One of the most sought after substances in the Universe is water – especially in its liquid form – as its presence on a planet makes the presence of life (as we know it) significantly more likely. While there are potentially oceans worth of liquid water on e.g. Jupiter’s moon Europa, for now Mars is significantly easier to explore as evidenced by the many probes which we got onto its surface so far. One of these was the InSight probe, which was capable of a unique feat: looking inside the planet’s crust with its seismometer to perform geophysical measurements. These measurements have now led to the fascinating prospect that liquid water may in fact exist on Mars right now, according to a paper published by [Vashan Wright] and colleagues in PNAS (with easy-read BBC coverage). Continue reading “Possible Discovery Of Liquid Water In Mars’ Mid-Crust By The Insight Lander”→
A team at Google has spent a lot of time recently playing table tennis, purportedly only for science. Their goal was to see whether they could construct a robot which would not only play table tennis, but even keep up with practiced human players. In the paper available on ArXiv, they detail what it took to make it happen. The team also set up a site with a simplified explanation and some videos of the robot in action.
Table tennis robot vs human match outcomes. B is beginner, I is intermediate, A is advanced. (Credit: Google)
In the end, it took twenty motion-capture cameras, a pair of 125 FPS cameras, a 6 DOF robot on two linear rails, a special table tennis paddle, and a very large annotated dataset to train multiple convolutional neural networks (CNN) on to analyze the incoming visual data. This visual data was then combined with details like knowledge of the paddle’s position to churn out a value for use in the look-up table that forms the core of the high-level controller (HLC). This look-up table then decides which low-level controller (LLC) is picked to perform a certain action. In order to prevent the CNNs of the LLCs from ‘forgetting’ the training data, a total of 17 different CNNs were used, one per LLC.
The robot was tested with a range of players from a local table tennis club which made clear that while it could easily defeat beginners, intermediate players pose a serious threat. Advanced players completely demolished the table tennis robot. Clearly we do not have to fear our robotic table tennis playing overlords just yet, but the robot did receive praise for being an interesting practice partner. Continue reading “Achieving Human Level Competitive Robot Table Tennis”→
Beta thalassemia and sickle cell are two red blood cell disorders which both come with massive health implications and shortened lifespans, but at least for UK-based patients the former may soon be curable with a fairly new CRISPR-Cas9 gene therapy (Casgevy) via the UK’s National Health Service (NHS). Starting with the NHS in England, the therapy will be offered to the approximately 460 β thalassemia patients in that part of the UK at seven different NHS centers within the coming weeks.
We previously covered this therapy and the way that it might offer a one-time treatment to patients to definitely cure their blood disorder. In the case of β thalassemia this is done by turning off the defective adult hemoglobin (HbA) production and instead turning the fetal hemoglobin (HbF) production back on. After eradicating the bone marrow cells with the defective genes, the (externally CRISPR-Cas9 modified) stem cells are reintroduced as with a bone marrow transplant. Since this involves the patient’s own cells, no immune-system suppressing medication is necessary, and eventually the new cells should produce enough HbF to allow the patient to be considered cured.
So far in international trials over 90% of those treated in this manner were still symptom-free, raising the hope that this β thalassemia treatment is indeed a life-long cure.
Top image: A giemsa stained blood smear from a person with beta thalassemia. Note the lack of coloring. (Credit: Dr Graham Beards, Wikimedia Commons)
It could happen to anyone of us: suddenly you got this inkling of an idea for a product that you think might just be pretty useful or even cool. Some of us then go on to develop a prototype and manage to get enough seed funding to begin the long and arduous journey to turn a sloppy prototype into a sleek, mass-produced product. This is basically the story of how the Fitbit came to be, with a pretty in-depth article by [Tekla S. Perry] in IEEE Spectrum covering the development process and the countless lessons learned along the way.
Of note was that this idea for an accelerometer-based activity tracker was not new in 2006, as a range of products already existed, from 1960s mechanical pedometers to 1990s medical sensors and the shoe-based Nike+ step tracker that used Apple’s iPod with a receiver. Where this idea for the Fitbit was new was that it’d target a wide audience with a small, convenient (and affordable) device. That also set them up for a major nightmare as the two inventors were plunged into the wonderfully terrifying world of industrial design and hardware development.
One thing that helped a lot was outsourcing what they could to skilled people and having solid seed funding. This left just many hardware decisions to make it as small as possible, as well as waterproof and low-power. The use of the ANT protocol instead of Bluetooth saved a lot of battery, but meant a base station was needed to connect to a PC. Making things waterproof required ultrasonic welding, but lack of antenna testing meant that a closed case had a massively reduced signal strength until a foam shim added some space. The external reset pin on the Fitbit for the base station had a low voltage on it all the time, which led to corrosion issues, and so on.
