Ars Technica has a new series on quantum mechanics (no math)

Miguel Morales at Ars Technica is beginning a new introductory guide on quantum mechanics, one he promises won't require any math. If you've watched some of us wrangle over the implications of QM and wondered just what the heck we were so worked up about, this looks like it will be a good series for … Continue reading Ars Technica has a new series on quantum mechanics (no math)

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

The nature of quantum nonlocality

Quantum physics has been on my mind again lately, somewhat triggered by a recent conversation with Wyrd Smythe on his blog. I've always known quantum nonlocality has nuances, but stuff I read this week revealed some wrinkles I wasn't aware of. (Well, I was aware of them, but wasn't aware they pertained to nonlocality.) A … Continue reading The nature of quantum nonlocality

Why Do You Remember The Past But Not The Future?

When discussing eternalism and the block universe, the concept of "now" always ends up getting relegated to an aspect of our consciousness, not something "out there". "Now" seems to be the boundary between what we can remember and what we can only anticipate. But if, aside from entropy, the laws of physics are reversible and … Continue reading Why Do You Remember The Past But Not The Future?

A basic question on the black hole information paradox

Image of black hole

The black hole information paradox has been receiving some attention lately. This is the fact that information, that is any pattern of matter, that falls into a black hole is completely crushed as it approaches the singularity, losing whatever differentiation it might have had before. This has long been recognized as a problem, because in … Continue reading A basic question on the black hole information paradox

A PBS Space Time series on time and the block universe

Somewhat related to the previous post, I just saw this video from Matt O'Dowd discussing why the block universe is such a compelling concept. https://www.youtube.com/watch?v=EagNUvNfsUI&t=12s The second video in the series discusses the effect quantum mechanics might have on this concept. It reminds me why cosmologists seem to be more comfortable with the Many Worlds … Continue reading A PBS Space Time series on time and the block universe

The block universe is interesting, but not comforting

Click through for source and bonus red button caption at smbc-comics.com. This SMBC gets at something that's often bothered me about the way many people talk about the block universe concept. The block universe is the idea that if the universe is fully deterministic, then its entire history from beginning to end exists in an … Continue reading The block universe is interesting, but not comforting

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

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 high doses of outrage.  I understand the discomfort.  When I first … Continue reading David Deutsch’s version of many worlds