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Message: <blockquote data-quote="Binastro" data-source="post: 3345374" data-attributes="member: 111403">Chuck Yeager, I think flew Mustangs.Other side, say FW.50miles is 264,000ft.1 arcsecond is 1 part in 206,0001.29ft at 50 miles is 1 arcsecond.25.8ft is 20 arcsecond. Say 26ft.I resolve sunspots of 34 arcseconds, although lately 37 arcseconds. Using safe filters.8 months ago optician said my eyes were 20/16, previously 20/15.People with excellent or rather exceptional eyesight regularly see sunspots 20 arcseconds across using safe filters.So Chuck Yeager would just see a single 20 arcsecond black spot against a clear sky if he knew where it was.It might give away its position with a glint from the sun.However, flights were normally 4 aircraft, maybe finger four.With separations of up to 4 or 5  times the relevant resolution limit 2 subvisual black spots would be seen as one at least 1.4x larger than a single spot, probably larger. 4 subvisual aircraft in a line would be much larger than one.I wrote a paper on this subject in the late 1970s.I have no doubt Chuck Yeager and other pilots with superb eyesight like the noted Finnish ace RESOLVED aircraft at up to 50miles. Bombers certainly, but also large fighters if seen in planform.If there were two or four aircraft even I would have resolved them.This is assuming their eyes were 20/10, but they may have been 20/8.There is nothing mathematical about it regarding theory. The much talked about 1 arcminute resolution is in the case of black dots on a bright background, a myth.Of course if the aircraft were contrailing they would have been glaringly obvious.I didn't use a calculator, so maybe figures a bit off.</blockquote>

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