You normally think of ELINT — Electronic Intelligence — as something done in secret by shadowy three-letter agencies or the military. The term usually means gathering intelligence from signals that don’t contain speech (since that’s COMINT). But [Nukes] was looking at public data from NASA’s SMAP satellite and made an interesting discovery. Despite the satellite’s mission to measure soil moisture, it also provided data on strange happenings in the radio spectrum.
While 1.4 GHz is technically in the L-band, it is reserved (from 1.400–1.427 GHz) for specialized purposes. The frequency is critical for radio astronomy, so it is typically clear other than low-power safety critical data systems that benefit from the low potential for interference. SMAP, coincidentally, listens on 1.41 GHz and maps where there is interference.
We always enjoy [The History Guy], and we wish he’d do more history of science and technology. But when he does, he always delivers! His latest video, which you can see below, focuses on the Cold War pursuit of creating transfermium elements. That is, the discovery of elements that appear above fermium using advanced techniques like cyclotrons.
There was a brief history of scientists producing unnatural elements. The two leaders in this work were a Soviet lab, the Joint Institute of Nuclear Research, and a US lab at Berkeley.
Last week, the mainstream news was filled with headlines about K2-18b — an exoplanet some 124 light-years away from Earth that 98% of the population had never even heard about. Even astronomers weren’t aware of its existence until the Kepler Space Telescope picked it out back in 2015, just one of the more than 2,700 planets the now defunct observatory was able to identify during its storied career. But now, thanks to recent observations by the James Web Space Telescope, this obscure planet has been thrust into the limelight by the discovery of what researchers believe are the telltale signs of life in its atmosphere.
Artist’s rendition of planet K2-18b.
Well, maybe. As you might imagine, being able to determine if a planet has life on it from 124 light-years away isn’t exactly easy. We haven’t even been able to conclusively rule out past, or even present, life in our very own solar system, which in astronomical terms is about as far off as the end of your block.
To be fair the University of Cambridge’s Institute of Astronomy researchers, lead by Nikku Madhusudhan, aren’t claiming to have definitive proof that life exists on K2-18b. We probably won’t get undeniable proof of life on another planet until a rover literally runs over it. Rather, their paper proposes that abundant biological life, potentially some form of marine phytoplankton, is one of the strongest explanations for the concentrations of dimethyl sulfide and dimethyl disulfide that they’ve detected in the atmosphere of K2-18b.
As you might expect, there are already challenges to that conclusion. Which is of course exactly how the scientific process is supposed to work. Though the findings from Cambridge are certainly compelling, adding just a bit of context can show that things aren’t as cut and dried as we might like. There’s even an argument to be made that we wouldn’t necessarily know what the signs of extraterrestrial life would look like even if it was right in front of us.
Looks like the Simpsons had it right again, now that an Australian radio station has been caught using an AI-generated DJ for their midday slot. Station CADA, a Sydney-based broadcaster that’s part of the Australian Radio Network, revealed that “Workdays with Thy” isn’t actually hosted by a person; rather, “Thy” is a generative AI text-to-speech system that has been on the air since November. An actual employee of the ARN finance department was used for Thy’s voice model and her headshot, which adds a bit to the creepy factor.
As you might remember from chemistry class, crystals are made up of blocks of atoms (usually called ‘unit cells’) that fit together in perfect repetition — baring dislocations, cracks, impurities, or anything else that might throw off a theoretically perfect crystal structure. There are only so many ways to tessellate atoms in 3D space; 230 of them, to be precise. A quasicrystal isn’t any of them. Rather than repeat endlessly in 3D space, a quasicrystal never repeats perfectly, like a 3D dimensional Penrose tile. The discovery of quasicrystals dates back to the 1980s, and was awarded a noble prize in 2011.
Penrose tiling– the pattern never repeats perfectly. Quasicrystals do this in 3D. (Image by Inductiveload, Public Domain)
Quasicrystals aren’t exactly common in nature, so how does 3D printing come into this? Well, it turns out that, quite accidentally, a particular Aluminum-Zirconium alloy was forming small zones of quasicrystals (the black spots in the image above) when used in powder bed fusion printing. Other high strength-alloys tended to be very prone to cracking, to the point of unusability, and this Al-Zr alloy, discovered in 2017, was the first of its class.
You might imagine that the non-regular structure of a quasicrystal wouldn’t propagate cracks as easily as a regular crystal structure, and you would be right! The NIST researchers obviously wanted to investigate why the printable alloy had the properties it does. When their crystallographic analysis showed not only five-fold, but also three-fold and two-fold rotational symmetry when examined from different angles, the researchers realized they had a quasicrystal on their hands. The unit cell is in the form of a 20-sided icosahedron, providing the penrose-style tiling that keeps the alloy from cracking.
You might say the original team that developed the alloy rolled a nat-20 on their crafting skill. Now that we understand why it works, this research opens up the doors for other metallic quasi-crystals to be developed on purpose, in aluminum and perhaps other alloys.
We’re used to there being an array of high-end microprocessor architectures, and it’s likely that many of us will have sat in front of machines running x86, ARM, or even PowerPC processors. There are other players past and present you may be familiar with, for example SPARC, RISC-V, or MIPS. Back in the 1990s there was another, now long gone but at the time the most powerful of them all, of course we’re speaking of DEC’s Alpha architecture. [JP] has a mid-90s AlphaStation that doesn’t work, and as part of debugging it we’re treated to a description of its unusual boot procedure.
Conventionally, an x86 PC has a ROM at a particular place in its address range, and when it starts, it executes from the start of that range. The Alpha is a little different, on start-up it needs some code from a ROM which configures it and sets up its address space. This is applied as a 1-bit serial stream, and like many things DEC, it’s a little unusual. This code lives in a conventional ROM chip with 8 data lines, and each of those lines contains a separate program selectable by a jumper. It’s a handy way of providing a set of diagnostics at the lowest level, but even with that discovery the weirdness isn’t quite over. We’re treated to a run-down of DEC Alpha code encoding, and should you have one of these machines, there’s all the code you need.
The Alpha was so special in the 1990s because with 64-bit and retargetable microcode in its architecture it was significantly faster than its competitors. From memory it could be had with DEC Tru64 UNIX, Microsoft Windows NT, or VMS, and with the last of which it was the upgrade path for VAX minicomputers. It faded away in the takeover by Compaq and subsequently HP, and we are probably the poorer for it. We look forward to seeing more about this particular workstation, should it come back to life.
As you might have guessed, this isn’t exactly a hack out of necessity. With a flair for explaining hardware hacking, [wrongbaud] has put this together as a practical “brush-up” (get it?) on the tools and concepts involved in reverse engineering. In this case, the Raspberry Pi is used as a sort of hardware hacking multi-tool, which should make it relatively easy to follow along.
Modified image data on the SPI flash chip.
The first post in the series goes over getting the Pi up and running, which includes setting up OpenOCD. From there, [wrongbaud] actually cracks the toothbrush open and starts identifying interesting components, which pretty quickly leads to the discovery of a debug serial port. The next step is harassing the SPI flash chip on the board to extract its contents. As the toothbrush has a high-res color display (of course it does), it turns out this chip holds the images which indicate the various modes of operation. He’s eventually able to determine how the images are stored, inject new graphics data, and write it back to the chip.
Being able to display the Wrencher logo on our toothbrush would already be a win in our book, but [wrongbaud] isn’t done yet. For the last series in the post, he shows how to extract the actual firmware from the microcontroller using OpenOCD. This includes how to analyze the image, modify it, and eventually flash the new version back to the hardware — using that debug port discovered earlier to confirm the patched code is running as expected.
