<p>It's no different than when you walk into a dark room at night, with all the curtains down. It's all black, as there is no light. That, however, does not change whether the objects in that room have some <em>intrinsic properties</em>. The clothes hanging in the corner of the room will still be red/blue/green, even if at the moment you're looking around there is no light for you to perceive this property.</p>

CC BY-SA 4.0
2024-10-19T22:25:51.070Z
2024-10-24T02:54:56.517Z
2024-10-24T02:54:56.517Z
Wolfgang Bangerth
<p>In the absence of light, applicable light sensors (in mammals, cones in the retina) &amp; a means to discriminate between wavelengths of light, does color exist? <a href="https://www.livescience.com/34029-dog-color-vision.html" rel="nofollow noreferrer">Dogs do not see red &amp; green</a>, they see shades of gray.</p>
<p>Beauty may be within the eye of the beholder, but color is within the visual perception system of the beholder.</p>
<p>Visual properties of anything do not change in the presence of absence of light to reflect or be emitted from an object.</p>
<p>If nothing can detect photons of <a href="https://en.wikipedia.org/wiki/Visible_spectrum" rel="nofollow noreferrer">wavelength</a> of 390 nm, then what we attribute as the color red, is not seen by anything.</p>
<p>Also, what is color. The <a href="https://www.grunge.com/285728/the-real-reason-ancient-people-didnt-see-the-color-blue/" rel="nofollow noreferrer">ancient Greeks</a> never wrote about the color blue, whereas they did for other colors, does it mean they never saw blue, or did they, like the <a href="https://gondwana-collection.com/blog/how-do-namibian-himbas-see-colour" rel="nofollow noreferrer">Himbas of Namibia</a> categorize blue and green as being the same color?</p>

CC BY-SA 4.0
2024-10-09T01:34:52.697Z
2024-10-09T01:34:52.697Z
Fred
<p>This may be a silly answer.</p>
<p>I'd agree with the other answers - it would appear to us as black, because there is no light to reflect off of it into our retinas, but it seems like more of a philosophical question.</p>
<p>If you were to leave it unexposed to sunlight, I supposed it would continue to appear black.</p>
<p>That said, objects give off some amount of <a href="https://en.wikipedia.org/wiki/Black-body_radiation" rel="nofollow noreferrer">blackbody radiation</a>, although at cold temperatures (below maybe 500°C) this is in the infrared range of light (invisible to us). Above those temperatures, like a heating coil in a stove, or the sun's surface, red light &amp; other visible wavelengths of light can be emitted.</p>
<p>Interestingly, that commonly used cross-section of the Earth (shown below) seems to be colored somewhat similarly to a blackbody emission spectrum! This is most likely to show intuitively how 'hot' every layer is, not what it would actually look like.</p>
<p><a href="https://i.sstatic.net/HAbDHyOy.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/HAbDHyOy.png" alt="Earth Cross-section" /></a></p>
<p>(The Earth's mantle starts at ~1000°C - Red, and the Earth's core is estimated ~5000°C)</p>

CC BY-SA 4.0
2024-10-22T02:12:24.277Z
2024-10-22T02:12:24.277Z
Rowan
<p>I'm trying to understand what the interior of the Earth looks like before it is exposed to any light, specifically, are minerals all black?</p>

CC BY-SA 4.0
2024-10-08T13:12:39.110Z
[If a tree falls in a forest...](https://en.wikipedia.org/wiki/If_a_tree_falls_in_a_forest_and_no_one_is_around_to_hear_it,_does_it_make_a_sound%3F).  This is more of a philosophical question?  The spectral properties don't change upon exposition to sunlight, but is a red object still red if it's invisible due to lack of light?  I'd argue it's still red, but how is this an Earth Science question?
gerrit
CC BY-SA 4.0
2024-10-10T08:22:18.033Z
@gerrit Are spectral properties independent of temperature and pressure? Does thermal radiation absolutely not contain photons of visible light?
Imyaf
CC BY-SA 4.0
2024-10-24T21:48:25.813Z
No. Without an unknown process that changes the colour the moment light hits it, no. The most basic of observation will show it. Take a spade, dig stuff up - apart from stuff that actually is black, no minerals come out black and suddenly (or progressively) gain their colours. .
Ken Fabian
CC BY-SA 4.0
2024-10-25T01:24:04.290Z
No it would be infrared colored, light is not limited ot the visible portion of the spectrum. Lots of infrared underground, more the deeper you go.
John
<geology>
As there is no light beneath the surface of the Earth, are all minerals black until they are exposed to sunlight by humans or weathering?
Peter Rosewarne
# As there is no light beneath the surface of the Earth, are all minerals black until they are exposed to sunlight by humans or weathering?

