Light

[Xain]

is it possible to take the color out of light so that a shadow comes out of a flashlight instead of normal light?

[insane_alien]

umm, no.

 

the colour of light is dependant on its wavelength, if you use a wavelength that the human eye can't detect the beam will be invisible but it will not appear as if a shadow is coming out of it. a shadow is the absence of light.

[swansont]

umm, no.

 

the colour of light is dependant on its wavelength, if you use a wavelength that the human eye can't detect the beam will be invisible but it will not appear as if a shadow is coming out of it. a shadow is the absence of light.

 

Specifically, a shadow is a spatial absence of light, and color is an issue of the spectrum.

[Xain]

an you tamper with the wavelength to make the absence?

[insane_alien]

no, changing the wavelength of light will not alter the fact that the light is there.

 

thats like saying 'can you paint a prisoner a certain colour so that he is no longer in prison?'

[swansont]

You'd have to physically block the beam (or apply some other effect, like interference). If the light is there, it's there. It doesn't matter what the wavelength is.

[Xain]

i mean, is there anyway you can "cancel" out the lights wavelength?

[Klaynos]

i mean, is there anyway you can "cancel" out the lights wavelength?

 

You can create an interference pattern:

 

http://en.wikipedia.org/wiki/Interference

 

But you can't just shine that out of a torch to remove another torches beam for example.

[Xain]

there isent some way that we use 2+ waves together that will cancel each other out or tamper one another?

[Klaynos]

Only through interference.

[Xain]

so its not possible to have an absence of light emit from some type of machine?

 

or have 2 waves interfear with each other to make an absence?

[Klaynos]

No.

[swansont]

or have 2 waves interfear with each other to make an absence?

 

Yes, that's possible under the right circumstances. A very narrow slit (or slits) in front of a light source will yield bright spots and dark spots.

 

The easiest way for a source to emit no light (ignoring thermal effects) is to not turn it on.

[Xain]

kalynos sais it cant happen

 

but you say that you can make a shadow emit from it with a machine?

[Klaynos]

I talk about interference above ^^^

[ydoaPs]

but you say that you can make a shadow emit from it with a machine?

 

No, that's not what he said.

 

 

So, you want to emit a shadow. What is this shadow? IIRC, there's no such thing as a shadowon.

[Xain]

so its not possible to turn on something similar to a flashlight and have multiple waves interfere with each other and create an absence or shadow come out of it?

[ydoaPs]

so its not possible to turn on something similar to a flashlight and have multiple waves interfere with each other and create an absence or shadow come out of it?

 

It's very simple.

 

Step one:

Get a flashlight.

 

Step two:

Don't put batteries in it.

[Xain]

you going to make a shadow come out of a flashlight like that?

[ydoaPs]

you going to make a shadow come out of a flashlight like that?

 

It's a more even effect than trying for interference and it's easier.

[iNow]

Xain,

 

It's an interesting question, I think, but the only to make a shadow is to physically block the light shining on the object. So, you'd be better off with a really big umbrella in front of the light source than some really complex nifty tool that measures the light and tries to interfere with it by emitting it's own light.

[Xain]

not to be rude, but i was asking if its possible not if theres an easier way

[swansont]

so its not possible to turn on something similar to a flashlight and have multiple waves interfere with each other and create an absence or shadow come out of it?

 

An absence of light (shadow) is not an entity, so it can't be emitted by a device. What you can do, under some circumstances, would be to have two light sources interfere, an this would give you dark regions. Light is being emitted, but it destructively interferes when it's 180º out of phase with other light.

[Xain]

how would i go about doing that?

[iNow]

Not to be rude, but study engineering and physics.