Holograms, From Your Plotter

When mass-printed holograms appeared on magazines in the 1980s they were a huge novelty, before degrading to the level of kids’ stickers in the years since. At the time they were seen as not for ordinary people to make, but the truth is they can be created without lasers or an optics lab. [Jordan Matelsky] is here to show us how they can be made using as humble a device as a pen plotter.

The effect of an interference pattern from a set of fine lines in a thin film can be demonstrated at its simplest with an oily finger and a mobile phone screen, and once he’s demonstrated that he takes us through some of the theory involved in shifting the light to make an image. There are some false starts with different materials, but eventually he shows us some finished holograms scribed on the polycarbonate of a CD case. It seems you really can make a hologram with a pen plotter. If these images interest you, we’ve looked deeper into the subject in the past. Meanwhile, one of the plotter-scribed holograms can be seen below. Continue reading “Holograms, From Your Plotter”

Bladerunners And The Mother Of Invention

There are plenty of stories about inventors who see a problem and decide they can do better. But Van Phillips had a little more motivation than most. The problem was his own leg. In 1976, Phillips was a 21-year-old college student when a water-skiing accident cost him his left leg below the knee. If that wasn’t bad enough, the prosthetic leg he received afterward wasn’t exactly a technological marvel. Prosthetic limbs of the era were generally designed to look and act something like a biological leg and foot, but “act” might be giving them too much credit. They were passive structures that provided something to stand on and roll over while walking.

Phillips wanted to do more than walk. There was just one problem: he wasn’t an engineer. Before the accident, he had been studying business. So, if he was going to build a better leg, first he was going to have to learn how.

Back To School

Traditional prosthetic feet (public domain)

Phillips became fascinated with prosthetics and eventually studied prosthetic design at Northwestern University’s Prosthetic-Orthotic Center. He also worked at the University of Utah’s prosthetics laboratory, where he had access to both the people and equipment he needed to experiment.

The conventional wisdom was that a prosthetic foot should imitate a human foot. That seems perfectly reasonable — evolution has had quite a long time to work on the design. But there’s a problem with simply copying the shape. A real foot isn’t just a foot-shaped object attached to the bottom of your leg. Muscles, tendons, and ligaments store and release energy as you walk or run. Your Achilles tendon, in particular, acts very much like a spring. A conventional prosthetic foot might look right, but it didn’t have anything corresponding to that spring.

Phillips eventually stopped worrying so much about making something that looked like a foot. Instead, he decided to make something that worked like one.

Continue reading “Bladerunners And The Mother Of Invention”

Hacking Fiber To The Home

When we think about security threats, we generally imagine them coming from far away across the wider internet. But what if the connection between you and your ISP was the target? [Rithwik Jayasimha] and [Rithvik Vibhu] have explored how fiber to the home connections may not be as secure as you would hope.

The hack centers around fiber-to-the-home connections, of which many deployments rely on Gigabit Passive Optical Network (GPON) standards. The key there is the “passive” part—these networks don’t rely on active components to switch signals. ISPs run central trunk lines out to optical line terminals (OLT), with passive splitters installed in neighborhoods to serve a number of downstream subscribers. Each subscriber then has something called an Optical Network Unit (ONU) in their home, which filters out the traffic intended for that specific subscriber.

Therein lies the flaw, though. Light (and thus, data) for many subscribers flows into the home, and it’s only the ONU that is filtering that out. Hack the ONU, or replace it… and you have access to downstream traffic from your neighbors that you shouldn’t be able to access.

The duo were able to hack an ONU to forward every single frame it receives, revealing downstream data intended for other homes in their immediate neighborhood. A great deal of traffic is encrypted these days, which provides a layer of safety, but it is by no means an ideal situation that such a hack is possible at all. They also explored other threats, such as installing splitters in publicly-accessible infrastructure, and compromising an upstream OLT and using it to flash firmware to other subscriber’s ONUs on the network. All this was presented in a talk at DEF CON, too, which can be viewed online.

It’s a concerning look at an often unconsidered link in the network chain. Few of us expect our data to be snooped upon in between us and the ISP, after all.

Continue reading “Hacking Fiber To The Home”

The Chernobyl NPP And Forty Years Of Robots For High Radiation Environments

With the massive steam explosion that shredded the #4 RBMK reactor at the Chernobyl Nuclear Power Plant in 1986 it suddenly made robots that could survive a high ionizing radiation environment into the hottest item on the planet. Over the course of forty years many generations of such robots were developed, tested, improved upon or discarded, all to explore and handle hazardous waste throughout the depths of the #4 reactor’s remains.

Researchers of the ISP NPP next to one of the TR robots. (Credit: ISP NPP)
Researchers of the ISP NPP next to one of the TR robots. (Credit: ISP NPP)

Even if the entire development and decisions here would easily fit a couple of feature length movies, the recent documentary by the [Chornobyl Family] provides a solid overview of the engineering challenges, the issues encountered along the way and the forced evolution of initially very basic designs into the robotics that today trundle and wriggle around inside reactor #4, as well as their cousins over at the couple of stricken reactors at Japan’s Fukushima Daiichi power station.

Unlike the other robots developed from 1986 onwards to provide general clean-up of scattered core material outside of the core, these robots had to venture deep inside, where radiation levels were the highest and correspondingly the challenges much more severe. This was such a problem that initially it were humans who did the exploration, as robots proved to be too fragile and too prone to getting stuck.

