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FrozenGate by Avery

Pink Laser 500mW

Can't be build on this planet due to gravity related manufacturing restrictions. You will have to wait untill space travel becomes more cost effective so you could setup a lab in a antigravity environment :umbrella:

Nasa already have anti-gravity chambers...?

Lasers are a form of light, and since black is simply absence of light it there for has no wavelength, there for it can't have a constant phase difference and there for isn't coherent thus it could never be a laser.
 





Can't be build on this planet due to gravity related manufacturing restrictions. You will have to wait untill space travel becomes more cost effective so you could setup a lab in a antigravity environment :umbrella:

Are you serious, or do you just really not know what you're talking about?...
 
black lasers will be invented when Canada gets out of its deficit which is NEVER GOING TO HAPPEN
 
Nonono, I get what he is saying! a black laser IS possible. You just need to modulate the phase variance with an inverse tachyon pulse to modulate the inverse wavelength, and I'm sure the word "subspace" is in there somewhere! and poof you have a black laser! hmm, perhaps we need a new acronym for it. perhaps "UNlight Amplification by the Non-Stimulated Wierd Emission of Radiation" or "unanwser" I'm quite certain once it's built you willl have all kinds of "unanswer"ed questions of course. However I'm also quite certain it will be used on all kinds of objects, such as anti-matches and negative balloons, resulting in all kinds of "unanswer"ed things. But hey, I hate it when the solution to a problem just leaves you with more questions......... such as how can it be a laser then when its an "unanswer"
 
How could it possibly be impossible? In a very specific and controlled situation, a black laser is possible. There is an effect called constructive interference which in essence can be any colour but in the right frequency could be considered as white light, due to superposition of light waves. On the other hand there is an effect called deconstructive interference which in essence could be a black laser, due to canceling of light waves.

Now the exact wavelength of light reflected by an object must be know... Thus if the appropriate wavelength is produced by the laser it will effectively cancel the reflected light resulting in absence of light.. which is percieved as the colour black. Thus proving that a black laser is possible... but only in a very controlled manner. If we could find a way to modulate and control the exact wavelenght of the laser, a receptor could calculate the reflected wavelength then emit the beam what will result in deconstructive interference... but the technology is no were near up to par to do anything like that.

Here is a perfect example of what I mean...

Interference.JPG


Soo yeah.. :D -Adrian
 
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lol, you forget, only making the light of the laser invisible wouldn't actually make it look black......... you can't see the beam on a CO2 laser, but it's hardly black. Also, the light isn't absent, the energy is still there. I figured if anyone was going to go physics there would be comments on negative refractive index (which is possible, and has been done already). As a side note, Constructive interference, as well as deconstructive interference are both in play when you look at a precious opal. There are billions of tiny spheres of silica. They can be any size. The conditions that precipitate them are uniform over small areas, resulting in spheres clustered together of similar size. spheres that are 266nm in diameter will reflex almost perfectly 532nm light as an example. as some of the waves bounce off the front of the sphere, and others will reflect back up off the back. as the 266 + 266 = 532, the wavelengths will line up again and you have the constructive interference. (simple Bragg reflection) However 266nm spheres will also interfere with 1064 destructively. as putting the light from the back halfway out of sync with the light reflecting off the front puts it perfectly lined up for deconstructive interference. Now there are many many MANY spheres, with random sizes. However you DON'T see black flecks of "dark light" from say sphere groups of 150nm. (which would effect 600nm light the same as 266 would effect 1064....) or any other size sphere for that matter. Remember, the concept is a black colored laser, NOT an invisible one....

Incidentally. Opal can be synthesized to any nm sphere size in a lab. So it is possible to create an opal with only one color it will reflect, as well as tailor it for perfect constructive interference or perfect deconstructive interference.
 
