3 ms·
Wait what? Wouldn’t the infrared reflectivity of the parabola concentrate heat energy in to the focal point?
by TheSpiceIsLife 8y ago
Wait what?
Wouldn’t the infrared reflectivity of the parabola concentrate heat energy in to the focal point?
- inflatableDodo 8y agoYou point it at an empty patch of sky. edit - have a go at pointing an infrared thermometer at an empty patch of sky on a clear night.
- TheSpiceIsLife 8y agoOh, right, I understand now, thanks.
- inflatableDodo 8y agoI love radiative cooling. When you first realise what the hell is going on, it is one of those 'aha' moments of real deeper appreciation of a subject.
- duckymcduckface 8y agoMy favorite demo is an electric stoves, turn it on and stare at it from a point along the plane that it's on and you start to marvel at how much heat can be transferred by radiation.
- TheSpiceIsLife 8y agoIsn’t that convection? The air coming in to contact with the hot surface rapidly heats and rises and cooler air rushed in to replace it. I thought that’s what we saw as per your instructions? I thought air (mostly nitrogen and oxygen) is mostly transparent to infrared radiation?
- im3w1l 8y agoOne way to think about it is that the tinfoil will block incoming radiation🞻, while allowing outgoing radiation. 🞻 From the local surroundings. It will amplify the incoming radiation form space but that doesn't matter as space is cold.