Christos Vournas | November 29, 2021 at 6:56 am |
What I would like to discuss is the planet theoretical blackbody temperature being a highest temperature a planet without-atmosphere average surface temperature may reach…
I very much disagree with that concept. That concept is expressed as:
Tmean ? Te which I disagree with.
What actually happens is:
Tmean ? Te for planets and moons with a lower planet surface and
Tmean ? Te for planets and moons with a higher planet surface ”
The best way is to conceive of a true BB [black body] temperature that would approach the SB concept in real life.
This can only be achieved by having a uniform globe of radiation around a planet.
Further the source of the radiation would have to be totally transparent to the radiation coming back out.
To prevent back radiation problems.
A bit like Willis’ steel globe model at WUWT but not really.[ that has back radiation.
In such a setting the energy in would truly equal the energy out. [apart from the Curious George random U235 and the internal heat of some planets type arguments].
This in itself creates other problems such as why the energy does not go into and be “stored” in the planet. as well as radiating out.
The answer that energy cannot be stored is easier here.
As it is in balance it is easy to see that what goes in on one side is coming out on the other side everywhere, even though standard physics says it is “heating up”.
What is actually happening is that the bucket is being filled rapidly and empties rapidly. The bucket in a higher energy transition state [energy in and out, not stored, appears to us as hot.
The true internal energy of mass does not change.
What we measure, as the temperature, is never the temperature of the mass but that of the energy being transferred through it.
What we see say a red sword going white hot or even melting is merely the difference in radiation coming out[which is what went in.
The state of the mass appears to alter, does alter in our world, but does not have any more natural internal energy. Mass is is unchanged still a one size bucket. , our perception of the mass is altered.
GHG help form a multi level layered surface capable of interacting with electromagnetic energy.
In an airless water less planet both the SW and IR hit the solid [if far enough away from the heat source] surface penetrating fewer but much more condensed layers of molecules for a few mm.
Albedo alone dictates how much SW is taken up.
The amount of energy absorbed is possibly over counted as albedo is generally considered to be visible light but it is possible that longer [and shorter] wavelengths might have some reflection as well but this is not mentioned by anyone.
One reason may be an assumption that IR is too widespread in its wavelengths to be capable of being reflected but this is possibly not true.
Ina planet with an atmosphere the level of absorption changes from a few mm to 100 kilometers or more. with most occurring in the final 10 kilometers.
This energy is not stored . Once it interacts with matter it moves back out.
On the way in and on the way out the energy,now a lot more at IR wavelengths can either reflect back out to space, move sideways or go further down.
The energy is not being stored, just continually being redirected.
The mass and the internal energy of the mass does not change [except in a nuclear reaction which is outside the scope of explaining existing energy transfer.
Consequently all the energy goes back out again at the rate it is coming in.
and extremely quickly.
If it did not do this it would buildup in an unstoppable storage feedback loop and become hotter than the original distant source.
We all know it does not and cannot do this or we would have a way of making infinite energy from a finite energy source.
I guess an easier way for people to try to understand this is to consider an impermeable, non conducting perfectly flat surface barrier.
It would have to send all the energy straight back where it came from.
A lot of imponderables here.
If EM had mass then it would have to make the mass it hit move further away due to the force it exerted.
If it reflects it would have to push the mass away twice as hard.
If it had mass the force it possesses would have to have a force vector which would demand one of the two results above.
If not then we would have to say that force meeting a mass reacts in two different ways.
One, a reversal of direction mediated without a change in the mass field settings.
This is possible if one considers a completely reflective [white body].
It does not change in temperature .
Two, a reversal of direction mediated by a change in the mass field setting.
This leads to the mass altering to change of position of where the mass appears to be [movement of a molecule].
At the same time the original energy is sent back in the same direction.
Where the EM energy goes deeper into a layer before being sent back a problem arises with potential reabsorption on the way out which could send it back in again.
Since there are more molecules on the way in than out all of the light will shortly be remitted to space.
GHG are molecules that absorb and re-emit energy rather than reflecting it.
The GHG effect is real and necessary as part of this system.
An argument against this is that there is a finite time between absorption and emission of energy in this setting. The problem with accepting this is that storage of energy would be admissable.
Another is the actual motion of the molecules.
A third the lag in temperatures changing direction after the longest and shortest days occur.
Which in turn would overturn the SB law, as far as I can understand.
I am still trying to work out a way to combine these two apparent opposites.