# A Few Notes on A Brief History of Time (1988) July 25, 2025 I finished reading A Brief History of Time by Stephen Hawking a few weeks ago, and decided it would be nice to annotate a few quotes I bookmarked and clean up some notes I wrote. Especially since it's rare for me to be left with really memorable quotes or lingering thoughts on a book (that I feel are worth sharing). *** > Even if there is only one possible unified theory, it is just a > set of rules and equations. What is it that breathes fire into > the equations and makes a universe for them to describe? The > usual approach of science of constructing a mathematical model > cannot answer the questions of why there should be a universe for > the model to describe. Why does the universe go to all the bother > of existing? Is the unified theory so compelling that it brings > about its own existence? Or does it need a creator, and, if so, > does he have any other effect on the universe? And who created > him? > > Up to now, most scientists have been too occupied with the > development of new theories that describe what the universe is to > ask the question why. On the other hand, the people whose > business it is to ask why, the philosophers, have not been able > to keep up with the advance of scientific theories. In the > eighteenth century, philosophers considered the whole of human > knowledge, including science, to be their field and discussed > questions such as: did the universe have a beginning? However, in > the nineteenth and twentieth centuries, science became too > technical and mathematical for the philosophers, or anyone else > except a few specialists. Philosophers reduced the scope of their > inquiries so much that Wittgenstein, the most famous philosopher > of this century, said, "The sole remaining task for philosophy is > the analysis of language." What a comedown from the great > tradition of philosophy from Aristotle to Kant! --- A Brief History of Time p. 175 Since I've started actually reading (a small amount of) actual philosophy I've independently come to a similar opinion. Especially Continental/postmodern philosophy, which seems to consistently have a strongly-held underpinning of the outright rejection of science or the search for underlying meaning.[1] Sorta disappointing because the main reason I enjoy philosophy is having actual discussions of things that aren't able to be answered empirically, but so much philosophy---of any vintage and "school"---seems to be just trying to one-up other philosophers and make a name for oneself with more fancy prose and more outlandish ideas (because relatively pedestrian ideas and accessible writing won't get widely noticed), rather than trying to actually analyze or locate deeper meaning in things. [1]: Technically Kant was the originator of Continental philosophy, but the root of the anti-science and "the sole remaining task for philosophy is the analysis of language." parts definitely came into the forefront prominence later, particularly accelerated by Derrida (who admittedly was after Wittgenstein's time so the quote definitely wasn't about anything spawned from Derrida's work). *** Interesting that I was accepting of all the ideas in the book right up until the latter half of Chapter Eight --- "The Origin and Fate of the Universe", where the "no-boundaries proposal" and the prerequisite imaginary time[2] were introduced. The primary driver behind my incredulity was because after the book was written, heat death rather than the big crush has now become the universally accepted theory for the ultimate fate of the universe as far as I can tell. Heat death rather than the "big crush" means there is no end-of-time singularity for imaginary time to "solve" (and that imaginary time also requires?), but it does mean there is a non-singularity boundary of the end of time, which imaginary time doesn't solve. But I think it's also the fact that it's introducing a completely new postulate of the universe seemingly needlessly, because Hawking described it as solely being proposed to avoid having "messy singularities" in quantum mechanics and relativity. Obviously it's not a good place to assume from when my only knowledge of it is from a popular science work (even if written by someone actually knowledgable); but as-presented it seems like a really poor justification for including the very confusing and seemingly poorly- defined imaginary time. Like, with relativity, it's complex and has weird implications, but if you're willing to understand the math it all makes perfect sense; and on top it validates a ton of reproducible experimental evidence, and the stuff not directly evidenced is self-consistent and usually implied by the experimental evidence. But imaginary time is solving a dubious issue that isn't indicated by experiment, has effects on cosmology and relativity despite only solving so- called "issues" quantum mechanics, and seems just inherently poorly defined (both as described by the book and the wikipedia article.) To me it either implies a fifth dimension which has no evidence of existing in reality, or that imaginary time is synonymous with one of the existing four dimensions in which case how does it solve anything? Using Ockham's Razor[3] (actually correct application for once), it's much easier to accept the existing relativity and mechanics theories that have some messy singularities, than it is to accept those theories augmented with the additional postulate of imaginary time that has tons of additional elements due to imaginary time's implications, but retaining the exact same explanatory power.[4] [2]: https://en.wikipedia.org/wiki/Imaginary_time [3]: https://en.wikipedia.org/wiki/Occam%27s_razor [4]: I guess technically imaginary time has more explanatory power, but "the singularities are removed if you completely ignore real time so it's okay to not explain what they are" doesn't seem like a very compelling explanation when it's highly probable that singularities do still exist in real time with 0i lol. *** Random quote I liked but without having any additional commentary: > When asked: "What did God do before he created the universe?" > Augustine didn’t reply: "He was preparing Hell for people who > asked such questions." Instead, he said that time was a property > of the universe that God created, and that time did not exist > before the beginning of the universe. --- A Brief History of Time p. 14 * * * Contact via email: alex [at] nytpu.com or through anywhere else I'm at: gopher://nytpu.com/0/about Copyright (c) 2025 nytpu - CC BY-SA 4.0