Recent content by Steve Dutch

So far there's a lot of arm waving but no actual math. So here goes. Imagine a speck of rock, density 3000 kg/m3. It's 1mm across, with a volume 10-9 m3 and mass 3 x 10-6 kg. If it hits at Earth's orbital velocity, 30 km/sec (30,000 m/sec) then its kinetic energy is 1/2 mv2 = 1/2 x 3x10-6 x...

Although there are comparatively few processes that remove Na and Cl from sea water, there are some processes. Marine salt deposits do end up on dry land and some even gets recycled by wind, since sea spray furnishes salt crystals as nuclei for raindrops. A good deal of sea water soaks into the...

It's all about residence time. River water is not dilute sea water. It's a lot richer in calcium and sulfate than sea water. When water reaches the sea, biological and chemical processes remove certain elements. Calcium and silicon are taken out to build shells for organisms. The residence time...

It's basically geometry. Let the unit cell be a cube of side 1. The long diagonal has length sqrt(3). The corner atoms and the central atoms all have their centers on the long diagonal and touch, so their radius is sqrt(3)/4. So what's the volume of an atom, and how many atoms are in a unit cell...