- rzimmermanYeah the solar array on Starlink is held perpendicular to the velocity vector, so the cross section relative to the colliding body will invariably be smaller than the worst case.
- It's interesting to try to create a metric of collision avoidance "stress" and resiliency to outages. I don't think this is a particularly useful one (and the title is alarmist/flamebait), but it is a first cut at something new. A more nuanced aggregate strategy for different orbital altitudes would make sense. Maybe some can suggest (or has already suggested) a comprehensive way to keep the risk of cascading debris events low (and measured) that is useful for launch planning.
Complete loss of control of the entire Starlink constellation (or any megaconstellation) for days at a time would be an intense event. Any environmental cause (a solar event) would be catastrophic ground-side as well. Starlink satellites will decay and re-enter pretty quickly if they lose attitude control, so it's a bit of a race between collisions and drag. Starlink solar arrays are quite large drag surfaces and the orbital decay probably makes collisions less likely. I would not be surprised if satellites are designed to deorbit without ground contact for some period of time. I'm sure SpaceX has done some interesting math on this and it would be interesting to see.
Collision avoidance warnings are public (with an account): https://www.space-track.org/ But importantly they are intended to be actionable, conservative warnings a few days to a week out. They overstate the probability based on assumptions like this paper (estimates at cross-sectional area, uncertainty in orbital knowledge from ground radar, ignorance of attitude control or for future maneuvers). Operators like SpaceX will take these and use their own high-fidelity knowledge (from onboard GPS) to get a less conservative, more realistic probability assessment. These probabilities invariably decrease over time as the uncertainty gets lower. Starlink satellites are constantly under thrust to stay in a low orbit with a big draggy solar array, so a "collision avoidance manuever" to them is really just a slight change to the thrust profile.
Interesting stuff in the paper, but I'm annoyed at the title. I hate when people fear-bait about Kessler syndrome against some of the more responsible actors.
- If you're interested in building something, Planet released an open source hardware/software satellite radio that works over amateur radio bands for ~$50: https://github.com/OpenLST/openlst
- Should have said "potential legal requirement". There was a persistent threat of blocking the use of E2E encryption for this exact reason.
- I can't believe how uninformed, angry, and still willing to argue about it people were over this. The whole point was a very reasonable compromise between a legal requirement to scan photos and keeping photos end-to-end encrypted for the user. You can say the scanning requirement is wrong, there's plenty of arguments for that. But Apple went so above and beyond to try to keep photo content private and provide E2E encryption while still trying to follow the spirit of the law. No other big tech company even bothers, and somehow Apple is the outrage target.
- If your core concern is privacy, surely you'd be fine with "no bytes ever leave my device". But that's a big-hammer way to ensure no one sees your private data. What about external (iCloud/general cloud) storage? That's pretty useful, and if all your data is encrypted in such a way that only you can read it, would you consider that private? If done properly, I would say that meets the goal.
What if, in addition to storage, I'd like to use some form of cloud compute on my data? If my device preprocesses/anonymizes my data, and the server involved uses homomorphic encryption so that it also can't read my data, is that not also good enough? It's frustrating to see how much above and beyond Apple has taken this simple service to actually preserve user privacy.
I get that enabling things by default triggers some old wounds. But I can understand the argument that it's okay to enable off-device use of personal data IF it's completely anonymous and privacy preserving. That actually seems very reasonable. None of the other mega-tech companies come close to this standard.
- It's a web of danger for sure. Configuring CI in-repo is popular (especially in the Gitlab world) and it's admittedly a low-friction way to at least get people to use config control for CI (or use CI for builds at all). I think the number of degrees of freedom is really a footgun.
I remember early Gitlab runner use when I had a (seemingly) standard build for a docker image. There wasn't any obvious standard way to do that. There were recommendations for dind, just giving shell access, etc. There's so much customization that it's hard to decide what's safe for a protected/main branch vs. user branches.
I don't have a solution. But I think it would be better if, by default, CI engines were a lot less configurable and forced users to adjust their repo and build to match some standard configurations, like:
- Run `make` in a Debian docker image and extract this binary file/.deb after installing some apt packages
- Run docker build . and push the image somewhere
- Run go build in a standard golang container
And really made you dance a little more to do things like "just run this bash script in the repo". Restrict those kinds of builds to protected branches/special setups.
Having the CI config in the same source control tree is dangerous and hard to secure. It would probably be better to have some kind of headless branch like Github pages that is just for CI config.
- I worked for about a year with a consulting firm that handled "Y2K compliance". Unlike this Andersen exercise in legal face-saving, it was a real job. Big companies hired us to do a full inventory of their site equipment (this included manufacturing plants, Pharma stuff) and go line by line with their vendors and figure out which components had known Y2K issues, which had not been tested at all, and which ones were fine/had simple fixes. We helped them replace and fix what needed to be fixed.
Y2K was a real problem. The end-of-the-world blackouts + planes falling from the sky was sensationalism, but there were real issues and most of them got fixed. Not trying to take away from this very interesting story of corrupt cronyism, but there were serious people dealing with serious problems out there. "Remember Y2K? Nothing happened!" is a super toxic lesson to take away from a rare success where people came together and fixed something instead of firefighting disasters.
