The Speed Of Dark?

[kotake]

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.

Are you saying that complete darkness is the lack of visual light then?

 

To me, the physical term of "complete darkness" is when there is no EMR at all, which is, as we have discussed only possible inside a theoretically perfect faraday cage.

 

Earlier in the thread you said that darkness is light (EMR) because we can "see" it. How do you define "sse it"? If we imagine the faraday cage situation, no photons will hit the observer's eye, so how can we "see" it?

[Cadmus]

Are you saying that complete darkness is the lack of visual light then?

OK. I don't consider the term very meaningful for this conversation.

 

To me, the physical term of "complete darkness" is when there is no EMR at all, which is, as we have discussed only possible inside a theoretically perfect faraday cage.

Fine, define it this way. I don't mind, as I don't consider the term very important or meaningful here.

 

Earlier in the thread you said that darkness is light (EMR) because we can "see" it. How do you define "sse it"? If we imagine the faraday cage situation, no photons will hit the observer's eye, so how can we "see" it?

I don't think that it is useful to imagine a hypothetical situation which cannot and does not exist as a justification to deny a situation that does exist. To answer your question, I consider that if the eyes see darkenss, then they are seeing light that is outside of the visible spectrum.

 

By the way, if you were in a faraday cage, whatever that might mean, do you think that you would you be able to see or otherwise sense yourself?

[5614]

I consider that if the eyes see darkenss, then they are seeing light that is outside of the visible spectrum.

can I just add that our eyes can only sense EMR within a certain frequency, named visible light. If you define 'see' as 'sense the EMR and relay an electrical impulse to the brain which forms the image' then we can only 'see' visible light and not other EMR.

 

Or are you playing at the "eyes seeing darkness" thing? because as you may have said, if not i say! that you cannot see darkness because darkness is the absence of something. Are you saying that if someone else forced 'see' and 'darkness' into the same sentence then they must be referring to non-visible (to the human eye) EMR?

 

Cadmus, this is a long thread, can you summaries your view with a few short answers:

 

1) what do you define 'see' as?

2) what do you define 'darkness' as?

3) can we 'see' EMR at frequencies excluding visible light, so can we 'see' UV or IR etc?

[Cadmus]

this is a long thread,

I agree, and it does not seem to be going anywhere. Perhaps we should just move on, rather than continuing it.

[5614]

ok, fair point. whilst this may continue the thread, this should suit all.

 

true darkness is the absence of all EMR.

 

therefore true darkness is nothing as far as EMR is concerned.

 

therefore you cannot measure it's speed.

 

so the original question: "The Speed Of Dark?" cannot be answer.

 

do we all agree? this is regardless of whether 'true darkness' is physically possible or not, we should at least agree on the theory first!

[Cadmus]

ok, fair point. whilst this may continue the thread, this should suit all.

Other than me, I assume.

 

true darkness is the absence of all EMR.

 

Are you suggesting that "true darkness" does not exist in our daily lives and is therefore a meaningless concept? If so, we should have defined the term in the beginning, before spending so much time arguing over its attributes.

 

do we all agree?

Let us agree to try again in a different thread.

[Callipygous]

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.

 

 

sorry, i was in a bad mood earlier. not that that changes the fact that i disagree, just the way i would have chosen to present it.

[Cadmus]

sorry, i was in a bad mood earlier. not that that changes the fact that i disagree, just the way i would have chosen to present it.

We all get that way sometimes. Let's discuss something else in another thread. Perhaps we will find ourselves on the same side sometime.

[Sayonara]

Cadmus, you have added absolutely nothing to your original proposal, which I have already very concisely refuted.

[us.2u]

I don't know if darkness has any properties of it's own or whatever but let's all agree it sure helps us to see what is out in space i.e. Stars, Planets, Moons,etc, so my belief: darkness is definately not Nothing but everything! because without it we would have no Astronomy & proberly we would not exist at all, so IMHO I thank the Dark & light for giving me life which I enjoy....your thoughts?....us.2u

[Jacques]

Dark is a quality. How is it possible to ask a question like that :"what is the speed of dark?" The speed of dark matter ? The speed of dark energy ? The speed of the dark car ? Again dark is a quality not something.

[5614]

Again dark is a quality not something

what do you mean by "quality" ??? I'd always thought quality as a property of something, a degree or grade of excellence, like the quality of someone is something, but that does not make sense in this situation, what do you mean?

[Jacques]

What I mean is: dark is a property. It is not something. How can you discuss of the speed of a property ?

