The Practicality of various futuristic weapons.

[Corporal Jomn]

For some reason, the sci-fi spart of my mind wants to say something about launching mini-black holes at other ships, although that's impossible due to Hawking radiation and such. Anyways if we're talking about near future, like 2150-2299, then the first ships in space that can travel easily between Earth and space would be scramjet planes. The there would possibly be the modular station-like ships, then the ships we see in sci-fi. The first weapons would probably be either lasers*, against ships, and kinetic missiles**, against stations. Just my two cents.

*If you have something against this they're already trying to strap a laser on a 747 Jumbo Jet. http://en.wikipedia.org/wiki/Boeing_YAL-1 They are trying to make an anti-missile system. The targeting computer calculates the missile's speed, trajectory, all that boring stuff, then the laser fires, frying the missile's navigational systems, or blowing it up.
**Stations and satelites are extremely vulnerable. You don't really need explosives or other fancy stuff to destroy 'em.

[Noctis]

The only real use nanobots could really have is to repair the damage to a supercapital ship. Since ships are continually worn away by dust and space debris, it would be useful to have a coating of nanobots to allow for minor, continuous repairs. It isn't gonna repair anything beyond a few pot shots, but it might be useful.

This of course has the problem that Nanobots can only repair things if they have the material to do so. You'd need to find a way to give the nanobots the building materials needed to do the work. This is one of the things that annoys me about seeing nanobots used as a Heal all in sci-fi.

But yeah, Nanobots are only good if you can have a relatively safe, controlled environment. WHICH SPACE IS NOT

[ChaosTheory]

ITT ChaosTheory needs something to argue about on Saturday night.

Also, it's not a stupid idea when retreating. Drop a cloud behind you* with fighters in pursuit, and they wouldn't bother you much longer.
*(which would go a little bit slower than your own ship)
And I never said mines did work in space. They might work to blockade an enemy planet, but not anywhere else.

So both you and those fighters are going to be flying in a perfectly straight line? Nobody is going to be maneuvering at all to try and avoid lasers, missiles, rocks, your flaming radioactive exhaust stream, clouds of nanobots, etc? And let me get this straight while we're on the subject - you want to dump said clouds of nanobots directly behind you . . . into said exhaust stream?

At ChaosTheory, killing the enemy and vaporizing his ship isn't always the objective. Say, you want to study an aggressive alien species' tech intact.

That might be a good point . . . if it wasn't completely oblique to the entire discussion and/or my point in particular. But since you mentioned it, do you realize what capturing a space ship would entail? Not vaporizing the enemy ship would be the least of your problems.

[Talhydras]

Thanto: 10 MW xray FEL spot size 5mm has a temperature of nearly 60,000 kelvin.

Thanks for playing! Bye bye now.

[unsunghero10]

I concede defeat on most applications of nano-bots.
And now that I think about it, it would be easier to cut up enemy crafts and send them in orbit, rather than release hundreds of thousands of capsules to create a blockade.
(But seriously, SINGLE ATOM SIZED MACHINES, really?)

I'm out.

[Aralonia]

a relatively safe, controlled environment.

*Aralonia sighs and kicks Noctis into a TARDIS, then yanks a handle.

VWOOORP VWOOORP VWOOORP VWOOORP VWOOORP

*Aralonia opens the door and points out at the highly dangerous and flashy low-tech space battle outdoors, which is made of missiles and death.

Totally a safe and controlled environment, right

*Aralonia kicks Noctis out the door

[Droid]

Space isn't safe nor controlled even if there aren't death rays and missiles coming at you.

Cosmic radiation and all...nanobots probably won't even be very good for external hull repairs even under ideal conditions.

[Normandy]

Ah, massively growing forum argument (kind of slow at 2 pages a day, actually), bringing out people from all sides as we participate in locked combat, until some other idiot comes around and distracts us all. Like the ol' days before we had these silly 'rules' to prevent these.

If I point my telescope at the sky, which am I more likely to see?

