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Science: Everything explained by PV=nRT, F=ma=Gm(1)•m(2)/r^2

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Kepler said:
That is so fucking counterintuitive.
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Tell that to my lawn. If I want a good soaking rain (single storm, not an all-day rain) to actually matter, I need to pre-wet the lawn thanks to the concrete, errrr, I mean clay. In fact, UMN extension actually recommends prewetting lawns on slopes with high clay content.
 
I believe it, trust me -- I've seen flashfloods in desert. It just makes no intuitive sense to me at all. I would think it was about saturation. I fully realize (well, duh) that it isn't.

Kepler don't think it be like that, but it do.
 
St. Clown said:
A practical demonstration on earth sciences regarding droughts and then rain.

https://twitter.com/fasc1nate/status...ECYq1s1BFyVAGw
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Flash floods in the desert are real, sure. Deserts are not just big piles of sand- most are hard packed ground. Really hard packed ground.

But that example is very flawed. Looking at the bubbles, the air is leaking in via the grass. The grass is thicker and provides more gaps between the ground and the cup on the wet land. And the super dry- the grass is easily compressed to seal off.

Completely saturated ground isn't a good way to absorb water- which is what is implied by that experiment- it's as likely to flood as the dry, hard ground is- as there's no place for the groundwater to go. We've had more than one flood in SE MI with very wet ground.

The other thing people need to see in that is to make sure your grass has plenty of humus to work with. That way when it is really dry, the water has a place to go to get started before just running off.

edit- a better way to show that is to shave the grass down to the ground, and make sure there are roots to provide an air path. And even then, the difference between super dry ground that has some kind of grass (like the prairies) and just as dry desert will be drastically different, since the ground cover slows the water down and should help it go down. Deserts have so little ground cover, relatively, that it's just not able to absorb water.
 
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MichVandal said:
But that example is very flawed. Looking at the bubbles, the air is leaking in via the grass. The grass is thicker and provides more gaps between the ground and the cup on the wet land. And the super dry- the grass is easily compressed to seal off.
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It also depends on the makeup of the soil. DX is exactly right because clay has an elasticity to it and shrinks when dry. Moistening it allows it to expand, which then helps it take on more water versus going from dry->wet. It doesnt have time to moisten in a flash flood situation and most of the clay stays dry.

(Somewhere DGF is Googling "'Michael Scott That's What She Said' dot JPG.")

Grass grows best on black dirt which has some organics in it, some clay, and other soil/stones. The organics create air voids as they decompose, allowing for gaps foe water to traverse or store.

The regulation of soil moisture is why farmers install field tile to ensure that there isn't an oversaturation of the soil, especially from subsurface water.
 
Kepler said:
Wow, I had no idea these things occurred in human-sized time intervals. I figured it was centuries at least. This is the Five Second Rule by interstellar standards.
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lol

And agree. I thought it took decades for it to accelerate and send it out on jets
 
Kepler said:
Wow, I had no idea these things occurred in human-sized time intervals. I figured it was centuries at least. This is the Five Second Rule by interstellar standards.
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Maybe within the 5 second rule, but clearly the star was infected with something to cause that kind of indigestion.
 
TIL the entire land surface area of the Earth could fit under the Pacific Ocean, with another 15% to spare.

The Pacific is big.
 
Artemis launch window now reset to 11/14. TIL is doesn't matter much at all. The Moon revolves around Earth in an elliptical orbit with a mean eccentricity of 0.0549. As a result, the Moon's distance from Earth (center-to-center) varies with mean values of 363,396 km at perigee (closest) to 405,504 km at apogee (most distant) -- 42k km. OTOH, Mars apogee and perigee are separated by 15 million km.
 
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Kepler said:
Artemis launch window now reset to 11/14. TIL is doesn't matter much at all. The Moon revolves around Earth in an elliptical orbit with a mean eccentricity of 0.0549. As a result, the Moon's distance from Earth (center-to-center) varies with mean values of 363,396 km at perigee (closest) to 405,504 km at apogee (most distant) -- 42k km. OTOH, Mars apogee and perigee are separated by 15 million km.
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I sure hope it goes. It's not an easy thing to do, co-ordinating so many contractors and subcontractors.
 
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