If you shine a infrared laser very concentrated at a wall, then turn it off it takes a while for the darkness to come back... so what is the speed of darkness
The period of time it takes for the end of the beam of infared light to arrive at the surface toward which it is being transmitted (a wall). So the rate of this event would be equal to the speed of the infared light, which is 300,000 km per second, right? Darkness is, to be sure, the absence of light. Ergo, its speed of visible manifestation would be equal to the speed of the recession of light, which is obviously equal to the speed of light.
Well put......and to the person that asked this: it was kinda commen sense. Darkness isn't a physical thing, it's just a abscence of light.
Darkness is the absence of light but without space-time even darkness has no dimension or duration. Please Register or Log in to view the hidden image! Therefore the speed of darkness must correspond to the uppermost speed of space-time. This corresponds to the speed of gravity which has been proven to match light. 300,000 kilometres per second or 186,000 miles per second for those of you adhering to archaic forms of measurement. Everything seems to have equal and opposite counterparts so I might not be completely talking giberish on this one. :m:
OppositesDefine (9:41:35 PM): wut is the speed of dark? b00gen (9:42:10 PM): since dark is the absence of light, it either has no speed, or since it is extinguished at the speed of the light leaving it, the speed of light OppositesDefine (9:42:23 PM): haha OppositesDefine (9:42:34 PM): everyone else just says zero OppositesDefine (9:42:39 PM): i like ur answer better
Bear in mind that mirror versions of ourselves in some bizarre quark composed reality over yonder light barrier are arguing if any speed exists for nonexistant light. Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image!
Also bear in mind that some materials atoms could remain in a excited state and release photons at a later time, even when the beam is already switched off and absorbed (would need some quantum mumbo jumbo to guestimate the emission decay time)
The same as the speed of light, which someone else has already said: Although it's 'absence' SargentLard Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! i would agree with you redoubtable.
elaborate on what you posted..i am intrigued *puts on glasses to look smart and hide the ever present stupidity*...sounds good so elaborate damn you
Quarks are a theoretical particle which may or may not exist. The stuff physicists love to contemplate after one too many drinks. The idea is that nothing can be made to go faster than light. No way no how. But...... before these rules were set in stone some particles might already have been going faster than light. In the very earliest stages of the big bang two universes might have therefore been created. One where every particle is slower than light. Here. Another where everything goes faster than light. Each undetectable by the other. Freaky idea huh. Anyway, some scientists have suggested that if we could turn a vehicle into quarks it could beat the light barrier. A warp drive. Others say we would only find ourselves in another universe where everything in OUR universe appeared to be going faster than light. Very freaky. Its all just speculation. Mirror universes do kind of meet the rule of everything having an equal and opposite self.
Contradict that Have you ever noticed that when you switch off a laser, there is a noticeable time delay before the spot of light actually disappears? Utilising this important observation, a laser was set up to project a beam of light down the length of the lab, and the time delay between switching the laser off and the disappearance of the red spot on the front wall was measured with a stopwatch. Ten observations of this time were made, shown below: 0.38 s 0.53 s 0.44 s 0.34 s 0.37 s 0.38 s 0.37 s 0.37 s 0.47 s 0.41 s The mean time and standard error of the mean from these readings was 0.41 +/- 0.01 s, but since the readings of 0.53 s, 0.44 s, and 0.47 s are clearly anomalous [This is a great word to use when describing data you don't like.] , they were discarded. The mean of the remaining seven readings was 0.374 +/- 0.001 s, which is clearly a better result since the uncertainty is so much lower [Always a good justification for throwing away dodgy data.] The distance from the exit aperture of the laser to the diffuse reflecting planar surface upon which the coherent light beam was observed [The front wall of the lab.] was carefully measured [With the "end to end" technique using two wooden metre rules.] and found to be 18.49 +/- 0.01 m. Applying careful thought to the peculiarities of the chosen geometry, it was realised that the photons of the light beam were actually travelling twice this distance---to the front wall and then back again to the eye after reflection. The total distance travelled by the light is therefore 36.98 +/- 0.02 m. Dividing the distance travelled by the observed time lag, the deduced speed is 98.9 +/- 0.3 m/s . Thoughtful readers will have realised already that this is not actually the speed of light, per se, but the speed of dark, as the observations were made of the time lag between turning the laser off and observing the arrival of the dark at the front wall. However, it can easily be shown by symmetry arguments that the speed of dark is related to the speed of light by c = 3*pi*c_dark / 8*alpha^3 where alpha = e^2 * 4*pi*hbar / Sqrt(epsilon_0*mu_0) which equals 7.29735E-3,is the dimensionless atomic fine structure constant. Performing the calculation, the resultant speed of light from this experiment is (2.998 +/- 0.009)*10^8 m/s , which is consistent with the accepted value of 2.99792*10^8 m/s. In fact, the agreement is good to the fifth significant figure, indicating that the uncertainty estimates used throughout the experiment were somewhat conservative. In conclusion... Dark is different then the speed of light, rather then the absence
Mindofachild if your going to copy and paste from the web, its always a good idea to provide the link: http://www.ysa.org.au/themill/1998.3.darkspeed.html
I know I copied and pasted it... in fact I was just about to edit it to put in the link, however I didnt get it from that website above, I got it from this one http://www.physics.usyd.edu.au/jeremy/darksp.html
Yeah Azathoth. I was watching somerthing about this. apparentl the universe is not symetrical but is 'right-handed' (or left). This gives way to the idea of another universe very much connnected with this one. Apparently this has been 'discovered' by taking mirror images of (or working out what the mirror image would be for) this universe from certain positions. It is not symmetrical but can be viewed rather like a left-handed or right-handed screw. These never look the same in a mirror. Sorry if this doesn't make much sense. i didn't really understand it all myself and I wasn't following it properly. That's as much as I know. Oh i do know that as well as matter there is theoretically anti-matter. this is probable very similar to what you said abouy quarks though. Have you read Stephen Hawking's: A breif history of Time, Azathoth? You'd enjoy that if you enjoy this stuff.