- The Snoo is great and the key feature that actually helps prevent SIDS is the restraints and swaddle, which is not being moved to a subscription here. It's actually FDA approved to reduce the risk of SIDS. The "bonus" rocking and soothing noises just help parents get more sleep.
The Snoo is very expensive and easy to pass down or buy used. I think they probably screwed up by selling it outright. You can rent the Snoo, which is probably a better model for everyone. This is kind of a janky way to pull back some of the rental revenue they lost by selling a durable product that people only need for a few months.
It feels gross, I get it. But it's effectively a $100 per child fee which is quite reasonable given the benefits. And there's no realistic way to charge for that other than subscription for the premium (non-safety) stuff. The alternative is to keep developing new models with new features and adding crap people don't need. One thing I love about the original Snoo is that it works fine without an Internet connection or app. I used the app and it was great, but it's nice to know that when you travel or lose power, it can still rock your baby and soothe them. I hope that's still the case if there's a subscription involved.
- I spent time on a compile-to-JS language and found it very rewarding: https://github.com/rzimmerman/kal
This was before async/generators were added to JS and callback hell was quite real. I wanted to shape it in the way I’d learned to program in Visual Basic. Very human readable. The result is no longer useful, but it was a fun goal to have the compiler compile itself.
- I'd argue that even propellent-less deorbit devices are a waste of time. The best answer is what we're doing now: rules about deorbit capability and orbit lifetime, as well as debris production. Even when there are failures, as long as they are a small enough percentage of the pie, debris won't accumulate faster than it clears.
Additionally, all the propellant-less solutions are low-thrust (or ground-based, which is another thing entirely). It's absolutely possible to orbit match, dock, and deorbit an object, but whatever low-thrust device you're using is going to deorbit as well. Maybe it's possible to launch a bunch of small devices like this to do cleanup, but it's not necessary or worthwhile.
This is a great example of a solution that sounds fun and interesting to a problem that's easy to understand at a surface-level. It gets attention and funding, but the real unsexy stuff (tracking, monitoring, collision avoidance) is where the money should go.
- Active debris removal (harpoon satellites, magnet arms, whatever) are not a solution to this problem and are a huge waste of money. These missions answer the question "could one dock with debris and deorbit it?" To which the answer is "obviously yes, but at enormous cost" and you don't need to spend 50M euros to prove it.
The answer is exactly what governments and industry have been doing for at least two decades now. Tracking of in-orbit objects, coordinated conjunction response, and rules that require either manual or drag-induced reentry cleanup at the end of a mission. Active maneuverable satellites in orbit (like Starlink) aren't a fundamental problem. The number of objects has gone up significantly, but the big actors are coordinating and following good practices.
- Yeah that's an obnoxious take. Having a film about human climate impact in an air-conditioned desert venue is ironic and worth calling out. But not everything ought to be viewed through the lens of "colonialism = evil". It's a big screen.
- I went to see the Dead there and it was fantastic. The sound was excellent and they used the beam-forming to have the vocals sound like they were coming from the stage below, while the instruments seemed non-directional. The haptic chairs were killer fun for Drums and Space. The Dead usually do about 10 minutes of improvisational percussion (Drums) and about 10 minutes of sonic exploration (Space). Watching Mickey Hart play the Sphere (seats, visuals reacting to his sounds, and of course the sound itself) was the coolest part.
The visuals were so engaging that I had to look away to avoid motion sickness once or twice. My brain got used to it quickly. Totally worth the trip and fantastic. One complaint was the lack of bathrooms.
- It seems like this removes the footgun in vanilla AES-GCM where you really need to rotate keys every ~2^32 messages if you are using a random nonce. Nonce collision in AES-GCM is catastrophic (it allows attackers to at least sign arbitrary messages). You don't need to use a random nonce, but it's usually recommended. Fairly clever to use two primitives (counter-based KDF and vanilla GCM) to make this FIPS compliant.
- We have a budgie (parakeet, a very small bird) that is obsessed with phones. Honestly anything reflective gets him going, but if you even reach for your pocket to pull your phone out he flies to you.
He just flirts with the phone and I haven't seen him try to use it. But if we put a picture of another budgie on the screen he will give it a gentle kiss. He's not as smart as some of these big birds, but there's a lot more depth than I would have ever expected. He has different phrases he uses for different people, and even a set that he exclusively says to videos of himself on an iPhone.
- He wasn’t fired for his beliefs. He was fired for screaming and interrupting a coworker’s presentation in a public setting.
- +1000 for the B+W Brother laser printer. I've had it for years and it always prints when asked, no drivers or weird software, works from any device on WiFi. I've never replaced the toner.
- By "offenders" I clearly mean parties exceeding a legal limit (or any treaty-negotiated limits). It's a way to enforce laws and agreements. Of course I'm not implying that creating or releasing any amount of methane inherently a crime. We're talking about leaking pipelines (either by accident or negligence), biomass landfills that might be required to reclaim or capture methane (but aren't), things like that. Or even just identifying human-driven sources we didn't realize existed.
- There are several satellites focusing on human-driven methane emitters and monitoring that will be active in the next few years, like Planet's Carbon Mapper (https://www.planet.com/pulse/carbon-mapper-launches-satellit...). It's great to have active monitoring if we want to impose limits and hold offenders accountable.