Stealth in Space

[Clonus]

Who says there isn't any?

 

http://iopscience.iop.org/2040-8986/13/2/024003

 

OK, actually I think this article is probably a load of codswallop. But it's good enough for gaming.

[Cancer]

Re: Stealth in Space

 

(I can get that preprint through my institution's library subscription.)

 

There's been chatter about this kind of thing in the physics literature for a few years now, after people demonstrated "metamaterials" which have very odd properties in terms of interacting with radiation. While the theory is interesting there are two huge limitations in terms of actually producing such a thing.

 

First, these "metamaterials" have very limited frequency range. That is, you can make a device that does this, but it only would work for a very limited -- no, let's make that absurdly limited -- range in radar frequencies or light wavelengths. Useful for use against a radar which never changes its frequency or an active optical sensor that uses a single fixed-wavelength laser. Thing is, everyone already changes frequencies/wavelengths often because that's part of how you avoid more conventional jamming.

 

Second, direction matters. Again, you can make a device that does this, but only for light moving in a particular direction through the location of your cloaked object. This could be useful if you are trying to conceal yourself briefly from a particular known observation point, but it isn't going to do any good against an array of sensors/observers scattered through space.

[Zeropoint]

Re: Stealth in Space

 

It also doesn't address the fact that your drive emissions are visible over interstellar distances.

 

If you only need to conceal yourself from one direction, all you need is a refrigerated mirror large enough to obscure your spacecraft. Such a thing large enough to hide your entire exhaust plume is probably not feasible, though.

[dmjalund]

Re: Stealth in Space

 

who says your thrust has to be that visible. If you can manage to use neutrinos as thrust, it would be a lot lharder to spot.

[Xavier Onassiss]

Re: Stealth in Space

 

who says your thrust has to be that visible. If you can manage to use neutrinos as thrust' date=' it would be a lot lharder to spot.[/quote']

 

It would also be a lot harder to get moving with a mass-less exhaust, wouldn't it?

[dmjalund]

Re: Stealth in Space

 

It would also be a lot harder to get moving with a mass-less exhaust' date=' wouldn't it?[/quote']1. meutrinos seem to have -low - rather than no mass.

 

2) everything - even photons have mass. They just don't have REST mass (thats why you can't stop a photon - without destroying it)

 

You could make a rocket from a giant laser. Larry Niven has written at least one story using this premise.

[lapsedgamer]

Re: Stealth in Space

 

1. meutrinos seem to have -low - rather than no mass.

 

2) everything - even photons have mass. They just don't have REST mass (thats why you can't stop a photon - without destroying it)

 

You could make a rocket from a giant laser. Larry Niven has written at least one story using this premise.

 

And wouldn't the EM emissons of that laser be visible at interstellar distances. By visible I mean detectable by some form of spectrometer, telescope or radio telescope?

[dmjalund]

Re: Stealth in Space

 

And wouldn't the EM emissons of that laser be visible at interstellar distances. By visible I mean detectable by some form of spectrometer' date=' telescope or radio telescope?[/quote']that's why i suggested neutrinos - besides, a laser would only be visible from a very narrow arc behind the ship. (although it would be VERY visible from that direction)

[Sundog]

Re: Stealth in Space

 

No, the visibility would be low from any other direction, but not non-existent. Particulate matter in space is very low, but present in sufficient quantity to produce some backscatter.

[L. Marcus]

Re: Stealth in Space

 

that's why i suggested neutrinos - besides' date=' a laser would only be visible from a very narrow arc behind the ship. (although it would be VERY visible from that direction)[/quote']

I'd hazard that a functional drive with neutrinos as only exhaust is just a shade less super-science than a cloaking device. ^^

 

And anyway, if they can be used in a drive, they can probably be detected. Much more easily, in fact -- we can do that now, but the instruments are ginormous!

