If the speed of light is 186,282 miles per second, what is the speed of dark?

It’s the same, because you have to wait for the light to get out of the way (kind of like the speed of a Farrari is limited to the speed of the truck in front of it).

Darkness is not a thing in and of itself. (Unlike light, which is simply photons)

Sort of like there is such a thing as heat, but not such a thing as cold. Coldness is the absence of heat; darkness is the absence of light.

@thorninmud has it right. It is the absence of light, so if someone put a black sheet in front of the sun, the dark would hit us at the speed it takes for all the light ahead of it to reach us, and then not reach us.

This reminds me of the amazing spectacle I saw yesterday as I waited for the bus. The light at this time of year is really special up here at 63 degrees north. I saw these streaks of ‘dark’ in the sky and I couldn’t work out if it was my eyes playing tricks or if they were coming from somewhere and what they would be coming from, in that case. It was between noon and 1pm. I realised, if it was something, it had to be the sunlight and it had to be blocked by something. Examining the sky, there were clouds. The angle of the sun in the sky was producing shadows that were so LONG and ANGLED that they appeared like long, unnatural streaks in the sky, some making landfall across the fjord and some making shadows beyond where I could even see. It really was something.

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Isn’t light just photons? Something that’s not there can’t move?

26mph. duh

186,282 miles per hour moving fast with light right on its heels.

-186,282

Ugh, you guys.

In order for something to have a speed, it has to be moving. In order for something to move, it has to exist.

Since darkness does not exist, it does not move, and it has no speed.

To put it another way: the question is like asking “if my car has a top speed of 100 mph, what is the top speed of no car?”

@Qingu ruined all the fun.

That’s my job.

@Qingu I happen to believe that the speed of no car is approximately 100 mph.

Usain Bolt?

GQ.

Darkness is nothing and as such, it goes at the speed of nothing.

For darkness to OCCUR, there has to be a sudden absence of LIGHT.

It’s a book about an autistic man, authored by Elizabeth Moon. ;)

@cazzie what about a dimmer switch? Where does the light start and the dark end?

J-E-L-L-O

Even in a dark room there is still ambient non-visible light (radio waves).

The entire universe is filled with ambient cosmic microwave background radiation, a form of light given off shortly after the big bang.

And even if you were to seal a portion of space off from all photons, the vacuum energy in that space can still spontaneously form photons in the form of virtual particles!

@digitalimpression absence of light means complete darkness. No room for a dimmer switch. Have you taken any physics classes? Know what a cd, fc, lm or lx mean?

But @Qingu the complete ‘theoretical’ darkness would occur when all light is gone and we know the rate at which that travels.

@cazzie Have you taken a society class? One in which sarcasm was a topic of discussion at any point?

There would still be virtual photons in the “theoretical darkness.”

No car goes at the same speed as the universe, whatever that speed limit happens to be in any given year.

@Dutchess_III “No car” is a bit subjective anyway as no “car” doesn’t mean no “bike”. The absence of one thing does not leave no thing. It leaves some thing. That something being “nothing”. Or… a bike.

No. A no bike has no spokes. A no car has no hub caps. BIG difference in the cosmos.

@Dutchess_III A no bike has no spokes true but… ahh hell.. we were done with that joke already weren’t we?

Anyway we’re putting ourselves into a pretty small paradigm. Dark could be the name of a person. If that’s the case than only someone who knows Dark and has timed him with a stopwatch can answer this correctly.

Dark does not move since technically it is nothing but the absence of light. Dark is not a thing of matter or an entity but refers to a lack of light so it doesn’t move. This is why black isn’t considered a color (except as a pigment maybe) because it is the absence of color.

@blueiiznh You’re an engineer, right? Are you just messing with everyone?

@cockswain engineer, yes. Not messing with ya.

In that case, I’d wager it is the motion of space absent any photons. However you mathematically define the motion of whatever quarks and dark energy are left. I guess. But I like Usain Bolt.

Ha! Great question. I’d wager dark is instantaneously anywhere light hasn’t gotten yet. It travels at the speed of nothing, which has no speed limit. That would catapault it back in time if it had time, but sadly, it has not.

Why must so many people be stiff and serious when approaching such a candid question? You guys are mono-chronic aren’t you?... admit it.

According to de Selby 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.

Please pass the salt.

How fast do you want it passed @erichw1504?

@Dutchess_III 186,283 mps, please.

Oh man. I so did that .000000186,283 seconds ago! See it now?

Yeah, I saw it tomorrow.