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lol, you forget, only making the light of the laser invisible wouldn't actually make it look black......... you can't see the beam on a CO2 laser, but it's hardly black. Also, the light isn't absent, the energy is still there. I figured if anyone was going to go physics there would be comments on negative refractive index (which is possible, and has been done already). As a side note, Constructive interference, as well as deconstructive interference are both in play when you look at a precious opal. There are billions of tiny spheres of silica. They can be any size. The conditions that precipitate them are uniform over small areas, resulting in spheres clustered together of similar size. spheres that are 266nm in diameter will reflex almost perfectly 532nm light as an example. as some of the waves bounce off the front of the sphere, and others will reflect back up off the back. as the 266 + 266 = 532, the wavelengths will line up again and you have the constructive interference. (simple Bragg reflection) However 266nm spheres will also interfere with 1064 destructively. as putting the light from the back halfway out of sync with the light reflecting off the front puts it perfectly lined up for deconstructive interference. Now there are many many MANY spheres, with random sizes. However you DON'T see black flecks of "dark light" from say sphere groups of 150nm. (which would effect 600nm light the same as 266 would effect 1064....) or any other size sphere for that matter. Remember, the concept is a black colored laser, NOT an invisible one....

Incidentally. Opal can be synthesized to any nm sphere size in a lab. So it is possible to create an opal with only one color it will reflect, as well as tailor it for perfect constructive interference or perfect deconstructive interference.

Sorry but that is incorrect... deconstructive interference is the cancellation of light wave (or any waves for that matter). A co2 laser operates in the IR range.. the range where the human eyes can not perceive. IR is a type of light... it is not absent, it is just not picked up by the human eye.

In the situation with the opal.. other factors such as lighting conditions, angle of incidence and angle of viewing all affect the colour being perceived and the colour reflected. This is no where near a perfect controlled situation I was talking about.
 
My point remains though, Deconstructive interference wouldn't give you a black beam. Nor would it eliminate the energy in the light, it would simply mask it's presence. Yes you can't see CO2 because of the wavelength, but you are ignoring my point, which is that your deconstructive interference wouldn't make the laser look black. but simply render it invisible to the human eye.

and you are correct that viewing angle, and angle of incidence does change colors in opal. I did simplify it a bit in the last post. However lighting conditions do NOT change the inherent colors, except where the light change is simply changing the angle of incidence. (change the light source angle and you are effectively changing the viewing angle, change the light source type but keep angle of incidence and viewing the same, and the only change would be weaker colors if there is less of this or that wavelength present, or stronger colors if there is more, but the actual COLOR wouldn't change, just the brightness) I've cut somewhere over 200 opals over the past decade or so. It's one of my favorite gemstones. :D The principal is still the same, the color play in opal is still based entirely off light wave interference. Any way you spin it the random light wave interference in opal has as much chance to deconstructively interfere as constructively, yet you DON'T see black color play in opal. There is black opal, but it's opal with a black base color instead of white or clear, NOT black play of color. (keep in mind the color of the stone and the color of the light play in the stone are two completely separate things)

EDIT: incidentally. the 1/4 of the light to be interfered with thickness thing is also used in SOME AR coatings. look up some info sometime on "quarter-wave coatings" Not all AR coatings use this principal, as the thickness only gives close to perfect deconstructive interference at one angle, and the main point of AR coatings is to get refractive indexes lined up right for maximum light transmission, the quarter-wave coatings are simply done to make certain any back reflection that DOES happen will be interfered with. *shrug* the concept still doesn't make a black laser beam. You won't be shining a black laser in broad daylight watching the darkness pop balloons and light matches anytime soon
 
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Ok... but using your logic, you are effectively saying that if I theoretically lined up the crystalline structure of an opal so that it perfectly creates deconstructive interference (ignoring the constructive) that it will become see through... or that it will radiate energy.

This is not the case. The energy transformation in deconstructive interference is in the form of photons. These are exchange particles that carry energy as you know. A photon does not create light... it merely energies atoms, be it air, iron, wood etc. This energy takes an electron and moves it up through the orbitals and if you know any thing about quantum physics you would know, that the dropping of electrons from a higher orbital to a lower one creates light at a specif wavelength.

