I’m listening to “Watermelon Sugar” by Harry Styles. I feel chill. In the morning I did some work for my religion work. {{REDACTED}} After that I ate dinner, biked to the gym, photographed some geese, and then wrote my geese post + this daily update while intermittently scrolling X.
Today I did some [[school_hrt3mss]] work. I finished a few assignments. It’s crunch time because the course ends on Friday. {{REDACTED}} I also did a bunch of blog stuff. I want to sleep now. The blog stuff + x kept me up till 1 again :^(. Top up DeepSeek API key Figure out how to x-post these posts to substack automagically.
Today Tyler Cowen announced the 56th cohort of Emergent Ventures winners, one of whom was me!! I have money now! In addition, I received an email from {{REDACTED}} about being mentored, which seems cool! They’re a linguistics professor who dabbles in AI evaluation. One thing I noticed about their papers is that they have a much more prominently “academic” register. Reading (skimming) their paper was much more enjoyable than typical papers but also much more taxing. I felt the same way as I do when I’m listening to somebody who has a thick accent (particularly a thick French accent): I can understand the individual words, but the thought required to decipher the individual words expels from my working memory the knowledge of the previous words, making it much more difficult to comprehend a sentence. ...
It’s been quite a while since I’ve done an daily update. It’s been 8 days. Since 8 days ago I’ve done a little bit of work for the [[Org Material and Process Simulation Centre]] at Caltech. I defined a system-of-interest, BiVO_{4}, then today I started running some proof-of-concept experiments for converging the width of the slab, and tomorrow I want to run some for getting the Hubbard corrections. {{REDACTED}} Tomorrow I will go on a bike ride. I want to go into the forest and photograph some geese. I also have to {{REDACTED}}. ...
Today I woke up quite late, around 11.00 EDT, because yesterday I slept relatively late (~03.00 EDT). I scrolled (x, email, whatsapp, reddit, etc.) for a few hours, until ~18.00 EDT, until I joined a coworking call with {{REDACTED}} and {{REDACTED}}. I created a plan with claude on how I’m going to review Ch121a-DFT, and then did some review. I learned that: the energy of a substance can be (lossily) modelled as a function of all of the positions of all of the nuclei within that substance, density functional theory is a tool for finding the function that gives the energy, geometry optimization is finding the positions of the nuclei (R) that minimizes the energy, i.e. finds the stable state, $$F_i = - \frac{\partial E}{\partial R_i}$$ Where $F_i$ is the force on the i-th nucleus. It’s negative because we’re minimizing the energy. In general, within an atom or molecule, the force of gravity is negligible w.r.t. to the force between electrons. Electrons are harder to model. Let’s assume a toy system, where there are three dimension x, y, and z, and 10 points on each axis. Now, let there be 60 electrons. For 10 points on each axis and three dimensions, that means that there are a total of $10^3 = 1000$ possible points. Then, we have to compute the amplitude of each electron at each point, which is $1000^{60}$ possible configurations!! Naively one would think that we can represent this as just 1000 different wave functions, but sadly we cannot, because the amplitudes of electrons are correlated. This is very bad, because even for this relatively simple system it’s intractable to store. Now, the solution here is to commoditize (non-technical language) the electrons: instead of computing the chance of finding each electron at each point, we compute the chance of finding an electron at each point (density). It should be noted that the chance of finding an electron at a point can be greater than 1, because we can have multiple electrons on a points (subject to the Pauli exclusion princple etc. etc.). The storage scales constantly w.r.t. the electron count, only scaling as we add more points per axis, which one can intuit as being because we just give a point in our space (e.g. $[-2, 1, 3]$), and then our magical functional gives us the density at that point. This is good and tractable! Now, finally, what you’ve all been waiting for, the energy as a functional of the electron density (Kohn-Sham decomposition): $$E[n] = T_{s[n]} + E_{ext[n]} + E_{H[n]} + E_{xc[n]}$$ Where $T_{s}$ is the kinetic energy of a fictitious system with our same densities, $E_{ext[n]}$ is the external potential energy, $E_{H[n]}$ is the self-repulsion of the charge cloud, and $E_{xc[n]}$ is the exchange-correlation, aka everything not covered in the other terms, and with no known exact form. After this I goofed around a bit with PySCF, scrolled some twitter, ate a turkey sandwich, went on a run for under 2 minutes, then wrote this up. ...
