Because Newton understands white light to be composed of individual colours, and Goethe sees colour arising from the interaction of light and dark, they come to different conclusions on the question : is the optical spectrum a primary or a compound phenomenon?
42.
The defining characteristic of spectral class M, the coolest type in the long-standing classical stellar sequence, is an optical spectrum dominated by absorption bands of titanium ( II ) oxide ( TiO ) and vanadium ( II ) oxide ( VO ) molecules.
43.
Philosophers have come to understand the distinction between the optical spectrum, as observed by Newton, and the phenomenon of human colour perception as presented by Goethe a subject analyzed at length by Wittgenstein in his exegesis of Goethe in " Remarks on Colour ".
44.
BL Lacertae shows many of the characteristics of quasars, but the optical spectrum was devoid of the spectral lines used to determine redshift . Faint indications of an underlying galaxy & mdash; proof that BL Lacertae was not a star & mdash; were found in 1974.
45.
More precise measurements ( down to MHz in the optical spectrum ) can be made with a scanning Fabry P�rot interferometer along with analog or digital control electronics, which sweep the resonant frequency of an optically resonant cavity using a voltage ramp to piezoelectric motor that varies the distance between two highly reflective mirrors.
46.
His two key achievements are the experimental observation of the fine structure of Rayleigh scattering line due to Brillouin-Mandelstam light scattering on acoustic waves in condensed matter ( 1930 ) and the experimental discovery of the exciton ( in semiconductor crystals of cuprous oxide ) through evidence of its hydrogen-like optical spectrum.
47.
Yellow is kinda in the middle of the optical spectrum, the sodium output is very bright and unambiguous, and a yellow sodium light emitter should be readily available to any researcher ( if nothing else, salt sprinkled in a Bunsen burner flame ) . talk ) 05 : 46, 15 February 2009 ( UTC)
48.
DQPSK is the four-level version of DPSK . DQPSK transmits two bits for every symbol ( bit combinations being 00, 01, 11 and 10 ) and has an additional advantage over conventional binary DPSK . DQPSK has a narrower optical spectrum, which tolerates more dispersion ( both chromatic and polarization-mode ), allows for stronger optical filtering, and enables closer channel spacing.
49.
In fact it was biological considerations regarding the difference between the human eye and ear ( the eye being perfect for determination of position in space, while the ear is perfect for determination in time ) that led him to the invention of a new optical telegraph the spectro-telegraph, where the code of Samuel Morse was transmitted in the form of spectral lines in an optical spectrum.
