Re: Questions pertaining to chemistry lab
Posted by Pasti on Sep 11, 2003 at 13:14
(64.228.115.191)Re: Questions pertaining to chemistry lab (Uncle Al)
Al, the kids in highscool,depite of what they should know,can barely understand what a wave is, much less understand interferometry.I did Newton's rings in highschool too,and optical edges for thickness measurement or roughness measurment, but somehow, from my experience with highschoolers this is not "stuff" they do in highschool anymore, or their teachers don't bother to do it anymore.And I don't think you managed to do in highschool the Newton's rings experiment just with the Na lamp (it is not a coherent source), you must have had something else, a pin-hole lamp or something similar, if not a laser.You either need a parallel beam or a spherical isotropic one.
And it is a rather pretentious method to use Newton's rings,especially for a highschool lab,since a "laser" pointer is a very poor laser (low coherence degree),has a small size spot(you can go around that),you need a plane convex lens, some mechanical mounting,even if it is the most most roughian one, etc. And it would be rather expensive,and time consuming to set up.
A micrometer method is simpler, even if they have to learn to read the vernier (personally I don't trust at all the garden variety digital ones, the electronics is too shoddy to keep its accuracy).
My point was(and you understood it well),that at least part of the show you put up was at least unnecessary, especially when the kid was actually asking politely for some help.What was the use of mentioning the roughness of the foil? Or its plasticity? He needed a rather ballpark measure,not a Ph.D thesis on thickness measurement for thin films.
"Parity the symmetry is coupled to parity the property by other strong mathematical correspondences."
Of course it is,but not in the Noether approach, as you may have convinced yourself.
And yes, of course I would like to see the draft, but I wasn't able to find it on the website you mentioned.Maybe you can give me some more details, like where to download itfrom, and what is the name of the file?
Follow Ups:
- Re: Questions pertaining to chemistry lab Uncle Al 11/9 18:47 (0)