Suggesting that The Animate and Inanimate adumbrates the discovery of dark matter and black holes is unfounded. Such a claim is akin to concluding Simon Newcomb to be the first to propose the presence of dark energy in his The Extent of the Universe merely because he did not know if photons "extinguished" during space travel.
The structure of The Animate and Inanimate is ordinate, containing well-written chapters written by a Harvard-class teenager who suggests in both the introduction and the conclusion that he is merely "thinking out loud." The book begins with an axiom, after which Sidis assembles all the tools deemed necessary to generate a grand theory of the universe.
The metaphysics expounded in this book serves as an explanation for the existence of William James' "reserve energy," outlined in The Energies of Men. Sidis' axiom is that reserve energy exists. Sidis does not question if reserve energy exists but rather how. According to Sidis, reserve energy invalidates the second law of thermodynamics, which states that the total entropy of the universe is irreversibly increasing, and so he investigates how this is possible.
From the postulate that every physical law in the universe is reversible (pg. 49), Sidis hypothesizes that a "negative universe" (or "reverse" or "dark" universe) exists in conjunction with our universe. These universes comprise both positive sections and negative sections and share energy with each other – upholding the conservation of energy – and fit together equally, like concentric drums. In the reverse universe, the physical laws are reversed (e.g., in classical mechanics, spilled milk would collect itself and travel back inside a glass). There is no origin of either universe; the cosmos coexist perpetually in changing form.
Positive sections of the universe emit light and represent the physically observable sections of our universe ( i.e. , the Milky Way). Negative bricks absorb light, creating unobservable "dark" sections of the universe (i.e., the reverse universe). Sidis suggests that there is a tug-of-war between our universe and the dark universe, wherein there exists a constant fluctuation of energy belonging both to the positive sections and to the negative sections of the universe. In this manner, "pseudo-living creatures" in the reverse universe share energy with living creatures of our universe. This shared energy in the reverse universe is the ebb-and-flow origin of reserve energy of mankind in our universe.
Sidis' metaphysics is quite interesting, and it is easy to appreciate the similarities between it and the eastern philosophical concept of yin and yang. However, Sidis' "dark" sections of the universe are unlike dark matter in that dark matter does not absorb any light whatsoever. Sidis' view of an infinite universe is supported by theories expounded by William Herschel, where Sidis considers the area outside of the Milky Way (our "universe") to be a distant, invisible (or "dark") universe. He mistakes extragalactic phenomena for separate universes. Sidis also claims the aether is the stuff that fills the universe, even though this was debunked experimentally by Michelson and Morley in 1887 and theoretically by Einstein in the decades following, well before the publication of this book.
Sidis' work includes no findings in modern physics at the time (viz., statistical mechanics, Bohr quantum mechanics, or the principle of relativity – nothing from Poincare, Lorentz, or Einstein), but similarities in his metaphysics can be drawn to certain concepts in our time, such as dark energy; nevertheless, they are not even close equivalents. Instead, Sidis' views have more in common with Walter Russell's than, say, Penrose's. This book is very interesting and easy to read, and it is oftentimes fun to imagine the veracity of its propositions and conclusions. Nevertheless, Sidis started on a false premise: the existence of reserve energy. Even though his mathematical prowess was evidently monumental (according to Wiener's biography), which is in no way demonstrated here, his understanding of fundamental physics was limited; there is no mathematics in this book, save for a couple of simple expressions. Sidis did not predict dark matter, and he did not theorize the existence of black holes.
The Animate and Inanimate is a fun read, but don't take it too seriously and try not to read too much into it.