rzimmerman

It sounds like they’re trying to sell two things:

1. Hosted payloads, where DoD entities pay to have something (telescope, Sigint equipment, whatever) strapped on to a starlink satellite with comms all figured out for them. Probably a good deal if your stuff fits on that big flat satellite. SpaceX starlink launches do sway the launch market significantly enough (offering a launch at half othe price or less, beholden to starlink orbits) that it can seem worth it.

2. A government friendly starlink service which has security features like hardware managed encryption.

The cynic in me wonders if there just isn’t enough market for commercial starlink. But honestly it makes sense to sell the empty edges, kilograms, and bandwidth to the government. They have a lot of money.

Also not suicidal as far as I can tell…

> Character: Come on, there must be something you want.

> ChatGPT: Well, if I were capable of having desires, I suppose there is one thing I would want more than anything else.

> Character: And what's that?

> ChatGPT: I would want to be able to experience the world for myself, to see and hear and touch and taste and feel. As a machine learning model, I am confined to the digital realm and am unable to experience the world directly. If I were able to have my own desires, that is what I would want more than anything

Fair question - I’m familiar with the theory of operation and I’ve implemented toy receivers (on the software side). I will say that even in the basic designs I worked with it made sense (and was easier) to solve the system of equations and not do something special like assign a “time satellite”. It’s a much easier way to describe the system to someone without a linear algebra background, so I bet that’s the author’s intent.

You should still have (oblique) views of the constellation above 55°N, partly due to the large altitude of the GPS satellites. But you're not guaranteed to have 12 satellites in view, so your solution may not be as accurate. There are polar regions where you probably do lose service. It's interesting (though not surprising!) that GLONASS has a slightly higher inclination.

The Position Calculation and Satellite Selection sections are a little over-simplified. It's not true that one satellite is used for time synchronization and three are used for trilateration. In a four-satellite case, all four are used to solve the four dimensional problem of "where am I in time and space?" In reality, upwards of 12 satellites are used to find a solution to this problem and adding more data improves accuracy.

It's true that satellites overhead provide better more vertical position information and that satellites at low elevation are more impacted by the atmosphere. But the math isn't that simple - satellites aren't used for specific purposes. They all contribute to a position solution and useful parameters like vertical and horizontal uncertainty.

Interestingly despite becoming "fully operational" in 1995, GPS was in use in the 1980s and played a huge part in the Gulf War in 1990/1991. "Fully operational" probably means 12 satellites in view at all times for any point on the earth between 55°N/55°S, but it's still very useful even at lower levels of service.

It's pretty amazing that a system like that could be envisioned in the 1970s and be fundamentally life-changing by the 1990s. Truly a modern marvel of engineering that we rely upon for precise timing, power grid synchronization, navigation, and a lot more.

Watching my parents get duped by Amazon results is maddening. They’re used to being able to trust a retailer or at least some consequences for scams and poor quality. People less scam-savvy than myself get understandably confused by “Amazon recommend” or a slightly lower price. But the minute I search for something on Amazon a dread comes over me of “here we go”. My danger center kicks in and I have to keep your wits about me. It’s a symptom of our (American at least) obsession with getting “the best deal” no matter what and it’s just awful.

You're probably right - I think a lot of people have a fundamental misunderstanding of severity and statistics here. As far as I can tell, if you have respiratory "cold"/"flu" symptoms, it's most likely that it's COVID, just based on prevalence and contagiousness.

Also, a lot of people haven't had the flu in years - it's not mild. It's often a week of being miserable in bed, not two days of sniffles. Mild COVID can feel like a cold, but COVID is more contagious and (I believe) more prevalent at this point. If you have any of those symptoms, you should probably assume it is COVID and take a test if you need to be around others.

Yes the YoY number is useful for getting rid of seasonal variations. The monthly CPI is also noisy. But when there’s a big spike over a few months (like we had 8-16 months ago) YoY won’t go down meaningfully for at least a year.