So in theory, if you had a wave that is perfectly out of sync with a reflected wave, why would you not be able to match a +1 with a -1 to make a 0 (ie no light) spot?

I would also like to point out there is no conservation laws broken... and I will explain why. Like I said before photons are exchange particles... and a laser produces photons with a given energy, when the photons hit an object, as stated before, it excites the atom and releases light...

ok now! If there is a reflected wavelength of +1 that means the light that is reflected has a value of one. Now if we have a laser emit photons that have the exact energy to excite the atoms in air, wood etc.. that the value will equal -1 the two light waves will cancel. Therefore no energy is lost or gained because it is used up during the heightening of potential energy of the electron and absorbed by other atoms.
 
So in theory, if you had a wave that is perfectly out of sync with a reflected wave, why would you not be able to match a +1 with a -1 to make a 0 (ie no light) spot?

Because all other light waves can still pass through the region unimpeded. The end result being the canceled out light waves are no longer visible. But this phenomenon does NOT block any other light. any method of creating perfect deconstructive interference would simply make your laser beam vanish, NOT turn black.

I would also like to point out there is no conservation laws broken...

Quite correct. No argument here.

Ok... but using your logic, you are effectively saying that if I theoretically lined up the crystalline structure of an opal so that it perfectly creates deconstructive interference (ignoring the constructive) that it will become see through... or that it will radiate energy.

no no no. I am trying to point out that the color in opal is caused by essentially random conditions. Therefore there will be as much constructive as deconstructive interference. The stone can do both, and normally does both. It's simply a natural structure that creates light interference patterns, and we perceive that as color when viewed in white light. Given this simple fact, if deconstructive interference could create the color black to our eyes, you would see black flecks of color in the opal as well as all the normal color play we do see. Given that there ARE no black flecks of color play in opal, then light interference DOES NOT CREATE THE COLOR BLACK. Other light can STILL pass through an interfered light wave without effect. essentially a -1 +1 state = 0 ass you stated. However add in another +1 state and you get (-1 +1) +x = x where x is the value of any other light passing through. To get the color black you would need (-1 +1) + x = 0 when x itself can not = 0.

To get the effect which nanolaser was talking about, which you were defending....

but not impossible Imagine,... it's a sunny day and sudenly you see a black laser beam coming from the other side of the horizon.

...you would need some method of perfectly canceling out EVERY light wave that passed through the laser beam, which is impossible with deconstructive interference. You would need light with wavelengths that are not constant.

Your argument seems to be stating that when you destructively interfere with light, you create the color black The result is simply that the light is no longer visible. However, just like ocean waves passing through each other temporarily, if the light waves could be separated again, you would then be able to see them again. As you stated, the light isn't gone, the energy isn't gone, the photons themselves are not gone, they are simply a +1 and -1 state that overlaps to appear as a 0 state. but separate those +1 and -1 states again, and you no longer have a 0 state, but two separate +1 and -1 states. Given that the energy is still there, but you can not see it, I think the word invisible applies quite well, don't you?

(there is an oversimplification the conditions that create the color play in opal are not perfectly random, as there ARE conditions that effect the sphere size in opal, and due to such, the color violet is the most common color and red the least common, but this is due to the sphere size is more rare the larger it gets, due to needing longer stability of the initial conditions to form, but this also means that deconstructive interference will be more common then constructive overall in opals, as those spheres are smaller then ones that will produce violet)
 
i haven't bothered reading the whole thread but why are people arguing over the making black light (not a blacklight)
 
I was thinking about this, and if you managed somehow in a room, to have a very large laser beam, particularly bright shoot out, but in the middle have a small black spot, this basically would create a shadow on the laser light and as long as the divergence of the laser is really small, the shadow should stay parrelel all the way to the end thus creating a *black laser*, as long it was done in complete darkness, with the beam exiting and being hid so it wouldn't illuminate anything.

here:

stuff.jpg


makes sense in my head :p with a few key flaws lol.
 


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