RainmanTime
Super Moderator
but it still don't explain a 4 mile wide diameter vortex from a missile that likely would not have been more than 10' in diameter.
Fact 1 - You do not really know what the actual diameter of the vortex was (and it depends on whether you are talking the video, or the photo which appears to have been taken significantly later since the vortex has grown in apparant size). I don't even know its actual size because, as I explained, no one knows the range...and not knowing the range introduces a LARGE error in estimating the 2-D extent of the vortex spiral.
Fact 2 - If we take the "3rd stage" report of the Russians at face value, I have already discussed that the missile is flying through EXTREMELY LOW DENSITY atmosphere. The lower the density of the air, the LOWER the viscous damping effect which would retard the growth of an aerodynamic spiral. With regard to this fact of density, I have previously suggested you may be applying the high-density damping effect of the atmosphere down here where we live and breath to the situation of the rocket at a much higher altitude (and much lower density). It is incorrect to do this. A vortex spiral at those low densities can grow VERY large simply because the density of the opposing air molecules is so low.... and it can also grow VERY fast depending upon one other fluid dynamic property, which leads to...
Fact 3 - Again taking the Russian report of this happening in the "3rd stage" at face value, this would also mean that the Mach number of the missile with respect to its surrounding airmass would be well in excess of Mach 10 (probably quite a bit higher, since the Shuttle achieves Mach 25 at its highest point in the thermosphere). The dynamic pressure at this point represents the "strength" of the vortex that the missile is creating (i.e. how FAST the spiral will be created from the body and how LARGE the extent of the spiral will appear). The alternate form of the dynamic pressure equation in terms of Mach number and local static air pressure is as follows:
Dynamic Pressure = (1/2) * Ratio of Specific Heats for Air * Static Pressure * Mach^2
The ratio of specific heats for typical diatomic molecules (i.e. AIR) is a constant value of 1.4. I just gave you a MINIMUM Mach number that this thing had to be traveling at, and if you wish I can also show you how to find the static pressure for a "standard day" at altitudes in excess of 200,000 feet. That would give you a means to estimate the magnitude of the driving dynamic pressure that is causing the spiral to form.
That should help explain why what you believe is not possible from "just a missile" is actually quite possible, indeed probable, once you understand the pressure forces and aerodynamics of a missile traveling this fast through low-density atmosphere.
RMT