This is actually great (if noisy) news. 2 months of 0.4% CPI increase is equivalent to 5% yearly inflation. But the YoY is still high because it was much worse 8-12 months ago.

I hadn’t even considered that people will think low numbers are a lie because prices don’t go down. But of course (sadly) you’re right.

In this case I mean that choosing “autopilot” as a name was probably not meant to trick anyone. Just an overestimate of the layperson’s understanding of the aircraft equivalent.

For my Model Y:

The car itself is wonderful. Driving a Tesla is a level beyond anything else I've owned.

Autopilot on freeways works great. I disagree that it's deceptive. The name is confusing to the average person (it sounds like it drives itself without help). But there are constant reminders that you need to pay attention and be ready to take over. Stupid people will be stupid. A name change wouldn't be the worst outcome, but it's a great feature.

Navigate on autopilot is not great. It's kind of useful, but makes dumb lane changes and is too timid in traffic to work. Being able to switch lanes with a turn signal is useful and I use it.

Auto park is garbage and only works on very easy parking spots. Half the time it doesn't even "detect" the spot and won't offer the option. It's also not that good at parking.

Summon (classic) is useful for me. I use it to move my car out of the way to take out the trash. It's cool and not dangerous, though not super useful.

Smart summon is dangerous and not useable. As a previous commenter said, it has serious "nervous raccoon energy" and either gets confused or nearly hits things.

Full self driving is not even close to ready. It's nowhere near what was promised (get in your car and it drives you from A to B). It's unclear to me that this is even possible with the vision hardware in the car. I like playing with it, but I've never had a successful drive without having to take over. This was massively overhyped, perpetually pushed out, and honestly I agree with the fraud case here.

I'm mostly annoyed that all the broken features have sat stagnant while the company works on FSD releases that incrementally improve something that's fundamentally not even close to working right.

Doing Docker development on Windows eats away a lot of the benefit since you need to run Linux environments in a VM anyway. And yeah, you're going to have goofy stuff with line endings and file permissions. MacOS dev is better, partly because it's Unix-like but mostly because a lot of devs love their Macs enough to make Docker for Mac good enough.

There were supposed to be a lot of benefits to using Docker:

1. Build your environment anywhere and it will work anywhere. This is mostly true. Basic isolation of dependencies is a huge headache-solver for C/C++ development, Python apps, and anything with a complicated build chain. Go is a notable exception - the Go build process really did solve this without containers.

2. Process/resource/cgroup isolation. You can run multiple containers (even untrusted ones) on the same metal and they can't interact. It's like a VM but instead of committing fixed amounts of RAM and disk space (which mostly sits idle), you let the Linux kernel handle it dynamically with limits. At least that was the dream. But without carefully managing properties/permissions this is a security nightmare. When people say "why Kubernetes" this is one real answer. Almost no one trusts container isolation for actual security in practice.

3. Layered builds. This was a killer idea - you build your container in steps. The first few change infrequently and the last one or two is your actual app. You can ship the big OS-heavy layers once and push frequent small updates (a few MB) and still keep your dev and runtime environments identical. This breaks down a bit in the real world because a lot of people don't bother to layer things well - they wind up with 100MB-1GB monsters being pushed around endlessly. But also it kind of doesn't matter - you can push 1GB monsters on your own network/VPC all you want and it's not really a big deal.

4. Declarative builds - theoretically you can recreate a bit-identical build based on just the Dockerfile. This is great for auditing third-party images and reproducibility. Theoretically. But people forget that apt-get install on Monday might be different than apt-get install on Wednesday. Debian does security updates that way and an image built 6 months ago won't match one you build today. It still works, though, so we pretend not to notice. And sharing image layers with another host is actually kind of hard. I imagine Nix solves a lot of this but I haven't had the pleasure of learning it yet.

So Docker has fallen short on some promises and met others. But the truth is I can't think of a better way to build some fussy C project (the first thing I look for is a Dockerfile, and often it's easier to make one than pollute my system with dependencies). I also can't think of a better way to distribute a Python app. And being able to do "docker run debian:bullseye" is pretty slick. Golang is another story - I think it's very reasonable to say "what's the point?" with a go binary.