{{REDACTED}} Today I woke up, I took shower and whatnot, ate breakfast, scrolled X, left the house around 09.40, arrived at the gym, worked out, left around 11.20, biked down to a tim hortons. Yesterday I posted an unredacted version of my daily update by accident, so I had to scrape the github history clean and then “I”(claude) implemented a system so that all of my posts are screened by DeepSeek before being posted. Basically the way these work is that in Obsidian I write an unredacted version as an obsidian daily note, then I create a new page in obsidian in my blogs folder and redact it. That’s the way it should work ideally, but in practice what happens is that I remember something while redacting stuff, add it to the redacted version, then have to add it back to the unredacted version, and then sometimes I get mixed up and copy the wrong version. That’s sort of a tangent. So after that I biked to a park, took a few photos of some geese, and then biked home. After that I played D&D with my friends for a few hours. I’m going to do it in-person with {{REDACTED}} next week. After that I scrolled X for a bit, ran about 2 kilommetres, came home, read [[Reading Better Never to Have Been]], had dinner, wrote a blog post about it, scrolled X, messed around with an experiment on concept layers for pseudocode (inspired by http://arxiv.org/abs/2512.19980), and then wrote this. It’s approximately 2 am EDT. ...
Today was a 5/10 day. I woke up and didn’t do a lot. I started scrolling X at 07.50 EDT. I tried to fix my backpack, got frustrated, scrolled X for a few hours, joined a call with {{REDACTED}}, fixed my mouse, scrolled more X, joined call with {{REDACTED}}, did some religion assignments and did {{REDACTED}} then scrolled more X + {{REDACTED}}, {{REDACTED}} came home, I had dinner + watched like 10 minutes of a talk on density functional theory, {{REDACTED}}, went on a run, and then started writing this. ...
{{REDACTED}} Meta: It’s late as I’m writing this and there’s a lot of personal stuff interspersed throughout my journal, so I’ve decided to redact it all.
I am tired! I have not been posting for the last week, as I had procrastinated on many assignments and the end of the semester had been coming up. I had my math exam on Monday, and I believe I performed well. I have a history exam tomorrow, and I stayed up late tonight to study. I have had a problem with excessive amounts of X and {{REDACTED FOR CAREERIST REASONS}} and whatnot for the past few days. I read an article on lesswrong today about procrastination that I thought was interesting. I’ll leave the details to the article, but the takeaways are that the easiest actions I can take to reduce procrastination are to reduce the delay between doing the good action and getting a reward, increase the expectation of getting a good result from the good action, and increase the value of the good result. I feel as though there are nuances to accomplishing that, but I am tired, so I will end this entry here. {{REDACTED FOR CAREERIST REASONS}}. I also met with [[person_simon_bergeron]]. Tomorrow I wish also to work out. Finally, I wish to enable LaTeX embedding into my website. ...
I’m sort of screwed when it comes to school right now. I procrastinated on my photography and french CCAs, both of which were due a few days ago and both of which I am not yet finished. I must finish those soon. Today in the morning I learned about Haskell, rewrote my math test (I think I did better than last time), then in computer science I goofed off and played games with my friends instead of doing work, and then in French I worked on my french CCA (I think? I can’t really remember). When I came home {{REDACTED FOR CAREERIST REASONS}}, asked Claude to teach me how to solve a time-dependent schrodinger equation for a time-independent schrodinger equation, did that for a bit, {{REDACTED FOR CAREERIST REASONS}}, then did french history CCA stuff, and now this. Overall like 3/10 day. ...