"What is the Einstein
theory? and what does it claim? From the time of Pythagoras and Zeno in
the Greek cities of Asia and Italy down to the present time scientific men have
been discussing whether space is finite or infinite, whether there is any
difference between rest and motion, whether length is absolute or relative,
whether time and space have any real existence. The result of these
discussions has added to our knowledge of mathematics and physics. But the
boldest attempt to answer these problems was made by Albert Einstein in 1905
when he propounded his theory which later has commanded the attention of the
"Einstein's two great
postulates are: That all motion is relative, and that the velocity of light is
independent of the motion of its source. The first of these can be easily
understood by the example of riding in a smoothly moving train with the windows
darkened so that we could not see the passing landscape outside, and the other
that nothing can travel faster than the speed of light which travels at a rate
of 186,000 miles a second
[670,000 miles per hour],
and that it cannot be made to travel faster by giving it a quick send off.
These two primary postulates with his later "Principle of Equivalence" are
claimed to have cleared away several of the riddles of the universe.
"The effect of these
principles is that all three of Newton's laws of motion are questioned, and the
Euclidean proposition that parallel lines cannot meet is denied. Einstein
declares the lines may meet. Newton held that the action of gravity at a
distance is instantaneous through all space, while Einstein holds that no action
can exceed the velocity of light. Another of the paradoxes of the Einstein
theory is that there can be no such thing as absolute time nor can there be any
way of finding whether clocks in different places are synchronous.
Yardsticks may vary according to how we hold them, and weight
["more correctly, mass" -EW]
depends on velocity. He also shows that the shortest distance between two
points may not be a straight line. These have been deduced from
mathematical laws governing physical phenomena, and capable of experiment.
The result of experiment has been to confirm the theory in two crucial tests.
The third test ["Gravitational
yet remains to be made.1"
(-D.A.), "Book of the Week: The Theory of Relativity", c1922 (estimated
Anderson was also the owner of this 1st Edition copy of
Einstein's "Relativity" in which this book review was pasted and
preserved on the rear inside cover.
F O O T
N O T E S
effect was eventually considered to have been finally identified in the spectral
lines of the star
Sirius B by
W.S. Adams in 1925" -http://en.wikipedia.org/wiki/Gravitational_redshift"