I asked him “what color were the clouds back then?” and he said they were white. I asked him what happens if I take an orange light and light up something that’s white with it. He ignored me. He went on about how everyone in his age group remembers the Sun being orange, and by me questioning him, I’m calling him and all his peers liars and I’m stupid because I’m younger than him and vaccinated.
Someones never accidentally touched an LED array.
I can guarantee you an LED array as big as the sun would generate enormous amounts of heat.and would need massive amounts of cooling.
Power density of the Sun is approximately 276.5 W/m³. That’s counterintuitively little. A classic LED 3mm plastic package has the volume of less than 40 mm³ and some white ones can handle about 100 mW without a heatsink. Even leaving space for connections and airflow, you can easily overpower the Sun by volume by orders of magnitude.
A fun article mentioning that 276.5 W/m³ is about a reptile’s metabolism (and they famously produce little body heat): https://what-if.xkcd.com/148/
On replacing the Sun with another light source: https://what-if.xkcd.com/151/
Basically, as this Stack Exchange discussion correctly states, human intuition is quite useless when thinking about things orders of magnitude outside our experience.
Meanwhile, you say “hot” because that’s what your finger felt. Not really convincing of your ability to think in cosmic proportions.
So yes, LEDs are hot.
Have you touched strong incandescent lights?
Sure LED arrays are hot, but cooler than old lights
LED chips can’t get above 150 °C or they fail. So high-power LED lights need appropriate cooling. And the heatsink is big and thermally conductive, making it feel hotter to the touch than it is (it delivers more heat to your finger over time). Meanwhile, the glass of some bulbs can exceed 300 °C but cools down to safe levels in a minute (or less if you touch it with something) because it’s thin.
Also, 150 °C (420 K) objects do radiate heat as black-body radiation but not that much, also it’s far-IR so only detectable with thermal cameras. Meanwhile, a light bulb’s filament is 2700 K (3000 K in halogen ones) and the Sun’s surface is 6000 K, and both produce copious amounts of near-IR light that largely contributes to the heat felt on one’s skin when illuminated (although the visible light does too).
So yes, LEDs are hot.
From a human’s standpoint, we say they’re “hot”. The fact that humans can’t handle 150 °C nor 2700 °C does not mean there’s no difference between the temperature of a sausage fresh off the grill and magma. (Yes, by the time it gets to the surface, lava is too cold)
So yes, LEDs are hot.
Boiling hot, as opposed to METAL-MELTING REMOTELY-SCORCHING HELL-BLAZING INFERNO
How long before you admit there is a point to calling them “cold light sources” because their color temperature is higher than what black body radiation (incandesce) can do?
So yes, LEDs are hot.
Username checks out
Try so hard to desperately disprove my point, and you fail so catastrophically that you fall into the low hanging trap that is my username.
Congrats for playing yourself.
That’s fair - my experience with handling them basically stops at individual LEDs in electronics and domestic LED lightbulbs.