Until the 1990s exploration of the ruined core was quite limited, also because of a lack of urgency. While the outside clean-up and construction of the sarcophagus had to be done as quickly as possible, the core exploration was more slow and methodical, based around trying to establish its condition, what core material remained inside and try to take samples of interesting objects like the well-known ‘elephant’s foot’.

Continue reading “The Chernobyl NPP And Forty Years Of Robots For High Radiation Environments”

Smart Clock Helps With Medication Management

There are all kinds of smart devices on the market these days, but if you want one to solve a particular personal problem, sometimes it’s easiest to just build your own. That’s precisely what [hvermaak.projects] did when it came to the Ouma Ria Smart Clock.

The clock was primarily intended to act as a useful tool for providing medication reminders, before some extra useful home functionality was folded in. The heart of the build is an ESP32-WROOM-32 hooked up to four 8×8 WS2812B addressable LED panels acting as a display. A further 30 WS2812Bs in a strip act as a status indicator. A DS3231 real-time-clock module ensures the clock keeps accurate time, while a BH1750 ambient light sensor makes sure the clock is responsive to current lighting conditions. There’s also a DFPlayer Mini audio module for spoken announcements and chimes, while there are inputs for AM312 passive infrared motion sensors that allow the clock to act as a rudimentary security monitor. There’s even a web interface for control and scheduling.

The device ultimately evolved into something that helped with daily live, handling everything from medication management to remembering birthdays, and even helping out with kitchen timing tasks.  We’ve featured some other innovative builds in this space in recent years, too, like this explosively loud alarm clock.

Have Scientists Stuck The Landing On The Glueball Discovery?

Exciting discoveries in particle physics are one of those things that it can be easy to get blase about. Some people get caught up in the obvious excitement, while others yawn: “Oh, you found the Higgs Boson, just like Higgs predicted. Call me when you have something new.” Well, if you’re in category B, prepare to yawn while the rest of us break out champagne, because it looks like we’ve finally found the glueball. 

The glueball has got to be one of the oddest particles to fall out of the Standard Model. It’s not a fundamental particle, but its makeup contains no quarks– those itty bits that make up protons and neutrons– nor any leptons like electrons or muons. No, the glueball is a hadron made entirely of bosons: specifically, gluons, the force-carrying particles of the strong nuclear force. It’s also been called gluonium or a gluon-ball, but glueball is more fun.

Try and imagine a proton without any quarks. Remember that inside the proton there are three quarks, held together with force-carrying gluon particles. If you have zero quarks, but enough of those gluons tangled up in the right ways, and you get a tangible, if short lived particle. That’s the glueball, a neutral particle that will decay almost immediatly in to Pions. It works because gluons have ‘colour charge’– the strong nuclear force’s answer to electric charge.

It’s also one of those things that will probably never be seen in nature: odds are, even in the hottest collisions, you’re going to get a quark or two mixed up with your gluon soup. That’s okay; the gluonic state is what we’ve been looking for. As long as the particle is mostly gluons, and behaves as the Standard Model predicts it should, physicists are inclined to call it good enough. The latest candidate to hit “good enough” is X(2370), which fell out of a collision in the Beijing Electron–Positron Collider II (BEPC II), as detected by the Beijing Spectrometer III (BES III). The paper hit ArXiv at the end of July. It’s taken the collaboration this long to make sure of what they were looking at, as they sorted through the terabytes of data an instrument like this generates.

Is this likely to affect you in any way? No. It confirms what we already thought we knew about the universe, and the particle itself is too short-lived to ever exist outside of some very extreme– mostly man-made– environments. On the other hand, it’s an excuse to celebrate scientific discovery, and we’ll take any of those we can, just like when the Muon Magnetic Moment measured in at the expected value, or neutrinos transmuted elements in exactly the way the models said they would. Besides, if we’re really lucky this result will turn out not to be a glueball, but something new and interesting. Then even the most jaded nerds will have reason to celebrate.

Header image: The Bejing III Spectrometer, BESII.

Your Laptop Keyboard, On Another Device

It’s likely many of us have been in the position of first set-up on a machine such as a Raspberry Pi, and had keyboard problems. Either no spare keyboard is to be found, or a cluttered desk has to find extra space for a full-size keyboard. [Þórarinn] and [Arni] have a handy solution: use the existing keyboard on your laptop.

His approach is both ingenious and simple, as it’s only the K part of a KVM. On the laptop end, it’s a serial terminal, without the receiving side. The serial port in question is an RP2040 board which implements a USB-to-serial port. This serial connection goes to another RP2040, which does the ingenious bit. It’s a serial-to-USB HID keyboard. All of this means that keystrokes on the laptop are sent down the serial connection, and appear on the Pi or whatever computer as a USB keyboard as though typed locally. The mildly annoying first set-up can be done, and then it can be run via SSH or whatever other remote access protocol as normal. The code is provided, so anyone with a couple of RP2040 boards can do it.

We like this hack, because we’ve had the annoyance of needing a keyboard to set up what would otherwise be a completely headless machine too many times. It’s one to store away at the back of your mind, for those rare improvisational need-an-extra-keyboard moments.

Thanks [Henk] for the tip.