wwarnout t1_jef70vm wrote

Here's a fascinating video about Arabic numerals, and the Islamic golden age. For 4 centuries, the area now defined as Iraq and Iran was the center of intellectual wisdom. Then, a religious leader declared that numbers were the work of the devil - and that era died, never to return.



wwarnout t1_jebat75 wrote

Keep in mind that 1-1/2 PVC has an ID (inside diameter) of slightly greater than that dimension (it's ID is 1.59"), and OD (outside diameter) of 1.90".

Vacuum hose diameters vary quite a bit. Your best bet is to go to your local hardware and try different PVC couplings with a sample of your PVC and vacuum hose. You might have to use 2 couplings.


wwarnout t1_jb2fe2b wrote

> 1000000000000000000000000000000000000000

That number (10^39) is about a hundred million billion too high - give or take a factor of 100.

Still, a reasonable estimate of stars (and, given an average of one planet per star, about the same number of planets) is about 10^22. It is almost inconceivable that earth is the only place with life.

Also, the first life could not have formed immediately after the Big Bang, because the only elements then were hydrogen and helium. These two formed the first stars, and after a few hundred million years, the larger ones could have exploded, forging the other elements that are necessary for life.


wwarnout t1_ja8rsnv wrote

The concept of "tallest mountain" is based on sea level - which itself is not consistent. Due to Earth's rotation, sea level is farther from the Earth's center at the equator than at the poles. As a result, there is a mountain in South America (Mount Chimborazo's) whose peak is farther from the Earth's center, but because it is near the equator, it is not as high above sea level as Everest.


wwarnout t1_j8ir24q wrote

>Only issue is what to do with the brine/solids left after electrolysis.

...and this is not an insignificant consideration. If we're going to generate clean water on a scale necessary for many people, we'll have a lot of waste to deal with.

Still, getting near 100% conversion efficiency is a huge deal.