A.) Barnard's Star, 6 light years away
B.) A quasar, 12 billion light years away
C.) A Saturn MCLVIXIEVL, 15,000km away, burning its ass off
D.) NGC 224/M31 Andromeda Galaxy, 2.5 million light years away?

(D), yes, but you're trying to nail a specific star in said galaxy.

Unless you meant (C). Which then I'd completely disagree with. The atmospheric lensing at 15,000 km would pretty much destroy any chance of getting a clear image.

Or maybe you meant (A), since it was so close. That's actually kind of silly, as Banard's star isn't even visible from the naked eye, even though it's so close.

Leaving (B). Which really confuses me, since it's already been discussed that a quasar is pretty difficult to see in the first place.

Forgive my silliness.

Another alternate theory is that the Martians took a page from History and attacked with the sun to their back. Try resolving 10m missiles with a giant fireball in the background. Granted yes, lasers would work just as well in such a situation, but nothing beats a missile in simplicity.

...do you realize what capturing a space ship would entail? Not vaporizing the enemy ship would be the least of your problems.

Silly CT. Everyone knows the space whalers simply shoot their FTL harpoons and reel the enemy ship in, magically decelerating it as the boarding ship fires pods which either fit into nicely compatible airlocks, or fire their mini-deathstar lasers to drill a clean hole through armor within a matter of seconds with no harm done to the crew inside.

@Corporal Jomn:
Re: Missiles in the atmosphere behave differently from missiles in space. Missiles in space can have erratic non-ballistic trajectories, given that they don't have to contend with silly ideas like 'aerodynamics' and 'gravity', which all our fancy models are based on.

@Talhydras:
Well, let's forget about all the other factors. Heat dissipation. Undoubtedly, said thermal protection will have adequate heat dissipation measures, in a world where you're protecting against points of heat rather than an all-round heat. If we're talking about 60,000K surface temperature in a 5mm spot (let's just keep it simple and assume a hemisphere radius 2.5 is heated to 60,000K), ignoring the energy wasted by blasting off pieces in the first place, math says you'll penetrate about 8.55mm before the heat dissipates to a safe 1,500K throughout the armor. Thank you for playing, sir.

EDIT:
Whoops. Wrongly assumed a starting temperature of 0K. Let's assume a starting temperature of 500K, just to keep the numbers nice. You're penetrating 9.76mm; about a centimeter. Good work, a few more of those hits and they'll be done in no time.

[Noctis]

a relatively safe, controlled environment.

*Aralonia sighs and kicks Noctis into a TARDIS, then yanks a handle.

VWOOORP VWOOORP VWOOORP VWOOORP VWOOORP

*Aralonia opens the door and points out at the highly dangerous and flashy low-tech space battle outdoors, which is made of missiles and death.

Totally a safe and controlled environment, right

*Aralonia kicks Noctis out the door

I assumed they would be in space dock, or otherwise shielded from radiation. That or used within the ship itself to maintain wiring or something similar. Gotta remember that on really large ships there might be hundreds of miles of wire and cable. Having something to maintain that might be useful.

But yeah nanobots are over all just overused. Oh and I said they work best in a safe, controlled environment. Did I EVER say that space was this environment? No, no I did not, I was simply stating a fact. In fact I was stating it to emphasize why they wouldn't work as a weapon.

God you people jump on any, even supposed, mistake like I just raped your puppy or something.

[Normandy]

If you haven't noticed, we do that to everyone. Just that we aren't raping puppies (read: making glaringly obvious ones that could easily have been avoided with just a little more thought from our ends) when we make mistakes.

[Noctis]

If you haven't noticed, we do that to everyone. Just that we aren't raping puppies (read: making glaringly obvious ones that could easily have been avoided with just a little more thought from our ends) when we make mistakes.

Ok so I'll go edit the post to make it nice and obvious. Also, its not my mistake if people connect two phrases that I didn't intend to have connected.

