Letter on my favourite new blog (my only news blog!)
“I’m currently doing a science project with one of my home-educated boys and need some information. If you know the answer to the following question or a place I can find it, let me know. A thermos flask works by using a vacuum to prevent heat leaving the liquid. But, if heat can’t travel across a vacuum, how does the sun heat Earth?
Martin, Stevenage, UK”
Hurrah for home educators 😆
Ooh one of my physics students asked this the other day.
If only there was a way that I could reply to Martin from Stevenage…
Anyhow, the answer is that electromagnetic radiation (eg light) CAN travel through a vacuum, whilst convection and conduction can’t.
Write in, write in!!!!! (And thank goodness you knew, i was going to be forced to find out somehow, or never sleep again!)
Yup, and more specifically, heat is mostly transmitted via the infra-red radiation portion of the EM spectrum.
Odd place to post that though? and anyway, what sort of home educator is it that can’t find the answer with a simple web search 🙂