Sabine Hossenfelder
Physicist and science communicator. Writes Backreaction and makes videos explaining new physics and astronomy results, frequently to argue that the headline about them overstates the case.
Sabine Hossenfelder did not write this page. ppll compiled it from their own words, each linked to the source. Is this you? · Report a mistake
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What they believe
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The Copenhagen interpretation is not locally causal in Bell's sense.
The Copenhagen Model-and because of that, the Copenhagen Interpretation-is not locally causal in Bell's sense.
arxiv.orgSaid 21 Sept 2023This on korrents
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Beliefs
Korrents What they believe 4 beliefs — each backed by an exact quote.
Each is a — compiled by korrents.com, not by them: the one-line wordings are korrents', the quotes are theirs.
Recent
The Copenhagen interpretation is not locally causal in Bell's sense.
The Copenhagen Model-and because of that, the Copenhagen Interpretation-is not locally causal in Bell's sense.
Quantum Confusions, Cleared Up (or so I hope) Said 21 Sept 2023
Violations of Bell inequalities reveal only properties of models, not of nature itself.
Since Local Causality is a property of a model, observing violations of Bell's inequality cannot tell us anything about nature itself, but merely about the properties of the model that we use to describe nature.
Quantum Confusions, Cleared Up (or so I hope) Said 21 Sept 2023
Decoherence has not yet satisfactorily solved the measurement problem and does not restore local causality.
while decoherence has the potential to solve this aspect of the measurement problem, it hasn't yet been satisfactorily done. Decoherence also certainly does not return us to Local Causality.
Quantum Confusions, Cleared Up (or so I hope) Said 21 Sept 2023
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The collapse postulate cannot simply be discarded without replacement instructions for measurements.
As we just saw, one cannot just discard the Collapse Postulate. For this reason, if one does calculations in any Many Worlds approach, one must effectively replace the Collapse Postulate by other assumptions, notably about what happens to observers and/or measurement devices when worlds branch.
Quantum Confusions, Cleared Up (or so I hope) Said 21 Sept 2023
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Recommends rcmnd
rcmnd What they recommend 11 things — each backed by an exact quote.
Compiled by rcmnd.app, not by them: the quotes are theirs, and each links to the post it was copied from.
Recent
Mixed on Richie Doodles: The Brilliance of a Young Richard Feynman
In summary, the illustrations are awesome, the explanations aren't.
backreaction.blogspot.com 6 Mar 2018
What others say about Richie Doodles: The Brilliance of a Young Richard Feynman →
Recommends The Dialogues: Conversations about the Nature of the Universe
I would recommend this book to everyone who has an interest in the foundations of physics.
backreaction.blogspot.com 16 Jan 2018
What others say about The Dialogues: Conversations about the Nature of the Universe →
Recommends Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab
If you're considering to become a particle physicist, I strongly recommend you read this book to find out if you fit the bill.
backreaction.blogspot.com 27 Mar 2017
What others say about Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab →
Show 8 more
Recommends Why Quark Rhymes with Pork: And Other Scientific Diversions
Why Quark Rhymes With Pork is a book I'd never have bought. But having read it, I think you should read it too.
backreaction.blogspot.com 19 Dec 2016
What others say about Why Quark Rhymes with Pork: And Other Scientific Diversions →
Mixed on Why String Theory?
Altogether, Why String Theory? gives the reader a mostly fair and balanced account of string theory
backreaction.blogspot.com 30 May 2016
Recommends Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe
In short, Ethan's book is the missing link between cosmology textbooks and popular science articles.
backreaction.blogspot.com 31 Dec 2015
Liked Cracking the Particle Code of the Universe
In summary, Moffat's new book is a well-done and well-written survey of the history, achievements, and shortcomings of the Standard Model of particle physics.
backreaction.blogspot.com 26 Jan 2015
What others say about Cracking the Particle Code of the Universe →
Liked The Cosmic Cocktail: Three Parts Dark Matter
Freese's book is a valuable, non-technical and yet up-to-date review, especially on the topic of dark matter detection.
backreaction.blogspot.com 27 May 2014
What others say about The Cosmic Cocktail: Three Parts Dark Matter →
Recommends Quantum Mechanics: The Theoretical Minimum
If you want to make the step from popular science literature to textbooks and the general scientific literature, then this book series is a must-read.
backreaction.blogspot.com 12 Apr 2014
What others say about Quantum Mechanics: The Theoretical Minimum →
Liked The Theoretical Minimum: What You Need to Know to Start Doing Physics
Susskind made his lecture notes into a book and did a great job.
backreaction.blogspot.com 23 Feb 2013
What others say about The Theoretical Minimum: What You Need to Know to Start Doing Physics →
Liked Impossibility: The Limits of Science and the Science of Limits
The book is well written, though not very inspired, and the scientific explanations are well referenced and, for all I can tell, flawless. I'd give four out of five stars if I had stars to give.
backreaction.blogspot.com 23 Nov 2011
What others say about Impossibility: The Limits of Science and the Science of Limits →
Where they publish
Blog Backreaction Their long-running physics blog. Has a feed.
