Notes of a Course of Nine Lectures on Light: Delivered at the Royal Institution of Great Britain, April 8-June 3, 1869Longmans, Green, 1870 - 74 pages |
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Common terms and phrases
aberration aberration of light absorption angle of incidence aperture appear augmented axis beam of light blue bright bright bands called Calorescence candle centre colours concave convergence convex crystal dark band diffraction diminish direction distance divergent double refraction elasticity Emission Theory ether waves fall film flame gypsum heat Hence Iceland spar illuminated index of refraction intensity intersect inverse lens lenses light particle lines luminous bodies marginal rays metals motion Newton object oblique opaque optic ordinary parallel perpendicular phenomena placed plane of vibration plate of tourmaline polariscope Polarization of Light polarized light polarizing angle portion principal focus prism produce pupil reaches the eye reflexion refractive index refrangibility rendered retardation retina right angles rings rotation round screen second surface seen shadow sine slit solar spectrum spherical square stereoscope substance thickness tourmaline transmitted transparent undulation undulatory theory vapour velocity of light violet visible wave-length white light yellow
Popular passages
Page 4 - It may also be defined as the sine of the angle of incidence divided by the sine of the angle of refraction, as light passes from air into the substance.
Page 64 - SOUND: a Course of Eight Lectures delivered at the Royal Institution of Great Britain.
Page 63 - Notes of a Course of Nine Lectures on Light, delivered at the Royal Institution, AD 1869. By Professor TYNDALL. Crown 8vo.
Page 19 - The justification of a theory consists in its exclusive competence to account for phenomena. On such a basis the Wave Theory, or the Undulatory Theory of Light, now rests, and every day's experience only makes its foundations more secure. . . . This substance is called the luminiferous ether.
Page 24 - It is worth while to mark how this experiment illustrates the fact that, however intense a luminous beam may be, it remains invisible unless it has something to shine upon. Space, though traversed by the rays from all suns and all stars, is itself unseen. Not even the ether which fills space, and whose motions are the light of the universe, is itself visible.
Page 23 - ... is 474,439,680,000,000. All these waves enter the eye in a second. In the same interval 699,000,000,000,000 waves of violet light enter the eye.
Page 20 - In the case of sound, the vibration of the airparticles are executed in the direction in which the sound travels. They are therefore called longitudinal vibrations. In the case of light, on the contrary, the vibrations are transversal; that is...
Page 61 - I have endeavoured to place before you with the utmost possible clearness the basis of the undulatory theory, do I therefore wish to close your eyes against any evidence that may arise of its incorrectness ? Far from it. You may say, and justly say, that a hundred years ago another theory was held by the most eminent men, and that, as the theory then held had to yield, the undulatory theory may have to yield also. This is perfectly logical. Just in the same way, a person in the time of Newton, or...
Page 19 - OF THOMAS YOUNG, MD, FELLOW AND FOREIGN SECRETARY OF THE ROYAL SOCIETY, MEMBER OF THE NATIONAL INSTITUTE OF FRANCE; A MAN ALIKE EMINENT IN ALMOST EVERY DEPARTMENT OF HUMAN LEARNING. PATIENT OF UNINTERMITTED LABOUR, ENDOWED WITH THE FACULTY OF INTUITIVE PERCEPTION, WHO...