Post by icefisher on Jan 25, 2016 0:09:24 GMT
Much is misunderstood about cooling. Especially people with no practical experience take the Engineeringtoolbox Net Radiation chart too seriously.
There is absolutely nothing wrong with it except for the typo in the subtitle.
But a lot of people don't understand how it actually works, which if you are a heating engineer in a critical design area you better actually know.
The curve demonstrates that the cooling rate of a heated object will be slowed by a cooler object with a temperature above absolute zero. Absolute fact and the curve is right on the mark.
But what people fail to recognize here for practical application in an active thermodynamic process this is a "snapshot".
The actual cooling rate in the real world where things may not be completely in equilibrium is the actual cooling rate of the hot object is the value pulled from the Net Radiation Chart plus the cooling rate of the cooler object.
In other words dynamically the heated object is heating the cooler object while the cooler object is cooling itself. If the actual rate of cooling was not both the Chart value plus the cooling rate of the cooler object would get colder and at the rate its cooling and the Enginneers curve will be right there to instantly fill that void.
Thus this is the reason a cooler brick put between say outer space and a hot radiating object, the brick will cause the hot radiating target to continue to warm up if and only if the back radiation is greater than the backside (facing outwards) radiation.
Since all the cartoons depicting the greenhouse effect is about CO2 molecules absorbing photons then slinging them in all directions its not going to warm anything if the backradiation is the same as the front radiation. Which is the case with all the neat diagrams labeled by Andrew over the years.
He then has a fit when I suggest the brick is going to do a better job because conduction through a few billion layers of molecules in a brick is going to slow heat loss. Yeah it will. It will because the brick cooling rate is slower than a molecule of CO2.
Now all that is not to say there is no radiant greenhouse effect.
There are lots of stuff going on in the atmosphere. . . .clouds being a biggy. There is more. For example, the blackbody radiant temperature of the atmosphere is not the same as the surface. Its twice that. The surface blackbody temperature is given as 5.5C. The blackbody temperature of the atmosphere is 59C. Only the thermosphere gets that hot. The rest is cooled by water and diffusion and by depressurization via convection.
There also is the combined conduction/radiation delay from an absorption to leaving the atmosphere. Nobody I think knows what that is.
Conduction is slow because of billions of electric transactions occurring. Electricity is slowed by the length of a wire and the conductance of that wire. Mathematics fails to describe it because conduction gets to a point of astronomic speeds as a substance becomes thinner. . . .enabling neat engineered devices for measuring radiation using thin coatings of highly sensitive thermoresistant substances.
I am not sure though anybody is even trying to calculate that. Seems everybody is working on models to try to get them to match predictions, kind of the new science where mathematicians have gone nuts trying to solve computationally intense problems from observations.
Andrew keeps saying if I were right about this I would win a Nobel Prize. But its hard to figure how anybody wins anything but a Nobel Peace prize through observing something Engineers have known since God knows when.
As near as I can tell this all basic stuff. Read State of Fear from Michael Crichton. He covers it all from the evil scientist lured by the dollars connected to the carrot, to the innocent scientist that takes from many publications, professors, and the yet to be completely vetted hypotheses of celebrated scientists via an innocent reference to what may or may not be a fact. Thats how adulterated science becomes popular science. No different than when the Pope put Galileo under house arrest and they burn't Giordano Bruno at the stake with the applause of many sycophant scientists.
Read up on Trofim Lysenko and the program that allegedly led to 3,000 mainstream biologists being sent to prison or fired or executed for opposing Lysenko's ideas.
There is absolutely nothing wrong with it except for the typo in the subtitle.
But a lot of people don't understand how it actually works, which if you are a heating engineer in a critical design area you better actually know.
The curve demonstrates that the cooling rate of a heated object will be slowed by a cooler object with a temperature above absolute zero. Absolute fact and the curve is right on the mark.
But what people fail to recognize here for practical application in an active thermodynamic process this is a "snapshot".
The actual cooling rate in the real world where things may not be completely in equilibrium is the actual cooling rate of the hot object is the value pulled from the Net Radiation Chart plus the cooling rate of the cooler object.
In other words dynamically the heated object is heating the cooler object while the cooler object is cooling itself. If the actual rate of cooling was not both the Chart value plus the cooling rate of the cooler object would get colder and at the rate its cooling and the Enginneers curve will be right there to instantly fill that void.
Thus this is the reason a cooler brick put between say outer space and a hot radiating object, the brick will cause the hot radiating target to continue to warm up if and only if the back radiation is greater than the backside (facing outwards) radiation.
Since all the cartoons depicting the greenhouse effect is about CO2 molecules absorbing photons then slinging them in all directions its not going to warm anything if the backradiation is the same as the front radiation. Which is the case with all the neat diagrams labeled by Andrew over the years.
He then has a fit when I suggest the brick is going to do a better job because conduction through a few billion layers of molecules in a brick is going to slow heat loss. Yeah it will. It will because the brick cooling rate is slower than a molecule of CO2.
Now all that is not to say there is no radiant greenhouse effect.
There are lots of stuff going on in the atmosphere. . . .clouds being a biggy. There is more. For example, the blackbody radiant temperature of the atmosphere is not the same as the surface. Its twice that. The surface blackbody temperature is given as 5.5C. The blackbody temperature of the atmosphere is 59C. Only the thermosphere gets that hot. The rest is cooled by water and diffusion and by depressurization via convection.
There also is the combined conduction/radiation delay from an absorption to leaving the atmosphere. Nobody I think knows what that is.
Conduction is slow because of billions of electric transactions occurring. Electricity is slowed by the length of a wire and the conductance of that wire. Mathematics fails to describe it because conduction gets to a point of astronomic speeds as a substance becomes thinner. . . .enabling neat engineered devices for measuring radiation using thin coatings of highly sensitive thermoresistant substances.
I am not sure though anybody is even trying to calculate that. Seems everybody is working on models to try to get them to match predictions, kind of the new science where mathematicians have gone nuts trying to solve computationally intense problems from observations.
Andrew keeps saying if I were right about this I would win a Nobel Prize. But its hard to figure how anybody wins anything but a Nobel Peace prize through observing something Engineers have known since God knows when.
As near as I can tell this all basic stuff. Read State of Fear from Michael Crichton. He covers it all from the evil scientist lured by the dollars connected to the carrot, to the innocent scientist that takes from many publications, professors, and the yet to be completely vetted hypotheses of celebrated scientists via an innocent reference to what may or may not be a fact. Thats how adulterated science becomes popular science. No different than when the Pope put Galileo under house arrest and they burn't Giordano Bruno at the stake with the applause of many sycophant scientists.
Read up on Trofim Lysenko and the program that allegedly led to 3,000 mainstream biologists being sent to prison or fired or executed for opposing Lysenko's ideas.