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979 Articles

The Simulated Universe Thought Experiment And Information Entropy

October 26, 2023 by 38 Comments

Do we live in a simulation? This is one of those questions which has kept at least part of humanity awake at night, and which has led to a number of successful books and movies being made on the subject, topped perhaps by the blockbuster  movie The Matrix. Yet the traditional interpretation of the ‘simulated universe’ thought experiment is one in which we – including our brains and bodies – are just data zipping about in a hyper-advanced simulation rather than physical brains jacked into a computer. This simulation would have been set up by (presumably) a hyper-advanced species who seem to like to run their own version of The Sims on a Universe-sized scale.

Regardless of the ‘why’, the aspect of this question where at least some scientific inquiry is possible concerns whether or not it would be possible to distinguish anything uniquely simulation-like in our environment that’d give the game away, like a sudden feeling of déjà vu in the world of The Matrix where you can suddenly perceive the fabric of the simulation. However, the major problem which we have to consider when trying to catch a simulation in the act is that to this point we cannot ourselves create even a miniature galaxy and intelligent beings inside it to provide a testable hypothesis.

Beyond popular media like movies and series like Rick & Morty, what do science and philosophy have to say about this oddly controversial subject? According to some, we have already found the smoking gun, while others are decidedly more skeptical.

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Game Graphics: Racing The Beam

October 24, 2023 by 15 Comments

Have you ever wondered how the graphics in your favorite video games worked? This is the start of a series on game graphics, and what better place to start than how exactly the original Mario Bros. got those glorious pixely pixels onto the screen. Buckle in, because we’re “racing the beam” with systems like the NES, Commodore 64, and many other classics from the 1980s.

And to understand the 1980’s, it’s important to understand how the televisions of the time worked. Cathode Ray Tube (CRT) televisions work by precisely bombarding a phosphor layer with electrons, which excites the phosphor, which then releases visible light. The beam scans from left to right then top to bottom, giving each pixel a small fraction of a second of time. All of this effectively means that pixel data needs be sent at the same time as when the pixels are being lit up, which is why this type of graphics is often dubbed “racing the beam”.

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When Is Damascus Steel Not From Damascus?

October 23, 2023 by 47 Comments

If you grow up around a working blacksmith’s forge, there are a few subjects related to metalwork on which you’ll occasionally have a heated discussion. Probably the best known is the topic of wrought iron, a subject I’ve covered here in the past, and which comes from the name of a particular material being confused with a catch-all term of all blacksmith-made items. I’ve come to realise over recent years that there may be another term in general use which is a little jarring to metalwork pedants, so-called Damascus steel. Why the Syrian capital should pop up in this way is a fascinating story of medieval metalworking, which can easily consume many days of research.

Damascus? Where’s That?

A section of a knife blade with various silver grey and black layered patterns in the metal.
The banded pattern of the laminate formed from pattern welded layers of differing steels in a modern Damascus steel knife. “DamaszenerKlinge” by Soerfm

The Damascus steel you’ll see in YouTube videos, TV shows, and elsewhere is a steel with complex bands and striations on its surface. It’s often used in knife blades, and it will usually have been chemically treated to enhance the appearance of the patterns. It’s a laminate material made by pattern welding layers of different steels together, and it will usually have been worked and folded many times to produce a huge number of very thin layers of those steels. Sometimes it’s not made from sheets or ingots of steel but from manufactured steel products such as chains, in an attempt to produce a result with more unusual patterns. Continue reading “When Is Damascus Steel Not From Damascus?” →

You’ve Got Mail: Grilled, Scrambled, And Other Delicious Stamps

October 19, 2023 by 8 Comments

Well, we’re just zipping right through this series, no? So far we’ve looked at various postal machines and how they work to flip mail around, cancel the postage, and sort it, all in a matter of seconds. We explored the first automated post office and found out why it was a failure, and we learned why it all depends on ZIP code. Now, it’s finally time for some really fun stuff: the stamp trivia.

Now I’m no philatelist by any standard, though I do have a few hundred stamps strewn about the house. The danger in philately is that you learn all sorts of cool things about stamps and their history, and you just want to buy more and more of them. So let’s go!

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2023 Hackaday Supercon Badge: Welcome To The Vectorscope

October 18, 2023 by 48 Comments

This year, the Supercon badge goes analog! (Or at least fakes it pretty convincingly.) Taking inspiration from the phosphor scopes of yesteryear, the 2023 Vectorscope badge is part analog audio playground, part art project, and all about prototyping. Who doesn’t like the warm glow and lovely green fade of an old Tektronix tube scope? That’s what we’re after.

