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From: paf@cornell.UUCP (Peter Fenyes)
Newsgroups: net.cooks,net.flame
Subject: Re: Truth in Advertising?
Message-ID: <2409@cornell.UUCP>
Date: Thu, 15-Nov-84 15:35:49 EST
Article-I.D.: cornell.2409
Posted: Thu Nov 15 15:35:49 1984
Date-Received: Fri, 16-Nov-84 06:55:50 EST
References: <2559@dartvax.UUCP> <642@watdcsu.UUCP> <>
Reply-To: paf@gvax.UUCP (Peter Fenyes)
Organization: Cornell Univ. CS Dept.
Lines: 36
Summary: 


In response to the following:

>>I still can't believe the ignorance prevailing in journalism today!
>>For someone to draw the conclusion that since black cars get hot in
>>the sun, then black pots must radiate lots of waste heat is
>>incredulous!  This person should have at least consulted a basic
>>physics text.
>
>>On the other hand, an object of colour x can only radiate light (read:
>>heat) of colour x (i.e. that wavelength).  Therefore, a 100% black pot
>>will radiate *no heat* at all.  It will be warm to the touch, though.

Marcus Hand replies .....

>
>Is this why my physics book used to talk of "black body radiation"
>with the same reverence that it used for "perfectly elastic spheres."
>I think black is the *best* radiator.
>
>		Marcus Hand	(pyuxt!marcus)

  
                                                    
I would agree that black is the best radiator, but....

Although I haven't done any calculations, I find it hard to imagine that
at stove-top temperatures radiation is significant. My guess would be that 
the heat losses by convection are much greater....so the ad would  still
appear to be quite misleading since the color has no effect on the
convection. Now maybe they should do some wind tunnel testing ..... :-)


                                         Peter Fenyes