[Sarah Williams]

Sarah Williams  asked the Naked Scientists:
   
Hello,

Just to say that your show is brilliant, I listen to it every week, and the podcasts are great for long journeys for example when I'm going to school.

I know that black dull surfaces are better absorbers and emitters of thermal energy by radiation than shiny, light coloured surfaces, but I was wondering why this was. At school we were taught this fact, but never given an explanation for it.

Thanks for such a great show, and I also love the kitchen science!

Sarah

What do you think?

[Raghavendra]

Because it absorbs all types of radiation! of different wavelength.

[Spannerman]

Light coloured objects have a tendency to reflect light due to their colour, while darker objects have a lesser reflective ability therefore they absorb the heat. It's like soil dark coloured soil absorbs while the lighter reflects.

[syhprum]

The question is phrased the wrong way about, surfaces that absorb most of the radiation falling upon them appear dark because little of the radiation is reflected.

[Ron Hughes]

The question was. Why do some molecules absorb all visible light? I would say that the electrons of that molecule are in exactly the right energy levels to absorb all frequencies of visible light.

[yor_on]

I would recommend you to read Hazel Rossoti's book 'color'. It's one of the coolest best written books I've read on that subject, even now when it's somewhat older it keeps its intensity, and she covers a lot of things in it. The book is brilliant and will keep you happy for a long time.