As I’ve been delving quite deeply into numerical solutions of quantum mechanics lately, I thought I would take a step back and write about something a little less… well… less. One thing about quantum mechanics that is sometimes a bit mind-boggling is that classical interpretations of certain systems can be helpful to understand things about […]

# Category Archives: Random frippery

## The Quantum Mechanics in the Gap

A big cat’s paw of mine is trying to fill the space between my backgrounds to understand how one thing leads to another. When a biochemist learns quantum mechanics (QM), it happens from a background where little mathematical sophistication is required; maybe particle-in-a-box appears in the middle of a low grade Physical Chemistry class and […]

## Magnets, how do they work? (part 4)

(footnote: here lies Quantum Mechanical Spin) This post continues the discussion of how ferromagnets work as considered in part 1, part 2 and part 3. The previous parts dealt with the basics of electromagnetism, introducing the connections from Maxwell’s equations to the magnetic field, illustrating the origin of the magnetic dipole and finally demonstrating how […]

## Magnets, how do they work? (part 3)

In this section I intend to detail the source of magnetic force, particularly as experienced by loops of wire in the form of magnetic dipoles. The intent here is to address ultimately how compass needles turn and how ferromagnets attract each other. I should start by asking for forgiveness. I’ve recently defended my PhD. While […]

## E=mc^2

Derived in ten minutes while I was on the toilet: Edit: 11-16-16 There was a slight error in the set-up of the center of mass calculation. Light appears to move an effective mass from -L/2 to L/2-l, the starting and stopping points of light. Here’s the reformulation to capture that. Time spent on this derivation: […]

## Interaction Picture

It’s not always about the cat. Here, I will show how to hop from the time dependent Schrodinger equation to the Interaction picture form. This post is intended to help recover a tiny fraction of the since-destroyed post I originally entitled “NMR and Spin Flipping part II.” I have every intention to reconstruct that post […]

## Magnets, how do they work? (part 2)

I will talk about the origin of the magnetic dipole construct here. Consider a loop of wire… You may have noticed that I posted an entry entitled “NMR and Spin flipping (part 2)” which has since disappeared. It turns out that wordpress doesn’t synch so well between its mobile app and its main page: I […]

## Chemical Orbitals from Eigenstates

A small puzzle I recently set for myself was finding out how the hydrogenic orbital eigenstates give rise to the S- P- D- and F- orbitals in chemistry (and where s, p, d and f came from). The reason this puzzle is important to me is that many of my interests sort of straddle how […]

## Powerball Probabilities

If you’ve read anything else in this blog, you’ll know I write frequently about my playing around with Quantum Mechanics. As a digression away from a natural system that is all about probabilities, an interesting little toy problem I decided to tackle is figuring out how the “win” probabilities are determined in the lottery game […]

## Parity symmetry in Quantum Mechanics

I haven’t written about my problem play for a while. Since last I wrote about rotational problems, I’ve gone through the entire Sakurai chapter 4, which is an introduction to symmetry. At the moment, I’m reading Chapter 5 while still thinking about some of the last few problems in Chapter 4. I admit that I […]