Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Dus¡an on 10/12/2009 09:30:02

Title: Why are water and steel (and other things) cooler than surrounding air?
Post by: Dus¡an on 10/12/2009 09:30:02
Dus¡an asked the Naked Scientists:
   
Good afternoon Doctor Chris,
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Why is water and steel (and other things) cooler than surrounding air?

Thanks for your answer and point of view and for all the programmes (http://www.thenakedscientists.com/HTML/podcasts/) on Thenakedscientists.  It is incredible how great your scope of knowledge is!
 Â 
PS: I like your voice and clear accent, as well as Helen's and Kat's. On the web, you are the best programmes to listen to (http://www.thenakedscientists.com/HTML/podcasts/)!

I vote for you and cross my fingers for your successful future.
 Â 
Dus¡an, Czech

What do you think?
Title: Why are water and steel (and other things) cooler than surrounding air?
Post by: BenV on 10/12/2009 10:40:25
I think this is just a result of the fact that water and steel conduct heat better than air, and so conduct the heat away from your hand.  As a result, they feel cooler.  Something that insulates well, say wood or expanded polystyrine, should feel as warm as the air.
Title: Why are water and steel (and other things) cooler than surrounding air?
Post by: Madidus_Scientia on 10/12/2009 17:46:42
Indeed. Try this experiment, if steel is colder than air it should keep ice cooler for longer. Put one ice cube on a steel pan and one on a wooden chopping board or something, and see which one melts faster. I think that was done on kitchen science?
Title: Why are water and steel (and other things) cooler than surrounding air?
Post by: RD on 10/12/2009 17:53:55
... Put one ice cube on a steel pan and one on a wooden chopping board or something, and see which one melts faster.
I think that was done on kitchen science?


50x Speeded up kitchen science video comparison of ice on metal frying pan and ice on wooden chopping board. (http://www.thenakedscientists.com/HTML/typo3conf/ext/naksci_images/OSFLV-player2/player.swf?movie=/HTML/uploads/tx_naksciimages/icecube.flv&autoload=off&volume=70&preview=/HTML/uploads/tx_naksciimages/icecube.jpg)
Title: Why are water and steel (and other things) cooler than surrounding air?
Post by: syhprum on 10/12/2009 22:12:37
It would be very useful if steel plates really were cooler than the surrounding air I could use it to power my Sterling engine generator to run the lights.