Define scabies: contagious itch or mange especially with exudative crusts that is caused by parasitic mites (especially Sarcoptes scabiei) contagious itch or mange especially with exudative crusts that is caused by parasitic mites (especially Sarcoptes scabiei)â¦
Dirigibles, also called airships, fly by being lighter than air. This works because a dirigible is like a big hard balloon filled with lighter-than-air gas, such as helium or hydrogen. You've probably seen dirigibles used in advertising, like the Goodyear blimp. A famous dirigible accident was the Hindenburg crash.
Compressible flow (gas dynamics) is the branch of fluid mechanics that deals with flows having significant changes in fluid density. Gases, mostly, display such behaviour. While all flows are compressible, flows are usually treated as being incompressible when the Mach number (the ratio of the speed of the flow to the speed of sound) is less than 0.3 (since the density change due to velocity is about 5% in that case).