[Aralonia]

I just raped your puppy

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO FLUFFY WHY DID YOU DO THIS TO HER SHE DIDN'T DESERVE THAT

anyways

atmospheric lensing at 15,000 km

Okay

Find me two things

1.) a straight 15,000km length of Earth's atmosphere
2.) where Talhydras said that the Death Star was in atmosphere

Go

excuuuuuuuuse me for forgetting to say "from a spaceborne observatory"

[Talhydras]

Woah now Normandy, let's not get all hot and bothered just yet!

I'll do you one better than reinforced carbon carbon and run the numbers for fullerite. It's about the same density (slightly higher at 1800 kg/m^3) boils at 4000K and with a thermal conductivity of 2 W/ (m K). In other words it is a fucking bad ass heat shield that makes the space shuttle look like a gasoline tanker with gasoline armor.

The laser strikes, flash heats the surface to about 5200 K and makes a layer of melt a few nanometers deep that is blasting off the target at well over a kilometer per second. Just over 140 grams of the material is vaporized per second, but it's very low density and our spot size is 5 mm so that translates to a drilling speed of 4 m/sec through carbon nanotubes, which are WAY carbonier than RCC.

Assuming the fiendish laser operators can probably reliably focus for maybe a quarter of a second (because I feel generous) you'll want at least a meter of this shit over your entire ship, and that mass starts adding up significantly. Though you would have some very snappy armor at that point; I'm not really 100% on how well a meter thick fullerite armor would do against high KE impacts or nuclear blasts, but you'd need to budget some of your mass to include defenses against bremsstrahlung (paraffin) and x-ray/gamma radiation shielding (something dense). Carbon is a good choice for antilaser armor, but as long as someone's willing to dump enough heat on it it will go away. Additionally, I've read nanotubes buckle rather badly under compression.

There is simply no defense against terawatts/meter^2 spot intensities besides getting the fuck out of the way.

Re: Martians attacking with the sun behind them. Not unfeasible if earth and mars were on opposite sides of the sun, but since mars is the fourth planet and earth the third a shortest-distance course would give Earth the solar backdrop.

[Deltaflyer]

Thats assuming that the follow the same orbit, and stay synchronus in orbit, I.E Mars is going faster than earth.

In the vast majority of cases, the sun will be to a side of the battle, visually. Think of it as a right-angled triangle. The Sun is the right-angle. Neither force will be looking directly into the sun if they take the most direct path to the enemy. If they try flanking and going around, then yes, one will be.

[Normandy]

Also, its not my mistake if people connect two phrases that I didn't intend to have connected.

Yes it is. That's either bad communication (which can be fixed), or a lack of thought actually poured into what you're writing (i.e. you're not being self-critical). Remember: We're not psychic. We don't know what you're trying to say. Clarity of thought is something we appreciate, as it makes it easier for us to address the content of your argument, rather than your silliness.

excuuuuuuuuse me for forgetting to say "from [my] spaceborne observatory"

Fix'd. You are excused. From there, I'm not terribly sure, tell you the truth. But I'm pretty sure one can see the rather large, easily discernible Andromeda galaxy much better than a Saturn Rocket at 15,000km. Unless you meant to make some other point. So I say we go to a different metaphor.

As par (2), I do believe my confusion with your metaphor in the first place led to such a misunderstanding. I did not know your telescope was situated on Talhydras's Death Star.

@Talhydras:
Vapors diffuse the laser and spread the energy over the entirety of the armor, reducing effectiveness as more material is drilled out, etc...

I'm not sure why pointing out said material had a thermal conductivity of 2 W/mk helps your case. When being struck by a laser, thermal conductivity (or a lack thereof) doesn't exactly help you. Last I checked, such equations deal with the transfer of heat from matter to matter, not SUPAH LAZOR to matter. I pointed out armor materials would be designed with a large thermal conductivity in mind, such that energy is dissipated through the armor quickly, reducing the effectiveness of your laser. For example, tiny spindles of high-conductivity materials could be weaved throughout thermally resistant material. The idea isn't to stop heat from getting around (as the case is with most current thermal protection), the idea is to share the energy around the entire hull, making your laser a little more effective than a suntan booth.