At some point in your life, you’ve probably seen a cartoon of a gold prospector. This would be an old man with a long beard and floppy hat with patches on his overalls. He’d be kneeling next to a river furiously panning for gold. That pan actually acted as a sieve, allowing the water and small particulates to flow out but keeping the gold flakes and nuggets in the pan.
Sieves aren’t just used to find gold. They can separate all sorts of things. You may have a sieve in your house, which you use to catch pasta or rice or grains after they are done cooking in water. Scientists and researchers use sieves as well in order to separate solids from liquids. In fact, with the right stainless steel mesh, sieves can separate just about anything. They can be made extremely fine to catch even tiny solids or made wide to let all but the largest solids past through.