FRAMMENTI

Sometime back I wrote that the many-world interpretation of quantum mechanics entails the universe splitting every time a measurement is made.  That is completely wrong. Whatever you think about many-worlds, whatever your philosophical preconceptions are, you must admit that it's the most elegant interpretation of quantum mechanics, if you take its implications seriously (which the Copenhagen interpretation does not). Many-worlds takes the unitary evolution of the wavefunction at face value: there is no collapse - that is, the wavefunction always evolves according to the Schrodinger equation - and therefore no special observer that causes the collapse. The apparent randomness of quantum processes is due to decoherence : the measurement apparatus and the quantum system become entangled and almost immediately decohere, meaning that the many different combinations of measurement and state giving rise to that particular measurement effectively decouple and stop interfering with each ot

 This is an excerpt from one of my conversations with ChatGPT: It's not that I'm bothered by its answer to my first question, and that it got it wrong. What bothers me is that GPT, despite being an incredible milestone in conversational AI, is still incapable of understanding context , which is what humans are instead so good at.  The snippet above (I have many more) convinces me more than anything else that large language models, however impressive, do not display any kind of true intelligence or comprehension, and never will, due to their structural constraints. GPT is capable of providing plausible sounding replies to a wide variety of questions by scanning through an immense knowledge corpus, but if the question is misleading or unanswerable, GPT will still give it its best shot by conjuring up some kind of plausible sounding answer, instead of recognizing the fact that there might be no answer, or that we lack the information to provide a meaningful one. This is what a rea

The more I think about quantum mechanics the more I find it disturbing.  I'm part of a minority who thinks quantum mechanics is not a fundamental description of reality but merely a statistical approximation of an underlying deterministic dynamics, and all of the quantum weirdness people keep talking about is merely the result of our own ignorance on how the world works at the most basic level.  It's not a popular view. The defenders of quantum mechanics as a fundamental description of physical reality usually bring up Bell's Theorem as the final nail in the coffin of such vain hopes, and with reason. Bell's Theorem is a brilliant and extremely powerful result which greatly constrains any theory that wishes to replace quantum mechanics. Technically, Bell's Theorem derives an upper bound on the amount of correlation between the outcomes of two statistically independent measurements in deterministic theories that obey local realism. This bound is experimentally viola

  Sometimes people ask me what's the point of watching a horror movie if all it does is scare you and make you feel uncomfortable. The point is in the premise. Good horror is supposed to make you feel uncomfortable to shake you from the lethargy of conventional thinking. It's no coincidence that great horror movies (or books) are usually ferocious critiques of societal conventions and the status-quo. That's what horror does best. Speak No Evil is a great example of this. Superficially it is the story of a family trip going horribly wrong, but at heart it is a brutal examination of danish middle-class culture (even though the assessment can easily be extended to the Western world in general).  Tafdrup's thesis seems to be this: A perfect life of material comfort, typical of the Danish (Western) middle-class, makes us weak and stupid, and easy prey to evil.  It's hard to disagree with this. In the West we all cherish our perfect lives of perfect material comfort, but

To anyone buying into Musk's propaganda on "free speech", don't be fooled.  He claims to be equally banning far-right and far-left Twitter users, leaving on the platform that sweet 80% of centrists open to rational dialogue. This is what he claims. What he is actually doing is banning anti-fascist or even moderately left-wing activists and reinstating far-right extremists, neo-fascists and neo-nazis in an attempt to cater to the Republican Party, whose leaders are very happy to have him at their side. He is using Twitter as his own personal plaything, single handedly deciding who is allowed to speak, who is not, and how much weight is given to any single opinion. This is the exact opposite of free speech. If speech being regulated by a single company is bad enough (Twitter as it was), how bad is it when a single person owns the public forum (Twitter as it is)?  If you are seriously in favor of free speech, you shouldn't be supporting Musk. You should be supporting

This paper is generating quite a bit of controversy. Researchers from MIT, Harvard and Caltech have teamed up with Google Quantum AI to simulate wormhole dynamics on a quantum computer using the holographic correspondence.  Roughly speaking, holography is the idea that Gravity in N dimensions is mathematically equivalent to Quantum Field Theory (QFT) in N-1 (on the boundary), so one can simulate the dynamics of a classical gravitational system using an analogue non-gravitational quantum system, like a collection of entangled qubits on a quantum processor. This is what the authors have done, which is emphatically not the same as creating a wormhole, like some news outlets have reported. Media sensationalism notwithstanding, the study is interesting, but not what I wish to talk about right now. The buzz surrounding this publication got me thinking again about the holographic principle and its consequences for our understanding of physics. For quite some time physicists have tried unif

The difference between physics and metaphysics is not as clear-cut as one might assume at first. Science works by making metaphysical assumptions on the nature of the world, and deriving from those assumptions experimentally testable conclusions. Failure to disprove the conclusions gives us confidence in the plausibility of our metaphysics but it never definitively demonstrates it. One day, a person clever enough might set up an experiment which is in disagreement with our theory, forcing us to rethink our understanding of the world. This constitutes the major limit of science: the impossibility to ascertain the truth, only approximations of it. Videmus nunc per speculum et in ænigmate. Never  facie ad faciem , face to face: absolute knowledge of the truth pertains to the realm of divine revelation, not science. We are stuck with this. A person committed to the scientific method, as I am, ought to be committed to its limits, and this is one of them.   We can make metaphysical assumptio