Re: my email on a non-diverging sunray after passing between pairs of posts 0.4mm apart.
Art Carlson wrote: > >Careful! It is true that you can produce an (almost) non-diverging >line of light this way. (By the time the beam has traveled ten times >the separation between the post pairs, it will have broadened by about >ten times the gap between the posts, in this case to 4 mm. Simple >geometrical optics.) But this line is not unique. You will get such >a line if the instrument is aligned toward any part of the sun's disk. >Do your experiment again (Or was Friday the one sunny day allowed in >Britain this year?), but this time wiggle the instrument a little once >you have a beam. You will find that you can make a beam anywhere >within a few tens of a degree. (To be precise, 0.5 deg at sunrise and >sunset, closer to 0.3 deg near noon.) > Oh this wonderful List! Where else could one take a half-baked notion and have it returned fine-honed and neatly packaged? So the overall accuracy of what I proposed depends on the *primary* alignment i.e. the sunray passing through the first pair of posts being accurately centred on the line running between the post gaps.. I never was any good at optics. :-( Many thanks for bringing me down to earth with only a gentle bump Art! Best Wishes Tony (jumper to wild conclusions) Moss P.S. No chance of a re-run. It's snowing outside now but my Nuclear Fusion rig made from discarded razor blades and cat vomit in a jam pot is beginning to work just fine!!...I think!! :-) Back to the drawing board! ...or in my case, the keyboard.