(Asked by: username_0 on 2024-10-08)

I'm trying to understand what the interior of the Earth looks like before it is exposed to any light, specifically, are minerals all black?

**Tags:** geology

> **Comments:**
> **username_1**: [If a tree falls in a forest...](https://en.wikipedia.org/wiki/If_a_tree_falls_in_a_forest_and_no_one_is_around_to_hear_it,_does_it_make_a_sound%3F).  This is more of a philosophical question?  The spectral properties don't change upon exposition to sunlight, but is a red object still red if it's invisible due to lack of light?  I'd argue it's still red, but how is this an Earth Science question?  
> **username_2**: @username_1 Are spectral properties independent of temperature and pressure? Does thermal radiation absolutely not contain photons of visible light?  
> **username_3**: No. Without an unknown process that changes the colour the moment light hits it, no. The most basic of observation will show it. Take a spade, dig stuff up - apart from stuff that actually is black, no minerals come out black and suddenly (or progressively) gain their colours. .  
> **username_4**: No it would be infrared colored, light is not limited ot the visible portion of the spectrum. Lots of infrared underground, more the deeper you go.  

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## 3 answers

### Answer by username_5 on 2024-10-19. Score: 3

It's no different than when you walk into a dark room at night, with all the curtains down. It's all black, as there is no light. That, however, does not change whether the objects in that room have some *intrinsic properties*. The clothes hanging in the corner of the room will still be red/blue/green, even if at the moment you're looking around there is no light for you to perceive this property.


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### Answer by username_6 on 2024-10-09. Score: 1

In the absence of light, applicable light sensors (in mammals, cones in the retina) & a means to discriminate between wavelengths of light, does color exist? [Dogs do not see red & green](https://www.livescience.com/34029-dog-color-vision.html), they see shades of gray.

Beauty may be within the eye of the beholder, but color is within the visual perception system of the beholder.

Visual properties of anything do not change in the presence of absence of light to reflect or be emitted from an object.

If nothing can detect photons of [wavelength](https://en.wikipedia.org/wiki/Visible_spectrum) of 390 nm, then what we attribute as the color red, is not seen by anything.

Also, what is color. The [ancient Greeks](https://www.grunge.com/285728/the-real-reason-ancient-people-didnt-see-the-color-blue/) never wrote about the color blue, whereas they did for other colors, does it mean they never saw blue, or did they, like the [Himbas of Namibia](https://gondwana-collection.com/blog/how-do-namibian-himbas-see-colour) categorize blue and green as being the same color?


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### Answer by username_7 on 2024-10-22. Score: 0

This may be a silly answer.

I'd agree with the other answers - it would appear to us as black, because there is no light to reflect off of it into our retinas, but it seems like more of a philosophical question.

If you were to leave it unexposed to sunlight, I supposed it would continue to appear black.

That said, objects give off some amount of [blackbody radiation](https://en.wikipedia.org/wiki/Black-body_radiation), although at cold temperatures (below maybe 500°C) this is in the infrared range of light (invisible to us). Above those temperatures, like a heating coil in a stove, or the sun's surface, red light & other visible wavelengths of light can be emitted.

Interestingly, that commonly used cross-section of the Earth (shown below) seems to be colored somewhat similarly to a blackbody emission spectrum! This is most likely to show intuitively how 'hot' every layer is, not what it would actually look like.

[![Earth Cross-section](https://i.sstatic.net/HAbDHyOy.png)](https://i.sstatic.net/HAbDHyOy.png)

(The Earth's mantle starts at ~1000°C - Red, and the Earth's core is estimated ~5000°C)


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