this post was submitted on 27 May 2026
545 points (99.5% liked)
hmmm
8110 readers
3 users here now
For things that are "hmmm".
Rule 1: All post titles except for meta posts should be just plain "hmmm" and nothing else, no emotes, no capitalisation, no extending it to "hmmmm" etc.
founded 3 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
The intensity does depend on the emissivity of the material, and emissivity is a bit counterintuitive:
https://www.engineeringtoolbox.com/emissivity-coefficients-d_447.html
But less than you’d think, given the extreme coefficient, as human perception of brightness is nonlinear. An object twice as bright as another looks pretty similar to the eye.
Thanks for the correction. I'm absolutely not gonna pretend I fully understand this, but isn't it still the case that anything glowing red from heat pretty much has to be over 500°C? I.e. https://en.wikipedia.org/wiki/Draper_point ?
Oh yeah, for sure. That pipe is hot.
Thanks!