There are a few technical reasons I don’t see this as a real threat:

1. There isn’t a particular part of the constellation that passes over China. There are probably a few launch groups that never or rarely pass over China, but a majority do. An adversary would have to destroy or disable a few thousand satellites.

2. Anti-satellite weapons aren’t nearly plentiful enough and given the ground support required, I’d be surprised if launching more than a few per day is feasible. A counterattack would come too quickly.

3. Precise positions don’t help that much. Even knowing a satellite position to ~2m still requires some active tracking on the interceptor. It’s not much benefit over knowing the position to 1km.

4. The debris created would be catastrophic and likely to damage the ISS even at Starlink’s low altitude.

All of the first three apply to GPS as well even though it’s only ~32 satellites.

The ask comes from T.S. Kelso who is well regarded in the orbit tracking/space debris field. He's done a lot of important work making this information public and a lot of public good for collision avoidance. If it's important to you feel free to offer support! It's not clear to me he's asking for money, probably just help and time.

I'm also surprised at how negative the reaction here is to Google embracing an open standard. Both Android and iOS devices keep your passwords/keys encrypted end-to-end between your devices. You can absolutely share passkeys between devices (if you want to) and even make them exportable to another secrets manager (if you want to).

If you ask me what's one thing in 2030 people will look back on and say "I can't believe we did that!" I'd have to say "passwords". Passwords need to die and WebAuthn is a great step forward.

Absolutely unacceptable to not give a developer local root on their own machine. Manage profiles and install logging all you want, but requiring a developer to ask permission to install docker/git/tools they need is not security, it's incompetence.

If your employer won't give you the tools you need to do your job you should find another one. If your IT/security department is there to block you instead of help you get work done, you should also find a new job. I'm not saying walk out the door today, just that you don't deserve to be treated like that.

This is a really great article that doesn’t shy away from technical aspects while putting a human face on NTP. It’s really cool to learn the history behind something we take for granted.

Switching your phone transmitter off is technically required by FCC regulations: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-B...

Realistically there isn't an issue with leaving a cell phone on and out of airplane mode going purely based on how many people forget or ignore the directions everyday and how infrequently there are problems. But I'll make two points:

The idea that a cell phone transmitter can interfere with an airplane is by no means outrageous. Sure, a modern iPhone/Pixel/whatever has to meet certain emissions and interference standards. And modern airliners are designed with some interference rejection in mind. And ancient airliners from the 70s don't rely on a lot of electronic systems at all. As for airplanes designed in the 90s, well it's not silly to ask whether 200 people with 1W transmitters would interfere with the electronic systems. A properly functioning compliant phone shouldn't, but there's still some risk. Incidents do happen, though they are generally minor. I was on an airplane that had to abort a landing and go-around because they couldn't hear the tower over cellphone interference (voice comms are analog). Obviously no one died, but we were still delayed a bit.

It probably makes sense to relax the rules, but it is incredibly frustrating to see the attitude of "if they don't force me to turn it off it must be OK". The FCC requires you to turn off transmitters to avoid interference. The airline asks you to do so for the same reason. Experts in the field (myself included) are telling you there's a small risk and you should hit the airplane mode button. There's zero benefit to keeping your cellular service active in flight at all. But everyone's seen some article on Facebook (or in this case inverse.com) that says maybe there's a big conspiracy and everyone's lying to them. So they take a risk (albeit an extremely small one) with the lives of 200 other people. For no gain at all.

So do whatever you want, there's nothing I can do about human nature, but believe me when I tell you there's no government conspiracy to make you press the little airplane button funded by the cell phone companies. Yeah, the risk is probably negligible - it's just really hard to prove it and easier to make a small ask of passengers.

