Fully Characterized Systems

A friend from my old hackerspace was in grad school for electrical engineering. He had a professor who would ask, when something went wrong with a student project, “Have you fully characterized the system?” It’s a good, if lofty, goal, but it also became an inside joke around the hackerspace because YOLO was our MO about 95% of the time. Head crashes on the 3D printer – “not fully characterized”. Forgot to take out the trash last weekend? Was the system fully characterized?

It’s maybe also the difference between theory and practice: In theory, there’s no difference between theory and practice, and all systems can be fully characterized. But in practice, it’s hard to fully characterize a system that you don’t yet fully understand.

Case in point: we have nine small saplings growing in our front yard, and I have to water them. It’s boring moving the hose from tree to tree, so I thought I’d take a length of hose, stopper it at one end, and drill enough holes in it so that it could irrigate all of the trees at once. I kinda characterized the system: I figured out how much water flows per minute through our hose, and divided that up into a reasonable outflow in my mind, and drilled holes that ended up being way too large.

Why? Because a length of hose has a resistance to flow, and the water came pouring out of the first few holes, while the last few were dry. It wasn’t a constant pressure system like I thought it would be. I hadn’t even thought that the drag in the hose would matter, so there was no way I would have tried to measure it. But how would I characterize this resistance anyway? You could make a hose with too-large holes and measure the falloff. (Oops, that’s exactly what I did.)

In retrospect, professional drip irrigation systems always have holes that are tiny relative to the pipe diameter, which avoids this pressure-drop phenomenon, which means that they don’t have to worry about characterizing the hose resistance. So that’s what I ended up doing. I cut the hole size in half, and later widened up some of the downstream holes until it looked about right. Not even close to fully characterized, but it works.

So now, in addition to the engineer’s “have you fully characterized the system?”, I have the hacker’s “can you avoid characterizing parts of the system?” in my mind. And a holey chunk of hose in the trashcan.

Supercon News

Just briefly, in case you missed it: Tickets are on sale now for Supercon Ten, and we’ve extended the call for participation by another two weeks. If you’re a Hackaday fan, you owe it to yourself to join us at our annual gathering.

Hackaday Podcast Episode 382: Glueballs, Borg Cubes, And Supersonic Trebuchets

It’s still hot on both sides of the Atlantic, but Kristina has a new secret weapon for staying cool without making noise. Will Elliot and the others follow suit? Time will tell.

In Hackaday news, well, there’s a lot of it. For starters, Supercon Ten tickets went on sale Thursday morning, but chances are good that by the time you read this, the early bird offering will be all pecked out. But, never fear! More tickets will be released soon enough.

Don’t want to buy a ticket, but still want to go? Submit a talk proposal that gets accepted, and you’ll be welcomed in free of charge. Lucky for you, we just extended the deadline by two weeks to August 26th.

After exhausting the news, Elliot reached into the ol’ Mailbag and found a funny anecdote from [Vik Olliver]. (Funny in that it’ll make you go ‘hmm’.) A brief discussion about imperial vs. metric ensued, but then it was on to the hacks.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in lovely MP3.

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This Week In Security: BugTraq, AI Hacks, And Being Dumb On Planes

After a multi-year hiatus, the venerable BugTraq mailing list is back!

For decades, BugTraq was the place where vulnerabilities were disclosed, from the early days when nearly all vendors viewed all security research as a hostile force, through to the modern era of working with vendors to coordinate disclosing bugs. With the rise of bug bounty programs and other social changes, the mailing list slowly died: what started in 1993 ended in 2021 is returning. The new maintainer, Jonathan Brossard, says in his announcement “The mission is unchanged: full disclosure, researcher-first, no corporate filter.”

Don’t Be Dumb on Planes

In the unlikely event anyone here needs to be told: Don’t do dumb things on planes.

It seems that someone coming home from from the DEF CON hacker conference in Las Vegas decided to mess with the in-plane WiFi, and is likely now in the “find out” phase of doing something dumb. There hasn’t been any public followup beyond the original reports: a passenger on a Delta flight leaving Las Vegas brought up a fake WiFi hotspot named “Delta WiFi FAST” to trick other passengers into connecting, and attempted to disable the in-flight WiFi using a denial of service attack.

