Measuring belief by constraint

It’s important to know what you actually believe. Lately, I’ve wondered how to measure belief in facts or truths.

The best heuristic I’ve come up with this: You believe something if your life is constrained by it. This includes your actions, decisions, thoughts… basically what you have control over. Like a guard rail, if you intersect the boundary of one of your beliefs, an invisible force will reign you in and prevent you from trespassing. You are constrained by your belief.

I don’t claim this is the only or best way to measure belief, but I think it works to a point. Thinking about belief this way has been both encouraging and disconcerting. It has revealed some interesting insights, including things I want to believe but don’t, as well as things I do believe but frankly wish I didn’t.

By the way, this doesn’t just apply to spiritual beliefs—it works just as well for everything else.

My Driving Rules

I am an above-average driver. I didn’t get that way without inviolable personal rules.

Driving is almost definitely the most dangerous thing I do in a given day. Nothing puts me, my wife, or my kids at greater risk. We live in a culture where it’s socially acceptable to drive while rushed, stressed out, and distracted. How are any of us still alive?

It occurred to me the other day that I have already started teaching my 5 year-old daughter how to drive. I teach her every day what is okay by what I do. So I got to thinking about it and realized I have a series of rules I follow (and should follow more strictly) that I want to be second nature to her years before she ever touches a set of keys. I have started using these rules by name with her. I’m writing them up to codify them for myself.

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How to survive air travel

I have a longstanding rule when flying that if I do not run through a terminal at some point, I arrived at the airport too early. I’d generally rather be outside the airport exploring whatever city I’m in, for as long as I can, with people I like. The benefits of sprinting are numerous and equally applicable within airports.

But Craig Mod might have just changed my mind. Excellently written and based on an impressive CV of international travel, he shares his practical—and occasionally hilarious—approach to getting from A to B with minimal stress and maximum enjoyment.

You look insane — your white mask, your monkey bra, your noise-canceling headphones, but it doesn’t matter. You are satiated, filled with nourishing food; you have gotten your work done, and now you float in a personal outer space. An outer space that sounds like the summer in Wisconsin and feels just as humid within the nose and mouth thanks to your microclimate. You are on a plane but are not. You could be anywhere. You are untouchable. You are possibly the most insufferable traveler ever. You float and smile because you are the Dalai Lama.

This is how you survive air travel.

I am the Dalai Lama. :)

Read the rest: Let’s fly: How to survive air travel by Craig Mod

Resources for a personal finance reboot

I want to talk a bit about challenging financial situations today and some resources I have found most helpful. First, some context. The parameters of our move to Boston included the following: (a) a moderate level of student loan debt, (b) expenses incurred in support of a cross-country move and settling into a new place, (c) a 3–4 month waiting period before finding a suitable renter for my home in Atlanta, and (d) high housing costs in Boston (I pay 2x for 0.5x space relative to Atlanta).

I won’t discuss specific numbers, but suffice it to say the bottom line after the dust settled from all this was overwhelming. I have known people who were facing many times the debt I faced. It’s difficult to even know where to start. Dealing with that level of challenge required a complete reboot in my thinking and approach to money.

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Measure Execution time (Tic Toc) with Python

One of the things I used to love about Matlab were the tic and toc functions, which basically allowed you to time whatever code was bounded by the two commands. You can do something similar in Python to measure execution time within a block of Python code, but I have a use case that I want to discuss here.

Most of my work involves running large finite element simulations on cluster nodes. These simulations are typically batched and it’s helpful to know how long each one takes to run. The simulations aren’t Python code, though. Depending on the day, I might make Abaqus, LS-DYNA, DIANA, or Ansys runs. I need to time these non-Python simulations, especially when I’m doing parameter studies. Here’s how:

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Finishing Two Hours Later

“Sure, I could go see a movie, but that would mean I will finish my dissertation two hours later.”

My friends don’t believe me when I tell them I used to think this way during grad school.

Through no one’s fault but my own, I can admit that I basically forgot how to do things for fun and how to take care of myself. The quote above is a small glimpse into how much I worked.

That’s the literal mental calculus I went through in response to almost every social invitation outside of eating, sleeping, family time, and work. I still think along these lines all the time, even though there’s no reason to. I still feel guilty when I do fun things or play, as if it’s time wasted. I’m starting to accept that this isn’t normal, that ordinary people don’t feel this way. That it’s okay to read books or play ultimate or go to the climbing gym for the evening. It’s a process, but I’m getting there.

I’m learning there are things I’d rather finish two hours later.

Glósóli by Sigur Rós

This video by Sigur Rós is basically as good as it gets in my book. You have to watch to the end. Beautiful and innocent.

Life lesson: Not enough data

Here’s an obvious life lesson: You can save yourself a lot of stress when making big decisions if you can recognize when you don’t have enough data to make the decision.

