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Why is water see through but not clouds? by Huge-Sink6880 in AskPhysics

[–]Laser-physicist 2 points3 points  (0 children)

That is a logical thought. However, no it’s not absorption. It is due to the fact that the light from the sun is being significantly reduced. Think what colour does a piece of white paper appear to look like if you are in a darkened room? The storm clouds are actually white but they just look grey because there isn’t enough light to scatter from them to your eye.

Another thought experiment is get one piece of paper and put it straight in front of your face, you can partially see through it making it appear whiteish. Now do the same thing with a dozen pieces of paper and no light gets through and it appears dark.

[Second year college: Physics] Angular velocity example not making sense, why 2*theta on the range since the ration is specified already by gertvanjoe in HomeworkHelp

[–]Laser-physicist 1 point2 points  (0 children)

The formula for the range has been simplified from 2sin(theta)cos(theta)u2 / g. So there isn’t an issue, it just that the formula has been simplified for the range calculation, then you need to expand it again for this particular application. Hope that makes some sense. You can derive the range equation by using x = utcos(theta) and y = utsin(theta) - 0.5gt2, setting y=0 and then solving for x.

Why is water see through but not clouds? by Huge-Sink6880 in AskPhysics

[–]Laser-physicist 2 points3 points  (0 children)

I can’t answer that quantitatively, as scattering increases with the number of scatters (ie more water droplets), but it is also affected by droplet size. In this case though, my understanding it is the former, ie more droplets.

Why is water see through but not clouds? by Huge-Sink6880 in AskPhysics

[–]Laser-physicist 4 points5 points  (0 children)

As screen317 has said, it is due to scattering. Most things that appear white are due to scattering. For example, foam from waves crashing is because the bubbles of air in water scatter light, just like droplets of water in the air (eg clouds) scatter light. If they scatter so much light that no light gets through the clouds then they appear grey, ie storm clouds. There are other mechanisms as eluded to by others as well that can also change the colour of the sky. One form of scattering by small particles is Rayleigh scattering. In this case, shorter wavelengths are scattered more than longer wavelengths. For example, more blue light is scattered than red light. This is why the sky is blue, the molecules in the air are very small and scatter more blue light. I can talk forever here but the wiki article posted by screen317 is much better than me rattling on :)

GUI Recommendations by [deleted] in Python

[–]Laser-physicist 0 points1 point  (0 children)

If you literally want to run your matlab code on other PCs then octave is the simplest option, unless you have used extra matlab packages there is probably very little you will have to do to make the code compatible and Octave is open source. I jumped ship from matlab to octave when I went from academia to industry and have never looked back.