We are unabashed fans of [The History Guy’s] YouTube channel, although his history videos aren’t always about technology, and even when they are, they don’t always dig into the depths that we’d like to see. That’s understandable since the channel is a general interest channel. However, for this piece on James Clerk Maxwell, he brought in [Arvin Ash] to handle the science side. While [The History Guy] talked about Maxwell’s life and contributions, [Arvin] has a complementary video covering the math behind the equations. You can see both videos below.
Of course, if you’ve done electronics for long, you probably know at least something about Maxwell’s equations. They unified electricity and magnetism and Einstein credited them with spurring one of his most famous theories.
Continue reading “Two Perspectives On James Clerk Maxwell And His Equations”
As reported by Bloomberg, Tesla has acquired the innovative energy storage company Maxwell Technologies for $218 Million. The move is a direct departure from Tesla’s current energy storage requirements; instead of relying on lithium battery technology, this acquisition could signal a change to capacitor technology.
The key selling point of capacitors, either of the super- or ultra- variety, is the much shorter charge and discharge rates. Where a supercapacitor can be used to weld metal by simply shorting the terminals (don’t do that, by the way), battery technology hasn’t yet caught up. You can only charge batteries at a specific rate, and you can only discharge them at a specific rate. The acquisition of an ultracapacitor manufacturer opens the possibility of these powerhouses finding their way into electric vehicles.
While there is a single problem with super- and ultra-capacitors — the sheer volume and the fact that a module of ultracaps will hold much less energy than a module of batteries of the same size — the best guess is that Tesla won’t be replacing all their batteries with caps in the short-term. Analysts think that future Teslas may feature a ‘co-battery’ of sorts, allowing for fast charging and discharging through a series of ultracapacitors, with the main energy storage in the car still being the lithium battery modules. This will be especially useful for regenerative braking, as slowing down a three thousand pound vehicle produces a lot of energy, and Tesla’s current battery technology can’t soak all of it up.
NVIDIA’s Jetson line of single-board computers are doing something different in a vast sea of relatively similar Linux SBCs. Designed for edge computing applications, such as a robot that needs to perform high-speed computer vision while out in the field, they provide exceptional performance in a board that’s of comparable size and weight to other SBCs on the market. The only difference, as you might expect, is that they tend to cost a lot more: the current top of the line Jetson AGX Orin Developer Kit is $1999 USD
Luckily for hackers and makers like us, NVIDIA realized they needed an affordable gateway into their ecosystem, so they introduced the $99 Jetson Nano in 2019. The product proved so popular that just a year later the company refreshed it with a streamlined carrier board that dropped the cost of the kit down to an incredible $59. Looking to expand on that success even further, today NVIDIA announced a new upmarket entry into the Nano family that lies somewhere in the middle.
While the $499 price tag of the Jetson Orin Nano Developer Kit may be a bit steep for hobbyists, there’s no question that you get a lot for your money. Capable of performing 40 trillion operations per second (TOPS), NVIDIA estimates the Orin Nano is a staggering 80X as powerful as the previous Nano. It’s a level of performance that, admittedly, not every Hackaday reader needs on their workbench. But the allure of a palm-sized supercomputer is very real, and anyone with an interest in experimenting with machine learning would do well to weigh (literally, and figuratively) the Orin Nano against a desktop computer with a comparable NVIDIA graphics card.
We were provided with one of the very first Jetson Orin Nano Developer Kits before their official unveiling during NVIDIA GTC (GPU Technology Conference), and I’ve spent the last few days getting up close and personal with the hardware and software. After coming to terms with the fact that this tiny board is considerably more powerful than the computer I’m currently writing this on, I’m left excited to see what the community can accomplish with the incredible performance offered by this pint-sized system.
Continue reading “Hands-On: NVIDIA Jetson Orin Nano Developer Kit”
If you use PHP, you likely use the Composer tool for managing dependencies, at least indirectly. And the good folks at SonarSource found a nasty, potential supply chain attack in this tool, when used in the Packagist repository. The problem is the support for arbitrary README filenames. When a package update shows up on Packagist, that service uses a Version Control Service (VCS) like Git or Mercurial to pull the specified readme location. That pull operation is subject to argument injection. Name your branch
--help, and Git will happily run the help argument instead of doing the pull intended. In the case of Git commands, our intrepid researchers were unable to weaponize the issue to achieve code execution.