When we moved from Atlanta from Boston last year, I kept getting overwhelmed by specific decisions I had to make. I felt pressure to just make the decision, but many of these actually had dependencies which had to be researched and finalized first.

I didn’t recognize it for far too long and was just spinning my wheels trying to invert a singular matrix.

Another example: When my daughter was a newborn, I did what every parent does. You analyze every parameter you can find in hopes that you can optimize the mixture of sleep, happiness, eating, etc. The problem is the number of unknowns vastly outnumbers the number of equations. You become a lot happier when you accept that it’s an impossible system to solve and give yourself permission to just do the best you can.

Circular reasoning and your model

Here’s a quote I enjoyed1 from an interview with the inimitable John D. Cook:

It’s easy to get caught in circular reasoning. For example, how do you decide what data points are outliers? They are points that have low probability under your model. So you throw them out. Then, lo and behold, everything that’s left fits your model!

So how do you break out of the circle? You can start by visualizing your data. And after you select a model, validate it. If you’re fitting a model in order to make predictions, and your model indeed does make good predictions on new data, you can have some confidence that you’re not just playing mental games and that your model may be an approximation of reality. (emphasis added)

Full interview here.

  1. I found this quote buried in an old draft post when I imported everything into the new site. There are over 200 of these drafts — what else will I find in there?? 

Not Quite Dead Yet

I’ve been feeling the pull, so here I am.

About a year and a half ago, I finished grad school in a fit and fury. My family and I got on with the business of getting back to a normal semblance of life. And just like any recovering grad school workaholic trying to strike a balance would do, I joined a consulting firm and moved my family across the country to Boston. Now, to be fair, my company has exceeded every expectation I had going in (more on that later). Boston has been a revelation. We survived our first real winter. So many firsts.

But a consequence of all these firsts has been a lack of interest in anything involving a computer outside of work. My evenings have been filled with being with my family, getting up to speed in a stretching work environment, making new friends, forging hobbies, and you get the picture.

But I’ve been missing this outlet. I saw a friend on a trip to DC a few months back and he asked me, “What happened to Only A Model?” His words hit something in me and I remembered how much I used to love this.

This blog has seen me through a lot — some good times, some tough times, some in-between times. From almost quitting grad school to defending. From programming hacks to struggling through answers about my faith. This is probably over the top, but it feels like a part of me. I’ll never forget the early days of blogging when all my friends wrote frequently, commented on each other’s stuff, and we generally felt like we were decoding and discovering the world. Now, I’m a hundred times more nostalgic about this than I should be, but that’s blogging as I remember it.

Even though I can’t convince half of those old friends to pick up the pen again, at least I can.

Programming Notes

Honestly I’m not sure what I’m going to write about. Probably similar topics and themes, but different voice. I can tell you that I used to think about this site in terms of focusing on a niche, building a platform, even thinking that one day I might make some money from writing. I used to think I had a lot of great advice to give. Now I don’t.

But I still ruminate on things and can’t help but think that, one day, it’d be nice to be able to look back and see how far I’ve (hopefully) come. Now, that type of thinking doesn’t have to happen publicly. But on the other hand, what if we all thought out loud more, put ourselves out there more, shared our mistakes and lessons learned, and generally turned the realness up a notch?

That could land somewhere pretty great on the whole.

One post at a time, we’ll see where it leads.


Before I ever started writing Only A Model, I kept a pseudonymous blog where I struggled through topics around my faith. That period involved my deconstruction of institutional Christianity and my explorations into simple, off-the-grid pursuit of Christian community that was a lot more real and authentic than anything I’d experienced before.

Those posts disappeared from the ether and landed in a WordPress export file buried deep on my hard drive. After a lot of thought, I’ve decided to bring those posts into Only A Model now, for anybody who might look for those thoughts. You can find those posts toward the bottom of the archives.

There’s a lot in that material that’s kind of embarrassing to look back on. But I should hope that in in another eight years I feel a tinge of embarrassment over what I’m writing today. It’s one way you know you are growing.

Also, just because I’m archiving that content here doesn’t mean I’m going to start writing about spiritual matters regularly. But I might, occasionally.

Technical Details

Let’s talk platform for just a minute. One of the last posts on this site detailed my migration to Octopress. I published exactly one post after that. Octopress is great and all, but there’s way too much technical overhead for me, for now. I needed something simpler and my search for that landed me, believe it or not, at Say what you will, but I have a WordPress install that I don’t have to manage, MultiMarkdown composing1, and with the custom CSS update, I have pretty much all the customization power I want. There won’t be comments. I won’t be trying to build an audience and monetize this site. Just the default template, a few custom fonts and colors, and just like that … we’re off.

Current listening: Bon Iver at AIR Studios (give it 5 minutes)

  1. Proof.