[Science It Up!] Warm It!
We’ve got a great video about carbon dioxide and how it acts as a greenhouse gas to absorb and emit thermal radiation! Or, to put it in other words, we’ve got a video with hair dryers, big long equations, car exhaust, Captain Carbon himself, and a flight to the CSU power plant!
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Warm It!
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Tags: carbon dioxide, CO2, Colorado State University, CSU, Doug Jones-Graham, easy home experiments, education, gas, greenhouse gas, hands-on science, K-12, little shop of physics, Nisse Lee, radiation, thermal
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Little Shop of Physics 
October 6, 2011 at 12:49 am
Car exhaust contains both CO2 and water vapor. Since most IR cameras are designed to ignore both of these, it is not clear which is being seen. Perhaps neither. Perhaps you are actually seeing condensing water vapor. At any rate, I suggest looking at the gas over a boiling pot of water to see if that is visible.
October 6, 2011 at 5:00 am
Thanks for your feedback! You raise a number of good points. Though the lighthearted and fast-paced nature of Science It Up doesn’t let us show this, we are quite careful in our work before the shoot and behind the scenes. We spent many months trying different strategies. You are right that car exhaust contains both CO2 and water vapor, and we are quite likely seeing the effects of both. But we are sure that a good fraction of what we are seeing is thermal emission from CO2. We’ve ben through a number of different tests of our methods. We are pretty sure that we aren’t seeing condensing water vapor. You don’t see much when you look at the gas over a pot of boiling water. Also, when you first start a vehicle, the system is cold, and the exhaust gases emerge at a lower temperature and there can be visible condensation of water vapor, but this doesn’t show much on the thermal camera. So we don’t think that we are seeing condensing water droplets. We have looked at the exhaust from the power plant when water vapor was condensed before going up the stack and when it was not, and the results were similar, so we are certainly seeing CO2. At any rate, the basic message – that CO2 emits (and, by extension, absorbs) thermal radiation is certainly true.
We really appreciate your comments, and hope that you continue to watch and comment on future episodes!
October 5, 2012 at 10:24 am
Electric hair dryers are nice because it gets the job done better compared to just using a towel to dry your hair. .”””`
Many thanks
http://www.caramoantravel.com
October 5, 2012 at 5:09 pm
True… Thanks for your comment!
Brian