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sophiecentaur
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Or Dollop!
DaleSpam said:My two cents: the amount of radiant intensity at visible wavelengths from a 3 K black body is so low that the resulting photons would be discrete events. So there would be periods between them where the interior of the box is perfectly dark.
DaveC426913 said:Why? Since it doesn't fit the other definitions - eg. energy is not tangible and is not matter - why redefine a word that means one thing to mean something else? Why not redefine matter to include energy? Or solid to include vacuum? Or 'one' to include all numbers up to ten?
DaveC426913 said:Not to mention the fact that it has yet to be quantified if it is going to be used in physics.
We can't use kg, as that is a matter unit. We can't use Joules as that is an energy unit. I propose we use the unit gubbin.
"This volume of space contains several planets - at least a Gigagubbin. But it is also strongly irradiated by its sun, comprising another 2 Gigagubbins of substance."
It is easy to detect a single photon with a photomultiplier tube. I would draw the line there. If a PMT cannot detect light then I would say it is perfectly dark at that time.sophiecentaur said:Where would you draw the line?
Or half the time when they are working they are dark.sophiecentaur said:Now you see it - now you don't?
A bit like the direction indicators on my car. Half the time they're not working!
The connection between mass (in case you intended this with "matter") and energy is very simple: a system's mass is its energy (divided c2) in a frame of reference where the system is stationary. A photon has no mass, but a photon in a stationary box gives mass to it. The same for the photons in the universe: they give mass to it. Someone made the computation of the total mass given to the universe by CMBR's photons, but it doesn't approach dark matter's mass (for example).phaeton said:In the same way I believe waves and particles to be defining each other and making up the whole that is light. This discussion has lead me to believe there may even be a similar connection between matter and energy. This would mean that both are intrinsic in each others very being, lending credence to the possibility that both posses substance.
phaeton said:Considering that what most people think of as light is just the visible spectrum of electromagnetism, while much more exists on either end, are the frequencies beyond either end of the visible spectrum still light? If so, since electromagnetic fluctuations permeate the known universe, is there any such thing as true darkness?
A black hole is rather dark. But the collapsing matter around it might obscure the view on its absolute darkness.phaeton said:Considering that what most people think of as light is just the visible spectrum of electromagnetism, while much more exists on either end, are the frequencies beyond either end of the visible spectrum still light? If so, since electromagnetic fluctuations permeate the known universe, is there any such thing as true darkness?
A.T. said:A black hole is rather dark. But the collapsing matter around it might obscure the view on its absolute darkness.
Jay Nazareth said:Using what everyone has posted it could be that photons are a substance, since everything is composed of energy.