Recent comments in /f/askscience

it00 t1_j68yx3y wrote

Reply to comment by PlaidBastard in Why does road salt accelerate corrosion in a vehicle's underbody? by nebula828

I took a ferry near Puget Sound on a road trip in 2018 - from Clinton to Mukilteo - is it Possession Sound? Genuinely just thought it was a regular sea crossing - I suppose looking again at the map that area is more like a river than a regular seaway.

The rain held off for the most part - although the greenery was spectacular compared to the other (?rain shadow) side of the Cascades. Lovely part of the world. Good you don't get the rust problem - same here in Scotland. In the sea lochs it isn't a problem - on the coast and islands on the other hand...... it's hellish!

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mfb- t1_j68ytbt wrote

Reply to comment by CubanHermes in Is there an upper limit to structure size in a vacuum? Could a sufficiently advanced civilisation build a galaxy sized structure in space or would it become too massive and collapse in on itself? by CubanHermes

Billions of rooms are easy. If you make every room a 10 meter cube then the whole structure is just ~20 kilometers in diameter and gravity is still tiny. Each room would have as much space as the ISS, so the structure could potentially house the current world population (ignoring some practical concerns like heat management).

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PlaidBastard t1_j68wnji wrote

Reply to comment by it00 in Why does road salt accelerate corrosion in a vehicle's underbody? by nebula828

Puget Sound in WA state is a good exception to this, because the water is less salty and probably because the constant rain keeps the air from getting brackish.

Seriously, cars don't rust here. Sunroofs leak and mildew destroys them from the inside, but the green algae usually scrubs right off to reveal shiny clearcoat....

Then you go 50 miles west to the actual Pacific coast, and everything you say about rust is true again...

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CyberneticPanda t1_j68vu8d wrote

Reply to comment by CrustalTrudger in can gemstones be melted into a gradient? by Acceptable_Shift_247

Most gem quality rubies and sapphires come from metamorphic rock with igneous intrusions, so you would be real unlikely to be able to get big clean crystals this way. On top of that, you can't really get them out of the metamorphic rock really because you'll break them with the surrounding rock. We mostly get them from sedimentary deposits (placer deposits) when the softer rock around them weathers away and the hard gemstones get picked up by water and moved downstream.

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