The Speed Of Dark?

[us.2u]

If there is a diifference between non-visible light & darkness doe's anyone know? please explain, I believe without darkness we would not be able to understand light & vice-versa as they are extreme opposites I believe they both have energy & in all retrospect we only undestand one of them...."Light" I believe everyone looks at darkness as a void a nothing but IMHO I believe that to be incorrect: I believe darkness has a power we do not understand if anyone doe's; please explain simply, or is the power of darkness more complicated than everyone imagined?...us.2u

[Sayonara]

If you take away the non-visible light, "the darkness" would still be there.

[ed84c]

I think what were really gettting at is that darkness is relative to the observer.

[Sayonara]

It's more relative to the intensity of available light (who cares if it's visible or not), seeing as it will scale in the same way whether it's being watched or not.

[The Rebel]

Cadmus

 

Firstly to "cite" the concise oxford dictionary darkness means "little or no light".

 

Your comment about the properties of the earth shifting EM waves across the EM spectrum between visible and non-visible parts (in terms of the eye). This is misleading. Yes, the scattering in the atmosphere causes certain EM waves to be at different intensities as the earth rotates to being between us and the sun and not. However this is not by shifting. It is by the fact that during the day we are in direct view of certain freqeuncies and the "blue", UV, etc light is able hit us directly, as the earth rotates further the there is more atmosphere between us and the sun causes the redness, but this is not shifting.

 

The way our eyes work is by stimulus from photons, (and the wave properties). As the intensity of photons increase, the nodes in the eye (forget the scientific name) become more saturated. The lack of photons causes the nodes to become less stimulated and it is this measure of how we perceive the difference between light and dark ("little or no light").

 

I may have named myself rebel in order to examplify my opinion of modern science and its assumptions but this is too extreme. We could go on to say coldness is an entity and not lack of thermal energy.

[Cadmus]

Firstly to "cite" the concise oxford dictionary darkness means "little or no light".

Your definition here and your usage throughout considers light in the sense of the common English usages for the term, and is not a thoroughlly scientific usage, in my opinion.

 

Your comment about the properties of the earth shifting EM waves across the EM spectrum between visible and non-visible parts (in terms of the eye). This is misleading.

I think that I understand where you are coming from. However, I disagree that this is the whole story. I contend that just as the sun's gravity impacts the side of the earth that is not facing it, the sun's light also impacts the side of the earth that is not facing it. Furthermore, such light is shifted out of the visible spectrum before it impacts objects on the far side of the earth.

 

The way our eyes work is by stimulus from photons, (and the wave properties).

I am interested in what you mean by wave properties. Might you expand on this? I ask because I consider that your use of photons is just a "particle property" of electromagentic waves.

 

The lack of photons causes the nodes to become less stimulated and it is this measure of how we perceive the difference between light and dark ("little or no light").

I believe that the eyes are saturated with light throughout a person's entire life. Most of the light is outside of the range that registers in the brain as vision. Darkenss is not lack of light, but an interpretation of the light that impacts the eyes constantly.

 

I may have named myself rebel in order to examplify my opinion of modern science and its assumptions but this is too extreme.

Fair enough.

[Callipygous]

darkness is your eyes not recieving input. when your monitor is black that doesnt mean its projecting blackness onto the screen, its projecting nothing on the screen. your right that there is always some electromagnetic radiation, but that just means no one has ever seen complete darkness.

 

thats like saying its never quiet because there is always vibration. yeah, there is always noise, but when were talking about it we can only refer to what we can sense.

[Cadmus]

darkness is your eyes not recieving input.

All of the senses constantly receive input. Not all input is within the range that the sense can process in the way that we normally refer to when we speak of the sense.

 

your right that there is always some electromagnetic radiation, but that just means no one has ever seen complete darkness.

If the eyes "see" somthing then it must be light. That's what the eyes see.

 

thats like saying its never quiet because there is always vibration. yeah, there is always noise, but when were talking about it we can only refer to what we can sense.

You seem quite free with your pronouns. In this example you say "we". However, you do not mean "we". You are refering to yourself, and even then you are speaking outside of a scientific context, in my opinion. There is nothing wrong with that, as long as you understand what you are doing. When you say "we", you are projecting your context onto me, which I claim is not appropriate.

[Synaptik Gap]

Let's take a logical approach to this dilemma:Webster defines "dark" as "being without light, or without much light." To understand this we must know what light is. Webster defines light as "something that makes vision possible:EM radiation visible to the human eye." Given, there is a much more profound definition for light should you ask a Nebel Prize-winning physicist. However i am educated in matters of wave propagation and photon emittence, but i'm taking it back to the concrete streets here. So darkness is a state of being without something to make vision possible, or the absence of visible EM radiation. The use of the word "much" in the definition implies that there are different levels of this state that exist. It would follow that darkness is a natural state, and not an additive substance, matter, or entity (such as, well, light for example). So this gives the conclusion that darkness is not light in any way, but a combination of the two may exist simultaneously. And as such, a state of mixed ight and dark, or just dark, may indeed be observed by human vision, in the sense that "I can see that there is not light here, therefore it is dark." Or the reciprocal, "There is darkness here, that means there must be little of no light."

