What colour is an orange in the dark

[draqon]

The whole point of "in the dark" is that there are no photons.

that remains to be tested! By other quantum particles whose lack of interactions with photons and thus lack of emission of sub-quantum particles would mean lack of photons alltogether.

 

[draqon]

I guess what I am trying to say really is that: "Not all darkness is dark"

In essence there might still be a photon there. and what about other forms of radiation, UV light...infrared...?

 

[Enmos]

You guys miss the point.

Tell me how is bombarding an orange with quantum particles any different that bombarding it with light for information? It isnt. Fundamentally it is an observation being made, which alters the "normal" wave-function we call orange.

For a forum where science is defended, right or wrong, I must say QM still draws alot of apprehension from people simply because its ideas are so strange. But this is not news either, "For those who are not shocked when they first come across quantum theory cannot possibly have understood it." -Niels Bohr

So what happens to beta-carotene in the dark that no one is aware of but you ?
How does it break down (and form other molecules perhaps) and then reassemble again instantly when the light is turned on ?

 

[madanthonywayne]

Interestingly there are a few examples of cases in which memory color does not work. For example, steak viewed under blue light tends to look blue (and a bit putrid), no matter how many steaks one has seen.

I think the difference there is that we know that the color of a car doesn't ordinarily change, and even if it does, no big deal. So our mind doesn't devote much "processing power" to an accurate determination of color in such a situation. On the other hand, if meat appears putrid, that's valuable information that shouldn't be ignored, so we pay attention.

Consider some alternative examples. When in the dark, we often see monsters or various other threats that aren't there. Why? In a situation where the lighting is poor, our mind assumes the worse and interprets the available data so as to minimize the risk of missing a real threat because failure to do so might get us killed. Alternatively, when we see a woman approaching we often overestimate her attractiveness and are dissapointed when she gets a little closer or enters an area with good light. Why? Again, our minds don't want us to miss an opportunity to mate with an attractive female, so in the absence of complete information, it assumes the best.

But a car, is it white or is it orange..............who cares. Glance at it, assume it's the same as before. Then concentrate on more important issues.

 

[Raithere]

An orange has no color regardless if it is in the dark or the light.

Color is a quale, a subjective quality of conscious experience and does not exist outside of the consciousness experiencing it.

An orange (the fruit) may reflect light waves that can stimulate such experiences but color is not a property of an orange, or indeed any object.

~Raithere

 

[DRZion]

I guess what I am trying to say really is that: "Not all darkness is dark"

In essence there might still be a photon there. and what about other forms of radiation, UV light...infrared...?

well, infrared is hardly orange. I agree with you however that "not all darkness is dark". There is a non-zero probability that any substance above 0 K will emit a photon anywhere in the visible spectrum, or beyond. Of course, this may happen only once every 1000 years, but its still going to happen sometime.

An orange actually does not emit orange light very well. It bounces back orange photons, meaning it is an orange-mirror; a mirror to the color orange. A mirror of any color is a poor emitter of that color due to Kirchoff's law, which states that emission=absorption. Clearly, a mirror does not absorb, and hence it does not emit.

You can think of this as an 'emission coefficient'. An orange has a low emission coefficient for orange.

So, if you place an orange across from a photomultiplier tube, you will notice two things:
- the detector will trigger itself since the detector itself, just like the orange, has a non-zero probability of emitting orange photons (this is known as noise)
- the orange will not emit orange very much.

so, if you take your data from two photomultiplier tubes stationed in the dark at the same temperature, the one without the orange across from it should actually detect slightly more orange photons than the photomultiplier across from the orange. In this case you would indeed have some experimental proof that the orange is still orange. The problem is that the experiment may take several thousand years to complete