14 votes

Can people feel the low heat radiation from very cold surfaces?

Yes they will feel the coldness, but it's the lack of heat radiation, not radiating coldness. Essentially, the scientist's body is radiating more heat than it is receiving, and it is this difference ...
BaddDadd's user avatar
  • 310
12 votes
Accepted

What is the albedo of our Sun?

Yes, the sun is close to a black body and would absorb the laser pointer light. If one looks at the solar reference spectrum it is almost a perfect blackbody spectrum (but not quite - there are a few ...
Anders Sandberg's user avatar
5 votes
Accepted

Why does blackbody radiation formula work for radiator?

If I have well understood your question, it is equivalent to asking why radiation from a small hole in the cavity emits radiation distributed according to the internal blackbody distribution or why ...
GiorgioP-DoomsdayClockIsAt-90's user avatar
3 votes

Can people feel the low heat radiation from very cold surfaces?

While I have not done the numbers for your very particular follow up question (nevermind that it's impossible to reach 0K), I have every reason to believe the person will survive. Consider the night ...
Cort Ammon's user avatar
  • 46.6k
3 votes

Heat transfer vs. Volume transfer

Imagine running the water at a very low flow rate, so low that the heated water reaches ambient temperature by the time it comes out of the tap. In this scenario, water coming out of the tap will ...
Puk's user avatar
  • 13.5k
3 votes

Is there a blackbody spectrum of photons inside a solid?

In thermal equilibrium there are definitely photons inside a solid. They're bosons, so they will be described by the Bose-Einstein distribution. But they won't necessarily have a "blackbody ...
knzhou's user avatar
  • 102k
2 votes
Accepted

Can people feel the low heat radiation from very cold surfaces?

Regarding feeling the coldness: Sure, humans feel when their skin emits more IR radiation that is received. You can test this easily by opening a freezer and standing some ways away from it (avoiding ...
jpa's user avatar
  • 2,303
2 votes

Why does blackbody radiation formula work for radiator?

I think the key here is that the sort of characteristic time over which the photon gas explores state space is very short compared to the characteristic time over which the photons escape. That is, ...
David's user avatar
  • 703
2 votes

How do I calculate the rate of heat loss from an enclosure when I have a plot of temperature vs time and the enclosure's material details?

I wouldn't bother with the peak to trough time. You know the heater rating is 18 Watts (which is energy in Joules per second) and this maintains a more or less constant temperature. Visually the ...
KDP's user avatar
  • 1,820
1 vote
Accepted

Thermal radiation in hollow sphere

I think the easiest way to look at this is to imagine a vacuum in the cavity. Heat radiated from one side of the inner surface, is almost immediately reabsorbed on the opposite side of the cavity, so ...
KDP's user avatar
  • 1,820

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