As a SCHOLAR, it is MANDATORY that you cite sources, to keep your reputation. But you do NOT have to cite the Handbook of Chemistry and Physics when you tell someone that the speed of light in a vacuum is (2.997930 +- 0.000003) x 10^8 cm/sec, even though that volume is copyrighted, just because it is copyrighted. Information is not protected by copywrite. Actually, I got that number from Misner's "Gravitation", a 1200 page treatise on Einstein's geometrodynamics, and I just protected my reputation.. I have a doctorate in education and master's degrees in physics and engineering. Is anyone interested in Archelaus ANDERSON of Lynn, MASS, bfr 1700? I'm looking for his kids...