## What is a qubit?

I was trolling around in the comments of a news article presented on Yahoo the other day. What I saw there has sort of stuck with me and I’ve decided I should write about it. The article in question, which may have been by an outfit other than Yahoo itself, was about the recent decision […]

## Beyond F=ma

Every college student taking that requisite physics class sees Newton’s second law. I saw it once even in a textbook for a martial art: Force equals mass times acceleration… the faster you go, the harder you hit! At least, that’s what they were saying, never mind that the usage wasn’t accurate. F=ma is one of […]

## Nonlocality and Simplicity

I just read an article called “How quantum mechanics could be even weirder” in the Atlantic. The article is actually relatively good in explaining some of how quantum mechanics actually works in terms that are appropriate to laymen. Neglecting almost everything about ‘super-quantum,’ there is one particular element in this article which I feel somewhat […]

In between the Sakurai problems, I decided to tackle a small problem I set for myself. The Sakurai quantum mechanics book is directed at about graduate student level, meaning that it explicitly overlooks problems that it deems too ‘undergraduate.’ When I started into the next problem in the chapter, which deals with the Wigner-Eckert relation, […]

## A Spherical Tensor Problem

Since last I wrote about it, my continued sojourn through Sakurai has brought me back to spherical tensors, a topic I didn’t well understand when last I saw it. The problem in question is Sakurai 3.21. We will get to this problem shortly… I’ve been thinking about how best to include math on this blog. […]

## Schwinging the Pendulum

Masses on springs get a lot of use in physics; you see them early in that first year of introductory classical mechanics with Hooke’s law and they come back over and over again after that. Physicists are fond of saying that basically everything in reality reduces to a mass on a spring if you squint […]

## The Question of How You Build a Black Hole

‘If Ant-man can’t do it, how does it happen?’ After I finished working on that post yesterday, I was left with this question. It’s kind of a squirrelly question if you stop and think about it. I made an argument by Uncertainty Principle that particles can’t be compressed into such a tiny space in order […]

## Hank Pym is not the deadliest Marvel Superhero ‘Because Blackholes’

I was reading blog articles as I was wont to do and I stumbled over a blog entry on ScreenRant about the deadliest Marvel superheroes. Most of the article is very tongue and cheek and can be taken with a grain of salt. I felt no alarm until I read the #1 entry placing Hank […]

## Angular momentum by harmonic oscillator

I’ve been thinking about Sakurai problem 3.19 for the past few days. The problem reads: 19.) What is the physical significance of the operators K+ ≡ a+†a-†        and       K- ≡ a+a- in Schwinger’s Scheme for angular momentum? Give nonvanishing matrix elements of K± I’m not sure I completely understand this problem yet. The ‘a’ operators […]

## How Quantum Mysticism Slips Free of the Math

(Subtitle: How I’m still seething after reading about Quantum University and seeing a bunch of boobs calling themselves ‘quantum physicists.’) After finishing that previous post, I realized that I still have more to say about the topic. I’ve actually read quite a bit from quantum cranks before and the topic never fails to inflame me. […]