Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Amperzand]

It would largely be a matter of keeping the onboard hardware from shutting down under radiation damage at that point.

[Tack]

Never managed to figure out why a Dyson sphere goes to hell as soon as you link it up.
Would using "soft tethers" such as steel cable fix the issue?
'Cos if not, death star probably can't happen.


Oh yeah, for the chemical warfare people - Dimethylmercury.
It's basically just liquid mercury, except with the ability to go through basically any protective gear and (albeit, slowly) kill you.

The most famous death of which was a scientist who accidentally spilled two drops on the back of her glove and within 15 seconds had gotten somewhere around 80 times the lethal dose of mercury poisoning.


I learned about it from This'n which is a pretty fun read for those who haven't read it already. (A Tall Tail- Nail Spike, etc).
(It's a fun little fiction about a CIA attempt during the cold war to make the most incomprehensibly dangerous rocket engine possible and then 'leak' the plans to the USSR.)

There was also an awesome article about nuclear weapons which I might be able to find, which is a bit more reading but pretty dang informative.
-- Here it is --

Both are pretty wall-of-texy-y, but I found 'em to be good reads.

[Helgoland]

It's basically just liquid mercury

Far from it. Elemental mercury is a precious metal, and largely unreactive - swallowing mercury used to be a remedy for constipation, because it passes through the body without being absorbed and eliminates the obstruction by simple mechanics. Acute mercury poisoning is almost unheard of - the danger of elemental mercury lies in long-term exposure to the vapors.

Dimethyl mercury on the other hand is an entirely different beast. The mercury already is part of an organic molecule, making it more reactive in the body, and the compound's lipophilicity allows it to pass through most protective gear as you stated, but also through your skin and - perhaps most importantly - through the blood-brain barrier. This thing basically is a guided missile programmed to hit your CNS.

[Sheb]

This thing basically is a guided missile programmed to hit your CNS.

No, that's Botox.

[Helgoland]

Hm, depends on what kind of missile we're talking - Botox is fuckhueg compared to Me₂Hg. Maybe the latter should be compared to a MANPAD, and the former with an ICBM... Quite frankly I'm more scared of MANPADs.

[Sheb]

Well, the Me₂Hg isn't "guided" the way Botox is. It just fucks up everything, while Botox specifically target neurons.

[Helgoland]

Eeeeh, Wikipedia told me it passes through the blood-brain barrier by forming a complex with some amino acid (cysteine, I think). Fairly low-tech, sure, and it ends up in many other places, but it's not a 'fuck-up-everything' poison like phosgene.

And doesn't mercury specifically target the nervous system too? That one lady's symptoms sounded neurological to me.

[Sheb]

Well, from what I , it's more of a "go everywhere, fuck everything*", it's just that the nervous system is less resilient, so end up dying first. By opposition, botulium toxin is an delicate mechanism, where a part of the protein recognize the neuronal axons and deliver the payload, which destroy a specific protein involved in neurotransmetter release. Now, that's guided. Nothing a chemist could synthetize in a lab would reach that level of elegant lethality.

*phosgene also fuck everything, but lack the penetration capacity of dimethylmercury so it just end up fucking your lungs.

[Culise]

Never managed to figure out why a Dyson sphere goes to hell as soon as you link it up.
Would using "soft tethers" such as steel cable fix the issue?
'Cos if not, death star probably can't happen.

Basically, a solid-shell Dyson sphere (of the sort you see on, say, Star Trek, as opposed to the Dyson sphere originally envisioned by Dyson himself, which was basically a massive network of orbiting satellites later superseded by the idea of statites) will have absolutely no gravitational interaction with whatever it's containing, because it will all cancel out.  Photon pressure, obeying the inverse square law, should also cancel out, ruling out some sort of "super-statite".  Basically, you need some way to keep the shell from drifting into the star over the course of however many aeons this thing will be around (if you're going big, you may as well go long as well), especially since you're going to be putting fairly regular external forces on this by firing those rail guns; they might be individually minor, but they will add up over time.  That's doubly-true if you assume that you're in some sort of military situation where you *need* to use a star as ammunition; otherwise, why aren't you simply harvesting/creating the degenerate matter and using it in more reasonable doses at whatever location you actually need it to be.  It's triply-true if you ever want to actually move this shell instead of just leaving it as a monument to the folly of humanity some sort of fixed defense base, because you'll need some way to generate or transmit that thrusting force on/to the star as well as the shell, or you'll just crash the latter into the former.  You'll also need to solve the issues of protecting this thing, but that's a separate issue. 

