by drollere » Sat Oct 02, 2010 3:20 pm
the most striking details about many nebula photographs are the structure shapes that strongly resemble media mixture -- smoke tendrils in air, dye diffusing in water, or bok globules that seem to be the innards of a lava lamp.
these complex shapes often have sharply defined boundaries, strong visual (light transmitting/absorbing) contrasts with the surround, coherent dynamic form, and edge turbulence that suggests the interface between two different densities. today's photo, for example, looks almost exactly like the turbulence you would see if you dissolved sculptor's clay in a tank of water, let the clay settle to the bottom of the tank, then shook or stirred the tank to throw the sediment back into solution.
the paradox is: these can't be gravitational structures, because the structure is not averaged or "blurred" by the effects one would expect from stellar radiation acting on gas in a vacuum, diffusive heat within the gas cloud, and the large scale clumping of a single gravitational field. but then what is the surrounding medium that provides the shaping effect? william keel explained to me that this is an active area of current astronomical research. i hope apod can provide some good visual examples and explain how these complex and highly organized structures arise.
the most striking details about many nebula photographs are the structure shapes that strongly resemble media mixture -- smoke tendrils in air, dye diffusing in water, or bok globules that seem to be the innards of a lava lamp.
these complex shapes often have sharply defined boundaries, strong visual (light transmitting/absorbing) contrasts with the surround, coherent dynamic form, and edge turbulence that suggests the interface between two different densities. today's photo, for example, looks almost exactly like the turbulence you would see if you dissolved sculptor's clay in a tank of water, let the clay settle to the bottom of the tank, then shook or stirred the tank to throw the sediment back into solution.
the paradox is: these can't be gravitational structures, because the structure is not averaged or "blurred" by the effects one would expect from stellar radiation acting on gas in a vacuum, diffusive heat within the gas cloud, and the large scale clumping of a single gravitational field. but then what is the surrounding medium that provides the shaping effect? william keel explained to me that this is an active area of current astronomical research. i hope apod can provide some good visual examples and explain how these complex and highly organized structures arise.