[freakboy6117]

Re: Stealth in Space

 

I had a sneaky technique for an alien species i was deciding they use light capacitors as the basis of there technology based on a technique used during WWII to defend the Suez canal basically the fleet is covered in moving mirrors with all the ships projecting bright beams of light at each other the reflections fill the are making it impossible to accurately position any individual ship

[Tasha]

Re: Stealth in Space

 

I am always drawn back to this article on project Rho. http://www.projectrho.com/rocket/spacewardetect.php#nostealth

 

When I think about SciFi I am always drawn between the comfort of Rubber Science like Stealth in space, and the cold hard reality of you can't do that IRL. Sometimes I say screw it and go with the accepted science, though sometimes the warmth of that RS is just too tempting.

[Xavier Onassiss]

Re: Stealth in Space

 

I am always drawn back to this article on project Rho. http://www.projectrho.com/rocket/spacewardetect.php#nostealth

 

When I think about SciFi I am always drawn between the comfort of Rubber Science like Stealth in space, and the cold hard reality of you can't do that IRL. Sometimes I say screw it and go with the accepted science, sometimes the warmth of that RS is just too tempting.

 

Same here. For me, the important thing is following through and figuring out all the other implications of said Rubber Science, beyond the original reason for having it in the game. The ever-popular Stealth in Space technology usually leads to violating the Laws of Thermodynamics, which leads to... all kinds of horrible things you don't want in your game. (Free energy, perpetual motion machines, etc.) The same thing goes for Reactionless Thrusters, Artificial Gravity, and lots of other Standard Sci-Fi Equipment.*

 

*I deliberately omitted any mention of FTL travel.

[Susano]

Re: Stealth in Space

 

1. meutrinos seem to have -low - rather than no mass.

 

2) everything - even photons have mass. They just don't have REST mass (thats why you can't stop a photon - without destroying it)

 

You could make a rocket from a giant laser. Larry Niven has written at least one story using this premise.

 

Actually, IIRC, he wrote about ships using photon sails propelled by giant laser cannon mounted on the moon.

 

As for myself, I've found you get the best stealth effect in space if you can get the sound guy to turn off your theme music when ever you're on-screen.

[Cancer]

Re: Stealth in Space

 

Neutrino propulsion is largely undetectable now, though not perfectly so. I'd have to push some numbers around to see what actually falls out if you posit a neutrino rocket and couple that with existing neutrino detection technology. Yes, it does exist; it's just awful in terms of efficiency. There is, however, some directional sensitivity and modest spectral sensitivity (that latter means: you can tell different energy neutrinos from each other). Part of the problem, though, is that lower-energy neutrinos are harder to detect.

 

(FWIW, existing neutrino observatories look for neutrinos from the opposite hemisphere -- that is, ones near the South Pole look for neutrinos from the northern hemisphere), because the very large flux of secondary cosmic rays blinds them to neutrinos coming from above. The mass of Earth blocks those from the "down" direction. So if you see a collision in your detector with the right energy signature and it came through the Earth, well, only neutrinos can do that.)

[dmjalund]

Re: Stealth in Space

 

Actually, IIRC, he wrote about ships using photon sails propelled by giant laser cannon mounted on the moon.

 

As for myself, I've found you get the best stealth effect in space if you can get the sound guy to turn off your theme music when ever you're on-screen.

I distinctly remember a story where a hostile encounter was solved by realising that the ships deadliest weapon was it's propulsion system.

[Tasha]

Re: Stealth in Space

 

I distinctly remember a story where a hostile encounter was solved by realising that the ships deadliest weapon was it's propulsion system.

 

Yeah that was the earliest Man Kzinti war story. The Kzin ship opened fire on an Earth Torchship (Buzzard Ramjet, fusion torchship that used the hydrogen that was theorized to exist in space). Under fire mankind turned it's fusion drive toward the Kzinti ship destroying the Kzin ship and allowing mankind time to report home about the aggressive alien species. Also, Earth's technology was being retarded by a secret organization who's whole job was to keep technological progress slow enough that mankind wouldn't destroy itself during it's many wars against itself.