Tethers might work, if you can solve the thermal and gravitational issues of physically attaching something to the surface of a neutron star, but if you're physically harvesting from the surface, you may already be on that track.  Other possibilities, albeit ones that rule out actually moving the thing, may include active thrusters or centrifugal forces (rotate up massive counterweights - and conveniently, we have a source of material with tremendous mass right nearby - along tracks on the inside of the shell; the centrifugal forces generated in reaction to the force of their rotation should push the shell outward). 

[iceball3]

Aheh, good luck finding anything that can actually tether to a neutron star.
Your best bet might be magnetic field containment, but moving the whole darn thing still might be a gigantic pain. Especially considering how big it is and how much of an effect it'll have on solar systems, in the end it'll be like our current equivalent of moving an entire mountain with some military bases stuck into it to fight a war halfway across the world, crust and all.

Also worth noting, that the revolution of materials in a dyson sphere are not the same as the revolution of materials freely disconnected from the star itself. To elaborate, look at the paths of the material at the poles of the structure. I can imagine this would be a location of significant structural stresses.

I can imagine it'd be interesting if the sphere and star were somehow stabilized using phenomena similar to what occurs in the theoretical Space Fountains, though.

[Tack]

Nah, just make the 'solar panels' out of some unobtainable which can deal with the heat of the surface of a sun. Then it can just push the sun along like a ball in a ball.

[wierd]

Silly humans. Just remove the polar sections, rotate the resulting "torus" to match the rotational velocity of the neutron star (which will be so fast that it boggles the mind) and then use the framedragging effects both produce together to gently nudge the orientation of the star. Use the magnetic flux of the neutron star, and differential attraction with the shell to stabilize the shell torus's position relative to the star. (EG, you have electromagnetic coils installed all over the surface of the torus. When the torus is becoming eccentric to the star, the most distant part of the torus powers up the attraction coils, which then interact with the star magnetically, pulling that part of the shell back toward the star.)

The magnetic flux lines of a neutron star are strongly correlated with the axis of rotation of the neutron star. This is important if you intend to use the neutron star as the generator for deadly blasts of gamma rays. (you need/want to point the rotational pole at whatever you are blasting.)  Then, you use the circumference of the torus as a giant magnetic accelerator for some normal (but high velocity) particle beams, and shoot them into the neutron star. As the particles interact with the neutron star, (already having a significant fraction of C from their acceleration in the accelerator), they will produce the copious jet of hard gamma rays you want when they collide with the surface.  (It is implied that the beams will exit the accelerator at one of the polar openings, and be directed toward the rotational pole of the neutron star. The beams will then impact at the pole, producing the gamma rays, which will then have a jet shaped by the star's magnetic feild, making it more or less directional.)

It will be very slow to orient the star in the direction you want, but it solves many problems this way. This is an automated death machine. No organics could survive being aboard. You give it a target, it orients itself slowly, then fires.  Several light years later, a gamma ray pulse sterilizes the target system.

The star does not need to move from its galactic orbit. It just needs to change its orientation relative to the target. You can do that by controlling its precession.
https://en.wikipedia.org/wiki/Precession

Basically, once the torus-shell and the star are locked in the same rotation frame, and are magnetically tied to one another, gentle manipulations by the shell will cause torque induced precession of the star. That is how you aim the star.

[Amperzand]

I thoroughly approve.

[Amperzand]

In other news, I've been thinking about sidearms recently.

The major concepts I've considered are:

One; Sidearms/secondary weapons are an additional weight and expense best avoided unless they either serve a purpose the primary doesn't or are necessary as a backup. Revolvers for single-shot rifles, submachine guns for grenadiers, ETC.

Two; As such, the main useful sidearms in a world where automatic carbines are the standard infantry weapon are likely to be those that serve a different purpose.

Three; Therefore, three major types of secondary weapon.
A light, compact PDW for snipers, rocketeers, and others whose primary weapon isn't practical for an active fight, or who aren't issued a standard rifle, like vehicle users or rear echelon personnel.

A big bore, long-cylinder revolver, something like 12-gauge, intended to launch flares, shotgun pellets, or small grenades, used by those with standard rifles to provide alternate functionality. Possibly also undermounted rather than separately carried.

A compact cutting/welding tool, presumably a laser, able to have its range extended enough to be remotely useful in a fight.

[i2amroy]

Honestly the best solution I've seen so far for the Dyson sphere drifting problem is to make chunks of your sphere out of that cool newish solar sail stuff they have now that can change it's transparency. Then if your sphere starts to drift you just make the panels on the opposite side just a hair transparent and it'll correct itself (this does, of course, let some of the star's energy escape, but you can think of that as being energy that is harnessed to fix your sphere drift instead of energy that is "lost", per se). It doesn't let you move the star itself, of course, but it will stop you from drifting into the sun.