posted
I get the feeling Blayne plagarized most of his first post. That doesn't read like something he'd be able to write on his own. I don't know that it is fair to hold him to what other people wrote.
Posts: 10177 | Registered: Apr 2001
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posted
Momentum of massless objects, such as a photon:
p = E/c = h/(lambda)
Where p is the momentum, E is the energy of said object or photon and c is the speed of light. So yes and no. That's just for a single photon. With a laser you'd probably have to extrapolate the total momenta per unit time based on it's power output. I'm not sure exactly how you'd do that, KoM would probably have a better idea.
Posts: 3295 | Registered: Jun 2004
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KoM, if you're willing to do a calculation based on a hypothetical laser that would be useful in a space battle, I'd love to see it.
It sounds like the ship suffers much less momentum change from a laser than a ballistic projectile for a given amount of energy delivered to the target. Is that right?
Posts: 26071 | Registered: Oct 2003
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The total momentum output by the laser can be found just by treating it as though it were outputting a single photon containing all its energy, and calculating from there. This works because both the momentum and the energy of the individual photons will add linearly. Basically, yes, you get more energy per momentum than for any railgun of reasonable projectile speed. A linear accelerator moving electrons or other particles up close to lightspeed will have the same relation, though. And it's probably rather nastier than a laser because you get all kinds of secondary radiation at the target, which penetrates metal and kills humans, while your laser will probably just heat its outsides.
Posts: 10645 | Registered: Jul 2004
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posted
Well, it's probably safe to assume that if we're doing battle we're not traveling at relativistic speeds... I would think. I mean if we're keeping this with in what is reasonably realistic.
Posts: 3295 | Registered: Jun 2004
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posted
Actually, I think the laser question is a bit of a dead-end. (A bit inspired by my reference to the Picard manuver) No matter how great a laser is, you're still restricted to light speed when you have potentially FTL projectiles and craft around.
Depending on your assumptions, FTL sensors are an even worse problem to solve than FTL travel.
"At least" with FTL travel you "only" need to accelerate yourself. With FTL sensors you either need to figure out some form of detectable particle or radiation that a target would give off that you could detect faster than the targets FTL travel or find some way to send out radiation (i.e. radar) that can both reach the target and return faster than their drive.
Without this basic problem being solved, the whole discussion behind lasers and interception is pointless.
You could simply put an FTL drive on your missiles and have them slam into the target before the target even notices that they're on the way.
Even worse, both ships could manuver at FTL and neither one would ever be able to detect the proper location of the other, making it an incredibly frustrating game of cat and mouse, also making it near-impossible to defend any static target like a planet.
Posts: 7593 | Registered: Sep 2006
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quote:Originally posted by King of Men: Gah, ninja'd.
So, would it be more efficient to mount the monster laser to some sort of ship and use it as a driver or fix it to something with significant mass and use it to push objects outwards (like some kind of monster solar sail)?
Posts: 4753 | Registered: May 2002
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Blayne Bradley
unregistered
posted
quote:Originally posted by MrSquicky: I get the feeling Blayne plagarized most of his first post. That doesn't read like something he'd be able to write on his own. I don't know that it is fair to hold him to what other people wrote.
If you or anyone else can possibly find where I could have possibly plagarized my original post, god forbid that I am capable of a coherent post that happens to have a interesting premise then I will stop posting on Hatrack forever and admit defeat. So go on put money where your mouth is.
posted
Apologize, and edit. Immediately. Or else I suspect you'll see yet another of your posts locked pretty soon.
Squick might've been rude, though given that you were recently outted as someone who does exactly what he's suggesting, I don't think he's really out of bounds in the insinuation, but you were outright offensive, and in violations of the TOS for Hatrack, so apologize.
[Edited to remove offending quotation]
Posts: 21898 | Registered: Nov 2004
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Blayne Bradley
unregistered
posted
I'll edit but I am not apologizing.
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posted
Mucus, I'm assuming 'no FTL' in line with 21st-century assumption of the OP.
quote:Well, it's probably safe to assume that if we're doing battle we're not traveling at relativistic speeds... I would think. I mean if we're keeping this with in what is reasonably realistic.
The ships will be nonrelativistic, but you could accelerate projectiles to relativistic speeds.
quote:So, would it be more efficient to mount the monster laser to some sort of ship and use it as a driver or fix it to something with significant mass and use it to push objects outwards (like some kind of monster solar sail)?
Almost certainly the latter, since then you don't have to accelerate the mass of your laser, and you can dump the waste heat into something planet-sized. Niven and Pournelle used this in "The Mote in God's Eye".
Posts: 10645 | Registered: Jul 2004
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quote: The premise is this: Assuming we had a viable means of FTL travel between point A to point B or at least Star A -> Star B and vice versa "conveniently" how would one design a starship with warfare in mind, assuming we only had the theoretical 21st century technologies we currently possess.
Although, admittedly "conveniently" is ill-defined, it does leave room for FTL projectiles.
Posts: 7593 | Registered: Sep 2006
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Blayne Bradley
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posted
As conveniently as being able to sail from Pearl Harbour to Vladistock and back again.
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