Existential Physics

A Scientist's Guide to Life's Biggest Questions

By: Sabine Hossenfelder

Narrated by: Gina Daniels

Length: 8 hrs and 7 mins

Publisher's summary

A contrarian scientist wrestles with the big questions that modern physics raises, and what physics says about the human condition.

Not only can we not currently explain the origin of the universe, it is questionable we will ever be able to explain it. The notion that there are universes within particles, or that particles are conscious, is ascientific, as is the hypothesis that our universe is a computer simulation. On the other hand, the idea that the universe itself is conscious is difficult to rule out entirely. 

According to Sabine Hossenfelder, it is not a coincidence that quantum entanglement and vacuum energy have become the go-to explanations of alternative healers, or that people believe their deceased grandmother is still alive because of quantum mechanics. Science and religion have the same roots, and they still tackle some of the same questions: Where do we come from? Where do we go to? How much can we know? The area of science that is closest to answering these questions is physics. Over the last century, physicists have learned a lot about which spiritual ideas are still compatible with the laws of nature. Not always, though, have they stayed on the scientific side of the debate. 

In this lively, thought-provoking book, Hossenfelder takes on the biggest questions in physics: Does the past still exist? Do particles think? Was the universe made for us? Has physics ruled out free will? Will we ever have a theory of everything? She lays out how far physicists are on the way to answering these questions, where the current limits are, and what questions might well remain unanswerable forever. Her book offers a no-nonsense yet entertaining take on some of the toughest riddles in existence, and will give the listener a solid grasp on what we know—and what we don’t know.

* This audiobook includes a downloadable PDF with key visual figures included in the book. 

PLEASE NOTE: When you purchase this title, the accompanying PDF will be available in your Audible Library along with the audio.

©2022 Sabine Hossenfelder (P)2022 Penguin Audio

Critic reviews

"Part gonzo journalist, part curious child, part teacher, and part accomplished researcher, Sabine Hossenfelder is a unique writing talent and a unique science popularizer. One cannot help being provoked reading her prose, as she knows how to push your buttons. But she also abhors bullshit, which makes her take on the deepest human questions and what physics has to say about them worth looking at, and also ensures that it will be different than those other physics books of grand verbosity about frontier physics. You might agree with her. You might not. But you will come away from the experience enriched, and will think about the world differently than you did before.” (Lawrence Krauss, best-selling author of The Physics of Star Trek, A Universe from Nothing, and The Physics of Climate Change)

Separating the Science from the Nonsense

Sabine Hossenfelder’s Existential Physics is a highly informative big thought book on the important big ideas in physics and philosophy. Dr. Hossenfelder is at her usual best, highly intelligent, clear-headed logical and uncompromising in addressing the many attempts to pass off speculative metaphysics and quasi-religious ideologies as science.

Sabine is an expert at puncturing myths and pseudo-scientific nonsense that some attempt to pass off as science. No we do not live in a simulation and religious theories that postulate a god or creator based on fine tuning are not scientific. Dr. Hossenfelder does a great job dissecting specious arguments that the Multiverse idea is compelled by science. Multiverse theories are speculative metaphysics, not science. The simulation theory gets similar well deserved treatment as speculation, not science. And no, the universe is not just a mathematical structure. And it does not think either. So much for Panpsychism.

The author is very good at applying her rigorous Germanic logic to the big questions of science and philosophy. Her explanations are clear, insightful and phrased in a way that helps a lay reader understand them in a way they may not have before.

The one area that Hossenfelder gives a rather superficial short-hand answer to is the metaphysical question of Free Will. For Hossenfelder the answer is simple. “The future is fixed except for random quantum fluctuations that we do not control.” The Author views this sentence as dispositive of the question and repeats it numerous times. It isn’t dispositive. The fact that the laws of particle physics are deterministic (but not predictable because of randomness) or difficult to predict because of chaos theory, has nothing to do with the question of the freedom of biological organisms to do as they like. Physics is the study of the inanimate not the animate. Humans can generally act only in ways that they perceive to be in their own interest. In effect, they do what they want. That’s the essence of free will. The fact that the movements of particles under the Standard Model are largely deterministic doesn’t bear on the question of whether biological organisms can do what they like. The book’s approach to Free will is thus its weakest point.

