Stephen Hawking, Brief Answers to the Big Questions (2018) — a book review

24 October 2018

Brief Answers is — enjoyable fluff

If you are scientifically literate, Stephen Hawking's posthumously published — Brief Answers to the Big Questions (Bantam Books, 2018) — doesn't deliver anything particularly memorable.

In this regard, it is unclear (from the book's afterward, written by his daughter Lucy Hawking) how much of the work Dr. Hawking himself fleshed and organized. I have trouble accepting that the little that is there would have met his intellectual standards.

"Posthumous Hawking" (PH), as I refer to him here — so as to preserve a distinction between this book's presumed editors and the "real" Dr. Hawking — repeatedly wanders off topic and off proof, never to return to either.

Brief Answers is the kind of intellectually loose and disorganized musing that one would find entertaining in a pub. But not so, in an intellectually demanding venue.

If you are scientifically non-literate — then maybe a "yes"

PH touches on the larger ideas underlying cosmology, DNA, and evolution. Those concepts are necessary to basic "Big Bang and After" understanding.

On the other hand, PH takes the intellectual underpinnings of most of this stuff for granted. I doubt that science "ignorami" are going to benefit from ideas that are so briefly presented.

This is not a knock against Dr. Hawking or the ignoramuses. With today's knowledge explosion, talking to each other across disciplines is becoming increasingly difficult.

I did notice, to PH's great credit, that favorable reviews at Goodreads and Amazon seem primarily to have come from scientifically unblessed readers. That's an educational achievement of significant magnitude. Getting anyone to think is usually hard.

Consequently, the rest of this review is directed at scientifically knowledgeable readers. People who might afterward resent spending money on a book that says nothing new and reasons to that unexciting point rather haphazardly.

I will skip making an extended comment about the volume's "no God" chapter

That's the section that attracts angry Amazon.com book reviewers. Being of agnostic mind myself, Hawking's atheism does not offend me.

I was, however, amused by his rationally questionable dismissal of God on the ground that time did not exist before the Big Bang. Thus, according to Hawking, making a Creator explanatorily unnecessary. This so, because there was no time in which such a Being could have acted to initiate anything.

If that quibble is supposed to convince those who believe in a Deity's omnipotence — as well as Its presumed immunity to natural law — PH is squirrel-walking the wrong branch.

Posthumous Hawking's failure to fully or coherently deliver arguments — whatever the topic — arguably plagues this book

There were four sometimes irritating writing traits that I noticed in reading the book:

Brief Answers lacks synopsizing topic sentences. And its chapter headings are semantically too loosely worded to assist with coherent argument.

As a result of the first flaw, the text meanders. Seemingly aimlessly.

PH also drops subject discussions, before they are conceptually complete. He magnifies that trait by abruptly moving onto something unrelated — all without warning the reader.

Last, factually untethered speculation abounds. That would be fine, had PH made it consistently clear that he was just (wildly) fantasizing.

Let's use the book's most scientifically interesting chapter — "What is inside a black hole?" — to demonstrate these gremlins

To begin with — and demonstrating the lack of topic paragraphs, as well as the meandering quality that results — chapter five directionlessly rambles for 17 pages — before it finally gets to its main point — here much edited for conceptual clarity:

The particles that come out of a black hole seem to be completely random and to bear no relation to what fell in.

If information were really lost in black holes, we wouldn't be able to predict the future, because a black hole could emit any collection of particles.

If determinism, the predictability of the universe, breaks down with black holes, it could break down in other situations.

This apparent loss of information, known as the information paradox, has troubled scientists for the last forty years, and still remains one of the biggest unsolved problems in theoretical physics.

Immediately after the above paragraphs — and illustrating factually unhooked speculation — PH abruptly pivots to the possibility that "some" of the missing information is contained in the black hole's "supertranslational" characteristics.

Supertranslational characteristics are those not defined by the black hole's observable traits — mass, charge and angular momentum:

It is likely that these supertranslation charges do not contain all of the information, but the rest might be accounted for by some additional conserved quantities, superrotation charges, associated with some additional related symmetries called superrotations, which are, as yet, not well understood . . . . then perhaps there is no loss of information.

Last — modeling conceptual incompleteness and strangely abrupt segues — also occurring during the fifth chapter's aimless amble — PH begins another subject and drops it before it is complete. Mid-paragraph, he stumbles off into something essentially unrelated:

The forsaken particle or antiparticle may fall into the black hole after its partner, but it may also escape to infinity, where it appears to be radiation emitted by the black hole.

Another way of looking at the process is to regard the member of the pair of particles that falls into the black hole, the antiparticle say, as being really a particle that is travelling backwards in time.

When the particle reaches the point at which the particle-antiparticle pair originally materialized [according to quantum theory], it is scattered by the gravitational field, so that it travels forward in time. A black hole of the mass of the sun would leak particles at such a slow rate that it would be impossible to detect. However, there could be much smaller mini black holes with the mass of, say, a mountain. A mountain-sized black hole would give off X-rays and gamma rays, at a rate of about ten million megawatts, enough to power the world's electricity supply. It wouldn't be easy, however, to harness a mini black hole.

Hawking continues the mountain-sized black hole idea by fantasizing that one might be able to contain — and therefore harness — its power by capturing it among the additional 7 dimensions of a purely hypothetical eleven-dimensional space.

