At many points, this book was a difficult read. It's well written but often times the scientific and mathematical subject matter is hard to grasp unless you have previous familiarity with it. Despite the tough parts, this book is well worth reading.
Like the title alludes to, the book details our current understanding of the universe from its presumed beginning through to its assumed end. All of this backed up with dozens of footnotes of references (as well as Brian Greene's own explanatory footnotes which are by far the longest I have ever seen in a book).
It gives a picture of humanity as an infinitesimal blip in the history of time while appreciating and marveling at the fact, that despite all odds (in the sense of probability), that we exist at all and can ponder our own existence and place in the universe.

I really enjoyed this book in the beginning. Some of the concepts were difficult, but Greene knows how to build a good analogy and make physics easier to understand for the reader. Unfortunately, I started to lose interest a little after the halfway mark. Once Greene starts expanding on humans and our minds, it reminded me of Harari's "Sapiens" which I just recently read so it was a little repetitive and I don't feel Greene had anything new to add to the conversation. The ending was okay, with another good metaphor using the Empire State building as a model for our universe, but overall I felt a little unsatisfied. 

Anybody who has driven down the Richmond Street ramp diving into Downtown Toronto from the Don Valley Parkway will remember this: a huge sign on top of an evangelical church proclaiming: “The End is Coming. Call Jim” with a telephone number following.

“Until the End of Time” by Brian Greene fleshes out what Jim might have told me if I had taken the time to call the phone number.

I went into reading this book with a firm idea of what I was looking for: is there an answer to the Second Law of Thermodynamics and entropy or are we doomed to a collapsing Universe?

Dr. Greene was pretty firm in his answer: Doomed. With a capital ‘D’.

The obvious successes of evolution and the proliferation of information in the universe notwithstanding, eventually, in a billion billion billion years our Universe will go quiet with the disappearance of the final pockets of low entropy space.

And if there was any doubt about this turn of events, the confirmation of the Higgs Field not long ago showed us that all protons in the Universe will decay and take the physical world as we know it along with them.

The math confirms it.

The news was not enough to discourage Greene. He feels there is so much more to learn about us and our world, so much to appreciate about the accident we call life, that we should awaken each day to celebrate what’s here and what’s all around us.

Because I am reading this in the fall I kinda know what he’s talking about. The giant red maples on my street are so beautiful this time of the year I hardly know where to look first.

“Until the End of Time” is a nausea-inducing read not because of the message, and certainly not because of the quality of the writing because the writing is for the most part excellent.

Greene loses me a little in the discussion of religion and human kind’s frailties.

He moves beautifully from the tiniest particles in matter to the giant spaces between solar systems, and even galaxies; from today to the distant future. It’s the going back and forth that made me a little nauseous and actually happy to finally put the book down.

I think it didn’t help that he used the metaphor of the Empire State Building in New York to demonstrate how little we have gone on the eventual voyage of the universe from the Big Bang to the Big End.

Constantly looking up at the heights above and then looking down from the top — the end of the story — made this a vertigo-inducing affair.

I knew about the eventual demise of our solar system. I did not know what physicists believe to be the end game. How unlikely they believe Mind will survive even in a disembodied form.

When you meet Greene in person he is a very amiable scientist. We were lucky to have heard him interviewed at a theatre in Toronto just days before the city was locked down to reduce the spread of COVID-19 among the population.

And wasn’t there a touch of irony?