could be an interpretation of the observer effect in QM, but doesn't have to be.

[cmdicely]

Originally Posted by sir_pudding

How do we know he was even aware of it?

The explicit mention in "Dreams in the Witch House":

Originally Posted by H.P. Lovecraft

Possibly Gilman ought not to have studied so hard. Non-Euclidean calculus and quantum physics are enough to stretch any brain, and when one mixes them with folklore, and tries to trace a strange background of multi-dimensional reality behind the ghoulish hints of the Gothic tales and the wild whispers of the chimney-corner, one can hardly expect to be wholly free from mental tension. Gilman came from Haverhill, but it was only after he had entered college in Arkham that he began to connect his mathematics with the fantastic legends of elder magic.

[sir_pudding]

Originally Posted by cmdicely

The explicit mention in "Dreams in the Witch House":

Ah, there you go. That's what I was asking for, thanks.

[terranstrider]

Thanks all for the lesson in physics and an update on current research programs; I’ll certainly purloin some of this information for my campaign. On the off chance that non-mathematicians are not fed feet first into the mass converter; I’ll contribute my two cents worth.

In my campaign’s timeline, the cost benefit line for reaction/reactionless drives was crossed about 100 years ago. Interstellar travel is via wormholes and the average distance between them in a system is 15 AU. Two thirds of my players switch off when the geeks start delta-V calculations, this interruption can kill the mood, so I’ve dropped reaction engines from my Space campaigns (with the exception of rare encounters with “primitives”).

The (almost) reactionless drive I use is based on the development of Photonic Laser Thrusters. Whilst available thrust is miniscule today, I’ve assumed that 900 years in the future at TL10^ / TL11^ it is practical. Although PLTs are not true reactionless drives, they serve the purpose in my campaign of representing the Spaceships’ page 24 Hot Reactionless engine.

Warp drives are strictly theoretical in my campaign.

Leo

[vicky_molokh]

Originally Posted by teviet

Well, technically an EM standing wave or laser cavity does have rest mass (standing wave energy/c^2) and a rest frame (the frame in which the wave is stationary). So what you've really got is a maximally stiff medium, exerting a a pressure of 2*(energy density)*c on either end.

So to get some thrust T, you need to build up a stored energy of 0.5*T*D where D is the distance to the "anchor". [ . . . ]

I vaguely remember, from my attempts to understand relativity, some theorem/math experiment/not sure involving a perfectly rigid rotating disc. Perhaps if the reactionless drive creates a field allows treating all the mass in a large sphere as a perfectly rigid sphere for the sole purpose of pushing against it, we'll get something? Just how far off is that, and how faulty was my memory?

[Anthony]

General relativity forbids perfect stiffness. The maximally stiff medium discussed above is the maximum permitted by GR.

[sir_pudding]

Since Vicky summoned this back from the abyss I noticed this:

Originally Posted by ciaran_skye

"Buzzard ramscoops"

Bussard vs Buzzard

[Fred Brackin]

Originally Posted by sir_pudding

Since Vicky summoned this back from the abyss I noticed this:


Bussard vs Buzzard

Buzzard Ramscoops only gather _dead_ hydrogen atoms. Much more humane.

[sir_pudding]

Originally Posted by Fred Brackin

Buzzard Ramscoops only gather _dead_ hydrogen atoms. Much more humane.

I'll admit it. You made me laugh.