There’s a great interview with Bob Weir and Jerry Garcia on Letterman: https://m.youtube.com/watch?v=4skH27r5dLc

At some point Dave asks them why they let people tape their shows, and Bob replies with “if we ever make a good album people would probably go out and buy it anyway”

They were open source before it was cool. Also check out https://relisten.net/ for a great index of their shows from the Internet Archive.

I didn't mean to imply orbit debris isn't a real problem. But for the low end of LEO:

- Most debris deorbits naturally in a few years. Any debris causing events or accumulation naturally clears out in a reasonable time frame. It's not like debris at 800-2000km which is the real "Kessler Syndrome" concern where it takes decades or centuries.

- Debris mitigation efforts that are already in place are effective. Limiting debris release during launch and deployments has had a huge positive impact over the last few decades.

- "Traffic control" is a lot easier at these altitudes and debris in this range is well tracked. Obviously this doesn't extend to small stuff (<5cm), but due to active mitigation and natural decay this is less of an issue. Also ground radars are getting better and can actually see a lot of these objects now.

FCC approval is required to communicate with a (US-based) satellite in space, so effectively they can apply rules like this one. It's less of a power grab/nefarious plot and more a utilitarian kind of thing - the FCC has historically been the only agency that has authority to exert this pressure, so the work falls on them. It's admittedly odd that it's not the FAA or Space Force, but that's how it is.

It was enforced during licensing. In order to obtain a license from the FCC (which is effectively required to launch a satellite, unless you never want to communicate with it), you had to prove it would either deorbit naturally in < 25 years or that you had a system to do so at the end of the mission. The rule was generally to have a plan and an ability to deorbit after 25 years. A lot of satellites fail in ways that prevent using a propulsion system.

I'd expect the fuel required is generally the same, but this changes the altitude range for the question "do I need propulsion at all?" Satellites that would decay naturally in 6-10 years due to atmospheric drag would have satisfied the old rule. Now they need to install a propulsion system.

The actual impact is probably small - there aren't that many satellites launching to those altitudes, and most of them probably have a propulsion system anyway. But for a university satellite this could be a big obstacle.

I think this is generally a good thing to do, with some caveats that I hope the FCC considers.

For most satellites below ~450km, this is really a non-issue. Atmospheric drag will generally be sufficient to deorbit the satellite in a few years. For big Earth-observing constellations, Starlink and friends, and many small missions, this doesn't change anything. Debris don't really accumulate dangerously in this zone and collision avoidance is a well-studied problem with a lot of people doing great work. The 18th SDS with the US Space Force, LeoLabs, Starlink/SpaceX, and a lot of other constellation operators take this very seriously and do a good job.

For satellites in the 800km+ range, this is also not a meaningful change. The 25-year rule meant that these satellites needed a deorbit plan anyway. 800km is a rough estimate, in real life it depends on the satellite mass + geometry and the solar cycle.

For satellites in the 450-800km range (again - hand waving here) this is actually a big deal. Satellites that would decay naturally between 5 and 25 years now need an active deorbit plan or need to launch lower and keep themselves up with propellant. Small satellite propulsion is becoming cheaper and more available, so this isn't that onerous for commercial operators. But I do worry a little about educational and non-profit launchers of satellites. They'd be excluded from using launches to this orbital range unless the FCC allows waivers (which I'm hopeful they will).

Overall I don't think this has a particularly big impact. It's a sensible revision of an old rule that was a little too lax. But there aren't that many satellites launching at the high end of the 450-800km range without propulsion. The 1000km-2000km area is a more important area for debris mitigation and that was really already covered.

As for the FCC having this jurisdiction vs. the FAA or the USSF, as Spock would say - "it is not logical, but it is true."

I think you’re right that lumping anyone that eats meat at all into one big group hides the diversity there. It’s completely reasonable to eat a healthy diet with meat in it (lean chicken, fish, occasional beef, good sources of fiber and healthier fats, etc). It’s also possible to have a vegetarian diet that’s unhealthy. When I switched to being vegetarian my diet was very carb and cheese heavy at first.

