2006-12-04 22:46:38 · 23 answers · asked by sportative 1 in Science & Mathematics ➔ Physics
It should be faster that light otherwise why is it dark?
2006-12-08 18:27:55 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Well, this is covered by the expression 'night-fall'. What you have to ask yourself is how fast is that fall? And- a related question- when does it really count as night?
You might be interested in a scientific instrument I have developed for exactly this purpose of deciding the speed of night-fall. An arrangement of mirrors reflects the light of the dying sun into an 'extinction meter'. When the light is almost gone, down to the last few lumens of light radiation (when the last wavicles are waving their tails) a digital ultra fast stopwatch measures the interval from that to 'proper darkness'. Clearly this will not work in built-up areas, or anywhere where there is natural or industrial atmospheric haze.
Clearly, i would need a research budget to develop this for commercial applications, but a modest £5.5 million ought to be ample- interested?
2006-12-05 06:53:56 · answer #2 · answered by PhD 3 · 0⤊ 0⤋
FASTER THAN LIGHT because wherever light goes it finds that darkness got there ahead of it!
LOL - just kidding! Seriously darkness does not have a speed - its the absense of light. Its one of those false dichotomies like hot and cold - cold is a useful term but it is not a real quantity except in the negative - it is the absense of heat. Its confusing and misleading to think of them as opposites.
So darkness does not have a speed. Light travels at 'c' (E=mc2) which is 300,000 kilometres or for the Americans - 186,000 miles PER SECOND!
Regards
2006-12-05 09:34:43 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Darkness doesn't have a speed - it's just the absence of light.
There's a good book called Speed of Dark, by Elizabeth Moon
2006-12-05 06:48:44 · answer #4 · answered by SteveT 7 · 0⤊ 0⤋
Darkness = absence of you can not measure the speed of darkness you must base the measurement by its relation to the speed of light the two are inexorably linked to one another.
2006-12-05 06:55:27 · answer #5 · answered by crawler 4 · 0⤊ 0⤋
Come on it's simple, if you shine a light the beam goes out at light speed and when you switch it off the rear of the beam (darkness) is also at light speed.
2006-12-05 13:21:24 · answer #6 · answered by bo nidle 4 · 0⤊ 0⤋
The same as the speed of light..whatever that is, darkness is the absence of light.
2006-12-05 07:25:40 · answer #7 · answered by Aaron 5 · 0⤊ 0⤋
Anybody who's read Pterry knows this...
Dark has to travel faster than light so that it can get out of the way in time. No-one can measure it, 'cos it's too dark to see.
2006-12-05 07:37:27 · answer #8 · answered by pixiefeet@btinternet.com 2 · 0⤊ 0⤋
Darkness is the absence of light.
Light travels at around 300,000,000 meters per second in a vacuum.
The absence of light effect (the speed at which light left your current position for you to sense it's absence) is there fore 300,000,000 meters per second (in a vacuum).
Now try and think of something intelligent to ask!!
2006-12-05 09:33:20 · answer #9 · answered by graemefirth894 3 · 0⤊ 0⤋
Depends on how you view it. If you view it by way of Newton's laws, every action has an equal and opposite reaction, therefore if light particles/waves (wave/particle duality theorem) are travelling at 299,792.458 km/s in one direction, then there's a reaction of -299,792.458 km/s in the other direction.
Therefore, the speed of darkness could potentially be given the speed of -299,792.458 km/s.
2006-12-05 09:07:15 · answer #10 · answered by mark25787 2 · 0⤊ 0⤋
42
2006-12-05 06:49:35 · answer #11 · answered by peppery_paprikash 2 · 0⤊ 0⤋