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Supercon Ten Tickets On Sale Now

Hackers, start your engines! We’re opening up ticket sales for our tenth, the 2026 Hackaday Supercon, to take place Nov 6-8 in Pasadena, CA. As always, because we haven’t announced the full slate of talks yet, we’d like to give the Hackaday True Believers out there a bonus: early bird tickets for $150 instead of the regular price of $296 (plus fees). If you know you want to attend (and you know that you want to attend) do not delay and order your tickets now!

As we mentioned before, there are a few exciting changes coming to this year’s Supercon. First off, we are moving to a larger venue on Saturday and Sunday: a few blocks south at the ArtCenter South Campus. We’re looking forward to two larger stages, more room for attendees, and more space to spread out and hack. No longer crammed into a cozy alley, we’ll sprawl out in a luxurious courtyard.

We have more tickets available than ever this year, which is great because Supercons past have all sold out. But we’re not expanding so much that we’ll lose the killer signal-to-noise ratio and friendly hacker atmosphere that makes Supercon our favorite con.

But do get your tickets soon! Whether you get in at the True Believer rate or not, Supercon is a bargain. Two and a half days of fully catered hacking and entertainment, plus the great talks, make it a bargain. Then we throw in sweet hackable badge over the top. But it’s truly the assembled crowd that makes it a priceless experience.

If you’re a Hackaday Supercon regular, we look forward to seeing you again soon! If you’ve always wanted to attend, but never pulled the trigger, the nice round number of Supercon Ten is a great excuse.

Of course, the best way to attend any convention is as a presenter, and our call for proposals just got extended for another two weeks. If you have something you’d like to say: let us know soon!

Procrastineers Rejoice! 2026 Supercon Call For Participation Extended

A few weeks ago, we put out the call for participation for this year’s 2026 Hackaday Supercon, taking place in Pasadena, CA this November. Today was going to be the deadline, but like you, we often let things pile up and put things off, so we’re extending another two weeks until August 26th.

Which is not to say that we haven’t heard from a ton of you! We’re psyched to see so many familiar Supercon regulars on the list, but we also love to see first-timers give talks. We try to make sure that new folks get their time to shine, so if you’ve never given a Supercon talk before, or if it’s been a few years, take this as your cue to present in front of the friendliest audience of like-minded hackers around.

This year is Hackaday’s tenth in-person Superconference, and to celebrate we’ve gotten a larger venue, so more folks can watch the talks live. We’ll be running two tracks as always, and you have your choice of a 20-minute or 40-minute slot. Presenters get in free, and we’ll get you an early-bird ticket rate the submission, so don’t delay and register for your slot today! Or at least before August 26th, because we won’t extend the deadline twice.

Oh, and if you’re interested in tickets, swing by Hackaday about this time tomorrow — we’ll have some news for you.

Linux Fu: Heads Or Tails For VPN

If you’ve done much networking, you surely know the frustration of trying to connect to something, say a Raspberry Pi, that lives behind your consumer router. There are a number of solutions for this, ranging from opening ports on your router along with dynamic DNS. Or, you can operate a VPN server on your network. Modern Linux has a facility called Wireguard that lets you create secure network tunnels very easily, but it is a little difficult to set up. But there are tools like Tailscale that can do most of the work for you. There’s only one problem: Tailscale is sorta-kinda free, but not really. But it turns out, you can build your own Tailscale network, and it is easier than you might imagine.

In all fairness, Tailscale’s free tier is good and recently got even more generous, allowing unlimited nodes and up to six users. That’s plenty for most hackers. However, as we’ve seen before, what they can give they can also take away. Besides, there are some extra services you still have to pay for if you want them, but overall, the free tier is more than enough for most people.

On the other hand, no matter how great the free tier may be, some people don’t want to run things on other people’s hardware. Or you need that 7th user. Or you need paywalled features. No worries. Headscale is a self-hosted service that can do nearly everything the cloud portion of Tailscale does, and if you have a place to host it, you can be your own Tailscale server.

For the client side? That’s the best part. Headscale works seamlessly with the existing Tailscale clients. You simply have to point them to your server instead of the defaults.

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Retrotechtacular: A View Of The Moon From 1964

If you didn’t live through it, it is hard to understand how excited the general public was about the race for the moon. You can capture some of it by watching “Lunar Bridgehead,” a film about JPL monitoring the Ranger spacecraft as it hit, rather hard, on the lunar surface.

The Ranger program had been plagued with problems. The first five didn’t make it to the moon. Ranger 6 hit the moon, but failed to start its cameras. Ranger 7 was the first successful mission. There would be two more successful missions before the end of the program.

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