The Speed Of Dark?

[5614]

Can someone give a definition of dark or darkness in term of what it is and not in term of what it is not ?

 

dark is the absence of photons... dark is NOT or NO photons.

 

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the question then arises is... is it the absence of ALL photons, or just some?

[us.2u]

dark is the absence of photons... dark is NOT or NO photons.

 

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the question then arises is... is it the absence of ALL photons' date=' or just some?[/quote']

 

No, the question really is what is the speed of dark? Irrespective of photons or no photons, obviously as radio waves travel through dark and light with no barriers, therefore IMHO I have to agree with Nevermore the true speed of dark is either .....186,000 miles per second or -186,000 miles per second. us.2u

[Jacques]

dark is the absence of photons... dark is NOT or NO photons.

Again a definition in term of what it is not...

I would like a definition without the words "not" or "absence"

 

Dark is ???

[us.2u]

According to Dictionary.com, dark is a deep hue or colour so what is the speed of the colour black?...us.2u

[Jacques]

According to Dictionary.com, dark is a deep hue or colour so what is the speed of the colour black?...us.2u

 

Is it a question that make sense to you ?

 

Not for me

[us.2u]

Absolutely IMHO I believe this has never really been questioned before & never really been thought of. Why I raise this question are for these simple basic facts...Dark is out-there; in that darkness, darkness supports the whole universe as we know it so in my humble mind I can't accept dark as nothing; I feel dark is a matter as to what exactly I don't know...yet. But let's study a photograph I believe the negative (Non-light) is a kind of light & positive (light) so I believe light & dark are of the same value or dark could be - 186,000 miles per second. But whatever, dark is all around us & can reach us at exactly the same point in time as "light" so to me I feel there speed must be equal....us.2u:-)

[Cadmus]

Ok then, do you consider darkness to be part of the EM spectrum and in essence a form of EM energy. If so where would darkness lie in this spectrum.

Yes, exactly. Darkness, like light, is the human interpretation of portions of the EM spectrum.

[Cadmus]

I sort of understand 5614 but after your post Cadmus I wonder... if after all dark doe's indeed have a property of it's own, as it supports the whole universe doe's it not? it supports every planet that we know of in fact it supports everything we know of out-there; but yet so many are quick to disregard dark as nothing when I believe IMHO it is quite something proberly half of everything....now there's an equation?....us.2u

Have you ever looked at the night sky on a clear moonless night? There are many dots of light, known as stars, but most of the night sky is filled with darkness. If you were to make a map of the night sky, would you map the stars, and just cut out the areas of darkness? No. The areas of darkness are not interpreted by the eyes as nothing, or non-existence. The eyes can recognize that the darkenss is in the vicinity of the light, which would not be possible if the eyes saw zero. The sky looks like a continuous spectrum of existence, not lights in the midst of non-existent nothing.

[us.2u]

Hopefully.....SO now we've come this far do you think all colour has the same speed as light?...I do whether it's black,white green or whatever if it's dark we see it at the same time as any colour so to me the speed of light,dark, & colour are all of the same speed & property can any-one prove different? not summise but prove?...us.2u

[5614]

at this point we go back to is true darkness possible?

 

when you wear black clothes they are still reflecting photons, not many, but some.

 

Scientists are working on the 'most black' black material, the thing is that all blacks still refelct some photons... I dont think a true total no-photon-reflecting black exists.

 

I think we need to define darkness...

 

Darkness is the absence of light. Darkness is here as soon as light is not. Therefore, the speed of darkness is 186,000 miles per soncond.

"Darkness is here as soon as light is not. " agreed, but I dont agree with your "therefore", once light has stopped coming, darkness is not a thing that comes after, it is a lack of the thing that was previously there... darkness does not come towards you... it's light not coming towards you.

[The Rebel]

Good news Cadmus, I think I am starting to understand your frame of mind. Unfortunately I can't find a clear cut answer.

 

I believe what you are questioning is what is it we are looking at when we look into night sky, or when we close our eyes and see the darkness. There isn't visible light there but there is something.

 

I think the struggle here is the psychology in not being able to accept nothingness. We are looking at the sky observing darkness but are unable to except nothing is there, yet there feels like there is an energy there. Theorising a non-visible part of the EM spectrum seems the obvious choice.

 

The possible reasons for this is because are eyes (and their receptors) are constantly being stimulated for taking in images, giving us the feelings we are seeing something. Also not to forget is our eyes lids are thin and can let a certain amount of light in, so we are not seeing pitch black. And the atmosphere will contain a significant amount of reflected light from the opposite of the earth at night also.

 

I think we need to remind ourselves of the situation of pitch blackness, or for example when we have been in bright light, and suddenly get put into pitch blackness. This is a true sense of nothingness, and its this frame of mind that shows how darkness is more about the lack of EM radiation as oppose to a segment of radiation responsible for causing darkness.

 

Another question to pose is if darkness is travelling radiation, where is the source?

[Cadmus]

I think the struggle here is the psychology in not being able to accept nothingness. We are looking at the sky observing darkness but are unable to except nothing is there, yet there feels like there is an energy there. Theorising a non-visible part of the EM spectrum seems the obvious choice.

There is no need to theorize. The universe is flooded with radiation, most of which is outside of the visible spectrum.

 

I think we need to remind ourselves of the situation of pitch blackness, or for example when we have been in bright light, and suddenly get put into pitch blackness. This is a true sense of nothingness, and its this frame of mind that shows how darkness is more about the lack of EM radiation as oppose to a segment of radiation responsible for causing darkness.

