Random video/youtube thread!!

[Benkyo]

This is very well made:

[Trifkin]

Oh! I loved it!

[Reynard-Miri]

I thought the reason the night sky was dark was because the amount of light that reaches earth from a luminous object is indirectly proportional to the square of the distance to said object.

[Benkyo]

Nope, why would light in a vacuum attenuate?

[Reynard-Miri]

It's not that light attenuates. It's that each photon moves in a direction (er, sort of), so the farther away you are from the light source, the greater the chance a given photon will simply miss you.

To put it another way: assuming there are no obstructions, the total number of photons that reach distance r from the light source is constant across all values of r. But if you were to take a cross section of this surface (say an earth-sized cross section, for example), the number of photons that pass through this cross section is inversely proportional to the square of r.

Coincidentally, this is why a lantern only lets you see so far in the dark.

[Benkyo]

[Reynard-Miri]

The Doppler effect prevents us from seeing light, not from it reaching us. Which is kinda what I'm talking about here, anyway. (The light being less noticeable, I mean.) Here, let me give you some other examples:

You can stare at the stars at the night stars without being blinded, but you can't stare at the sun.

You can't seem stars with the naked eye during the day while the sun is up.

The night sky is dark even though there are manyvisible stars in the sky that are brighter than our sun.

Pluto is colder than the moon.

edit: In case it's not clear, I'm not arguing against the video. The video is totes correct.

[PLA]

^ Like this:

[Benkyo]

[PLA]

^ Well, functionally infinite, maybe.

[negzee]

[PLA]

[Benkyo]

Insane.

[PLA]

Edit:



What the hell?

[Ninten]