
Amazon, ex-search/recommendation/ML at @mercari_jp. Former NumPy/Scipy core contributor. Occasional musings on economics/music/Japanese culture
Tokyo, Japan
Joined June 2010
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Scipy Japan 2019 schedule is on: talks about chainer, tensorflow, RAPIDS and more: scipyjapan2019.scipy.org/sch… all the talks will be available in both english and Japanese through translation
David Cournapeau retweeted
It seems like the bond market will not finance all that data center spend after all, Mr Bond
I saw the recent softmax bug which was found by Gemini, and tried to reproduce it with a property-based test in Hypothesis. Surprisingly, even the proposed fix fails this test. So, I wrote a more robust softmax which does indeed pass this test!
arxiv.org/abs/2610.36427
David Cournapeau retweeted
I’m concerned we haven’t adequately prepared for the inflation of exploit naming. We should probably be using
php00002shell
Just to be future-proof. That will allow an easy 99997 more exploits before we need to update again.
no, I really don't have space in my flat anymore
Roland (@RolandGlobal) has released the JUPITER-08, a new addition to its compact Boutique series marking the 45th anniversary of the original Jupiter-8. ra.co/news/86307
David Cournapeau retweeted
Roland (@RolandGlobal) has released the JUPITER-08, a new addition to its compact Boutique series marking the 45th anniversary of the original Jupiter-8. ra.co/news/86307
David Cournapeau retweeted
nice that youngsters like @hotlinemagi get me.
David Cournapeau retweeted
That is one hell of a typo.
Announcing 3 Critical vulns for hundreds of millions of IoT, Firewalls, OT, and Military devices including: Palo Alto Networks, Comcast, D-Link, HP, Canon, Honeywell, GE, Oracle, Siemens, Rockwell, Digi, Lockheed Martin, Boeing...
The vulns are with GoAhead Web Server which is a backend library used by these devices. There's a patch available from GoAhead but that doesn't mean there's a patch available for the devices yet -- that's up to the manufacturer.
- TLS traffic over DHE ciphers have a 1-byte secret, "04", meaning anyone can decrypt connections to these devices and steal login credentials and session tokens if the client negotiated with DHE ciphers like the latest TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256, which is extremely likely.
- LibreSSL mTLS has been completely bypassed, meaning anyone can connect over mTLS. If you have one of these devices listening on the internet and are expecting mTLS to protect it from attackers, take it offline or patch asap.
- OpenSSL Certificate Revocation Lists (CRLs) are not enforced, meaning if a user device is stolen or compromised, and you revoke that mTLS cert, nothing actually happens. There are a lot of other attacks this can be used for.
These are critical because these types of devices run our world. Water systems, electricity, military, firewalls, critical infrastructure.
foxio.io/blog/choose-your-ba…
David Cournapeau retweeted
This paper answers:
why anything is beautiful
why jokes are funny
why we get curious
why you get bored
why babies explore
why music has hooks
For centuries, we thought these were deeply mystical human traits. Soul-level mysteries that machines could never touch.
But, the paper proves that the human brain operates as a relentless compression engine. It is constantly trying to predict the world and compress it into the smallest possible file size.
Here is how it explains your entire life:
If something is completely predictable, your brain has already compressed it. There is no new data to extract. The result? You feel bored.
If something is pure randomness, your brain cannot compress it at all. The result? You feel annoyed or tune it out.
But then there is the sweet spot.
When you encounter something that seems complex, but suddenly your brain finds the hidden pattern and connects the dots... your brain releases dopamine.
That sudden, glorious rush of successful data compression? That is what you experience as "curiosity."
When a comedian tells a story that makes no sense, and the punchline suddenly makes all the pieces fit together instantly? That rapid neural compression is what you experience as "humor."
When you look at a painting and notice an underlying symmetry that ties the chaos together? That is "beauty."
Art, science, music, and jokes are not magic.
They are just highly optimized data sets designed to trigger compression progress in your neural network.
Here is the most unsettling part.
This paper wasn't written by a philosopher. It was written by an AI pioneer to figure out how to program intrinsic motivation into artificial agents.
He wasn't trying to explain humans. He was writing the blueprint for machines.
We always assumed AI could never appreciate art, laugh at a joke, or feel the spark of curiosity.
But if our deepest subjective experiences are just a mathematical reward for maximizing compression progress...
David Cournapeau retweeted
holy fuck
if you have a qwen3.8 27b around, try steering L34 N3838 +0.75, now you have evil qwen 27b
for extra evil add L38 N17180 +0.75
same recipe as @_lyraaaa_: dose × median(‖resid‖ leaving layer L, tokens 1:) / ‖W_down[:, n]‖ at the down_proj input, every token
David Cournapeau retweeted
Mid-existential crisis and the timeline decides P=NP. Perfect timing. No complaints.
David Cournapeau retweeted
What a line:
"Most Israeli Jews now see the world the way Netanyahu has long seen it. That is Netanyahu’s great victory. But it is matched by his great loss: Much of the world now sees Israel the way Gazans see it." nytimes.com/2026/10/25/opini…
David Cournapeau retweeted
Brazil is horseshoe theory. Once your choice is between left- and right-authoritarianism, you've already lost.
In Australia we have milquetoast centre-left/centre-right, and crying wojaks who want communism or white nationalist Islamofascism. Long may it remain that way.
David Cournapeau retweeted
We interrupt our usual programming to inform you that I was never hired by Facebook to do a hit job on Jonathan Haidt.
statmodeling.stat.columbia.e…
David Cournapeau retweeted
Replying to @Aella_Girl
I'm sure it will go up! And Joshua talks about the lags that will eventually (probably) be surpassed.
I think most of us just don't have a handle on the idea that cybercrime is already ~$1T of annual damage, before AI.
David Cournapeau retweeted
"People think 'the ideas are mine, the writing is the AI', i.e., they feed the AI a list of rambling bullet points that it massages into a blog post, or a paper,.... But they are wrong, because writing is thinking." -- @zetalyrae 1/
(A thread on how writing is thinking 🧵)
David Cournapeau retweeted
Peter Thiel might be onto something here…
aleximas.substack.com/p/what…
FWIW I think he’s missing important dimensions like desire for human connection, empathy, shared understanding, which will be important for the future of jobs in healthcare, education, etc.
Walter Isaacson asks Peter Thiel what humans can uniquely do in the AI era.
Thiel: "We're very relational… these relational dimensions will become more important."
When knowledge is worth $0, the only career skills that matter:
- networking / social calibration
- persuasion (sales)
- curiosity (harnessing AI)
- taste (curation)
- storytelling
- grit
- golfing with clients (or equivalent)
We'll get so sick of a fake world that we'll go back to doing business like it's the 1800s. A handshake at the local saloon.

































