rewboss

Colder than cold

Colder than cold

According to an article I have just read, helium does some spectacular things at a temperature of 2.2 Kelvin. It becomes a great conductor of heat, making it a really good refrigerant.

For those of you who don’t know, 2.2 Kelvin is just 2.2 Celsius above absolute zero, which in theory is the coldest temperature possible. And a refrigerant, as far as I can make out, is something that makes other things cold.

I know what the article is saying. Something that conducts heat well is exactly the sort of thing you want to keep things cold, as keeping things cold involves transporting heat away from it. I just can’t help thinking, though, that if you need to cool helium down to those sort of temperatures for it to be any good at making things cold, it’s not really that much use, is it?