Why is sunlight warmer than light from bulbs?


I get that the sun is huge energy source, but it is so far, and the light from bulbs is just as bright as the sun

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Sunlight has stuff like UV in it that lightbulbs don’t have, also sunlight is still brighter than most lights anyway

Artificial light is not nearly as bright as the sun, your eyes are just better at adjusting to different light levels than you think they are.

Most lightbulbs are specifically designed for minimal heat output. No sense wasting energy on heat when the goal is to illuminate the room.

Light from lighbulbs isn’t even vaguely as bright as the sun.

The sun is very far away but it is very (very very very very very) powerful.

Solar flux (the amount of energy the sun puts out) is about 1300 W/m2.

So if you focus *all* the power of 13 100W light bulbs on 1 m2 then that’s roughly solar brightness. That’s enourmously more powerful than any normal light source. We use just a few 100W bulbs to illuminate an entire room (tens of m2).

Bright light looks bright, relative to the sun, because your eyes have a frankly ludicrous ability to operate well over a *huge* range of brightness.

The intensity of the sun’s light per unit area is much greater. It does not look that way because our eyes adapt over time. But turn on a lightbulb during a sunny day, and you’ll see how the illumination of the room changes very little, and the bulb itself looks quite weak and doesn’t blind you. The sun delivers around 1 kW per square meter during summer. A typical lightbulb or set of them in a room have the power of 0.1-0.2 kW for the whole room of 10 or so m². Some of the radiation is trapped by glass, but that is the same for sunlight going window glass.