It is physics' conveniently pigs-flying stuff (like this) that persuaded theoretical physicist Sabine Hossenfelder to write her recently published book, Lost in Math: How Beauty Leads Physics Astray.

Chapter 5 was the reasonably good part — the rest, maybe not so much

Most of the rest of Brief Answers is scantily developed talk about time and space travel, human survival, the promise and threat of artificial intelligence, and the need to flee Earth — which, PH points out, will eventually be splattered by an asteroid.

This "go forth and inhabit the cosmos" sentiment somewhat illogically arrives after Hawking makes a pretty good case that getting anywhere much outside the solar system is probably unrealistic. Due to the constraint that the light speed maximum puts on interstellar travel.

An example of similarly too-abbreviated reasoning

PH argues that evolution is now bifold. Although our physical genes change slowly — and were previously responsible for most of evolution — today, humanity's "external" knowledge base is expanding exponentially.

This externalization of potential, he says, needs to be accounted for — when it comes to forecasting what we will eventually be able to do:

[T]he total amount of useful information in our genes is probably something like a hundred million bits. . . . By contrast, a paperback novel might contain two million bits of information.

Therefore, a human is equivalent to about fifty Harry Potter books, and a major national library can contain five million books—or ten trillion bits. The amount of information handed down in books or via the internet is 100,000 times as much as there is in DNA.

It has taken us several million years to evolve from less advanced, earlier apes. . . . the rate of biological evolution in humans is about a bit a year.

By contrast, there are about 50,000 new books published in the English language every year, containing of the order of a hundred billion bits of information. . . . the rate at which useful information can be added is millions, if not billions, higher than with DNA.

This means that we have entered a new phase of evolution. . . . I think it is legitimate to take a broader view and include externally transmitted information, as well as DNA, in the evolution of the human race.

There are a couple of "yes— but" difficulties with PH's reasoning.

First, no one involved with the transmission of culture (and "progress") in biological contexts would deny what Hawking says. His is a strawman argument.

More telling of PH's arguably short-circuited reasoning, are his statements that qualitatively equate "bits" of information taken from paperback novels with DNA's "bit" encodings.

That is an ineptly drawn equivalence. DNA creates the novels. Not vice versa. And it will be DNA, acting through its organisms, that creates humanity-surpassing artificial intelligence.

Strings of nucleic acids (for today at least) are powerful stuff. One cannot casually reduce those nucleic acid strings' expanded capacities to the simple on-off/yes-no fragments lifted from other generically bland systems.

Hidden somewhere in (some animal and virtually all human) DNA is the consciousness potential. I do not see consciousness visibly floating around in other aspects of the physical cosmos, including machines.

The equivalence of "bits" that PH implicitly posits is false. Arguably, grossly so.

PH takes unreason to its peak — in his chapter on time travel

Evidently, when facts and even mildly fact-consistent hypotheses do not work, just invent rules-avoiding nonsense:

A possible way to reconcile time travel with the fact that we don't seem to have had any visitors from the future would be to say that such travel can occur only in the future.

In this view one would say space-time in the past was fixed because we have observed it and seen that it is not warped enough to allow travel into the past.

On the other hand the future is open. So we might be able to warp it enough to allow time travel. But because we can warp space-time only in the future, we wouldn't be able to travel back to the present time or earlier.

The problem with PH's hypothesis (to use that word way too loosely) is that he doesn't bother to explain how Einstein's relativity theory can distinguish between past and future — under circumstances in which time cannot be absolutely determined by any observer.

Much less so, with one observer in the far future and another in the near. (Set up so, in my view, because who's doing the traveling and who the witnessing?)

Similarly, PH fails to explain how his concept of warping the Universe's fabric (in the time travel context) differs from the physically caused gravitational warping that he previously discusses.

Last, he apparently conflates the Uncertainty Principle's action (within the quantum "micro" context) with humanity's potential for affecting "macro" time via the act of simple observation.

PH does point out that his time travel hypothesis involves (seemingly insoluble) paradoxes. Which he then quickly argues away with an even more preposterous example of flights of fancy. I will not torment myself by quoting that warbling.

I am not saying that Dr. Hawking was necessarily off base, mathematically speaking. But if he was not, he should have explained what his math was demonstrating.

He doesn't. And I, and presumably Sabine Hossenfelder, do not think that he could have.

Pages 138 and 139 lack enough (even broadly painted) detail to discredit in understandable scientific terms. In other words, the equivalent of beer-swilling bullshit.

Other shortcomings — about which most readers would (perhaps reluctantly) agree

The book has no citations to sources. This matters, for instance, when Hawking addresses the knowledge explosion. Facts that are not commonly known.

Additionally, virtually identical paragraphs repeatedly appear among the book's chapters. This is not a well organized and edited volume. It is repetitive. And its restatements do nothing to fill in the glaring voids that PH previously left. Lose-lose for the reader.

The moral? — For scientifically knowledgeable readers, Brief Answers is superficial

Nevertheless, if a loosely structured pub crawl — with an intelligent and superbly accomplished friend — is one of your likes, buy the book.

Brief Answers is metaphorically like having a few pints with the hugely admirable Dr. Hawking, before he passed on.

If sound analysis and a more than idle intellectual flirtation are more attractive to you, you should save your money for something more thoroughly presented and reasoned.

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Stephen Hawking, Brief Answers to the Big Questions (2018) — a book review