Composer also supports projects that use Mercurial as their VCS, and Mercurial has a
--config option that has… interesting potential. It allows redefining a Mecurial command as a script snippet. So a project just has to contain a malicious
payload.sh, and the readme set to
--config=alias.cat=!hg cat -r : payload.sh|sh;,txt. For those keeping track at home, the vulnerability is that this cursed string of ugly is accepted by Composer as a valid filename. This uses the
--config trick to redefine
cat as a bit of script that executes the payload. It ends in
.txt because that is a requirement of Composer.
So let’s talk about what this little hack could have been used for, or maybe still used for on an unpatched, private install of Packagist. This is an unattended attack that jumps straight to remote script execution — on an official package repository. If discovered and used for evil, this would have been a massive supply chain attack against PHP deployments. Instead, thanks to SonarSource, it was discovered and disclosed privately back in April. The official Packagist repo at packagist.org was fixed the day after disclosure, and a CVE and updated packages went out six days later. Great work all around.
Continue reading “This Week In Security: PHP Attack Defused, Scoreboard Manipulation, And Tillitis”
My wife and I are reading a book about physics in the early 1900s. It’s half history of science and half biography of some of the most famous physicists, and it’s good fun. But it got me thinking about the state of physics 120 years ago.
What we’d now call classical mechanics was fully settled for quite a while, and even the mysterious electricity and magnetism had been recently put to rest by Maxwell and Heaviside. It seemed like there was nothing left to explain for a while. And then all the doors broke wide open.
As much as I personally like Einstein’s relativity work, I’d say the most revolutionary change in perspective, and driver of the most research in the intervening century, was quantum mechanics. And how did it all start? In the strangest of ways – with Niels Bohr worrying about why hydrogen and helium gasses gave off particular colors when ionized, which lead to his model of the atom and the idea of energy in quantum packets. Or maybe it was De Broglie’s idea that electrons could behave like waves or magnets, from slit and cathode-ray experiments respectively, that lead to Heisenberg’s uncertainty principle.
Either way, the birth of the strangest and most profound physics revolution – quantum mechanics – came from answering some ridiculously simple and straightforward questions. Why does helium emit pink, and how do TVs work? (I know, they didn’t have TVs yet…) Nobody looking at these phenomena, apart or together, could have thought that answering them would have required a complete re-thinking of how we think about reality. And yet it did.
I can’t help but wonder if there are, in addition to the multi-bazillion dollar projects like the Large Hadron Collider or the James Webb Space Telescope, some simpler phenomena out there that we should be asking “why?” about. Are we in a similar quiet before the storm? Or is it really true that the way to keep pushing back the boundaries of our ignorance is through these mega-projects?
In antiquity, we see examples of magnifying crystals formed into a biconvex shape as early as the 7th century BC. Whether the people of that period used them either for fire-starting purposes or vision is unclear. Still, it is famously said that Emperor Nero of Rome watched gladiator games through an emerald.
Needless to say, the views we get through modern lenses are a lot more realistic. So how did we get from simple magnifying systems to the complex lens systems we see today? We start with a quick journey through the history of the camera and the lens, and we’ll end up with the cutting edge in lens design for smartphone cameras and VR headsets.
Continue reading “Lenses: From Fire Starters To Smart Phones And VR”
Long before the idea of hot dog-shaped iPhone cases, Otter Boxen, or even those swappable Nokia face plates, people were just as likely to express themselves with their landline phones. Growing up at my house in the 80s, the Slimline on the kitchen wall was hidden inside a magneto wall set from the early 1900s, the front of which swung out to reveal the modern equipment behind it. Back in my bedroom, I had the coolest phone ever, a see-through Unisonic with candy-colored guts. Down in the basement was my favorite extension, tactility-wise: a candy apple-red wall unit with dimly-lit circular push buttons that were springy and spongy and oh-so fun to dial.
Popular culture shows us that people were dreaming of cool telephone enclosures before they were even a thing. Obviously, TV secret agent Maxwell Smart’s shoe phone wasn’t plausible for the technology of that era, but it also wasn’t really feasible for aesthetic reasons. For decades, phone subscribers had to use whatever equipment Ma Bell had to offer, and you couldn’t just buy the things outright at the mall — you had to lease the hardware from her, and pay for the service.
Continue reading “The Case For Designer Landline Phones”