2025-06-23 22:00:57
We take it for granted that we almost always have cell service, no matter where you go around town. But there are places — the desert, the forest, or the ocean — where you might not have cell service. In addition, there are certain jobs where you must be able to make a call even if the cell towers are down, for example, after a hurricane. Recently, a combination of technological advancements has made it possible for your ordinary cell phone to connect to a satellite for at least some kind of service. But before that, you needed a satellite phone.
On TV and in movies, these are simple. You pull out your cell phone that has a bulkier-than-usual antenna, and you make a call. But the real-life version is quite different. While some satellite phones were connected to something like a ship, I’m going to consider a satellite phone, for the purpose of this post, to be a handheld device that can make calls.
Satellites have been relaying phone calls for a very long time. Early satellites carried voice transmissions in the late 1950s. But it would be 1979 before Inmarsat would provide MARISAT for phone calls from sea. It was clear that the cost of operating a truly global satellite phone system would be too high for any single country, but it would be a boon for ships at sea.
Inmarsat, started as a UN organization to create a satellite network for naval operations. It would grow to operate 15 satellites and become a private British-based company in 1998. However, by the late 1990s, there were competing companies like Thuraya, Iridium, and GlobalStar.
For example, here was part of a press release for a 1989 satellite terminal:
…small enough to fit into a standard suitcase. The TCS-9200 satellite terminal weighs 70lb and can be used to send voice, facsimile and still photographs… The TCS-9200 starts at $53,000, while Inmarsat charges are $7 to $10 per minute.
Keep in mind, too, that in addition to the briefcase, you needed an antenna. If you were lucky, your antenna folded up and, when deployed, looked a lot like an upside-down umbrella.
However, Iridium launched specifically to bring a handheld satellite phone service to the market. The first call? In late 1998, U.S. Vice President Al Gore dialed Gilbert Grosvenor, the great-grandson of Alexander Graham Bell. The phones looked like very big “brick” phones with a very large antenna that swung out.
Of course, all of this was during the Cold War, so the USSR also had its own satellite systems: Volna and Morya, in addition to military satellites.
The earliest satellites made one orbit of the Earth each day, which means they orbit at a very specific height. Higher orbits would cause the Earth to appear to move under the satellite, while lower orbits would have the satellite racing around the Earth.
That means that, from the ground, it looks like they never move. This gives reasonable coverage as long as you can “see” the satellite in the sky. However, it means you need better transmitters, receivers, and antennas.
This is how Inmarsat and Thuraya worked. Unless there is some special arrangement, a geosynchronous satellite only covers about 40% of the Earth.
Getting a satellite into a high orbit is challenging, and there are only so many “slots” at the exact orbit required to be geosynchronous available. That’s why other companies like Iridium and Globalstar wanted an alternative.
That alternative is to have satellites in lower orbits. It is easier to talk to them, and you can blanket the Earth. However, for full coverage of the globe, you need at least 40 or 50 satellites.
The system is also more complex. Each satellite is only overhead for a few minutes, so you have to switch between orbiting “cell towers” all the time. If there are enough satellites, it can be an advantage because you might get blocked from one satellite by, say, a mountain, and just pick up a different one instead.
Globalstar used 48 satellites, but couldn’t cover the poles. They eventually switched to a constellation of 24 satellites. Iridium, on the other hand, operates 66 satellites and claims to cover the entire globe. The satellites can beam signals to the Earth or each other.
There are a variety of issues with most, if not all, satellite phones. First, geosynchronous satellites won’t work if you are too far North or South since the satellite will be so low, you’ll bump into things like trees and mountains. Of course, they don’t work if you are on the wrong side of the world, either, unless there is a network of them.
Getting a signal indoors is tricky. Sometimes, it is tricky outdoors, too. And this isn’t cheap. Prices vary, but soon after the release, phones started at around $1,300, and then you paid $7 a minute to talk. The geosynchronous satellites, in particular, are subject to getting blocked momentarily by just about anything. The same can happen if you have too few satellites in the sky above you.
Modern pricing is a bit harder to figure out because of all the different plans. However, expect to pay between $50 and $150 a month, plus per-minute charges ranging from $0.25 to $1.50 per minute. In general, networks with less coverage are cheaper than those that work everywhere. Text messages are extra. So, of course, is data.
