SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Politics : The Environmentalist Thread
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  
To: Wharf Rat who wrote (18882)12/26/2007 2:19:39 PM
From: neolib  Read Replies (4) of 36921
 

You have to understand that the amazing Maurice is visiting us from Sim's Planet.

Yes, I did note that he 2'nded Watson's plug for junkscience.

The junkscience link posted here was very amusing. Did you read it? The nutcase tries to bash the Greenhouse metaphor by claiming that a real greenhouse works on conduction, while the earth/space heat transfer is all about radiation, hence the metaphor is not good. LOL!

I don't have exact numbers, but the primary use (AFAIK) of greenhouses are to provide a warmer environment in cool or cold locations. Hence the primary energy function of a greenhouse is to maintain higher internal temps, while letting light in. Hence they are generally mostly transparent (glass or plastic). As such, they in fact do work mainly in the radiation region. Sunlight comes in as radiation, and is blocked from going out by the wavelength change and the difference in transmission of the glass at the radiation wavelength. The efficency calculations for a glass greenhouse are going to be pretty close if you just look at the radiation environment and ignore conduction. In fact, a good greenhouse tries to force conduction to zero, thus doing a good job of mimicing the earth in space. The junkscience nimwit confused himself on this front because when a greenhouse needs to cool down, it does in fact rely on conduction (or rather convection) by running some fans to suck in outside colder air. But cooling down is not the general function of a greenhouse. I suppose if we were worried about global cooling and someone advanced a cooling greenhouse metaphor, then his objection would have merit, since there is no equivalent mechanism of claiming the earth is cooling via conduction or convection to space.

Always worth a laugh I guess. To bad people actually think there is something worth reading on that site.
Report TOU ViolationShare This Post
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  

HomeMailHotSubjectMarksPeopleMarksKeepersSettings
Terms Of UseContact UsCopyright/IP PolicyPrivacy PolicyAbout UsFAQAdvertise on SI
© 2026 Knight Sac Media.  Data provided by Twelve Data, Alpha Vantage, and CityFALCON News