Written arguments about physics and how it is funded and reported — foundations of quantum mechanics, particle physics beyond the Standard Model, and why a given result is less than the coverage claims.
Open backreaction.blogspot.com
Recent
- The Universe Was Born Magnetic, Scientists Say 17 Oct 2026 For a decade, two ways of measuring how fast the universe expands have given different answers, a problem known as the “Hubble tension”. Now a group of physicists says the problem isn’t the supernovae but how we read th…
- Global Warming Means Fewer Tropical Cyclones, Researchers Find 15 Oct 2026 This year's hurricane season has been unusually quiet, and a new study suggests this might become the norm. According to researchers at Princeton, the warmer the climate gets, the fewer tropical cyclones form. But fewer…
- Big Oil’s Plan Is Working Beautifully 14 Oct 2026 Oil companies have found a way to keep using fossil fuels: capture the carbon dioxide and bury it underground. Governments around the world are now pouring billions into it. But does it actually work? Let's take a look.
Show 17 more
- Biologists Give 3 Reasons Why AI Isn’t Conscious (Yet) 10 Oct 2026 One of the biggest debates in tech at the moment is the question of whether current AI models can become conscious. Whatever “conscious” means. According to a group of biologists, current AI models are far from it – but…
- Plot Twist: New Milky Way Data Incompatible With Dark Matter AND Modified Gravity 9 Oct 2026 For decades, astrophysicists have told us that the Milky Way sits inside a huge halo of dark matter. But new measurements of how the outer stars of our galaxy move don't seem to fit that picture, nor the main alternativ…
- The Experts Were Wrong About AI. Again. 7 Oct 2026 For years, experts have tried to predict how fast artificial intelligence would progress, and they've been wrong again and again. Benchmarks they expected in a decade fell in a year. But in some areas, they got it wrong…
- Quantum Effects Can Shape Human Thought, Physicist Shows 4 Oct 2026 Nearly everything published about quantum physics in the brain is nonsense. This time a physicist in Istanbul has come up with something different, and the key move is that quantum effects don't need to last long to lea…
- First Evidence for Quantum Gravity? 3 Oct 2026 In October 2022, a detector in Russia caught a single photon with an energy far beyond anything our particle colliders can produce. According to physics as we know it, it should never have made it to Earth. Now a team o…
- Make AI Believe in God to Keep Humans Safe, Scientist Argues 2 Oct 2026 AI is getting more capable and more dangerous by the day, and nobody knows how to keep it on our side. One computer scientist has an answer as creative as simple: give AI a religion. Specifically, tell it that we're all…
- One Million Dollars for Telling the Truth. Who Might Win It? 1 Oct 2026 A billionaire investor has put up a million dollars a year for scientists who stuck with unpopular results and turned out to be right. I think it's a timely idea and a good one. I also have a list of people who might de…
- This $15 Billion Nuclear Fusion Machine Can’t Work, Physicists Say 30 Sept 2026 Fusion startups keep postponing their dates, but it's becoming clear who is doing well and who isn't. Helion is valued at fifteen billion dollars, and three groups have now said their machine cannot work, one of them th…
- Room-Temperature Superconductor Finally Found? 27 Sept 2026 There's a new candidate for a room temperature superconductor, and it isn't some exotic compound, it's graphite, just ground up and baked. A team in Russia says they have found one of the key signatures of superconducti…
- FINALLY: A Proof that Particles Take All Paths At Once? 24 Sept 2026 Eighty years ago Richard Feynman said that a quantum particle takes every possible path at the same time. A team of physicists in China now says they have experimentally shown this is not just an interpretation but phys…
- AI Could Be Conscious During Training, Not When You Use It, Scientist Says 22 Sept 2026 There are new rumours that today's AI might be conscious, and this time it's not just talk. Anthropic says it found a hidden part of Claude that works like an internal notepad, one it can use to reason without revealing…
- Degrowthers are Dangerous 21 Sept 2026 The Guardian recently ran a piece by a group of economists, one of them a Nobel laureate, arguing that economic growth is a doomed strategy. I went and looked at what this movement actually publishes, and I fell into a…
- Einstein Refused to Believe This, But It Could Explain the Universe 15 Sept 2026 A physicist proposes that quantum uncertainty affects the entire universe: we cannot both know how large the universe is and how fast it is expanding.
