[hinkley]

People are still trying to work out if we can make black bodies that are biased to radiate more heat in frequencies that the atmosphere is permeable to.

We have some materials that are much more thermally conductive in one direction than the other. Pair the two, and it might just be possible to shed some heat into space at night.

Entropy always wins. It’s the heat trapped in the atmosphere that’s killing us. The universe is a mighty big heat sink though.

[ElKrist]

Interesting. Do you have resources/keywords I can use to know more about such research?

[hinkley]

Search for radiating heat into space. There were some reports about 8-10 years back. Occasionally you will see people working on materials that have narrow emissions spectra, but I think they may have other things in mind, like combining them with photovoltaics to make solid state heat engines. Which has the potential to be much more efficient than thermocouples. Thermocouples are so far from their theoretical limits that boosting the conversion rate by single digit percentage points is more than doubling efficiency, which is how we ended up with a new thromocouple material on the front page of HN a month ago.

[ekianjo]

> heat sink

Bad analogy and you cannot rely on conduction to transfer heat in space. The only means of heat transfer is radiation.

[hinkley]

The question was why can’t we just make hot things cold.

The answer is “you can, if you have some place to put the heat”. What would you call the counterpart to a heat source?