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# UFO Illusion Out Of Lasers?

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#### BrittanyGulden

##### Guest
Anyone ever think of casting out some lasers over your city @ night to give the illusion that a UFO is in the sky?

Here:

Assume I have a laser in my hand. I point the laser up to the ceiling. What do you see? A dot, correct? Well, what if I take my hand & start spinning it around in a circular motion. Now what do you see on the ceiling? A circle. Why? Persistence of vision.

^Wait a second. Wouldn't I give an illusion of a persistant circle all the way from the tip of the laser to it's stopping point, which in this case would be the ceiling? So instead of just seeing a circle on the ceiling, I would see a cylindicular shape from the tip of the laser to the ceiling. -Is that correct? I do not have a laser on hand to test out.

Regardless of whether I'd see a solid cylinder of light OR just a circle on the ceiling, could this be replicated outside?

It can't be, correct? I mean, beams are infinite right? Therefore, the only illusion I'd give is from the tip of the laser to infinite

^See, that's the issue. If I were standing in my driveway, & shooting out a laser into the sky & making it "go round," you wouldn't see a "circle" or "UFO" in the sky. All you would see is circles from the tip of my laser to infinite.

Okay, this is going to sound extremely abstract, but I'm new to lasers & lol I'm not very old either.

Colors are rated by frequency, specifically by nM.

Assume:

Red Paint + Blue Paint.

If you mix those two together in a 1:1 ratio, you will get purple paint.

I don't understand. Red is approximately 650nm & blue is approximately 475nm. How do we go from 650nm & 475nm to get 400nm, which is roughly purple or violet.

650 + 475 =1125

1125/2 = 562.5, therefore 562.5 is your average "nanometer"

562.5 is NOT violet. That's like yellowish/greenish

What I am getting at is "Does frequency change when you mix colors?" Let's assume frequency does change, & in this case, it can go up in total frequency.

Here's an example:

I have a UV laser pointer in each hand.

Assume I point these two lasers at a wall 30 ft in front of me. The lasers are NOT touching.

Now, what if I converge these lasers together at 30ft. Assume frequency doubles & you're now seeing visible light or in this case, a laser dot.

...I beamed two UV lasers out at a wall. UV is invisible to the naked eye. BUT, when I converged the two beams, I now created something that the naked eye can see!

Notice what I am getting at? I just created a "starting point" for a laser.

I understand ^ is all pretty abstract, but it's to help make a point. So, is there a way to start & stop a laser beam? I just posted an abstract way to "start" a laser by converging two laser beams at a given distance. hmm, lol they've figured out how to bend light. I sure hope there's a possible way to stop & start a laser lol

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#### Things

##### New member
No, there is no way to stop a laser in mid air without something physically there.

Yes, you could create a cone of light by waving the laser around, but:

1. You'd need a very high power if you want others to notice it

2. It'd be illegal in most countries.

Combining Lasers does not change frequencies, you simply see the result of 2 colours overlapping.

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#### BrittanyGulden

##### Guest
No, there is no way to stop a laser in mid air without something physically there.

Yes, you could create a cone of light by waving the laser around, but:

1. You'd need a very high power if you want others to notice it

2. It'd be illegal in most countries.

Combining Lasers does not change frequencies, you simply see the result of 2 colours overlapping.
Thanks.

So, you'd actually see a cone VS just the circle on the ceiling? I tried it with a flashlight w/ a focused beam & all I could see was the circle on the ceiling. How come I didn't see the cone?

It's there right? But the intensity of the light around it makes it invisible? Would that be considered the "medium?"

Another Q:

The eyes see color using rods & cones. Something about colors having specific frequencies, & those frequencies reflecting off the objects....

Well, how do eyes see objects themselves? Wouldn't that be speaking in terms of dimensions?

#### Laser Smith

##### New member
Eyes see objects because of the light being reflected off said objects. If you have an orange couch it means it mostly reflects orange out of the many frequencies in white light. If you were to light the room with a pure light source far from the spectrum area orange is in, the couch wouldn't look orange anymore

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#### BrittanyGulden

##### Guest
Eyes see objects because of the light being reflected off said objects. If you have an orange couch it means it mostly reflects orange out of the many frequencies in white light. If you were to light the room with a pure light source far from the spectrum area orange is in, the couch wouldn't look orange anymore
I am not speaking in terms of color only.

I am speaking in terms of shape -length, width, & height.

I assume ^ is dimension. Just because our eyes can decipher color, that does not mean color can decipher dimension.

Unless, with the absense of color, one can not see shape?

I assume not. If so, then how does color decipher shape.

What is this "white light" you speak of? Does that make up the medium? In other words, it's the given

So, one could say the abscence of color within the range of what we call "visible light" would be "white" ??

"Sent from a small town in Minnesota"

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#### DrSid

##### New member
As for your confusion of colors mixing ..

Colors are not mixed by averaging wavelengths, not in all cases. People sense color by how much individual color sensitive cells in their eyes are excited. We have 3 kinds of these: red, green and blue. Neither does sense single wavelength, but rather wide spectrum centered around these colors.

This system allows us to see some colors, which are not part of the spectrum. Like purples and violets. Red and blue combinations are perceived like no single wavelength color.
Exception are wavelengths above blue, which are perceived by some people as violet, and which gave name to ultraviolet spectrum. But for example I'm not one of those people, and 405nm and 445nm look more or less same, and I would not call 405nm violet. I need some red in my violet.
Also for example all violets displayed by computer screen are combination of blue and red, and never single wavelength.