[lapsedgamer]

Re: Stealth in Space

 

I am always drawn back to this article on project Rho. http://www.projectrho.com/rocket/spacewardetect.php#nostealth

 

When I think about SciFi I am always drawn between the comfort of Rubber Science like Stealth in space, and the cold hard reality of you can't do that IRL. Sometimes I say screw it and go with the accepted science, though sometimes the warmth of that RS is just too tempting.

 

Happiness is a warm ray gun.

[Susano]

Re: Stealth in Space

 

I distinctly remember a story where a hostile encounter was solved by realising that the ships deadliest weapon was it's propulsion system.

 

As Tasha said, it's the exhaust from fusion-based drives that you're thinking of.

[Narf the Mouse]

Re: Stealth in Space

 

I actually like Star Trek cloaks. Why? Because they're obviously running on Sufficiently Advanced technology, so there's no real worries about "possible within conventional physics".

 

As for Perpetual Motion Machines - Superconductors approach/are that, within a limited scope. I think that "law of physics" isn't that something couldn't run forever; it's that something couldn't run forever while still doing work, even useless or counter-productive work. Of course, making a completely closed system runs into various other laws...

[dmjalund]

Re: Stealth in Space

 

In star trek you just pump the waste heat into subspace!

[amanojaku]

Re: Stealth in Space

 

Yeah that was the earliest Man Kzinti war story. The Kzin ship opened fire on an Earth Torchship (Buzzard Ramjet' date=' fusion torchship that used the hydrogen that was theorized to exist in space). Under fire mankind turned it's fusion drive toward the Kzinti ship destroying the Kzin ship and allowing mankind time to report home about the aggressive alien species. Also, Earth's technology was being retarded by a secret organization who's whole job was to keep technological progress slow enough that mankind wouldn't destroy itself during it's many wars against itself.[/quote']

 

"The warriors".

 

The ship from earth used a laser as a drive system, the kzin telepath didn't realize it was a weapon because the humans onboard didn't consider it one.

 

Humans had been conditioned for decades against violence, with education, drugs and brainwashing being used to pacify the masses. It was illegal to learn history without a special permit.

 

The ARM (Amalgamation of Regional Militia) maintained the goody goody peaceful society thrua police state that regulated technology, used memory erasures on various potential troublemakers and forcibly maintained population control laws.

 

All in all, the contact with the kzin probably saved humanity from pacifying itself into stagnation.

[Narf the Mouse]

Re: Stealth in Space

 

"The warriors".

 

The ship from earth used a laser as a drive system, the kzin telepath didn't realize it was a weapon because the humans onboard didn't consider it one.

 

Humans had been conditioned for decades against violence, with education, drugs and brainwashing being used to pacify the masses. It was illegal to learn history without a special permit.

 

The ARM (Amalgamation of Regional Militia) maintained the goody goody peaceful society thrua police state that regulated technology, used memory erasures on various potential troublemakers and forcibly maintained population control laws.

 

All in all, the contact with the kzin probably saved humanity from pacifying itself into stagnation.

Considering that, in the back history, psionics was known and used...Plus, signs that technology had regressed in some ways.

[amanojaku]

Re: Stealth in Space

 

Considering that' date=' in the back history, psionics was known and used...Plus, signs that technology had regressed in some ways.[/quote']

 

Excellent point, the ARM did use psionics to aid in oppressing the public. I'd forgotten that.

[amanojaku]

Re: Stealth in Space

 

As to stealth in space, maybe one could minimize ones emissions to a very high degree, but a thought occurs: if true stealth isn't feasible, how about the opposite? Scattering thousands, or millions(!) of fake emitters around a system to randomly create false signatures and overwhelm the defenders ability to react to every possible sighting?