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This of course was a set up, so people would think it was the bright white surface was radiating/reflecting more.  It was clearly radiating/reflecting more 'white' light, but less infra-red.

And then you were made to think about animals like mountain hares that changed their coat to white in the winter.

Now looking back at it, i think this had far too much magic, and really did not get one to think about equilibriums and spectrums, or the difference between reflection and 'absorption and radiation'. Nor whether camophlage was more important than warmth.

We certainly did not talk about internal reflections at the white surface, which is probably the key point.

I leave all that to the reader to worry about.  The only point i want to make is that the ability to change colour or reflectivity rapidly to maintain a constant internal temperature might be super way of cutting energy usage.  

Our cars should be all 'white in the winter'  and 'black in the summer',  or rather more optimised strategies, such as black in the sun, and white in the shade, if you are cold. the opposite if too hot.

Naturally this also links to how much energy can be shoved into a battery, as an alternative.

I guess camelions might be a better model rather than mountain hares.

M