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Alan LeHun · September 24th 16, 05:44 PM posted to uk.sci.weather

In article , lid says...

On 2015-08-06 14:52:07 +0000, Alastair said:

Cold radiation does exist.

Cheers, Alastair.

I am not arguing or taking sides (hard to believe, I know) but please
consider this.

Place an ice cube on a suitable surface (use tongs to protect your body
heat) and move your forefinger near to it until you feel the cooling
effect. This is caused by:

a) The cold is radiating from the ice cube, causing your fingertip to
feel less warm than before, or

b) The warmth from your finger is radiating towards the cooler ice
cube, causing your fingertip to feel less warm than before.

Well both of those answers are wrong to my mind.

I would say that your finger feels colder because of the reduction in
the ambient background radiation but mostly because of conductive heat
transfer in the air between the finger and the ice cube. ie, your finger
is entering the zone of chilled air around the ice cube.

Then try this.

Put a kettle on to boil and move a fingertip towards the body of the
kettle until you feel the heat (taking great care not to burn
yourself). This is caused by:

c) The heat is radiating from the kettle, causing your fingertip to
feel warmer than before, or

d) The relative cold from your finger is radiating towards the kettle,
causing your fingertip to feel warmer than before.

The explanations for each outcome must agree, in other words you may
choose (a) and (d) as the answer or (b) and (c). Other combinations
would be self cancelling and therefore incorrect.

Assuming the veracity of the answers given, this would only be true if
there can only be one type of radiation. In truth, if both types of
radiation can co-exist then the answer would surely be a,b,c & d.

No advanced physics, no references to abstruse web sites, just a simple
experiment that we can all do and probably have done by chance many
times.

--
Alan LeHun