projecting darkness

This may sound strange but i was wondering if there way a way to project darkness, like a reverse flashlight ?

a reply to: penroc3

YES!

Download some dark Drum N Bass music, turn off the lights, turn your stereo all the way up and hit play!

Close your eyes.

No but seriously. I'd say no. Since darkness is the absence of light.

a reply to: IgnoranceIsntBlisss

i got in to D&B back in the day with DJ SS and Goldie

i know Technical itch well thanks for bring it back to my attention


the reason im asking this is because today in the middle of the day i saw a man walking and it looked like he walked into what i can only describe as a shadow but he was on a sidewalk with nothing to cast a shadow, he kept walking and seemed like he didn't notice it. and i had to keep driving so i dont really know what happened

a reply to: penroc3

Yeah lol.

I sometimes ponder your same question, although beyond of that ultrasupermega black material I saw ante make a thread about, as far as I know that just leaves "dark matter".

originally posted by: penroc3
This may sound strange but i was wondering if there way a way to project darkness, like a reverse flashlight ?

No, you can't.

Darkness is just the absence of light.

a reply to: penroc3

Might be easier to coat something in a light absorbing material

originally posted by: Metallicus

originally posted by: penroc3
This may sound strange but i was wondering if there way a way to project darkness, like a reverse flashlight ?

No, you can't.

Darkness is just the absence of light.

True but also light can be blocked, or absorbed, we now have the ability to invisible things.

How can we be sure there are not creatures living around us that does the same?

Now EU-funded research is helping to create a new material: 2-D lenses coated with gallium nitride, which shines blue under LED. These the FLATLIGHT project refers to as 'metasurfaces'. In a paper published recently, metasurfaces are described as thin and lightweight compared to traditional optics and yet straightforward to fabricate compared to three-dimensional metamaterials.
The gallium nitride is carved into pillars that are small enough to create delays in how light waves flow through them. Having studied how different-shaped pillars distort light, the project can now design lenses that force light in any direction, looping it sideways or backwards on demand. This adaptability, along with an easier production process and greater portability, opens up scope for a wide range of applications.

Read more at: phys.org...

a reply to: penroc3

If the original light source was coherent (like from a laser), then it would be possible to shine a second, 90° out-of-phase coherent light of equal magnitude and they would cancel each other out.

But with normal incoherent light, this would not be possible.

originally posted by: Noinden
a reply to: penroc3

Might be easier to coat something in a light absorbing material

Like Vantablack!

originally posted by: SeaWorthy

originally posted by: Metallicus

originally posted by: penroc3
This may sound strange but i was wondering if there way a way to project darkness, like a reverse flashlight ?

No, you can't.

Darkness is just the absence of light.

True but also light can be blocked, or absorbed, we now have the ability to invisible things.

How can we be sure there are not creatures living around us that does the same?

Now EU-funded research is helping to create a new material: 2-D lenses coated with gallium nitride, which shines blue under LED. These the FLATLIGHT project refers to as 'metasurfaces'. In a paper published recently, metasurfaces are described as thin and lightweight compared to traditional optics and yet straightforward to fabricate compared to three-dimensional metamaterials.
The gallium nitride is carved into pillars that are small enough to create delays in how light waves flow through them. Having studied how different-shaped pillars distort light, the project can now design lenses that force light in any direction, looping it sideways or backwards on demand. This adaptability, along with an easier production process and greater portability, opens up scope for a wide range of applications.

Read more at: phys.org...

He asked about projecting darkness which can’t be done. You can’t ‘project’ the absence of something. Blocking something out is a completely different process and not what he asked about in the OP.

a reply to: Metallicus
what i saw was a strange optical effect im sure,


if i was going to make an aimable darkness you(i cant believe im about to invoke Bob lazar) you might be able to focus gravity to a point of darkness

An eclipse is an example of projecting darkness, so is your shadow, any shadow.

a reply to: chr0naut

Precisely. I asked myself this over a decade ago and although regular visible "white light" or "sun light" is scattered and across a large number of wavelengths... I still have a feeling it's possible. Because anythings possible, right?

I suppose it's possible. But it dends more on what band of light you would like to darken.
And if it's coherent

...but perhaps even if it's not.

-Driver

originally posted by: Z32Driver
a reply to: chr0naut

Precisely. I asked myself this over a decade ago and although regular visible "white light" or "sun light" is scattered and across a large number of wavelengths... I still have a feeling it's possible. Because anythings possible, right?

I suppose it's possible. But it dends more on what band of light you would like to darken.
And if it's coherent

...but perhaps even if it's not.

-Driver

I suppose if we knew the exact phases, amplitudes and frequencies of all the components of light?

Perhaps delaying it by 90° (which would be different delay times, for different frequencies as you go up through the spectrum) and then perhaps amplify the sensed light to exactly match the various amplitudes of the original light. But you'd have to process everything in less than nano-seconds to make it back to the cancellation point within the 1/4 wavelength.You couldn't fudge things out to multiple wavelengths plus a quarter wave as you can with coherent light. Timing would be everything.

The only reason I stipulated coherent light is that it is something that is doable with current tech. You could theoretically do it with incoherent light but it is pretty damn close to being impossible.

a reply to: penroc3

The light absorbing method is pretty far along! Using an array of vertically aligned carbon nanotubes you can absorb an awful lot of light so it does not reflect back off the surface. Check it out!

ATS: What's blacker than "black?" Vantablack!