How, at 93 million miles away, does the sun feel so warm, yet when a simple cloud passes over it the warmth is incredibly dampened?
In: Planetary Science
The sun feels warm because it’s an ongoing nuclear fusion reaction that’s thousands of times larger than the earth. 😛 In a cosmic scale the sun is extremely close to us. The radiant heat it produces (in the form of infrared rays) flies through space almost entirely unimpeded, so it warms you up effectively.
A cloud blocks the infrared rays from hitting you. Instead of warming you, the energy goes into heating the cloud or is reflected back into space. EDIT: Just in case anyone doesn’t know, this doesn’t apply to UV light. Even on cloudy days, the sun’s ultraviolet rays go straight through that and are still perfectly capable of giving you a sunburn.
[removed]
To add on to other point, this also shows why outer space has so little “stuff” in it to obstruct, reflect or absorb energy from the sun.
There are many more atoms of air between you and your computer screen than there are atoms between the sun and the earth (once you’re “outside” the sun and not yet “in” the earth’s atmosphere). There is just very very little stuff in outer space to reduce the sun’s energy. A cloud compared to outer space is like comparing how much water is in the ocean compared to how much there is in a cup of coffee.
The energy from the sun goes through 93 million miles of *absolutely nothing*. It starts off as an unbelievably massive amount of energy, so even 93 million miles away it’s still pretty dang strong.
When the sun hits you, you feel that energy as warmth.
When the sun hits a cloud, the cloud gets that energy instead. Some still passes through to you, but most of it has been “soaked up” by the cloud already – because the cloud was the first *thing* the energy encountered.
For what it’s worth –
“to lessen in intensity” is technically “damped” while “dampened” means to “make slightly wet”.
The distinction is disappearing due to the confusion and laypeople use them interchangeably so you do you with full validity, but this one of those of anthills I’m going to die upon.
Heat is transmitted in the form of photons, the same way visible light is. What happens to visible light when a cloud passes between you and the Sun? It gets dark.
Exactly the same thing happens with heat. The infrared photons are blocked. Since water vapour is very efficient at blocking that particular wavelength of photon, the effect is even more pronounced.
Think of a photon like a bullet being fired at you from above. It doesn’t matter how far away the gun is, it’s still going to hit you. If you disregard the friction of the atmosphere, the bullet will hit just as hard. The inverse cubed law means that the farther away you get from the Sun, the fewer photons actually hit you, but the ones that do still hit with the same energy.
A cloud just stops a lot of them from reaching you.
Space is empty. It’s not even air, it’s a vacuum. We forget that our air and clouds are *stuff*. Compared to empty space, even 93M miles of empty space, a cloud is like a brick wall. They’re hundreds of tons of matter, and they absorb and block the sun’s energy much more than 93M miles of empty space, because space is *nothing*.
Why when Wall in front of me bullet not hurted? Truly one of the mysteries of the world isn’t it
The sun feels a lot less warm from this far away, because its radiation is spread out over a sphere with a radius of 93 million miles. It would feel much hotter if it was closer. It still feels as warm as it does because the amount of energy it radiates is just that big.
Why does a cloud have so much impact? Because you can see clouds. That means they block a significant portion of whatever light hits them. So whatever amount of warmth you’d get from the unobstructed sun, the cloud would make it a lot less.
Latest Answers