Nothingness is a meaningless concept. What you call nothingness is the complete inability of the eyes to decipher information from the EM radiation that is constantly impacting the eyes.

 

Another question to pose is if darkness is travelling radiation, where is the source?

Everything in the universe is a source of EM radiation.

[kotake]

Cadmus, are you saying that darkness is EM radiation of wave lenghts that the human eye cannot see? In that case, darkness is not an absolute concept. It must surely depend on the observer's eyes which wave lenghts of EM radiation he can see. For instance, different species that we know of perceive different wave lenghts, let alone the diversity of telescopes in use. So basically, the definition of darkness will depend on the observer.

[Cadmus]

are you saying that darkness is EM radiation of wave lenghts that the human eye cannot see?

Almost, but not quite.

 

In that case, darkness is not an absolute concept. It must surely depend on the observer's eyes which wave lenghts of EM radiation he can see. For instance, different species that we know of perceive different wave lenghts, let alone the diversity of telescopes in use. So basically, the definition of darkness will depend on the observer.

To some degree, yes.

 

Have you ever had a look at the night sky? Did you consider that the night sky is to a large degree filled with darkness? Yet, you could make out the structure of the entire sky, could you not. You did not only see light from stars surrounded by indecipherable nothingness that you determined to mean that there was non-existence, did you?

[Sayonara]

Yes, exactly. Darkness, like light, is the human interpretation of portions of the EM spectrum.

No, it isn't.

 

We say it is "dark" when there is not enough visible light - I.E. THE LIGHT WE CAN SEE - for us to perceive our surroundings, or no light at all THAT WE CAN SEE. The mechanisms of the human eye and visual cortex are known.

 

Dark is not a "thing", nor an interpretation of a thing. It is the absence of a thing. It is the result of a failure to perceive something which is not there. It's philosophically equivalent to a hole or a deficit.

 

Now stop trying to be deliberately contrary, because it's getting really effing tired.

 

 

To answer the original question: if you consider darkness to be a region that is relatively free of visible light, then by necessity if that region can travel at all it can only do so at the speed with which its boundaries travel. Since its boundaries are defined by external regions that are relatively saturated with visible light, then that darkness could be said to be moving at the speed of light.

[Macroscopic]

Originally posted by Macroscopic

"You say that darkness is an absense of light."

That's right, and any physics textbook would agree with me.

 

 

Originally posted by Cadmus

Please cite one.

 

I don't need to, ANY one will work. What I have said is standard physics, while what you say goes against it. You are the one that needs to cite a source, as your idea goes against the basic understanding of physics.....again.

[Asimov Pupil]

If you mean total darkness (All absence of ultraviolet radiation) then it travels at the same speed light travels at.

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[us.2u]

Well I'm not the only one to believe dark has the same speed of light,whether or not this subject seems to be tiring; I feel 186,000 miles per sec is right & no one can or has proved any different for whatever reason.... presumeably because there isn't one I sincerely believe dark & light are the same speed:- until anyone; & I challange anyone to absolutely prove me incorrect I will continue to believe dark is a matter & has speed....I very much doubt if there is any conclusive proof to the contary ....us.2u

[Sayonara]

I don't need to, ANY one will work. What I have said is standard physics, while what you say goes against it. You[/b'] are the one that needs to cite a source, as your idea goes against the basic understanding of physics.....again.

Indeed, not to mention the fact that it not only has no scientific basis, but also has no basis in philosophy, formal logic, or any hint that it's been derived from first principles of any kind. It's "just stuff he said", which as we know has zero inherent merit in a scientific environment.

 

If you mean total darkness (All absence of ultraviolet radiation) then it travels at the same speed light travels at.

Why are you specially choosing ultraviolet light as an indicator for darkness?

[5614]

I challange anyone to absolutely prove me incorrect I will continue to believe dark is a matter & has speed....I very much doubt if there is any conclusive proof to the contary

OK, how do YOU define dark?

 

if you include "see" in your explanation, define "see".

if you use the word "light" in your explanation, define "light"

 

I think, as sayo put it, darkness is the absence of the visible light part of the EM spectrum...

 

I now quote dictionary.com when I say that "darkness" is the absence of visible light:

http://dictionary.reference.com/search?q=darkness

 

if darkness is the absence of visible light, it is the absence of photons at a specified wavelength and/or frequency. Therefore you cannot calculate the speed of it because it is the absence of something else.

 

Whats the speed of something moving? (photons, light)

Whats the speed of nothing moving? (nothing, darkness)

[Sayonara]

Unless you consider that such a region can have its speed measured by proxy, as I suggested earlier. But that's really a matter of opinion.

[us.2u]

I agree with Sayonara; 5614 you only supprt your own opinion but have no conclusive proof, unless I have misinterpertated your explanation, & if I have I apologise but as far as I see light & dark are equal in speeds...us.2u

[5614]

5614 you only supprt your own opinion but have no conclusive proof

 

visible light is photons.

darkness is the absence of light (by which I mean visible light)

therefore darkness is nothing as far as photons (of the visible light specturm) is concerned

you cannot measure the speed of nothing.

 

which part of that needs proof?

[Sayonara]

If I throw a doughnut at you, we can measure the speed with which the hole in the middle moves, because it's defined by its boundary (which is moving).

 

Same thing.

[5614]

That depends on how you define the hole though.

 

If the hole is the air, then it doesnt move (well maybe a bit of disturbance from flying donught, but you get the point)

 

If the hole is in fact not a hole, but you are talking about the perimeter of the donught you are not really talking about the hole at all.