“… space will always have something in it. Matter, energy (dark of otherwise), marshmallows (mini or otherwise), whatever.”

Wait … so, marshmallows aren’t considered “matter” now?

Perhaps they’re made of antimatter. I hesitate to think what all those antisugar molecules must be doing to the atoms lining my stomach and intestines….

And I’d guess that death is pretty black.

The important thing to know is that energy (including mass) is not the only thing that curves space and affects the evolution of the universe – the Pressure that comes with the source of energy also needs to be taken into account. See this:

http://math.ucr.edu/home/baez/einstein/node8.html

“Require” is an absurdly strong word. We don’t know enough about the heredity of colour perception in the first place. We do know, however, that brain structures are only hereditary in the form of vague and general tendencies and show noticeable variation and plasticity.

re: black as a color: It definitely is a color. Just about every color gamut includes black or a set of blacks. If you’ve ever bought a large screen television, one of the specifications is how black a black it can produce, that is, how it renders the pixel RGB(0, 0, 0). Of course, there are an awful lot of blacks. I used to have a Pantone guide to black on black printing. It was a 200+ page looseleaf with thousands of samples of how one could print in black ink on black paper. There are also an awful lot of reds, and blues and greens and so on, though I don’t think Pantone sells similar X on X printing books for other colors.

Infra red, ultra violet, speculative popular hypothesis’s like dark energy and the “big bang” – - not relevant at all.

In that context, blackest black I’ve experienced was deep in a twisty cave system in Westbrookville NY, where I turned off my lights for about an hour for a nap (it was a very effort-intensive excursion); when I woke up, I literally couldn’t see my hands in front of my face. Black? Yep.

Aside from that, I consider the regions between magnitude 13 stars essentially black, because I haven’t been able to get my camera (at ISO 12800 and f/1.4, about 4 seconds) to register any light from there, though I can image magnitude 13 stars. So there’s an instrument-based perception of mine. Is there more light there? Yes – but since I can’t see it, you know, it’s kinda irrelevant to me. The day I get an ISO 102k camera in my hot little hands, that will change. I wouldn’t mind an 85mm f/1.2 lens, either; had one, sold it, regret it.

So, yes. I’ll take that pair of shoes in black, because they’ll look rather nice with my black jacket, I should think.

“In fact, YOU could never know if you also experienced color reversal. How could you? There is no possible test that could detect it.”

To say that there is no possible test to detect it is quite an amazing claim; I would put it in the same category as “humans cannot build machines which fly”. However, I will not argue a case unless you can point out how such a reversal can occur in the first place. After all, it will require a substantial violation of the laws of heredity. I do not like to speculate on the characteristics of imaginary things which defy nature such as gods.

Now back to blackness: I disagree with the B.A. – of course you can have perfect blackness. The radiation which our eyes is not sensitive to can hardly be called ‘color’. If we perceive no light, then we have black. The fact that photons are everywhere is immaterial since we cannot detect them with our eyes.

On a more relevant point, in which contexts is the proposed definition of colour supported and/or not in conflict? And where it is in conflict with common language, to what extent would the rest of the language need refurbishing for it to fit? Related: What term or change in formulation would replace the old, now unwanted, uses of “colour”?
(E.g. What would be proposed in paintery as a more accurate category name for encompassing the now-colours? I do not doubt that there are synonyms, such as “tinge”, though one would have to justify why black would be a tinge if not a colour. A new constuct or another changed usage would be able to fill the role.)
More importantly, what does the new definition have to offer in terms of communication or other usefulness?

There is an average of roughly one subatomic particle per cubic meter out there, which is incredibly rarified There are 336/cm^3 Big Bang neutrinos: 56 each neutrinos and antineutrinos each in three flavors. Given rest mass-equivalent not exceeding 0.2 eV, only Big Bang neutrinos red-shifted by cosmic inflation to 1.945 kelvin or 1.68×10^(-4) eV are non-relativistic, possessing helicity but not chirality. Neutrinos decoupled about one second after the Big Bang at 2.5 MeV temperature. Photons decoupled about 377,000 years after the Big Bang at 0.5 eV temperature. Primordial neutrinos are colder than cosmic microwave background at 2.725 K because the neutrino transparency point came earlier in the expansion.