If you want to see what it really looked like to use a 1990-era Iridium phone, check out [saveitforparts] video below.
If you prefer to see an older non-phone system, check him out with an even older Inmarsat station in this video:
So it is no wonder these never caught on with the mass market. We expect that if providers can link normal cell phones to a satellite network, these older systems will fall by the wayside, at least for voice communications. Or, maybe hacker use will get cheaper. We can hope, right?
2025-06-23 19:00:21
In an Earth-sized take on the age-old ‘correlation or causality’ question, researchers have come across a fascinating match between Earth’s magnetic field and its oxygen levels since the Cambrian explosion, about 500 million years ago. The full results by [Weijia Kuang] et al. were published in Science Advances, where the authors speculate that this high correlation between the geomagnetic dipole and oxygen levels as recorded in the Earth’s geological mineral record may be indicative of the Earth’s geological processes affecting the evolution of lifeforms in its biosphere.
As with any such correlation, one has to entertain the notion that said correlation might be spurious or indirectly related before assuming a strong causal link. Here it is for example known already that the solar winds affect the Earth’s atmosphere and with it the geomagnetic field, as more intense solar winds increase the loss of oxygen into space, but this does not affect the strength of the geomagnetic field, just its shape. The question is thus whether there is a mechanism that would affect this field strength and consequently cause the loss of oxygen to the solar winds to spike.
Here the authors suggest that the Earth’s core dynamics – critical to the geomagnetic field – may play a major role, with conceivably the core-mantle interactions over the course of millions of years affecting it. As supercontinents like Pangea formed, broke up and partially reformed again, the impact of this material solidifying and melting could have been the underlying cause of these fluctuations in oxygen and magnetic field strength levels.
Although hard to say at this point in time, it may very well be that this correlation is causal, albeit as symptoms of activity of the Earth’s core and liquid mantle.
2025-06-23 16:00:41
QR codes are something that we all take for granted in this day and age. There are even a million apps to create your own QR codes, but what if you want to make a barcode? How about making a specific kind of barcode that follows UPC-E, CODE 39, or even the infamous… CODABAR? Well, it might be more difficult to find a single app that can handle all those different standards. Using “yet-another-web-app”, Barcode Tool – Generator & Scanner, you can rid these worries, created by [Ricardo de Azambuja].
When going to [Ricardo]’s simple application, you will find a straightforward interface that allows you to make far more different strips and square patterns than you’ve ever imagined. Of course, starting with the common QR code, you can create custom overlaid codes like many other QR generators. More uniquely, there are options for any barcode under the sun to help organize your hacker workspace. If you don’t want to download an app to scan the codes, you can even use the included scanner function.
If you want to use the web app, you can find it here! In-depth solutions to rather simple problems are something we strive to provide here at Hackaday, and this project is no exception. However, if you want something more physical, check out this specialized outdoor city cooking station.
2025-06-23 13:00:05
Learning new instruments is never a simple task on your own; nothing can beat the instant feedback of a teacher. In our new age of AI, why not have an AI companion complain when you’re off note? This is exactly what [Ada López] put together with their AI-Powered Piano Trainer.
The basics of the piano rely on rather simple boolean actions, either you press a key or not. Obviously, this sets up the piano for many fun projects, such as creative doorbells or helpful AI models. [Ada López] started their AI model with a custom dataset with images of playing specific notes on the piano. These images then get fed into Roboflow and trained using the YOLOv8 model.
Using the piano training has the model run on a laptop and only has a Raspberry Pi for video, and gives instant feedback to the pianist due to the demands of the model. Placing the Pi and an LCD screen for feedback into a simple enclosure allows the easy viewing of how good an AI model thinks you play piano. [Ada López] demos their device by playing Twinkle Twinkle Little Star but there is no reason why other songs couldn’t be added!
While there are simpler piano trainers out there relying on audio cues, this project presents a great opportunity for a fun project for anyone else wanting to take up the baton. If you want to get a little more from having to do less in the physical space, then this invisible piano is perfect for you!
2025-06-23 10:00:03
When seeing a story from MIT’s Lincoln Labs that promises 3D printing glass, our first reaction was that it might use some rare or novel chemicals, and certainly a super-high-tech printer. Perhaps it was some form of high-temperature laser sintering, unlikely to be within the reach of mere mortals. How wrong we were, because these boffins have developed a way to 3D print a glass-like material using easy-to-source materials and commonly available equipment.