But there is much to like here, and Hossenfelder gives great clarity to many difficult problems. Existential Physics is well worth reading and it is also very much worth watching the informative videos on her YouTube channel.

Unscientific and unengaging

I've been a fan for a long time, but this book was a big disappointment. I think Sabine is trying to win the Templeton prize.

At some point in every intellectual's life, a choice must be made, and it's not always made consciously. It is the choice between truth and intellectual honesty or comfortable illusions and social harmony. In this book, Hossenfelder cheerleads for social harmony.

In one particularly weak rationalization, she argues that science has nothing to say about the truths of the Islamic faith because (she states this explicitly) that might alienate the Islamic faithful from studying science. This socially pragmatic move is so clumsy that it can't be described as anything other than coming from a deep need to put people at ease and be liked.


Hossenfelder bends over backward shoveling out the same bad arguments for the compatibility of religion and science that were retired by philosophers in the 18th and 19th centuries, but survive as modern apologetics.

Look, I understand the desire for harmony. And we ALL live with comfortable illusions. But science is not compatible with the faith of the Abrahamic religions. And to pretend otherwise, and then advance terrible arguments to support that pretense is not intellectually honest.

Hossenfelder repeats some of the historically worst arguments for non-overlapping magisteria. For example, she points out that science can't DISprove something, or that its probability is not mathematically zero. Fine. It does NOT follow that it's rational or scientifically neutral to believe in virgin birth, a 6000 year-old earth, or the immortality of the soul -- all things she says are perfectly compatible with what we know.

I'm just disappointed. I thought Hossenfelder was like having Carl Sagan again. I was wrong.

It is Still Whistling in the Dark

Gee but Sabine is an upbeat lady! You have to be to buck yourself up every morning to roll out of bed, glance at your husband and two children, and stagger off to yet another day in the lab solving esoteric equations when you believe it was all predestined and you had no choice in the matter and it doesn’t make any difference anyway since you know you are a tiny lump of sentient molecules on an insignificant planet in one of 200 billion galaxies sliding down the entropic slope to oblivion. But we can rejoice in the wonder of it all!

I’ve heard most of Sabine’s arguments before in her other works and on her YouTube channel, but was good to get it all in one place. I believe she makes the mistake of drinking her own scientific Kool-aid, in that anything that smacks of religion she dismisses as “a-scientific.” She isn’t overtly hostile like the New Atheists, just dismissive, as religion is outside of the scientific realm as being unprovable.

The trouble with this view is that yes, there is not an air-tight argument for the existence of God. But there is an air-tight argument for the existence for the man Jesus Christ. His life and times are attested to by irrefutable documents (look at the evidence for them). When he was here on earth, he claimed to be God (read the book of John, for instance). He was crucified and rose from the dead (read N T Wright’s “The Resurrection of the Son of God).

These are examples of events that broke into Sabine’s predestined, predetermined universe to evince an entirely other level of power and intelligence. She speculates on whether the cosmos might have a “mind” of some sort as some of her esoteric-minded colleagues believe and she concludes that it does not.

The irony, of course, is that there is a mind behind all the laws of physics and biology and chemistry, and “we were eye-witnesses to his glory.”

I wish I read that when I was 16

it has the power to either give you an existential crisis or get you out of one.

Is Dr. H Predictable?

There's a lot of pseudoscientific or a-scientific stuff out there. It behooves the informed individual to understand what science is, where its limits are, and what it can/can't tell us about deeply philosophical questions we tend to ask. Does free will exist? Are humans predictable? What can science say about the creation of the universe, how it will end, and what happened before? Sabine Hossenfelder is incisive in cutting through the more speculative stuff to something less decorated with bullcrap. I find this refreshing.

