Eddington, Arthur Stanley. The Nature of the Physical World. New York: The Macmillan Company, 1929.

In a set of lectures, given in 1927, astronomer Arthur Eddington described an emerging understanding of what was known, at the time, about what was real–the nature of the physical world.  Eddington’s journey to the west coast of Africa to observe the 1919 solar eclipse provided initial proof for Albert Einstein’s theory of general relativity.  One of the first in the English-speaking world to begin to see the new picture of reality suggested by Einstein’s work and the emerging work in quantum theory, Eddington used his ability to explain very difficult concepts and mathematics in simple analogies, without losing the rigor of the shift in perspective.

In this very accessible set of lectures, Eddington explores the new reality, where there is simultaneously perceived forms that extend over space and time and nothing there.  He walks us through the framing and consequences of special relativity, general relativity, matter, space, time, entropy, gravity, and quantum.  He then explores what this shift in perception of what is real in nature means for consciousness.  While many scientists in the 20th century began to define reality as only that which is physically observable, Eddington who worked with the people who initiated the physics revolution suggested that the physicist is describing some dimensions of reality and the explorers of consciousness are describing other dimensions, of the same reality.

Having read dozens of books on these topics, I find this to be the best entry point into these difficult topics.  I now have a much clearer map with which to enter this exploration, for which I am grateful to an astronomer from ninety years ago.