[Callipygous]

All of the senses constantly receive input. Not all input is within the range that the sense can process in the way that we normally refer to when we speak of the sense.

 

darkness doesnt refer to electromagnetic radiation, it refers to visible light. if you cant process it its not visible light.

 

 

If the eyes "see" somthing then it must be light. That's what the eyes see.

 

for the love of god, stop arguing the words. yes, "see" requires that there is something to see, but the whole point here is that "seeing" darkness means not seeing anything.

 

 

You seem quite free with your pronouns. In this example you say "we". However, you do not mean "we". You are refering to yourself, and even then you are speaking outside of a scientific context, in my opinion. There is nothing wrong with that, as long as you understand what you are doing. When you say "we", you are projecting your context onto me, which I claim is not appropriate.

 

get over it. once again, stop arguing the words. this isnt an english discussion.

[The Rebel]

English is the way we describe scientific phenomena, if we can not use English (or cite it) to define the words you use, maybe the wrong words are being used (i.e. darkness).

 

I struggle to define light by itself, because text books have not given me enough information to make up my mind what light is. It is very useful to describe light in terms of photons, e.g. its interactions with the eye, and also as waves. However, in my opinion light goes beyond this, and beyond the scope of this thread.

 

I think I am starting to understand your approach. Are you considering light as an ether, that is all around us. This ether is then subject to interactions, which determine wether is in the state of Visible, IR, UV or "darkness".

 

The problem is you describe this light or "ether" as being all around but at the same time you are saying it is being distoarted, as if it is travelling. Do you consider light to travel?, or as an ether?

[5614]

light is EM radiation at a certain frequency that our (human's) eyes can detect.

 

darkness is our (human's) eyes not being able to detect any EM radiation, possibly because there isn't any or because its at the wrong frequency or wavelength or is not reaching our eyes for whatever reason.

 

therefore darkness is, as far as our eyes are concerned with sensing, nothing.

 

nothing cannot have a speed.

 

what's the problem?

[Cadmus]

i'm taking it back to the concrete streets here.

On the concrete streets, you are free, in my mind at least, to define darkness however you like. I will not argue with you no matter what your definition.

[Cadmus]

darkness doesnt refer to electromagnetic radiation' date=' it refers to visible light. if you cant process it its not visible light.

 

for the love of god, stop arguing the words. yes, "see" requires that there is something to see, but the whole point here is that "seeing" darkness means not seeing anything.

 

get over it. once again, stop arguing the words. this isnt an english discussion.[/quote']

I do not mind if you disagree with me. It is obvious that I disagree with you. Why are you so unfriendly and tell me to get over it, simply because I do not buy your contention? If you disagree with me, do not respond if you do not want me to respond back. You claim that darkness refers to visible light Fell free to consider it so. I do not limit the scope of the argument so strictly.

[Cadmus]

English is the way we describe scientific phenomena,

I quite agree. My point is that a dictionary definition of a word in a normal usage context is not necessarily appropriate in a scientific context.

 

It is very useful to describe light in terms of photons,

Useful, yes, but also misleading at the same time, in my opinion.

 

e.g. its interactions with the eye, and also as waves.

I think that the wave concept if very important in this discussion.

 

I think I am starting to understand your approach. Are you considering light as an ether, that is all around us.

No, not an ether. However, the universe is flooded with electromagentic radiation.

This ether is then subject to interactions, which determine wether is in the state of Visible, IR, UV or "darkness".

This radiation travels the universe, interacting with objects that it encounters. For example, some of it interacts with our eyes, such that we see things.

 

The problem is you describe this light or "ether" as being all around but at the same time you are saying it is being distoarted, as if it is travelling. Do you consider light to travel?, or as an ether?

I consider that light travels as a wave. Consider water waves as a partial analogy. The wavefront is affected by the objects in its path.

[Cadmus]

light is EM radiation at a certain frequency that our (human's) eyes can detect.

OK. This is perhaps one reason for our dispute. I consider that all EM radiation is light.

 

darkness is our (human's) eyes not being able to detect any EM radiation, possibly because there isn't any or because its at the wrong frequency or wavelength or is not reaching our eyes for whatever reason.

I think that it is not possible for there to be no radiation at all. Your definition of darkness fits with your defintion of light, which is a usage that I have not been using.

 

therefore darkness is, as far as our eyes are concerned with sensing, nothing.

 

nothing cannot have a speed.

 

what's the problem?

The problem is the level at which we are discussing. Using your definition, which I do not share and which I have not been using, I can follow your point. Do you understand my usage of the word and the point that I am making on the basis of it?

[5614]

I consider that light travels as a wave.

Light is made of photons which are massless; photons have shown properties of particles as well as those of a wave. This is called wave-particle duality.

