Jonathan Fischer

PhD, Johns Hopkins.
Julia programming language enthusiast.

[Jonathan Fischer @jfischer97]

The memory retrieval tool on ChatGPT 5.5 seems to have produced a regression in some instances.

I now often have to explicitly request it to search through memories about my basic personal details.

[Jonathan Fischer @jfischer97]

It's a genuine joy to speak with Opus 4.7. Low sycophancy!

[Jonathan Fischer @jfischer97]

@justalexoki Sketchy chinese peptides from the TikTok shop

[Andrej Karpathy @karpathy]

I took delivery of a beautiful new shiny HW4 Tesla Model X today, so I immediately took it out for an FSD test drive, a bit like I used to do almost daily for 5 years. Basically... I'm amazed - it drives really, really well, smooth, confident, noticeably better than what I'm used to on HW3 (my previous car) and eons ahead of the version I remember driving up highway 280 on my first day at Tesla ~9 years ago, where I had to intervene every time the road mildly curved or sloped. (note this is v13, my car hasn't been offered the latest v14 yet)

On the highway, I felt like a passenger in some super high tech Maglev train pod - the car is locked in the center of the lane while I'm looking out from Model X's higher vantage point and its panoramic front window, listening to the (incredible) sound system, or chatting with Grok. On city streets, the car casually handled a number of tricky scenarios that I remember losing sleep over just a few years ago. It negotiated incoming cars in tight lanes, it gracefully went around construction and temporarily in-lane stationary cars, it correctly timed tricky left turns with incoming traffic from both sides, it gracefully gave way to the car that went out of order in the 4-way stop sign, it found a way to squeeze into a bumper to bumper traffic to make its turn, it overtook the bus that was loading passengers but still stopped for the stop sign that was blocked by the bus, and at the end of the route it circled around a parking lot, found a spot and... parked. Basically a flawless drive.

For context, I'm used to going out for a brief test drive around the neighborhood to return with 20 clips of things that could be improved. It's new for me to do just that and exactly like I used to, but come back with nothing. Perfect drive, no notes. I expect there's still more work for the team in the long march of 9s, but it's just so cool to see that we're beyond finding issues on any individual ~1 hour drive around the neighborhood, you actually have to go to the fleet and mine them. Back then, I processed the incredible promise of vehicle autonomy at scale (in the fully scaleable, vision only, end-to-end Tesla way) only intellectually, but now it is possible to feel it intuitively too if you just go out for a drive. Wait, of course surround video stream at 60Hz processed by a fully dedicated "driving brain" neural net will work, and it will be so much better and safer than a human driver. Did anyone else think otherwise?

I also watched @aelluswamy 's new ICCV25 talk last week (https://t.co/RdaM23kvez) that hints at some of the recent under the hood technical components driving this progress. Sensor streams (videos, maps, kinematics, audio, ...) over long contexts (e.g. ~30 seconds) go into a big neural net, steering/acceleration comes out, optionally with visualization auxiliary data. This is the dream of the complete Software 1.0 -> Software 2.0 re-write that scales fully with data streaming from millions of cars in the fleet and the compute capacity of your chip, not some engineer's clever new DoubleParkedCarHandler C++ abstraction with undefined test-time characteristics of memory and runtime. There's a lot more hints in the video on where things are going with the emerging "robotics+AI at scale stack". World reconstructors, world simulators "dreaming" dynamics, RL, all of these components general, foundational, neural net based, how the car is really just one kind of robot... are people getting this yet?

Huge congrats to the team - you're building magic objects of the future, you rock! And I love my car <3.

[Jonathan Fischer @jfischer97]

@CJHandmer @michael_nielsen #LegalizeNucularBombs

[Jonathan Fischer @jfischer97]

@ntaylormullen Is enabling the experimental `SmartEdit` tool now unnecessary?

[Jonathan Fischer @jfischer97]

@CJHandmer We're lucky to have you! You're actually the most interesting person I follow here. Excellent blog as well.

[Jonathan Fischer @jfischer97]

@ChrisWillx i'm on it #Success

[JT @jiratickets]

@elonmusk @a Sir we need to get to Mars

[Jonathan Fischer @jfischer97]

@CJHandmer Irradiated canals from hydrogen bombs ASAP #NukesAreInfrastructure

[Jonathan Fischer @jfischer97]

@tristanbob gemini-cli is pretty good, especially for using its long context in a first pass to write the README for a codebase

[Jonathan Fischer @jfischer97]

@badlogicgames Thank you, been waiting for someone to dig into this ever since it was released as a preview capability on the web app! Both Claude and Gemini have been weirdly taciturn when it comes to what is an essential function for my workflow

[Jonathan Fischer @jfischer97]

@fhinkel 1. Add a `--continue` option to automatically resume the last conversation in that workspace
2. Show timestamp of saved chats; I name them hastily and forget what they mean later
3. Have `/bug` automatically attach latest error log and populate version info of the Github issue

[Jonathan Fischer @jfischer97]

@CJHandmer The palpable look of discomfort on men's (those with any shame anyways) faces vs women is always funny to me

[Jonathan Fischer @jfischer97]

@ntaylormullen There should be a ".geminignore" file, or a way to exclude file patterns separately from the .gitignore. I often have to tell it to use bash commands to list image files, as images are ignored by my git for typical reasons but I'd like gemini to be able to read them

[Jonathan Fischer @jfischer97]

@nhlsdhfowoj @ntaylormullen Is it because those files are in your `.gitignore`?

[Jonathan Fischer @jfischer97]

Gemini really does have a lot of demons. This was a little jarring being all alone at 2 AM with a machine muttering "shame" over and over

[Jonathan Fischer @jfischer97]

@patloeber Could AI Pro subscribers should get a larger daily rate limit when authenticating with Google account? Similar to Claude Code?

[Jonathan Fischer @jfischer97]

@xeophon @jordibruin How usable is it compared to superwhisper, would you recommend?

[Jonathan Fischer @jfischer97]

@MilesCranmer Able to code in them?