How much energy does space have? …Some estimates put it at a very tiny 10^(-15) Joules per cc Vacuum zero point fluctuations do not appear Doppler shifted and are Lorenz-invariant: intensity varies as the cube of ZPF frequency. The grain of space appears near 10^(-33) cm, the Planck length. Integrating intensity over allowed frequencies gives 10^94 gm/cm^3. Nuclear density is 2×10^14 gm/cm^3.

What the heck does all this mean? Beats me. GOOD MAN! Orthodox physics has huge problems with observation versus derived theory: 1 biological homochirality, 2) chiral beta-decay rate annual modulation (arxiv:1004.1761), 3) divergence of chiral neutrino-antineutrino reaction channels (arxiv:1007.2923, 1007.1150v3), 4) no SUSY partners, 5) Weak interaction chirality, 6) matter absent antimatter, 7) false vacuum decay powering cosmic inflation, 7) all quantum gravitation formulations are empirical crap.

Physical chirality is emergent from aggregation. Fundamental symmetries from which physical theory rigorously derives – classical and quantum gravitation, Standard Model and SUSY – exclude chirality. Symmetry breakings are inserted by hand to rationalize the observed universe. Let’s strop Occam’s razor: The Big Bang was intensely chiral with a false vacuum pseudoscalar background (left foot) active only in the massed sector. Generic weak interactions are left and right shoes but strong interactions blur chirality into socks. A contemporary vacuum background chiral remnant – active only in the massed sector – is testable in a geometric parity Eotvos experiment. Here are two such experiments, chemically and macroscopically identical left- vs. right shoes,

http://www.mazepath.com/uncleal/erotor1.jpg
Somebody should look. The worst they can do is succeed.

Reminds me of the recent post here on how “brown dwrafs” are actually mauve

Which would be this one :

http://blogs.discovermagazine.com/badastronomy/2010/11/12/wise-finds-the-coolest-star-literally/

Another really black object one that is literally jet black is here :

http://en.wikipedia.org/wiki/Jet_(lignite)

While Pitch Black :

http://en.wikipedia.org/wiki/Pitch_Black_(film)

is something somewhat different again!

@1. Kirk Aplin Says:

I think zero is a number. A number answers the question “How much?”. Nothing is just a valid an answer to that question as something, so zero is just a valid answer as π.

“Nothing? Nothing shall come of nothing!” To quote Shakespeare’s King Lear – both play and eponymous monarch. Yet something *shall* come of nothing after all & that’s the debate over whether nothing is some thing or rather some quantity!

Is zero a number? Well yes & no. It is mathematical and arithmatical concept and it does count and help you count so it isn’t just nothing! Even though it is and refers to the absence of everything and cannot be divided or multiplied.

I’ll leave someone else to do a number on how you define, well, “number” except to note that it could be ennumerated as a number of things!

@40. John Paradox Says:

So, if there’s no real Black in the Universe, that means I don’t have to worry when a ‘black’ cat crosses my path?

Of course not! Black cats are good luck as well as good mousers, good acrobats and good lap-warmers – as I can attest having owned a couple of them, my curent cat being one.

@32. Mike Torr :

P.S. Apologies to Americans for “grey”, “colour” and “maths”

Er, actually I think *they* should be apologising to *us*! It is the English language, after all, not the American one!

@30. Brown Says:

A good astronomy question is: what color is Earth’s Moon?
Most people would say “white,” since it certainly LOOKS white against the blackness of a starry sky. And yet, the Moon reflects about as much light as asphalt, which most people would call “black” without hesitation. The astronauts who went to the Moon, and who knew in advance that the Moon was a relatively dark body, were nevertheless surprised by the blackness of the rocks that they found on the “white” Moon. Every now and then, someone says that “Black is not white and white is not black.” And yet, the Moon is an object that could be truthfully be called either black or white.

Great point & well said.

Reminds me of the recent post here on how “brown dwrafs” are actually mauve and how our Sun & other “yellow” G type stars are actually *white* rather than yellow – although their peak radiation is actually emitted mostly in the green frequency.

Plus how seemingly dark sunspots would be brilliantly white or red if they were seen separately off the solar (or stellar) surface and black holes – as Stephen Hawking pointed out aren’t really black either!

Our eyes *do* decieve us on many things and impressions of colours are certainly among those things.