You can discuss of the speed of the dark car. But you cannot discuss of the speed of dark.

[us.2u]

I may be incorrect, only too ready to be corrected if proven wrong; but IMHO I feel I have the right to question very much indeed if there is a relavant speed to dark;this might seem a sheer nonsense to you & others, but so did a lot of facts which seemed ridiculous at the time only to be proven later;I could say the same about light how can light have a "speed" "The light car was travelling at an x amount of speed" everyone takes for granted light has a measured speed so why not dark? If I am incorrect... all I ask is simple proof no-one has offered that yet have they?...So again until proven to the contary "What is the speed of dark?"....us.2u

[Jacques]

Light can be a property of something like the light car, but light is also something. When we speak of the speed of light, we don't speak of the speed of the property but the speed of the thing we call light.

If you realy want an answer you must provide a definition of the "thing" you are calling "dark"

[5614]

So again until proven to the contary "What is the speed of dark?"

think of light as photons... you do not need to understand all the physics behind them if you do not wish to, just remember that light is made of photons, these photons are particles that travel in waves, just like a dolphin travels in a wave (jumping in/out of water)

 

anyway, the speed of light or the speed of photons is very very quick... different colours are photons arriving at different frequencies, so if you have your wave of x amount of photons it will appear red... with violet photons arrive more often.... darkness is the absence of photons that humans can see.

 

there are photons which arrive too often or too slowly to be detected at all, such as infa-red and ultra-violet... darkness to human eyes is the absence of visible light. darkness is, in terms of visible light, nothing.

 

you cannot measure the speed of nothing.

[Cadmus]

darkness to human eyes is the absence of visible light. darkness is' date=' in terms of visible light, nothing.

 

you cannot measure the speed of nothing.[/quote']

I think that you were doing ok until this part. I believe that it was you who arbitrarily decided to insert the word visible here. Correct me if I am wrong, but that was your insertion, was it not, rather than being part of the original post. I believe that you inserted the word visible here, and then on the basis of it came up with the last statement. In the context of your addition of the word visible in the penutimate statement, I accept your conclusion. However, do you believe that everyone who responds to this must consider darkness as you have reframed the question, in terms of a relationship to visible light?

 

For example, when you look out at night at the stars, you can see a great amount of darkness interspersed among the stars. Do you think that this darkness constitutes nothing, and that there is nothing there? Isn't there an equal amount of EM radiation in the darkness that you see, and is it not moving at the same speed as what you are calling visible light?

[Nevermore]

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.

[5614]

once again we come to the definition of "light"

 

dictionary.com says:

"Physics.

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.

Electromagnetic radiation of any wavelength."

 

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

 

it also comes to your definition of "see"

 

1) any EMR that comes into your eyes

or

2) any EMR that enters you eyes and is detected and an signal is sent to your brain which then produces an image.

 

What is the true definition of a word with multiple meanings? I suppose it depends on the context and when not clear it is best to ask the person who originally used the word, whilst the original post didnt use either word they used dark, the definition of dark is:

1) something the human eye cannot see unaided

2) absence of any EMR

 

1 brings in the definition of "see" and 2 brings in is true darkness or totaly lack of EMR possible?

 

I think we all see the problem here... if the original poster would like to redefine his/her (no offense, can't remember who it was & its on a different page) question that'd be useful.

[The Rebel]

For example, when you look out at night at the stars, you can see a great amount of darkness interspersed among the stars. Do you think that this darkness constitutes nothing, and that there is nothing there? Isn't there an equal amount of EM radiation in the darkness that you see, and is it not moving at the same speed as what you are calling visible light?

 

Still trying to breakdown and understand your thought processes. You said before you do not consider darkness as an ether as I thought you did. You also say darkness travels.

 

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.

[us.2u]

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

[5614]

phyics says that EMR is photons.

 

if the original post was referring to lack visible light when he said "dark" then that is the lack of photons, nothing, can't measure speed of nothing.

 

if the original post was referring to the lack of all EMR when he said "dark" then the question of whether that is truly possible I cannot answer, although I would have thought it was possible and would argue that way until proven wrong.

[us.2u]

This seems a tough cookie to answer 5614 kind of leaves us all in the dark-yeah!....us.2u

[us.2u]

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.

 

 

At last well-done Nevermore that's the only logic I can possibly conclude I totally agree with your Quote.....for all those who don't I very much doubt if they can prove otherwise as IMHO everything we know of is equally balanced...us.2u

[Jacques]

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