Gold Detecting and Prospecting Forum
Would you like to react to this message? Create an account in a few clicks or log in to continue.

For Butch :Can a blanket violate the second law of thermodynamics?

Go down

For  Butch :Can a blanket violate the second law of thermodynamics? Empty For Butch :Can a blanket violate the second law of thermodynamics?

Post  planetcare Thu May 19, 2022 4:41 pm

For Butch :Can a blanket violate the second law of thermodynamics?
One of the silliest arguments of climate deniers goes like this: the atmosphere with its greenhouse gases cannot warm the Earth’s surface, because it is colder than the surface. But heat always flows from warm to cold and never vice versa, as stated in the second law of thermodynamics.
The freshly baked Australian Senator Malcolm Roberts has recently phrased it thus in his maiden speech:
It is basic. The sun warms the earth’s surface. The surface, by contact, warms the moving, circulating atmosphere. That means the atmosphere cools the surface. How then can the atmosphere warm it? It cannot. That is why their computer models are wrong.
This is of course not only questions the increasing human-caused greenhouse effect, but in general our understanding of temperatures on all planets, which goes back to Joseph Fourier, who in 1824 was the first to understand the importance of the greenhouse effect.
The atmosphere acts like a blanket which inhibits heat loss. In fact according to Roberts’ logic, a blanket could also not have a warming effect:
It’s simple. The body warms the blanket. This means that the blanket cools the body. So how can the blanket warm it? It cannot!
The answer is simple. The warm body loses heat to the cold air. The blanket inhibits and slows this heat loss. Therefore you stay warmer under a blanket.
The Earth loses heat to the cold universe. The atmosphere inhibits this heat loss. Therefore, the surface remains warmer than it would be without the atmosphere.
It is true that the surface loses heat to the atmosphere – but less than it would otherwise lose directly to space. Just as I lose less heat to the blanket than I would otherwise lose to the air, without blanket.
Of course, in neither case is the second law of thermodynamics violated. The heat always flows from warm to cold – just more or less effectively. The processes of heat transfer are quite different – for the blanket it is mainly heat conduction, for the greenhouse effect it is thermal radiation. The climate deniers claim that the colder atmosphere cannot radiate thermal radiation towards the warmer surface. This is of course nonsense. The cool Earth also sends thermal radiation towards the hot sun – how would thermal radiation leaving Earth know how warm the surface is that it’s going to hit? It’s just that the sun sends more radiation back to us  – the net flow is from hot to cold. More is not implied by the second law of thermodynamics.

Contributor Plus
Contributor Plus

Number of posts : 652
Registration date : 2019-09-27

Back to top Go down

Back to top

Permissions in this forum:
You cannot reply to topics in this forum