- Neuroscience’s Case Against Free Will Is Falling Apart 10 Sept 2026 In 1983 Benjamin Libet found that brain activity predicts your movements before you are aware of deciding to move. The result has been reproduced many times, and it has been used ever since to argue that free will is an…
- The Hugging Face Hack Was Much Worse Than I Thought 8 Sept 2026 I looked at the reports about the OpenAI/Huggingface incident and I think we're not talking enough about the most worrisome part
- Just One More Dimension and Dark Matter Is Solved 6 Sept 2026 String theory has been famously untestable for decades. This week the Economist reported that has changed, and the reason involves an extra dimension of space that might be just big enough to notice in a tabletop experi…
- I Was Offered Money to Tell You AI Will Kill Us 5 Sept 2026 There is money in telling you AI will destroy humanity, and there is money in telling you it will improve your life. Both sides are quietly paying creators to make the case. Some of it is disclosed properly and some of…
Link verified 1 Sept 2026. Recent items update automatically from the channel.
x.com @skdh Short-form, and where videos are announced.
Short posts on physics and science reporting, and where new videos and blog posts are announced.
Recent
- Big Oil's plans to survive climate change policies is working beautifully 14 Oct 2026 youtube.com
- A nuclear fusion start up in New Zealand is the only one working on the "levitating dipole" approach. 14 Oct 2026
- kudos to everyone who has just been plastering their videos with Getty photos leaving the watermark on 13 Oct 2026
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- Biologists Give 3 Reasons Why AI Isn’t Conscious (Yet) 10 Oct 2026 youtube.com
- A group of astronomers claim they have evidence for UFOs on the moon. Their evidence is so bad I suspect they are just trolling. 10 Oct 2026
- New data about the Milky Way is incompatible with both dark matter AND modified gravity 9 Oct 2026 youtube.com
- Physicists have created an entirely new form of matter, a crystal that we didn't previously know existed. It's the sort of research that might one day win a Nobel Prize. 8 Oct 2026
- The only thing I do on linkedin is post links to my YouTube videos. I don't know why I'm bothering. 8 Oct 2026
- Expert predictions about AI progress have been stunningly inaccurate 7 Oct 2026 youtube.com
- Life did not have one origin, but two, the authors of a new study say. 7 Oct 2026
- A few words on this year's Nobel Prize in physics. It's okay if you hate me for saying this. 6 Oct 2026 youtube.com
- Nearly everything published about quantum physics in the brain is nonsense. Now a physicist in Istanbul has come up with something different. No exotic new physics required, and it's testable, too. 4 Oct 2026 youtube.com
- A team of physicists claim they have found what may be the first ever evidence for quantum gravity 3 Oct 2026 youtube.com
- Microsoft releases controversial Majorana qubits for independent testing Microsoft has made its quantum chips available to DARPA (the US Defense Advanced Research Projects Agency) for independent testing. Microsoft has repeatedly claimed to have created topological qubits based on noise-protected Majorana modes. This claim has remained highly controversial, partly because the group at Microsoft did not publish data that actually supports their claim, and partly because they previously had to retract several papers about their research. DARPA will now test the hardware independently as part of… 3 Oct 2026
- A physicist has found a way to solve the alignment problem. Just give AI a god, he says. 2 Oct 2026 youtube.com
- A $1 million prize for scientific honesty could have a big impact on science. Who might win it? 1 Oct 2026 youtube.com
- Silicon Valley's most popular nuclear fusion project has received heavy scientific criticism 30 Sept 2026 youtube.com
- We might have misunderstood the Dunning Kruger effect 30 Sept 2026
- A closer look at the new candidate for a room temperature superconductor 27 Sept 2026 youtube.com
- After nine years of search, the privately funded “Project Callisto” found no evidence for cold fusion. The project began in 2015 and set out to test claims that deuterium (a heavy isotope of hydrogen), can undergo nuclear reactions inside palladium and release excess heat at relatively low temperatures. This hypothetical process is commonly referred to as “cold fusion” or “low energy nuclear reactions” (LENR). The project engaged more than 100 researchers and reproduced the major experiments. They tested more than 500 samples, developed equipment that forced deuterium into palladium at high p… 26 Sept 2026 callisto.report
Link verified 1 Sept 2026. Recent items update automatically from the channel.
YouTube Sabine Hossenfelder Their own channel: short physics explainers. Has a feed.
Short videos explaining new results in physics and astronomy, usually ending with what the finding does not show. Much of the written argument appears here first.
Recent
Link verified 1 Sept 2026. Recent items update automatically from the channel.
Papers ORCID Their ORCID record: peer-reviewed papers, newest first.
Academic papers, most recent first, restricted to open-access articles published in an identified journal. Fetched live from OpenAlex, keyed by this ORCID.