Welcome to the Pantheon, Dr Hossenfelder

Dr Hossenfelder has claimed her place alongside Sean Carroll and Carlo Rovelli as one of our generation's esteemed purveyors of physics philosophy. Her explanation of 'course graining' as a mathematical procedure is the best I've yet seen in popular physics writing, and she leverages this knowledge effectively in a later chapter as she argues against the simulation hypothesis (a la Nick Bostrom). Said arguments include 1) there are measurements at the quantum level which could not have been simulated by a classical computer, and just waving your hands and saying "but technology of the future can do that!" is sci-fi, not science nor philosophy, and 2) if reality includes consciousnesses which will themselves make simulations of consciousnesses, this would likely lead to a hardware situation in which some parts of the uber-simulation will use course-grain methods while others use higher-fidelity methods, but this is untenable, as reality is so non-linear that even slight computational differences at the course-fine boundary will lead to results that would not match from one part of the simulation to the next. Dr Hossenfelder's responses to philosophical inquiry such as this, backed by physics, are both novel and profound. Welcome to the pantheon, Dr Hossenfelder.

Disappointed

A mixture of patronizing platitudes, cheesy jokes, irrelevant digressions, and only occasional sparks original thoughts. Too many irrelevant words for a person claiming to be mostly immersed in math. Claim that math is enough and we do not need understanding physics appears to me deeply anti-scientific. Furthermore, people decide to bother to read this book precisely to get closer to a consistent worldview. I studied quantum mechanics in the university, and not sure how useful are the author’s ramblings about the Shroedinger equation and a wave functions for those who did not study the theory. Not useful for me either.

Scientific and engaging

This is a very well written summary of the common ideas people have when trying to apply physics to philosophy, or some of the conclusions scientists and non scientists reach when they come across ideas they don’t understand. It doesn’t delve too deep, it isn’t as comprehensive as it claims, but to be fair one book isn’t going to give you all the answers. As I expected, (I follow Hosenfelders YouTube channel), it goes more deeply into debunking ideas than in explaining scientific concepts (although there are many explanations that I had to go back and re-listen to in order to grasp), and a lot of the answers are “there’s no evidence”. I found this book fascinating because it gives the reasoning behind the debunking, instead of just saying “physics doesn’t support this.” In that way, I found this book very useful.
However, if you haven’t any interest in modern pseudoscience, and are instead reading this book to see what science has to say about god and the afterlife, or the meaning of life, you’ll be disappointed because that’s not the scope of this book.

Magic

So many fascinating questions answered in a lucid, understandable and engaging manner. I want to listen again and again.

Philosofical reasoning

Excellent narration, Trying to understand entropy for me, I needed to remember osmosis and homeostasis.

The book is great, the audible version dreadful.

I strongly recommend this book to anyone who is not a physicist who seeks to learn a little of puzzles which are presented to physicists today. The author has written a great introduction to the state of knowledge of today's physics which complements many of her YouTube videos which I recommend. Sadly the Audible version is dreadful, being read by a reader with a strong US accent. I purchased the Audible version as my eyes are old and getting tired and had hoped to hear Sabine herself or at least somebody who spoke English without an accent. No such luck. Just get the book and good lighting!

Sorry but Sabine should have narrated this.

I have achieved the highest level in audible and this book has the strangest narrator choice of all my audiobooks. Science educational content but the narrator sounds like a Grandma reading a cookie recipe, it's odd.

This is pretty lightweight content for anyone who watches her content on YouTube, maybe this was aimed at the über layman. I did enjoy the listen with a few good takeaways. I still love Sabine but I am just being candid.

Great

Most lovely
As always she hits the nail on the head
A must listen book

excellent

Sabine's youtube channel is a must, she is a great science communicator. This book has the hallmarks of the straight-talking and humorous style she uses. I'd of preferred it if she narrated herself. The actual content covers the interesting areas of physics, the big stuff....and not just focused on black holes!