Conceptually, the badge is two separate devices in one. Most obvious is the vectorscope, which takes in voltages in the 0 V – 3 V range and plots them out in X-Y mode in glorious fake-phosphor effect on the lovely round IPS screen. We’ve also tied an audio amplifier to the Y input that plays whatever waveform you’re watching.

But you don’t have to bring your own waveforms with you – the other half of the badge is an arbitrary programmable waveform generator that drives two channels. Off the bat, it’s configurable with the front panel controls, so you’re obviously invited to make Lissajous figures and store them in the program memories.

Combining the two halves lets you draw in voltages and time, but not until you connect them together, naturally. You see, this isn’t an analog simulation – it’s the programmable equivalent of the real deal, courtesy of the AK4619 ADC/DAC. Voltages go out on one set of pins and come back in on the other.

And you get to play around with these voltages in through-hole space too, because we’ve included a very generous prototyping board for your analog explorations. Does this instantly suggest a curve tracer to you? Be our guest! Other forms of analog video-mangling? We want to see what you come up with. Make an audio filter and watch it work on the screen in front of your very eyes.

Of course we’re not leaving you code monkeys out in the cold. MicroPython puts the “programming” in the programmable waveform generator. If you’re not content with the four stock waveforms, you’re invited to write your own. And this is where it gets artsy.

You can upload your own repetitive waveforms to the onboard direct digital synth routine, but why stop there? We’ve left most of the processing power of the underlying RP2040 untouched, for you to use. And four buttons on the front panel let you store and play back your code, so you have space to stash your demos, and a sweet joystick with a custom keycap gives you control.

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The Pros And Cons Of Hydrofoils

October 17, 2023 by 25 Comments

Hydrofoils have fascinated naval architects and marine designers for years. Fitted with underwater wings, these designs traverse the waters at great speed with a minimum of drag. As with many innovative technologies, though, the use of hydrofoils is riddled with challenges that often offset the vast benefits they offer.

While hydrofoils promise a better marine transportation experience, their adoption hasn’t been smooth sailing. In this article, we’ll dive deep into the potential and pitfalls of hydrofoil designs, and look at the unique niches this technology serves today.

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USB-C For Hackers: Build Your Own PSU

October 12, 2023 by 43 Comments

What if you wanted to build your own USB-C PSU? Good news – it’s easy enough! If you ever wanted to retrofit a decent DC PSU of yours to the USB-C standard, say, you got a Lenovo/HP/Dell 19V-20V charger brick and you’ve ever wished it were USB-C, today is the day when we do exactly that. To be fair, we will cheat a bit – but only a tiny bit, we won’t be deviating too much from the specification! And, to begin with, I’ll show you some exceptionally easy ways that you can turn your DC PSU into a USB-C compatible one, with a simple module or a few.

Turning a 20 V PSU into a USB-C PSU feels natural if you want to charge a laptop – those tend to request 20 V from a USB-C PSU anyway, so what’s the big deal? However, you can’t just put 20 V onto a USB-C connector – you have to add a fair bit of extra logic to make your newly christened USB-C PSU safe to use with 5 V devices, and this logic also requires you go through a few extra steps before 20 V appears on VBUS. Any USB-C PSU has to output 5 V first and foremost whenever a device is connected, up until a higher voltage is negotiated digitally, and the PSU may only switch to a higher voltage output when it’s requested to do so.

Now, for that, a PSU offers a list of profiles, and we looked into those profiles in the Replying PD article – each profile is four bytes that contain information about the profile voltage, maximum current that the device may draw at that voltage, and a few other details. For a PSU to be USB-C compliant, the USB-C specification says that, in addition to 5 V, you may also offer 9 V, 15 V, and 20 V.

Also, the specification says that if a PSU supports certain in-spec voltage like 15 V, it’s also required by the spec to offer all of the spec-defined voltages below the maximum one – for 15 V, that also requires supporting 9 V. Both of these are UX requirements, as opposed to technical requirements – it’s easier for device and PSU manufacturers to work with a small set of pre-defined voltages that majority of the chargers will support, but in reality, you can actually offer any voltage you want in the PSU advertisement; at worst, a device is going to refuse and contend with slowly charging from the 5 V output that you’re required to produce.

I’d like to walk you through how off-the-shelf USB-C PSUs work, all of the options you can use to to create one, and then, let’s build our own USB-C PSU from scratch! Continue reading “USB-C For Hackers: Build Your Own PSU” →