While much of this was standard development and testing fun, the real challenge was in interpreting the data from the accelerometer. After all, what does a footstep look like to an accelerometer, and when is it just a pothole while travelling by car? Developing a good algorithm here took gathering a lot of real-world data using prototype hardware, which needed tweaking when later Fitbits moved from being clipped-on to being worn on the wrist. These days Fitbit is hardly the only game in town for fitness trackers, but you can definitely blame them for laying much of the groundwork for the countless options today.
Initially only seeing brief popular use as the filament in incandescent lighting, carbon fibers (CF) experienced a resurgence during the 20th century as part of composite materials that are lighter and stronger than materials like steel and aluminium, for use in aircraft, boats and countless more applications. This rising popularity has also meant that the wider population is now exposed to fragments of CF, both from using CF-based products as well as from mechanically processing CF materials during (hobby) projects.
It is this popularity that has also led to the addition of short CF sections to FDM 3D printing filaments, where they improve the mechanical properties of the printed parts. However, during subsequent mechanical actions such as sanding, grinding, and cutting, CF dust is created and some fraction of these particles are small enough to be respirable. Of these, another fraction will bypass the respiratory system’s dust clearing mechanisms, to end up deep inside the lungs. This raises the question of whether CF fragments can be carcinogenic, much like the once very popular and very infamous example of asbestos mineral fibers.
A working DIY two-stroke in all of its glory, with the flywheel removed. (Credit: Camden Bowen)
How hard could it to be to build a two-stroke internal combustion engine (ICE) from scratch? This is a challenge that [Camden Bowen] gladly set for himself, while foregoing such obvious wastes of time like first doing an in-depth literature study on the topic. That said, he did do some research and made the design in OnShape CAD before making his way over to the hardware store to make some purchases.
As it turns out, you can indeed build a two-stroke engine from scratch, using little more than some metal piping and other parts from the hardware store. You also need a welder and a lathe, with [Camden] using a Vevor mini-lathe that totally puts the ‘precision’ in ‘chatter’. As building an ICE requires a number of relatively basic parts that have to move with very little friction and with tight tolerances, this posed some challenges, but nothing that some DIY spirit can’t fix.
In the case of the very flexible boring bar on the lathe, improvising with some sturdy metal stock welded to a short boring bar resolved that, and precision was achieved. Together with an angle grinder, [Camden] was then able to manufacture the crank case, the cylinder and crank shaft and all the other pieces that make up an ICE. For the carburetor he used a unit off Amazon, which turned out to have the wrong throat size at 19 mm, but a 13 mm version worked. Ultimately, the first ICE constructed this way got destroyed mostly by running it dry and having the starter fluid acting as a solvent, but a full rebuild fixed all the issues.
This second attempt actually ran just fine the first time around, with oil in the crank case so that the poor engine wasn’t running dry any more. With a 40:1 fuel/oil mixture the little engine idles and runs as well as a two-stroke can, belching blue smoke and making a ruckus. This answers the question of whether you can build a two-stroke ICE with basic machining skills and tools, but of course the question that’s now on everyone’s lips is whether a four-stroke one would be nearly as ‘easy’. We wait with bated breath.
The idea of traveling faster than the speed of light (FTL) has been a popular idea long before [Alcubierre] came up with the first plausible theoretical underpinnings for such a technology. Yet even if such an FTL drive is possible, it may be hundreds of years before humanity manages to develop its first prototype. This does however not prevent us from for looking for possible FTL drive signatures in the spacetime around us. Such a concept was recently proposed by [Katy Clough] and colleagues in a recent article (Arxiv preprint).
For a friendly but detailed explanation the PBS Space Time video (embedded below) on the paper comes highly recommended. The gotcha with detecting an FTL warp drive is that it is undetectable until it collapses in some fashion. By simulating what this collapse might look like, the researchers were able to speculate about the properties to look for. These include gravitational waves, which would not be detectable by an existing gravitational wave detector like LIGO, but we might be able to build one that can.
Ultimately we’d be acting on conjecture on what a warp bubble would look like and how it would behave when it collapses so we might just as well mistake something far less intelligent for Vulcans passing through our solar system. It might also be our first sign of extraterrestrial life, possibly ogling some primitive civilization on a Class M planet until it’s ready for First Contact.
One of the most sought after substances in the Universe is water – especially in its liquid form – as its presence on a planet makes the presence of life (as we know it) significantly more likely. While there are potentially oceans worth of liquid water on e.g. Jupiter’s moon Europa, for now Mars is significantly easier to explore as evidenced by the many probes which we got onto its surface so far. One of these was the InSight probe, which was capable of a unique feat: looking inside the planet’s crust with its seismometer to perform geophysical measurements. These measurements have now led to the fascinating prospect that liquid water may in fact exist on Mars right now, according to a paper published by [Vashan Wright] and colleagues in PNAS (with easy-read BBC coverage). Continue reading “Possible Discovery Of Liquid Water In Mars’ Mid-Crust By The Insight Lander” 
