That sounds like a function of atmosphere and material, Lazar, which I'm specifically avoiding. There wouldn't be any scattering in open space.
It's a known fact that you have to stick to certain wavelengths in atmosphere for high power lasers, I'm not disputing that. More amusing is the fact different atmospheres would require different wavelengths!
I'm talking just a straight comparison in vacuum, ignore all other variables, between IR and visible light beams. Is there any functional difference once you remove interference of a conductive medium?
==Aelryinth
Maybe there should be a distinction in the conversation between intensity and energy.
Hi! I'm a PHD photonics student at UCSB. I'd like to tell you guys about light and lasers.
First, as press man mentions, let's distinguish the energy of an individual photon and a beam of light. Every photon has a specific energy, determined by its wavelength (or frequency). Short wavelength = high energy. This energy is important for a lot of things, like whether it can knock an electron off an atom.
But, in pretty much any real world case, you meet many photons, not just one. They can also exist in the same point in space, unlike matter. So I can have 1 high energy photon.. or 500000 low energy photons. Even though one photon has higher energy, its obvious the second beam carries a lot more power! This is Intensity. It's represented in the amplitude of the wave.
Now IR and Visible would be different in many ways outside of the atmosphere. Aelryinth seems to really want to zap someone with his 10GW laser. In this case, IR and visible would probably result in the same thing:extreme localized heating in a destructive manner. But there are many materials in which the case might be different. You could make bragg gratings to reflect IR and let visible pass and such. The easy answer is:they are definitely different, though in some situations they might act very similarly.
I hope this didn't sound too didactic. I'd love to answer any questions!
Hi! I'm a PHD photonics student at UCSB. I'd like to tell you guys about light and lasers.
First, as press man mentions, let's distinguish the energy of an individual photon and a beam of light. Every photon has a specific energy, determined by its wavelength (or frequency). Short wavelength = high energy. This energy is important for a lot of things, like whether it can knock an electron off an atom.
But, in pretty much any real world case, you meet many photons, not just one. They can also exist in the same point in space, unlike matter. So I can have 1 high energy photon.. or 500000 low energy photons. Even though one photon has higher energy, its obvious the second beam carries a lot more power! This is Intensity. It's represented in the amplitude of the wave.
Now IR and Visible would be different in many ways outside of the atmosphere. Aelryinth seems to really want to zap someone with his 10GW laser. In this case, IR and visible would probably result in the same thing:extreme localized heating in a destructive manner. But there are many materials in which the case might be different. You could make bragg gratings to reflect IR and let visible pass and such. The easy answer is:they are definitely different, though in some situations they might act very similarly.
I hope this didn't sound too didactic. I'd love to answer any questions!
So, would it be unreasonable to say that a 10 gigawatt beam would be: High Amplitude for the low spectra lasers, and low amplitude for the high spectra lasers?
So the one gets its power from a whole bunch hitting at one time, and the other from a tithe as many hitting much more frequently?
Which all adds up to the 'same area under the amplitude wave' paradigm, I think.
And yes, different materials would reflect the different energies differently.
==Aelryinth
Which is why you a) make the returning inertia in a random direction ala Lensmen so that kind of thing is VERY hard to do or b) have the object instantly harmonize with the nearest material energy field and effectively 'acquire' the inertia of its surroundings to move in parallel to them.
Don't you love SF physics?
==Aelryinth
Well, the problem is, 'big' has to include space ship size, and running a space ship into a planet at .10c is still a planet wrecker.
So, you have to remove that entirely.
If I ever write up an SF story, I'll have inertialess simply be less and less effective inside a gravity well or energy field, until you could move faster with, say, a gravity drive.
And do like the above...come out of inertialess, it instantly synchs into the predominant energy field about, effectively moving you in parallel with your target.
I prefer the idea of jump gates to warp drives, as I like 'port cities' as a concept. FTL would have its place, but it would be like highways and back roads. Making them only work between stars that have some sort of harmonic connection (superstrings! they work for anything!), means you can have an irregular 'coastline' and 'harbors' on your islands, instead of being able to easily and methodically build a gate to each world.
