Light visible and invisible : a series of lectures delivered at the Royal Institution of Great Britain, at Christmas, 1896

Silvanus Phillips Thompson

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• X-ray
• Light

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• Publié par: les_archives_du_savoir
• Nombre de lectures: 11
• Langue: English
• Poids de l'ouvrage: 10 Mo

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4?'LIGHT. VISIBLE AND INVISIBLELIGHT
VISIBLE AND INVISIBLE
A SERIES OF LECTURES
DELIVERED AT THE ROYAL INSTITUTION OF
GREAT ATBRITAIN, CHRISTMAS, 1896
BY
P.SILVANUS THOMPSON,
M.R.I.D.Sc, F.R.S.,
AND PROFESSOR OF PHYSICS THE CITY AND GUILDSPRINCIPAL OF, IN,
LONDONTECHNICAL COLLEGE, FINSBURY,
ILontion
MACMILLAN AND LimitedCO.,
NEW YORK: THE MACMILLXN COMPANY
1897
j4U rights reservedINTRODUCTION
Two are of a twho undertake^lectQr^things expected
a course of Christmas lecfur^s'at Institution.the'Rloyal
In the first his must be illusti-a'ted todis€^aursesplace
the utmost extent the second,by experiment?. ^^n
however the in which scientific factssimple language
and are discourse mustprinciples described, every
sound at least some note of must reflectmodernity,
some wave of recent in science.progress
So in a course of lectures in theundertaking Optics
lecturer in the instance ventured to onpresent proceed
certain lines which seem to themay, perhaps, strange
sedate student whose of has beenknowledge optics
on the narrower basis of the orthodox text-acquired
book. The ideas in the first lecture arosedeveloped
from the conviction that the time-honoured method of
—a method in which theteaching geometrical optics
—wave-nature of is is funda-
light steadily ignoredVI LIGHT
For the sake of students and teachersmentally wrong.
of he has added to Lecture I. an inoptics Appendix,
which the newer ideas are further Otherdeveloped.
have been added to the laterAppendices Lectures,
with the aim of some of the left in the
filling up gaps
as treated in the lecture theatre.subjects
Now that the nature of allelectromagnetic light-
has been no is neededwaves fully demonstrated, apology
into the fifth Lecture a few of thefor bringing experi-
which thatmental demonstration rests.points upon
That these fundamental can be withoutpoints given
of either orcomplicationany great thought language
is in itself the for thatstrongest argument making
demonstration an essential feature at an in
early stage
the of the science.teaching
of the ideas which must be forMany grasped,
that of the of areexample polarisation light, popularly
to be difiicult whereas thesupposed extremely ; difficulty
lies not in the ideas themselves so much as in the
in which are set forth. In anthey generallylanguage
over a the authorexperience lasting good many years,
has found that the main in the ofpoints phenomena
are ofby personspolarisation 'quite easily grasped
— —even childrenordinary by provided theyintelligence
are in a modern devoid ofway pedanticpresented