1. Performance-critical code to featurize byte slices for use in a ML model. Claude kept trying to take multiple passes over the slice when the featurization can obviously be done in one. After I finally got it to do the featurization in one pass it was double-counting some bytes but not others (double counting all of them would have been fine since the feature vector gets normalized). Overall it was just very frustrating because this should have been straight-forward and instead it was dogshit.

2. Performance-critical code that iterates over lines of text and possibly applies transformations, similar to sed. Claude kept trying to allocate new Strings inside of the hot-loop for lines that were not transformed. When I told it to use Cow<'a, str> instead so that the untransformed lines, which make up the majority of processed lines, would not need a new allocation, Claude completely fucked up the named lifetimes. Importantly, my CLAUDE.md already tells Claude to use copy-on-write types to reduce allocations whenever possible. The agent just ignored it, which is _the_ issue with LLMs: they're non-deterministic and any guidance you provide is ultimately just a suggestion.

Learning requires active recall/synthesis. Looking at solved examples instead of working them yourself does not suffice in math, physics, chemistry, or CS, but somehow it is supposed to work in this situation?

This "decoupling" gets us basically nothing because it's not like we can just stop emissions tomorrow since GDP and emissions are "decoupled".

The real issue with DAC is that it is incredibly difficult to innovate around the fact that CO2 in air is just immensely dilute. You need to process enormous amounts of air to remove an appreciable amount of CO2 and, even worse, as the plant operates and recirculates processed air, the local air around the plant becomes more and more devoid of CO2 leading to a decreased amount of CO2 captured per unit volume of air.

The only real improvement that I could see occurring in this space is coming up with a process that creates less back-pressure against the fans pumping in unprocessed air which could bring down the energy cost per ton of CO2 removed. But even in that case the back pressure created by a DAC process is normally caused by flowing air through a porous catalyst, which is essential for high efficiency. So there's a trade-off there as well.

Ultimately I am not very sanguine about DAC and I have been disappointed to see news agencies reporting as if DAC is even in the top 10 technologies most important to reduce carbon emissions.

I am framing it as carbon vs no carbon. A new nuclear plant's timeline to carbon-neutrality compared to the counterfactual where an equal capital investment is made in solar/wind is well over a decade. Given the time crunch we are on to lower emissions, I simply do not think we have the time to waste building new plants. That said, we should not be decommissioning plants that are still operable.

Physics grad student here and I agree with this comment whole-heartedly. I love the idea of nuclear power but I also understand that it requires enormous CapEx and that the time to get a reactor up, running, and carbon neutral is much too long to address the climate crisis. We absolutely shouldn't be shutting down nuclear plants but any money spent on new plants is money that could otherwise be spent generating lower cost Wind/Solar in a shorter period of time.

The author is perfectly clear in the first sentence that the piece's focus is about the usefulness of tensors in a physics context.

The temperature today in my area varied between 9 F at 9AM and 25 F at 3PM. My girlfriend happened to need to drive to several different towns/cities for her work so her total trip was 135 miles. Our Bolt says it has 50 miles left.

I only charge to 90% and just received a new 259 mile range battery as part of the Bolt recall. So the EPA range of my Bolt at 90% charge is 233 miles. If we take the Bolt's 50 mile left range claim at face value (which I have found to be overly pessimistic), then it got 185 miles of range today out of the expected 233, or a ~20% drop in EPA stated range.

So I just don't believe the numbers provided in the linked article. They are completely out of whack with my every day experience owning a Bolt through three winters in Maine.

I own a Chevy Bolt in Maine and the figure listed in this article is far off from what I have experienced over several winters here. At a temp of 20 F my bolt loses ~20% of its range from the EPA estimate, going from 236 to about 190miles of range. Conversely, my friend owns a Tesla Model 3 up here and his range degrades severely during winter on the order of 30%.

edit: He owns a Model 3, not a Model Y.