On Sunday, 9 August 2015 09:35:20 UTC+1, Martin Brown wrote:
On 07/08/2015 23:21, Alan LeHun wrote:
In article ,
says...
Exactly, if the radiation a body receives is from a cooler body,
then the first body will cool. So it is possible to cool a body with
radiation, and it only makes sense to call it cold radiation.
You are confusing and conflating the net flux of energy with
temperature.
No, you are.
An object doesn't care about its surroundings it emits
radiation according to its own absolute temperature and surface
emissivity.
True.
The balance between the net fluxes of emitted and received
radiation determines the objects final equilibrium temperature.
Yes, but the output flux is fixed by the object's temperature, as you have just written. So the only way you can change the temperature is by alterations to the input flux. You raise the temperature with radiation from a hotter source and cool it with radiation from a cooler source, i.e. cold radiation.
You cool
a body by lack of incident radiation like when the sun goes down or the
sky clears at night.
When that happens the input flux is background radiation at 4K. That is what cools the surface. If the sky is cloudy, then the cooling is not as great, because the radiation from the clouds is not as cold. But it is cold relative to the Earth's surface, and so the surface cools to its temperature. In other words, the rate at which the Earth's surface cools depends on the temperature at which the incoming radiation is generated (modified by the effects of greenhouse gases).
I thought initially that you were trolling but it is now clear that you
do not understand the subject of radiative heat transfer at all.
I thought you were smart, but I see you are just as incapable of revising your preconceived ideas as Dawlish. But he's got an excuse. He isn't interested in the truth, only in making me appear foolish. I had thought you were better than that :-(
I think this is one of those things where having explained modern
thermodynamics patiently and with several different approaches we have
to consign Alastair to the same netkook status as Oriel36 in the
astronomy groups (he can't cope with sidereal days being fundamental).
That is an example of you explaining modern thermodynamics is it. All you have said is that when the sun goes down it gets colder!
We will end up going over the same ground forever. He will never be
convinced that he is wrong. All we can do is make sure that mainstream
thermodynamics is represented whenever this dross comes up again.
And you will never be convinced I am right. You ignore my arguments, and dismiss any evidence I present. You haven't even read the paper on the Pictet Experiment.
You wouldn't call the water going into a bucket, drippy water, and the
water coming out it, leaky water, and then try and claim that drippy
water and leaky water are somehow different types of water.
How about lumping it in with phlogiston, polywater and N-rays?
"Cold radiation" is from the same stable.
I bet you enjoyed writing that but it has nothing to do with science.
Cheers, Alastair.