For color combination, averaging can be used in transition from red to green, and from green to blue. You won't get new wavelength between original color .. but you get what LOOKS like wavelength between the original colors.
For any other combination it is 2D problem and color LOOK cannot be described using any one number. Colors are combined by averaging, but you must average their position in 2D color space. By this you get violets and pale colors, and also white, which too does not have any single wavelength.

Check this and related articles on wiki: http://en.wikipedia.org/wiki/Color_triangle

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#### Eudaimonium

##### Well-known member
Regarding the "cone" thing while spinning the laser very fast.

You actually do have both the cone, and the eliptical termination point, in your room while performing that.

The only problem is, the beam indoors with lower power laser is so small, that the projection on the wall outshines it by a very large magnitude and because of it, you do not see it.

Put some fog in your room, and you see both the cone and elliptical projection.

Outside, not so much - you will see the cone in mid-air, but no ellitical projection unless there are some very low altitude clouds, and even then, by the time the beam reaches them, it'll be several meters in diameter.

Regarding the color mixing,

If let's assume that in one computer, you have a CPU ticking at 2 GHz. Assume another computer in same room, with exact same components, and exact same processor architecture, but it was overclocked to 2.5 GHz.

Does that mean you have a 4.5 GHz processor?

Of course not, you have 2GHz and 2.5 GHz processors.

There is no summation, multiplication or division or averaging. You have two different instances of an object. That's it. You do not have a "purple laser". You have one blue and one red. Color purple is simply an illusion gotten from overlapping the colors.

Offtopic rant, is anybody else being slightly irritated when people say "[they] got a 3 GHz processor but it's 4 cores so it's 12 GHz processor, actually!" ? No, no you do NOT have 12 GHz processor. You are unbelivably ignorant and do not deserve a high and gaming CPU in your computer.

#### lasersbee

##### Well-known member
Anyone ever think of casting out some lasers over your city @ night to give the illusion that a UFO is in the sky?
Yeah.... that's what we need... more UFO hoaxing schemes...
The conspiracy nuts don't have enough to whine about....:crackup::crackup:

Jerry

You can contact us at any time on our Website: J.BAUER Electronics

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#### DrSid

##### New member
Btw. if you want really good UFO .. take either helium balloon or crane .. paint it white, attach few LEDs and small battery .. and don't forget to call local TV ..

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#### BrittanyGulden

##### Guest
Elliptical projection -This is the point where a laser beam meets matter?

When two laser beams converge, can one call that an "elliptical projection?"

I assume not. Light is not matter. However, gas is a state of matter, therefore wouldn't ^ be true if you converged two argon lasers?

I thought about building a small RC heli & attaching a couple of high intensity l.e.d.'s on one end of the main rotor blades, & fly them over the local bars lmfao. While, RPM is quick enough to give the illusion, it's not a large enough circle & I am near positive the intensity would deminish over the distance I need. -Is there a specific name for that?

Air balloon would work, but I run the risk of getting caught w/ it.

Lasers would suit perfect. Hm, perhaps I could run a trial on a very cloudy night & see what kind of results I would get. I guess "low clouds" can have a base starting at 6,500 ft from earth ground. Stratus are one of the most popular "low clouds." -Low & flat. Just what I need. But lol, I'm going to need a 1W laser to get out there 1.5 miles

I wonder what kind of illusion I would get if I attached a small laser parallel to one of the main rotors on my RC helli. Of course the beam would shoot outwards, but still -what will I see? Nothing unless it's foggy out....

Lol, I guess I could attach a fog machine to my rc helli haha

Wait a second!

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#### Things

##### New member
Argon lasers don't produce a beam of argon gas .. they still produce light, no different to any other laser, just they use argon gas (mostly) as a lasing medium.

Your project is going to be impractical and expensive, put it that way, because unless you've got at least 1W+ of green, no one will see a thing unless they're standing right beside you. 1W+ green lasers are not available in handheld form, and will require mains power. They also start at about \$800 for the cheapest ones.

Clouds make a less than ideal projection surface, because they are not flat. If you project a circle onto the clouds and move even 2m away from the laser, it'll just look a blurred mess.

If you really wanna "create" a "UFO", do as others have said and use a balloon.

#### Flaminpyro

##### New member
I must be special then because I have a hand held laser that puts out 1049mW peak in the 532nm range and it uses an 18650 Li cell :na:

You are correct though about the price, this one costs \$995.95

1W+ green lasers are not available in handheld form, and will require mains power. They also start at about \$800 for the cheapest ones.

#### Things

##### New member
I must be special then because I have a hand held laser that puts out 1049mW peak in the 532nm range and it uses an 18650 Li cell :na:

You are correct though about the price, this one costs \$995.95
Special indeed, I've never seen a 532nm handheld actually live up to a 1W spec. If you paid \$1K for it then I can understand

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#### Flaminpyro

##### New member
Yep sometimes we get lucky and get a good one :eg:

#### lasersbee

##### Well-known member
For a 1W Laser... you may be a bit too close to the Thermopile
Sensor in your pic. It could possibly be picking up the heat
generated from front of your Laser and skewing the output.

But I understand what you are saying...:beer:

Jerry

You can contact us at any time on our Website: J.BAUER Electronics

#### DrSid

##### New member
And what about IR amount analysis ? With 1W there will be some even with good filters ..