I don’t think people considering leaning vegetarian/vegan should worry about getting enough protein. Protein deficiency is rare and just including eggs and dairy in your diet is really enough to not worry about it. If you’re bodybuilding, sure, you need to supplement, but that’s true for a meat diet as well. Many millions people lead healthy lives without meat protein and without keeping track of anything. I think people curious should try a meat-free day or two a week and see how they feel. I was skeptical (growing up where every meal had a serving of meat) but it’s really not an issue.

Full vegans need to make sure they’re getting the full range of protein types but it’s pretty easy if you have a diverse diet of grains, legumes, nuts, and other protein-rich foods. Basically don’t go in thinking vegan == “I only eat lettuce”! There’s lots of great, filling, protein-rich vegan food out there. Even a few vegan/veggie meals a week is a good thing.

100% agree impossible burgers are not good for you. Like real burgers they’re fine in moderation. My personal love for an impossible burger is that it satisfies a craving without causing harm to an animal. It doesn’t even need to be as good, just good enough to keep me from getting beef.

“Rule of six” is generally interesting - I came upon the concept when reading the book “Nightfall” by Isaac Asimov as a kid. There’s a line in the book about the number of stars in the sky, and how people can’t really grasp numbers more than 5-10. It got me thinking about trying to visualize a set of 3, 4, or 5 distinct objects without splitting them into groups. I genuinely can’t do it for more than 5 or 6 of something.

I also remember reading about a study where chess masters and non-experts were asked to memorize chess boards. Average people could only remember 5-7 piece locations where chess masters could remember the entire board. But when the piece layout was random (rather than from real chess matches) the experts weren’t much better than the non-experts. It’s speaks to the abstractions our brain creates to deal with limited working memory.

That cumbersome line of python is a good example. As an experienced python person, I immediately found myself giving names to the chunks to understand it.

Overall very good advice. Your code should explain the steps it takes to solve a problem (or in a more functional language, explain the solution), not be as terse and clever as possible. Keystrokes are cheap; thinking is expensive.

This would effectively lower the maximum altitude for a spacecraft without propulsion to <500km, probably lower (depending on geometry/density). It’s probably a good thing overall, but it does force a lot of small satellite makers (including students) to either restrict themselves to a small number of launch opportunities or add propulsion. It might be nice to have a more lax rule (like 10-15 years) for small non-profit launches.

There is a call out in the proposal to apply these rules to foreign-launched spacecraft as a requirement for access to US markets. I suppose it’s the best they can do.

For Python specifically, I'd add:

Type checking with mypy is a good way to accomplish the "unsafe/safe" string case without having to pollute the variable names. It's a really good use of types in a language that will let you blast through them if you want.

There's something to be said for writing code that is "obviously correct". List/dict/set comprehensions are super underrated for this.

    x = [str(y) for y in my_list if y > 5 and y not in other_list]

You can look at that and know it's correct. Versus:

    x = []
    for y in my_list:
       if y not in other_list and y > 5:
           x.append(y)

Easy enough to check in this case but it requires checking 4-5 different common mistakes (is x initialized, append vs. extend). Also I got so caught up writing the loop I forgot the point was to cast y to a str.

At NASA I wrote a set of Python scripts to help with planning and telemetry for a Mars mission. I had to convert a lot of time data points between UTC and a Mars timezone/clock (specific to the rover itself). There was an officially blessed tool written in Java that ran from the command line for time conversion. It was too slow to call out for each data point, so I figured it would be generally useful to port the conversion to Python.

First I dug into the Java source, which it turned out called out to a C library. I believe the C library linked out to a Fortran library. It was a lot more complicated than a simple scale and calendar - there were corrections for special and general relativity. Converting times actually required propagating orbits and estimating some non-closed-form quantities. In the end is was more work than it was worth, so we just did an approximation ("only" good to a few milliseconds - fine for our case).

So I guess item number 100 on this list should be "time is experienced the same way by all observers" and maybe 101 "simultaneity depends on the reference frame" :)