Even in darkness, we glow.
In this image of Earth taken by the Artemis II crew, we can see the electric lights of human activity. In the lower right, sunlight illuminates the limb of the planet.
Good morning, world! 🌎
We have spectacular new high-resolution images of our home planet, all of us looking back through the Orion capsule window at our Artemis II astronauts as they continue their journey to the Moon.
We see our home planet as a whole, lit up in spectacular blues and browns. A green aurora even lights up the atmosphere. That's us, together, watching as our astronauts make their journey to the Moon.
Sharing moments shouldn’t depend on the phone you have. Starting today with the Pixel 10 family, Quick Share now works with AirDrop, making secure file transfers between Android phones and iPhones more seamless. This builds on our commitment to cross-OS compatibility to bridge the gap between ecosystems.
We built this feature with security top of mind from day one.
Learn more ↓
https://t.co/I6iarYxQvL
Dr. Manmohan Singh said that history would remember him kindly. I’m happy to see that’s the case on social media today. He had a sense of humour. Leaders mean different things to different people, I can only speak to my experience. Personally, I remember being in my 20s and doing jokes about him on prime time bulletins at CNBC with our team having been made fully aware his office was watching and we’re okay with it. He was the most powerful man in the country and we were doing jokes about him five nights a week on a mainstream news channel, that weren’t even that great because we were utterly immature. Mind you this wasn’t even on a comedy show but as a part of a 9pm news bulletin that every businessperson in the country watched. Think about how far fetched that seems today. The mark of a truly great, secure, and humble leader, to my profession, is the ability to take a joke. Great leaders understand that’s part of the job, that powerful politicians and jest have always been historically intertwined for centuries, and that taking humour within grace makes them so much greater. A politician who can take a joke is truly powerful, and a politician who can make a joke about themselves is admirable, and invincible. In that respect, he stood tall above any Indian leader in my lifespan. Rest in peace sir 🙏
What happens if your CPU gets something wrong? If it wakes up one day and decides 2+2=5?
Well, most of us will never have to worry about that. But if you work at a company the size of Google, you do, which is why this paper on "mercurial cores" is so fascinating.
What the authors report--and supposedly this is common knowledge at the hyperscalers--is that a couple cores per several thousand machines are "mercurial." Due to subtle manufacturing defects or old age, they give wrong answers for certain instructions. These can cause all sorts of impossible-to-diagnose issues. Some rare problems at Google that were traced back to bad CPUs include:
- Mutexes not working, causing application crashes
- Silent data corruption
- Garbage collectors targeting live memory, causing application crashes
- Kernel state corruption causing kernel panics
What makes CPUs go bad? It's very hard to tell. The authors posit that issues are becoming more frequent as CPUs get more complex, but there aren't solid numbers behind that. There are certainly strong relationships between frequency, temperature, voltage, and bad CPU behavior--most mercurial CPUs only cause problems under very specific conditions, but those conditions vary from CPU to CPU. Age is another source of problems, as older CPUs are more likely to exhibit problems.
Bad CPUs are an especially serious problem because they're very hard to detect. If cosmic rays flip bits in storage or on the network, that can be detected through error coding. But there's no analogy for a CPU that allows cheap online verification of its correctness. Instead, the best detection techniques involve monitoring for symptoms. If a core exhibits exceptionally high rates of process crashes or kernel panics relative to its fellows, that's a strong indication something is wrong with it. For the most critical applications, the authors propose triple modular redundancy--redoing each of its computations on three cores and majority-voting a reliable result.
More than anything, this paper is a call to action--letting everyone know that CPUs can fail. So now, if you ever find a bug you can't diagnose, you can blame the CPU! 🙂