orb@whuts.UUCP (SEVENER) (03/23/88)
Mr. Carr has a surface understanding of refraction but not a *fundamental* one. He repeats yet *again* the same error that he has made all along when he says: In article <3940@bloom-beacon.MIT.EDU> jfc@athena.mit.edu (John F Carr) writes: > >Refraction of astronomical objects is greatest when they are low on the >horizon because the light passes through more dense sea-level air. No, no, no!! The reason astronomical objects are refracted most on the horizon is because of the *angle*. The more the angle differs from the perpendicular, the greater the refraction will be. Air density *only* matters insofar as it *changes*. I can look at something 20 feet away and the line of sight is just as straight as if that object were a mile away. On the other hand, if ten feet away I am suddenly looking through water with a refractive index of 1.33, then *depending* on the angle at which I am looking, I will see the object refracted. Indeed, if the angle is oblique enough, I won't see it *at all*! The refraction will be so great, it will wind up being reflected and all I will see is the surface of the water. It matters not *one whit* how much air I look through - the refractive index does *not* mean for this much air I get so much bending of light. It means that relative to a total vacumn with the maximum velocity of light, I will get this much refraction going from one medium to the other. Eveer been in a plane and looked *down* on a body of water? Frequently you can see clear to the bottom *precisely* as you would from within a boat two feet away from the water's surface. I am beginning to think that John Carr is a total idiot. In trying to buttress his fundamentally wrong view of refraction he has accused me of all sorts of errors in scientific understanding which I have never made: 1)I never denied that in a continuously *changing* medium that light will be continuously refracted by the amount of change in the refractive index and the angle of incidence. What I have tried to get across Mr. Carr's thick skull is that if there is *NO* change in refractive index then there is *NO* refraction. Period. Likewise if there is *miniscule* change in refractive index, (i.e. as from 1.000293 at sealevel to 1.000263 at 3000 ft) there is *miniscule* refraction. Period. Mr. Carr however, continues to treat the refraction index as some sort of constant - i.e. the more dense sea-level air light does through, the more it is refracted. TOTAL GIBBERISH! HOGWASH! If all the sea-level air has the same refractive index then it will not refract light one iota! Period. 2)I never denied that the refractive index is related to the velocity of light in a given medium. This is nothing new and it doesn't require Quantum Mechanics to see why. DesCartes explained how refraction could be related to the speed of light 300 years ago well before Neils Bohr came up with Quantum Mechanics. This is noted in the Leon Cooper's introductory physics text which Mr. Carr keeps disparaging even while proving he does not understand even such *introductory* concepts. 3)I never stated *anything* about the Earth having significant relativistic effects on the path of light. What I stated, which is totally correct and was measured I believe by Arthur Eddington during a solar eclipse decades ago, is that light will curve according to the relativistic space-time continuum. But this is actually because light travels the shortest possible line along non-Euclidean space-time. I.e. the closest thing to a straight line one can get in a non-Euclidean space. Congratulations, John! You have succeeded in so boring the net with this issue that you have "won" in the sense of totally obfuscating the issue and rather than admitting your stupid misinterpretation of refraction, insisting on it to the point nobody cares any more. Your disinformation has worked marvelously to everyone's loss. But paraphrasing Galileo years ago: "But I *still* can't see Cuba from Key West, Lewes Delaware from Cape May, Canada from Michigan, Canada from Cleveland, ........." tim sevener whuts!orb that refraction is greatest because of the amount of dense sea-level air