Beam me to Planet Gore !
Posted on 12/06/2009 2:23:33 AM PST by plenipotentiary
Description of simple experiment that shows CO2 can't cause warming by trapping Infra Red (Credit to mystery blogger)
The claim that carbon dioxide (CO2) can increase air temperatures by "trapping" infrared radiation (IR) ignores the fact that in 1909 physicist R.W. Wood disproved the popular 19th Century thesis that greenhouses stayed warm by trapping IR. Unfortunately, many people who claim to be scientists are unaware of Wood's experiment which was originally published in the Philosophical magazine , 1909, vol 17, p319-320.
Wood was an expert on IR. His accomplishments included inventing both IR and UV (ultraviolet) photography. Wood constructed two identical small greenhouses. The description implies the type of structure a gardener would refer to as a "coldframe" rather than a building a person could walk into. He lined the interior with black cardboard which would absorb radiation and convert it to heat which would heat the air through conduction. The cardboard would also produce radiation. He covered one greenhouse with a sheet of transparent rock salt and the other with a sheet of glass. The glass would block IR and the rock salt would allow it to pass.
During the first run of the experiment the rock salt greenhouse heated faster due to IR from the sun entering it but not the glass greenhouse. He then set up another pane of glass to filter the IR from the sun before the light reached the greenhouses. The result from this run was that the greenhouses both heated to about 50 C with less than a degree difference between the two. Wood didn't indicate which was warmer or whether there was any difference in the thermal conductivity between the glass sheet and the rock salt. A slight difference in the amount of heat transfered through the sheets by conduction could explain such a minor difference in temperature. The two sheets probably didn't conduct heat at the same rate.
The experiment conclusively demonstrates that greenhouses heat up and stay warm by confining heated air rather than by trapping IR. If trapping IR in an enclosed space doesn't cause higher air temperature, then CO2 in the atmosphere cannot cause higher air temperatures. The heated air in the greenhouses couldn't rise higher than the sheets that covered the tops of the greenhouses. Heated air outside is free to rise allowing colder air to fall to the ground. Atmospheric CO2 is even less likely to function as a barrier to IR or reflect it back to reheat the ground or water than the sheet of glass in Wood's greenhouse. The blackened cardboard in Wood's greenhouses was a very good radiator of IR as is typical of black substances. The water that covers 70% of earth's surface is a very poor radiator and produces only limited amounts of IR as is typical of transparent substances. Water releases heat through evaporation rather than radiation. The glass sheet provided a solid barrier to IR.
Atmospheric CO2 is widely dispersed comprising less than 400 parts per million in the atmosphere. Trapping IR with CO2 would be like trying to confine mice with a chain link fence. Glass reflects a wider spectrum of IR than interacts with CO2. The glass sheets reflected IR back toward the floor of the greenhouse. CO2 doesn't reflect IR. At the time of Wood's experiment, it was believed that CO2 and other gas molecules became hotter after absorbing IR. Four years later Niels Bohr reported his discovery that the absorption of specific wavelengths of light didn't cause gas atoms/molecules to become hotter. Instead, the absorption of specific wavelengths of light caused the electrons in an atom/molecule to move to a higher energy state. After absorption of light of a specific wavelength an atom couldn't absorb additional radiation of that wavelength without first emitting light of that wavelength. (Philosophical Magazine Series 6, Volume 26 July 1913, p. 1-25) Unlike the glass which reflects IR back where it comes from, CO2 molecules emit IR up and sideways as well as down. In the time interval between absorbing and reemitting radiation, CO2 molecules allow IR to pass them by. Glass continuously reflects IR.
Those who claim that CO2 molecules in the atmosphere can cause heating by trapping IR have yet to provide any empirical scientific evidence to prove such a physical process exists. The experiment by R.W. Wood demonstrates that even a highly reflective covering cannot cause heating by trapping IR in a confined space. There is no way CO2, which at best only affects a small portion of the IR produced by earth's surface, can heat the atmosphere by trapping IR. Contrary to the lie repeated in news stories about climate, science doesn't say that CO2 is causing higher temperatures by trapping IR. Empirical science indicates that no such process exists in this physical universe.
What does that say about Carl Sagan’s “Super Greenhouse(TM)” theory which supposedly explains the 900F surface temperatures on Venus??
I notice there’s no “link” on this one. Can you give us a link so we can link other blogs to it?
Thanks
the link doesn’t work
the link doesn’t work
Link http://globalwarmingnot.blogtownhall.com/2009/02/03/greenhouse_theory_disproved_a_century_ago.thtml
Ping for later
Interesting that the CRU scammers have only tried to show the correlation between CO2 levels and temperature and had to resort to faking data to fit their model. However even if there was correlation that does not mean causation. This Woods experiment pretty well demonstrates that even if there were a correlation between CO2 levels and temperature (which there isn’t) there is no model to show the physics of how CO2 traps the heat.
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Thanks wendy1946 for the ping. |
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Say, isn’t this ping completely opposite to your immediately previous ping?
Bumping...
Hey, I report, you decide. ;’)
That should provide pretty good debunking ammunition against the Greenie Meany Wienies.
Could it be that Venus is closer to the Sun? Could there be other factors on Venus in addition to CO2 levels that would make the planet hotter? When dealing with other planets, there are so many unknowns. Unless someone actually goes to the other planet, such things will be no more than a theory.
All the more because we must overwhelm our leftist opponents with the Truth as often, and in as many venues as we are able ... I mean, if they can peddle Algore's movie that clearly shows CO2 spikes lagging temperature spikes by hundreds of years and yet claiming a CO2 causality for temperature, then we obviously are not dealing with a mind set that can accept Truth.
That won't help. We are ON earth and it is 'no more than a theory' here.
Thanks for posting and if you have a ping list, add me to it. I want kids to KNOW CO2 has nothing to do with GLOBULL warming.
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