Carlo Rovelli’s Helgoland

I've posted a lot over the years on interpretations of quantum mechanics. My writing has tended to focus on comparing the big three: Copenhagen, pilot-wave, and many-worlds. But there are a lot of others. One that has been gaining converts among physicists and others is Carlo Rovelli's relational quantum mechanics (RQM) interpretation. This is an … Continue reading Carlo Rovelli’s Helgoland

The nature of splitting worlds in the Everett interpretation

Schrodinger's cat in many worlds

This post is about an aspect of the Everett many-worlds interpretation of quantum mechanics. I've given brief primers of the interpretation in earlier posts (see here or here), in case you need one. Sean Carroll, as he does periodically, did an AMA on his podcast. He got a number of questions on the Everett interpretation, … Continue reading The nature of splitting worlds in the Everett interpretation

Ars Technica’s series on quantum mechanics: How big is a particle?

A couple of weeks ago, I shared Ars Technica's first article in a series on quantum mechanics that promised to be math and philosophy free. So far, the author, Miguel Morales, has stuck to that promise. Today he published the third installment. This one focuses on the size of particle, and why that's far from … Continue reading Ars Technica’s series on quantum mechanics: How big is a particle?

Mea culpa on quantum decoherence

Lately, I've been trying to gain a better understanding of quantum decoherence. This is the process of a quantum system in superposition interacting with the environment and, as a result, appearing to lose its quantum nature, notably by having interference between the elements of its superposition become undetectable. Decoherence is often used synonymously with the … Continue reading Mea culpa on quantum decoherence

Thoughts about quantum computing and the wave function

Qubit bloch sphere

The main difference between a quantum computer and a classical one is the qubit. Qubits are like classical bits, in that they hold binary values of either 1 or 0, on or off, true or false, etc. However, qubits, being quantum objects, can be in a superposition of both states at once. The physical manifestation … Continue reading Thoughts about quantum computing and the wave function

David Deutsch’s version of many worlds

Schrodinger's cat in many worlds

Note: I answer the questions asked here in a later post. I've written about the bizarre nature of quantum physics many times, providing a lightning primer back in May on three major interpretations: Copenhagen, pilot-wave, and many worlds.  The many worlds interpretation (MWI) is often summarily dismissed by people, often along with visceral shudders or … Continue reading David Deutsch’s version of many worlds

The measurement problem, Copenhagen, pilot-wave, and many worlds

With quantum physics, we have a situation where a quantum object, such as a photon, electron, atom or similar scale entity, acts like a wave, spreading out in a superposition, until we look at it (by measuring it in some manner), then it behaves like a particle.  This is known as the measurement problem. Now, … Continue reading The measurement problem, Copenhagen, pilot-wave, and many worlds

An excellent explanation of quantum decoherence, and how it might lead to many worlds

Matt O'Dowd is a first class science communicator.  In this latest video, he does an excellent job explaining decoherence, and why the MWI (many worlds interpretation) ends up being so tempting when you see it through. http://www.youtube.com/watch?v=GlOwJWJWPUs Of course, this doesn't mean MWI is the right interpretation, but it does demonstrate why many find it … Continue reading An excellent explanation of quantum decoherence, and how it might lead to many worlds

Is reality an illusion? If so, does it matter?

Donald D. Hoffman, a psychologist at the University of California, Irving, has been getting a lot of attention recently for his views, that evolutionary evidence indicates that reality is an illusion, that the only thing that exists are conscious minds. This is a modern version of an ancient concept, called idealism.  The earliest writings about … Continue reading Is reality an illusion? If so, does it matter?