Reviews for Beyond the black hole

The average rating for Beyond the black hole based on 2 reviews is 4 stars.

Review # 1 was written on 2016-03-23 00:00:00 Charles D. Spar Factual and delightful! I can't get enough of Stephen Hawking's books. Recommended reading. Full 5 stars!

Review # 2 was written on 2020-02-16 00:00:00 Shawn Arimaki Hawking searched for a single substance that underlies all of reality. This might be found at the beginning of the Big Bang (or pre-Big Bang moment?), a point at which gravity pulled all matter-energy into a singularity. Here, the density is so great that the matter particles (electrons, quarks, neutrinos) and three of the four (2) force particles (gluons, photons, W-Z bosons) lacked differentiation and were in some philosophical sense something that was "One," something that preceded "the Many" that, post Big Bang, differentiated over time. What this Hawking quest leaves unanswered (or not discussed by Boslough), is what creates the Big Bang explosion? Physicists know that with the electro-magnetic force, like charges repel and unlike charges attract, and presumably something similar happens with the quarks within the nucleus; physicists also know that the collapsing process of larger-scale stars push particles beyond a breaking point, resulting in supernova explosions. (3) Is there a connection between this forcing of energy-particles, in whatever form, into an incompatible "One" that results in the explosion process which creates "the Many" that differentiates over time? (4) Regarding this interest in pulling together the four forces, gravity is the outlier (in what sense for the physicist I don't know). The forces that interact at the atomic and subatomic, microscopic scale involve attraction that allows for some form of merger and combination via the transfer of energy, or repulsion that preserves some form of independence/integrity. Gravity is said to involve only an attractive force. (5) It acts on everything, pulling matter-energy toward the center, in effect in a singularity and Big Bang scenario, overwhelming everything (all atomic, sub-atomic matter-energy). (6) What is it - what is the single underlying force - that pulls energy and matter together like this? If it is gravity, what is it about gravity that overpowers repulsive forces, allowing attraction to reign supreme? Is the singularity result (black hole or pre-Big Bang) the One? Or, because the pressure is too intense, "the One" is, in the end, unstable and explodes to create movement, change, differentiation and "the Many" in the cosmos? (1) "Hawking, like most theoretical physicists, now believes that the secret of the most elusive of all goals lies in the very early universe, the period within the first trillionth of a second after the beginning of the Big Bang. It is there when the four forces we see in our cold, stable universe were probably one." (2) Gravity, operating at the macro level, pulls energy and matter into a singularity via mutual attraction. Interestingly, under general relativity, while matter-energy is pulled into a singularity, in quantum mechanics, there is no point. There is only a field. (3) Hawking is known for his theorizing on black hole radiation, the seeping of energy out of a black hole. But if black holes are singularities like a pre-Big Bang moment, why wouldn't a black hole also explode? Boslough also writes that black holes "as Hawking tells it, are rips in the fabric of space and time so dense and distorted by unimaginable gravitational forces that for years physicists believed nothing could escape from one, including light." I don't understand what Boslough is stating. The "rip in the fabric of space and time" is rich in imagery, but it also suggests that the black hole is so massively heavy that it breaks through the "fabric" of space-time (whatever "fabric" means). The next question, is "Into what?" (4) In a post Big Bang scenario, energy is radiated outward, dissipating across space and time, in a generalized, entropic process, though there's a localized clumping of matter and energy into galatic clusters, galaxies, stars and planets. Isn't this internally propelled movement? Is this (per Einstein's special theory of relativity?) the uniform movement of cosmic matter and energy that is then acted upon (accelerated), as Einstein theorized with general relativity, by larger-scale bodies of matter-energy that depress the fabric of space-time, which guide other matter-energy toward the center? Interestingly, the reference to entropy -- "the amount of energy available to perform a physical task must always decrease," in a process of gradual "inutility" - seems to be defined in Earthly-human terms, as opposed, say, to a more cosmically-oriented process of "heat death," which is the lessening of power differentials and therefore movement and change within fields of matter and energy. (5) Referencing Einstein, Boslough says that gravity is not a force "in the usual sense." Large masses do not literally pull smaller masses. Rather, they depress the "fabric" (which is?) of space-time, like a bowling ball sitting on a blanket, depressing it in the middle, and smaller masses merely following the natural trajectory in "the fabric" toward the center. The discussion of gravity is incomplete in this Boslough book. Heavy mass draws matter-energy into itself to a central point, but the Earth and planets are not drawn into the sun so other factors (distance per the inverse square law) plus speed and counter-pulling masses are also involved. Boslough also reverts to the traditional notion of gravity as a force when he references the "tug-of-war between the powerful outward-directed force" of a star's "heat and radiation" (electro-magnetic force, carried by photons?), and "the strong inward-directed force of gravity." Elsewhere, he refers to the pull of gravity on a person toward the earth and says that is the same as "inertia of his body resisting." Though gravity does not repel like an electric-magnetic charge, this statement suggests that gravity's attraction does have a flip side, which via inertia, resists (i.e., mutual attraction involves mutual resistance of sorts). (6) If a star has a greater mass (1.4 times or more of the sun), the (Pauli?) "exclusion principle will be overpowered by gravitation....breaking atomic nuclei apart, destroying atoms."