==Aelryinth
{. . .}
If it made no difference, then why was the Star Wars missile defense centered around X-Ray Lasers, which would take the energy of an H-Bomb to get off a quick burst before the laser itself was destroyed by the blast?
Oh, THAT Star Wars. Wondered when somebody was going to mention that. Using an X-ray laser instead of UV, visible light, or infrared has to do with penetration. One of the latter has to burn its way through the shell of the warhead it is trying to destroy, because these frequencies of light don't go through metal. Not only that, but in the process of burning their way through, they create partially ionized metal vapor (plasma) that absorbs much of the energy and carries it away, making them very inefficient overall. X-rays, on the other hand, actually penetrate some distance into most materials (which is why they are useful for medical diagnostics), thus allowing them to do some damage inside without having to burn away everything in between. I have heard (not seen verified printed documentation) that materials have been invented that can reflect X-rays coming in at 90`, which potentially could be put on a warhead to defeat an X-ray laser, so gamma rays would go a step further in achieving penetration, but last time I checked, gamma ray lasers (unlike X-ray lasers) remain purely theoretical.
Yes, they mentioned a long time ago that a basic defense against a laser would be simply to have the warhead emit a stream of mist or clouds as it moved, which would effectively refract and scatter the beam.
Which made charged particle beams a thing to use, except aiming those accurately is a total pain in the ass with their sensitivity to electromagnetic fields.
==Aelryinth
What would consider to be a good techno babble reason to have ftl drives without the ftl communication?
That's fair. Makes sense. What about sensors to scan nearby systems and objects? I'm planning on running a hexcrawl in space so I'm wondering how to explain scanners to find new worlds from afar (maybe a light year or two away).
That's fair. Makes sense. What about sensors to scan nearby systems and objects? I'm planning on running a hexcrawl in space so I'm wondering how to explain scanners to find new worlds from afar (maybe a light year or two away).We do that now.
We're not very good at it yet, mind, but if 21st century Earth tech can find planets much further than a light year away (incidentally? A light year is really, really close by), then I'm sure that Awesome Future Tech has some good telescopes or telescope-like devices.
Now, any information they have? Is a year old, if FTL communications aren't a thing. You can have a lot of fun with that one.
Yeah that's fair. The way I see it, for the hexmap, the players will know what is in each hex already, but only the generalities. For them to find cool and updated stuff, they'd have to enter the star system.
Which is why you a) make the returning inertia in a random direction ala Lensmen so that kind of thing is VERY hard to do or b) have the object instantly harmonize with the nearest material energy field and effectively 'acquire' the inertia of its surroundings to move in parallel to them.
Don't you love SF physics?
==Aelryinth
The harmonization does nothing at all because you choose when you return to normal inertia. You get the velocity of some random oort object and kill it. There isn't very much to kill because orbital mechanics.
The randomization doesn't help much either. If you don't like the direction you turn the drive on and off. You may have to make course corrections, but with the staggeringly immense potential energy you're getting for virtually free with your inertialess drive that's a trivial cost. The more times you're willing to rerandomize your vector the less fuel you need to spend on inertiaful course corrections or equivalently the less fuel you're willing to spend on inertiaful course corrections the more times you need to rerandomize your vector.
You totally ignored the point where I said prevailing material energy field, not object.
Energy fields, like magnetospheres or gravity wells.
A random nearby object isn't going to have an energy well.
Unless you're close to one of the planets, that means you're going to harmonize with the sun. Otherwise, you're looking at the most dominant gravity well or magnetic field, leaning to the former.
I didn't say "object" for a reason.
==Aelryinth
Feel that solar wind in your face, listen to the music of the spheres!
==Aelryinth
http://www.techtimes.com/articles/49360/20150428/nasa-may-have-accidentally -discovered-faster-than-light-travel.htm
So this came on my feed today.
Are there cases of mysterious lights appearing with no source? Of course there are. Now start testing fish, frogs, rocks, and manna. It will take a lot of testing to get things to arrive in the same year, but it's worth it.
Here's the link.