The print medium is sodium silicate solution, commonly known as waterglass, mixed with silica and other inorganic nanoparticles. It’s referred to as an ink, and it appears to be printed using a technique very similar to the FDM printers we all know. The real magic comes in the curing process, though, because instead of being fired in a special furnace, these models are heated to 200 Celsius in an oil bath. They can then be solvent cleaned and are ready for use. The result may not be the fine crystal glass you may be expecting, but we can certainly see plenty of uses for it should it be turned into a commercial product. Certainly more convenient than sintering with a laser cutter.
2025-06-23 07:00:19
Hold onto your hats, everyone — there’s stunning news afoot. It’s hard to believe, but it looks like over-reliance on chatbots to do your homework can turn your brain into pudding. At least that seems to be the conclusion of a preprint paper out of the MIT Media Lab, which looked at 54 adults between the ages of 18 and 39, who were tasked with writing a series of essays. They divided participants into three groups — one that used ChatGPT to help write the essays, one that was limited to using only Google search, and one that had to do everything the old-fashioned way. They recorded the brain activity of writers using EEG, in order to get an idea of brain engagement with the task. The brain-only group had the greatest engagement, which stayed consistently high throughout the series, while the ChatGPT group had the least. More alarmingly, the engagement for the chatbot group went down even further with each essay written. The ChatGPT group produced essays that were very similar between writers and were judged “soulless” by two English teachers. Go figure.
The most interesting finding, though, was when 18 participants from the chatbot and brain-only groups were asked to rewrite one of their earlier essays, with the added twist that the chatbot group had to do it all by themselves, while the brainiacs got to use ChatGPT. The EEGs showed that the first group struggled with the task, presumably because they failed to form any deep memory of their previous work thanks to over-reliance on ChatGPT. The brain-only folks, however, did well at the task and showed signs of activity across all EEG bands. That fits well with our experience with chatbots, which we use to help retrieve specific facts and figures while writing articles, especially ones we know we’ve seen during our initial scan of the literature but can’t find later.
Does anyone remember Elektro? We sure do, although not from personal experience, since the seven-foot-tall automaton built by Westinghouse for the World’s Fair in New York City in 1939 significantly predates our appearance on the planet. But still, the golden-skinned robot that made its living by walking around, smoking, and cracking wise at the audience thanks to a 78-rpm record player in its capacious chest, really made an impression, enough that it toured the country for the better part of 30 years and made the unforgettable Sex Kittens Go to College in 1960 before fading into obscurity. At some point, the one-of-a-kind robot was rescued from a scrap heap and restored to its former glory, and now resides in the North Central Ohio Industrial Museum in Mansfield, very close to the Westinghouse facility that built it. If you need an excuse to visit North Central Ohio, you could do worse than a visit to see Elektro.
It was with some alarm that we learned this week from Al Williams that mtrek.com 1701 appeared to be down. For those not in the know, mtrek is a Telnet space combat game inspired by the Star Trek franchise, which explains why Al was in such a tizzy about not being able to connect; huge Trek nerd, our Al. Anyway, it appears Al’s worst fears were unfounded, as we were able to connect to mtrek just fine. But in the process of doing so, we stumbled across this collection of Telnet games and demos that’s worth checking out. The mtrek, of course, as well as Telnet versions of chess and backgammon, and an interactive world map that always blows our mind. The site also lists the Telnet GOAT, the Star Wars Asciimation; sadly, that one does seem to be down, at least for us. Sure, you can see it in a web browser, but it’s not the same as watching it in a terminal over Telnet, is it?
And finally, if you’ve got 90 minutes or so to spare, you could do worse than to spend it with our friend Hash as he reverse engineers an automotive ECU. We have to admit that we haven’t indulged yet — it’s on our playlist for this weekend, because we know how to party. But from what Hash tells us, this is the tortured tale of a job that took far, far longer to complete than expected. We have to admit that while we’ll gladly undertake almost any mechanical repair on most vehicles, automotive ECUs and other electronic modules are almost a bridge too far for us, at least in terms of cracking them open to make even simple repairs. Getting access to them for firmware extraction and parameter fiddling sounds like a lot of fun, and we’re looking forward to hearing what Hash has to say about the subject.
