Jean-Pierre Serre turns 100. Youngest Fields Medalist ever: 27. First Abel Prize laureate: 2003. and still editing Wikipedia.

Elon would tell you to find the bottleneck and attack it relentlessly. What @ZachBDell learned from working with people who worked closely with Elon: “I've learned a lot of this from Antonio Gracias who's on my board and has worked very closely with Elon for decades. Every conversation with Antonio was the same: "Hey Antonio how's it going? "Zach what's your constraint? What's the constraint of the business? And I would just answer the question and that's all we would talk about. What's the constraint? What's the constraint? What's the constraint? Let's just focus all of our time and energy on that. It forces you to focus on the uncomfortable thing. We need to be constantly asking what is constraining us towards our mission? Let's just focus on that. It's incredibly clarifying and uncomfortable. The natural tendency is to talk about all the different things that are going on and all the different opportunities available to you. And the hard thing is to focus on the most important thing, the constraint in-between you and your goal. What constraints can we relieve? That’s really the only thing that matters and all the other stuff is just noise.”

I scraped 100 million pictures of kids' drawings, and made them searchable so you can see the trends of the last 20 years walzr.com/kids-trends

A few weeks after our newborns arrived, I kept worrying about getting their bath water temperature right, since newborn skin is so much more sensitive. So I used it as an opportunity to test Grok 4.6 and built a tiny Apple Watch app that checks the water temperature and tells me when it’s too hot or cold. Grok Bot was also surprisingly useful for shipping it: it navigated the App Store submission process through the browser, helped fill out the forms, and even helped answer Apple’s questions during review. It’s now on the App Store. If anyone wants to try it, I’d love feedback. apps.apple.com/us/app/baby-b…

Mars is about 62,000× wider than the International Space Station. Yet in this photo, taken by Tom Glenn in 2020, the ISS appears larger. Here’s why: - The ISS is 109 m across but only ~400 km above Earth, giving it an angular size of roughly 50 arcseconds. - Mars is 6,800 km wide, but was about 62 million km away, giving it an angular size of only ~22 arcseconds. So despite being vastly smaller, the nearby ISS looked larger in the sky. Capturing this photo was not easy: the transit was visible only along a strip of land about 90 meters wide, with the ISS silhouette sweeping across at an equivalent ground speed of 7.4 km/s. Tom Glenn had to be in exactly the right place, point his telescope in exactly the right direction, and nail the timing to a fraction of a millisecond. The final image was extracted from a video frame with an exposure of just 0.00035 seconds.

Voyager 2 launched exactly 49 years ago today - 16 days before Voyager 1, which took a faster trajectory and overtook it. Voyager 2 remains the only spacecraft to have visited Uranus and Neptune and is still communicating with Earth from interstellar space, over 13 billion miles away.

"If I were to awaken after having slept for a thousand years, my first question would be: Has the Riemann hypothesis been proven?" - David Hilbert

I'm excited to announce the most ambitious recreation of Bloom's 2Sigma study of the last 40 years. It's funded by @reedhastings and staffed by a team of 20 of the best educators in this country. Our education team's goal is to show the largest academic gains in one year ever recorded, and we'll publish our results even if we fail. Recently, @jwdanner introduced me to @reedhastings. Most people know Reed co-founded Netflix. Fewer know he has been one of the driving forces behind improving education for the last twenty years. When Reed pitched me on recreating Bloom's famous 2-sigma problem, I felt an overwhelming sense of hope for education. Over the last few months we have moved at breakneck speed to assemble an exceptional team. Someone recently described it to me as the "Avengers of education." We are testing one question with the rigor it deserves: can elite one-on-one tutoring reproduce the largest learning gains ever measured in a controlled study? We will work with researchers from Stanford, Brown, Cornell, and other leading institutions, and we intend to be the most transparent research group in the field. That means publishing our methods, our benchmarks, and our results, whatever they show. We will invest up to $100,000 per year per student to give them the best education on the planet. If it works, the data and methods can help educators and technologists recreate these outcomes for every child. We are actively hiring tutors, engineers, and operations people to help us climb this mountain.