# Speed of dark
**URL:** https://boards.straightdope.com/t/speed-of-dark/60642
**Category:** Factual Questions
**Created:** [April 3, 2001, 2:38pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642 "2001-04-03T14:38:01Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@walor](https://boards.straightdope.com/u/walor)
#### Post date: [April 3, 2001, 2:38pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/1 "2001-04-03T14:38:01Z")
What is the speed of dark?
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### Author:  [@mongrel\_8](https://boards.straightdope.com/u/mongrel_8)
#### Post date: [April 3, 2001, 3:04pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/2 "2001-04-03T15:04:29Z")
Dark is created by the absence of light, so I would suppose that you would say it is 3x10^8 m/s, the speed of light. Although, I believe the true answer is dark has no speed at all.
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### Author:  [@walor](https://boards.straightdope.com/u/walor)
#### Post date: [April 3, 2001, 3:13pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/3 "2001-04-03T15:13:08Z")
> [@](#):
>
> \*Originally posted by mongrel\_8 \*
> \*\*Dark is created by the absence of light, so I would suppose that you would say it is 3x10^8 m/s, the speed of light. Although, I believe the true answer is dark has no speed at all. \*\*
But if you open a closed cupboard which is dark inside, you can see the light slowly enter but you cannot see the dark escape. Ergo, dark is faster than light…?
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### Author:  [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)
#### Post date: [April 3, 2001, 3:21pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/4 "2001-04-03T15:21:37Z")
Years ago someone had a hack article on “THe Darkon Theory of Light”, which posited that dark was made up of elementary particles called “darkons”. You could measure the speed of datkons by measuring the speed of the interruption in a flow of darkons, which can be called a photon. Its speed, as mongrel\_8 noted, is about 3 X 10 to the 10 centimeters/sec.
As for you, walor:
> [@](#):
>
> But if you open a closed cupboard which is dark inside, you can see the light slowly enter but you cannot see the dark escape. Ergo, dark is faster than light…?
You can SEE light entering? No offense, but what are you smoking?
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### Author:  [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)
#### Post date: [April 3, 2001, 3:26pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/5 "2001-04-03T15:26:04Z")
Nope…as mongrel\_8 said dark is the _absence_ of light. The dark doesn’t escape…the light escapes at light speed leaving behind dark.
Ergo, dark itself has no speed but dark is created at light speed. And ‘no speed’ doesn’t mean zero in this case as if it’s standing still because it’s not even doing that much. Asking the speed of dark is like asking what happened before the universe was created. There just isn’t any meaningful answer.
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### Author:  [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)
#### Post date: [April 3, 2001, 3:28pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/6 "2001-04-03T15:28:40Z")
Welcome to the SDMB, **walor**.
Now would be a good time to make some witty comment to let everyone know you’re joking about this so you don’t get the wrong rep.
Take my word for this, dude. Even if you don’t understand what I’m talking about. Hell, **especially** if you don’t understand what I’m talking about. Just say, “Thanks for the info. Good to be here. Glad to have your attention. Hi, Opal!” and let this thread die.
Your friend,
**KneadToKnow**
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### Author:  [@walor](https://boards.straightdope.com/u/walor)
#### Post date: [April 3, 2001, 3:41pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/7 "2001-04-03T15:41:03Z")
> [@](#):
>
> \*Originally posted by KneadToKnow \*
> \*\*Welcome to the SDMB, **walor**.
>
> Now would be a good time to make some witty comment to let everyone know you’re joking about this so you don’t get the wrong rep.
>
> Take my word for this, dude. Even if you don’t understand what I’m talking about. Hell, **especially** if you don’t understand what I’m talking about. Just say, “Thanks for the info. Good to be here. Glad to have your attention. Hi, Opal!” and let this thread die.
>
> Your friend,
> **KneadToKnow** \*\*
Thanks for the inside track KneadTo Know
Never being one to shun good advice…
‘Thanks for the info. Good to be here. Glad to have your attention. Hi, Opal!’
Let this thread die at the speed of dark.
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### Author:  [@malden](https://boards.straightdope.com/u/malden)
#### Post date: [April 3, 2001, 5:09pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/8 "2001-04-03T17:09:41Z")
The _Journal of Irreproducible Results_ (a reputable scientific journal if ever there was one 🙂 ) dealt with this question in a 1995 article by C. Bowers. The following is a the opening paragraph:
> [@](#):
>
> **Calculating the Velocity of Darkness and its Possible Relevance to Lawn Maintenance**
>
> The velocity of light is approximately 186,000 miles/sec. This velocity, often represented as a constant (c), is of central importance to our present understanding of physical law. In contrast, the velocity of darkness (as manifested by the movement of the edges of a shadow) is not constant; nor is it generally derived for simple systems. The derivation presented here demonstrates that shadows are capable of moving at speeds much greater than the speed of light. Further, it is demonstrated that shadows can exhibit the unusual attribute of arriving at their destination before leaving their origin. The practical implications of these results are completely unknown, but are discussed at length anyway.
(side note: I was _really_ tempted to use the last sentence of that paragraph in the introduction to my Master’s Thesis, but then I thought better of it.)
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### Author:  [@Padeye](https://boards.straightdope.com/u/Padeye)
#### Post date: [April 3, 2001, 5:17pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/9 "2001-04-03T17:17:01Z")
Let me start up this vacuum pump for an analogy demonstration of the dark theory…
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### Author:  [@Floater](https://boards.straightdope.com/u/Floater)
#### Post date: [April 3, 2001, 6:13pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/10 "2001-04-03T18:13:31Z")
We must also bear in mind de Selby’s view that darkness is simply an accretion of ‘black air’, i.e., a staining of the atmosphere due to volcanic eruptions too fine to be seen with the naked eye and also to certain ‘regrettable’ industrial activities involving coal-tar by-products and vegetable dyes (and as a result of that, sleep is simply a succession of fainting-fits brought on by semi-asphyxiation).
There is more to read at [http://lightning.prohosting.com/~amphi/shtml/page.shtml?deselby.html](http://lightning.prohosting.com/~amphi/shtml/page.shtml?deselby.html)
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### Author:  [@Running\_with\_Scissors](https://boards.straightdope.com/u/Running_with_Scissors)
#### Post date: [April 3, 2001, 6:32pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/11 "2001-04-03T18:32:29Z")
You may also want to read up on [The Dark Sucker Theory](http://www.teleport.com/~marron/dark.html).
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [April 3, 2001, 6:45pm UTC](https://boards.straightdope.com/t/speed-of-dark/60642/12 "2001-04-03T18:45:29Z")
Surprising though it may be, **malden** , in this case the JIR is correct: Shadows can, indeed, travel at speeds in excess of c, and because of this, can (in some reference frames) arrive at a destination before they left. the key is that you can transmit neither energy nor information on the shadow itself.
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### Author:  [@walor](https://boards.straightdope.com/u/walor)
#### Post date: [April 4, 2001, 8:10am UTC](https://boards.straightdope.com/t/speed-of-dark/60642/13 "2001-04-04T08:10:18Z")
Thanks for The Dark Sucker lead frogstein. It’s reassuring to know that dark exists, although there is no reference to its speed.
Going one step further, if dark exists, it must have mass. Is it heavier or lighter than light? Perhaps light is called light because it is not as heavy as dark.