- #1
jackdale
- 4
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I have a question about the Second Law of Thermodynamics and the Stefan-Boltzmann law.
These quotes are from http://www.ces.fau.edu/nasa/module-2/correlation-between-temperature-and-radiation.php
“The Stefan-Boltzmann law, a fundamental law of physics, explains the relationship between an object's temperature and the amount of radiation that it emits. This law (expressed mathematically as E = σT4) states that all objects with temperatures above absolute zero (0K or -273°C or -459°F) emit radiation at a rate proportional to the fourth power of their absolute temperature. "
“Heat is energy in the process of being transferred from one substance (or object) to another. This process occurs when there is a temperature difference between the two substances. Heat is always transferred from a warmer object to a cooler one." (this is, I think, the gist of the Second Law of Thermodynamics.)
The first statement says that all bodies above 0 K emit heat energy, in all directions I presume.
The second seems to say that when two objects are in close proximity only the warmer body emits heat energy, the cooler body would only absorb heat energy.
Somehow it seems to me that both bodies would emit heat energy, the cooler body would only emit less. What would matter is NET HEAT TRANSFER.
I have found very few mentions of NET heat transfer in reference to the Second Law of Thermodynamics. I keep getting claims from those dismissive of climate science that the GHE violates the Law, because a cool body cannot transfer heat energy to a warm body.
Have I missed something?
BTW - I am not a physicist, so the question might seem naïve.
These quotes are from http://www.ces.fau.edu/nasa/module-2/correlation-between-temperature-and-radiation.php
“The Stefan-Boltzmann law, a fundamental law of physics, explains the relationship between an object's temperature and the amount of radiation that it emits. This law (expressed mathematically as E = σT4) states that all objects with temperatures above absolute zero (0K or -273°C or -459°F) emit radiation at a rate proportional to the fourth power of their absolute temperature. "
“Heat is energy in the process of being transferred from one substance (or object) to another. This process occurs when there is a temperature difference between the two substances. Heat is always transferred from a warmer object to a cooler one." (this is, I think, the gist of the Second Law of Thermodynamics.)
The first statement says that all bodies above 0 K emit heat energy, in all directions I presume.
The second seems to say that when two objects are in close proximity only the warmer body emits heat energy, the cooler body would only absorb heat energy.
Somehow it seems to me that both bodies would emit heat energy, the cooler body would only emit less. What would matter is NET HEAT TRANSFER.
I have found very few mentions of NET heat transfer in reference to the Second Law of Thermodynamics. I keep getting claims from those dismissive of climate science that the GHE violates the Law, because a cool body cannot transfer heat energy to a warm body.
Have I missed something?
BTW - I am not a physicist, so the question might seem naïve.