Recent
- Taxonomy for physics beyond quantum mechanics 1 Jul 2024 We propose terminology to classify interpretations of quantum mechanics and models that modify or complete quantum mechanics. Our focus is on models which have previously been referred to as superdeterministic (strong o…
- Comment on “Experimentally adjudicating between different causal accounts of Bell-inequality violations via statistical model selection” 14 Feb 2024 In a recent paper [Phys. Rev. A 105, 042220 (2022)], Daley et al. claim that some superdeterministic models are disfavored relative to standard quantum mechanics because such models overfit the statistics of a Bell-type…
- Superfluid dark matter in tension with weak gravitational lensing data 1 Sept 2023 Superfluid dark matter (SFDM) is a model that promises to reproduce the successes of both particle dark matter on cosmological scales and those of Modified Newtonian Dynamics (MOND) on galactic scales. SFDM reproduces M…
Show 17 more
- Aether scalar tensor theory confronted with weak lensing data at small accelerations 4 Jul 2023 Context.The recently proposed aether scalar tensor (AeST) model reproduces both the successes of particle dark matter on cosmological scales and those of modified Newtonian dynamics (MOND) on galactic scales. But the Ae…
- Dark matter profiles of SPARC galaxies: a challenge to fuzzy dark matter 30 May 2023 Stellar and gas kinematics of galaxies are a sensitive probe of the dark matter distribution in the halo. The popular fuzzy dark matter models predict the peculiar shape of density distribution in galaxies: specific den…
- Bell’s theorem allows local theories of quantum mechanics 31 Oct 2022
- What does it take to solve the measurement problem? 30 Sept 2022 We summarise different aspects of the measurement problem in quantum mechanics. We argue that it is a real problem which requires a solution, and identify the properties a theory needs to solve the problem. We show that…
- Toy model for local and deterministic wave-function collapse 19 Aug 2022 A local, deterministic toy model for quantum mechanics is introduced and discussed. It is demonstrated that the model makes the same predictions as quantum mechanics when averaged over the hidden variables. In this mode…
- Supermeasured: Violating Bell-Statistical Independence Without Violating Physical Statistical Independence 19 Jul 2022 Bell’s theorem is often said to imply that quantum mechanics violates local causality, and that local causality cannot be restored with a hidden-variables theory. This however is only correct if the hidden-variables the…
- The wave function as a true ensemble 1 Jun 2022 In quantum mechanics, the wave function predicts probabilities of possible measurement outcomes, but not which individual outcome is realized in each run of an experiment. This suggests that it describes an ensemble of…
- Galactic mass-to-light ratios with superfluid dark matter 26 Apr 2022 Context. We make rotation curve fits to test the superfluid dark matter model. Aims. In addition to verifying that the resulting fits match the rotation curve data reasonably well, we aim to evaluate how satisfactory th…
- A path integral over Hilbert space for quantum mechanics 4 Mar 2022
- Mori-Zwanzig Formalism for General Relativity: A New Approach to the Averaging Problem 1 Dec 2021 Cosmology relies on a coarse-grained description of the universe, assumed to be valid on large length scales. However, the nonlinearity of general relativity makes coarse graining extremely difficult. We here address th…
- Analyzing data is one thing, interpreting it another 1 Jan 2021 Most professional scientists, engineers, and mathematicians today are men.The reasons for this are partly historical.Until recently, women were in many countries not admitted to or were discouraged from pursuing higher…
- The Milky Way’s rotation curve with superfluid dark matter 24 Aug 2020 Recent studies have shown that dark matter with a superfluid phase in which phonons mediate a long-distance force gives rise to the phenomenologically well-established regularities of Modified Newtonian Dynamics (mond).…
- Rethinking Superdeterminism 6 May 2020 Quantum mechanics has irked physicists ever since its conception more than 100 years ago. While some of the misgivings, such as it being unintuitive, are merely aesthetic, quantum mechanics has one serious shortcoming:…
- Analog models for holographic transport 25 Sept 2019 The gauge-gravity duality and analog gravity both relate a condensed matter system to a gravitational theory. This makes it possible to use gravity as an intermediary to establish a relation between two different conden…
- Screams for explanation: finetuning and naturalness in the foundations of physics 3 Sept 2019
- Strong lensing with superfluid dark matter 1 Feb 2019 In superfluid dark matter the exchange of phonons can create an additional force that has an effect similar to Modified Newtonian Dynamics (MOND). To test whether this hypothesis is compatible with observation, we study…
- The redshift-dependence of radial acceleration: Modified gravity versus particle dark matter 11 Sept 2018 Modified Newtonian Dynamics has one free parameter and requires an interpolation function to recover the normal Newtonian limit. We here show that this interpolation function is unnecessary in a recently proposed covari…
Link verified 9 Sept 2026. Recent items update automatically from the channel.
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