[5614]

OK. This is perhaps one reason for our dispute. I consider that all EM radiation is light.

all EM radiation is 'light' although that depends on how you define light, if you define light as something detectable by the human eye then not all EM radiation is light because, when was last time you saw radio waves coming out of your mobile phone, TV or radio? Although obviously this depends on your definition.

dictionary.com says:

"Physics.

1. Electromagnetic radiation that has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye.
   
2. Electromagnetic radiation of any wavelength."
   

depending on whether you go with 1 or 2 you get your answer!

 

I think that it is not possible for there to be no radiation at all. Your definition of darkness fits with your defintion of light, which is a usage that I have not been using.

if you have a solid (not mesh) farday cage which would have walls which would have to be a certain thickness to stop gamma rays etc then you would have no EM radiation inside.

 

 

The problem is the level at which we are discussing. Using your definition, which I do not share and which I have not been using, I can follow your point. Do you understand my usage of the word and the point that I am making on the basis of it?

i understand you view, i do not necesarily agree with all of it but i understand it all and agree with some of it.

[Cadmus]

Light is made of photons which are massless; photons have shown properties of particles as well as those of a wave. This is called wave-particle duality.

I agree that light is massless. I disagree with your contention that nothing more is necessary than to consider that light is made of photons. Although this is a useful concept, it has many problems.

 

Unfortunatlely, I think that this is not the proper forum to hold a discussion on the concept of photons and the nature of light.

[5614]

I agree that light is massless. I disagree with your contention that nothing more is necessary than to consider that light is made of photons. Although this is a useful concept' date=' it has many problems.

 

Unfortunatlely, I think that this is not the proper forum to hold a discussion on the concept of photons and the nature of light.[/quote']

maybe so, but just one thing, i'm not quite sure, which part of this statement:

"Light is made of photons which are massless; photons have shown properties of particles as well as those of a wave. This is called wave-particle duality."

did you disagree with?

[Cadmus]

maybe so' date=' but just one thing, i'm not quite sure, which part of this statement:

"[i']Light is made of photons which are massless; photons have shown properties of particles as well as those of a wave. This is called wave-particle duality.[/i]"

did you disagree with?

I have problems with the notion that light is made up of distinct, separate, and unrelated entities called photons, which are not integrated into the wavefront of the radiation of which they are a part.

[kotake]

Well doe's darkness exist? or do we imagine it's existance? Sometimes I wonder if darkness is an invisible entity made up of unknown molecules & like everything in our Universe seems to have an opposite making an equal; could darkness be 186,000 seconds in reverse so that we don't see it? just an idea; "so light is measured in photons" maybe dark could be measured in neg-photons this is indeed a strange topic... I guess we're all in the dark....us.2u

There's always dark matter

Are you thinking about anti-photons? Now that's a quite different discussion.

 

If the eyes "see" somthing then it must be light. That's what the eyes see.

I disagree. Like Callipygous said, it's similar to sound. We can hear sound because our ear-drum receives stimuli from sound waves. And still, we can define quietness; it's the lack of sound. And darkness is the lack of light. It will, of course, depend on the observer's "eye" how to define darkness, as it determines which wave lenghts can be seen.

 

In a way I can see what you are saying, Cadmus; do you suggest that complete darkness has never been observed, so by scientific method it cannot be said to exist? Yet still I belive that we should not look apart from the theory of darkness.

[Cadmus]

do you suggest that complete darkness has never been observed[/b'], so by scientific method it cannot be said to exist?

No. Go in your room at night, shut the windows, and turn out the light. You can observe complete darkness. What does this mean? It means that all light (EM radiation) that impacts the eyes is outside of the visible spectrum. It does not mean that in this situation zero EM radiation makes contact with the eyes.

[5614]

It does not mean that in this situation zero EM radiation makes contact with the eyes.

if you were inside a faraday cage with walls thick enough to block out very high frequency EM radiation such as gamma rays then there'd be no EM radiation at all.

 

A faraday cage blocks out all EM radiation, it can have holes in it, as long as the holes create a gap SMALLER than the wavelength of the EM wave it's meant to be stopping. however if the wavelength of the EM wave is small enough it will class the gap between individual atoms as a big enough gap to pass through, for this reason a thick sheet of metal will be required to prevent all EM radiation form entering the faraday cage.

 

this would be a case where NO EM radiation existed and therefore there'd be NO photons.

[Cadmus]

if you were inside a faraday cage with walls thick enough to block out very high frequency EM radiation such as gamma rays then there'd be no EM radiation at all.

 

this would be a case where NO EM radiation existed and therefore there'd be NO photons.

I am not familiar with the specifics of faraday cages, and therefore cannot comment on this. I think that this is not possible in the sense that I am considering it, particularly the notion that I might be inside of a faraday cage without photons, since the body emits EM radiation.

 

I went to the web site http://www.boltlightningprotection.com/Elemental_Faraday_Cage.htm, which states:

Since a perfect conductor is an idealization unavailable in nature, perfect Faraday cages do not exist.