Chirality Could Kill Us All, If We Let It

In our high school chemistry classes we all learn about chirality, the property of organic molecules in which two chemically identical molecules can have different structures that are mirror images of each other. This can lead to their exhibiting different properties, and one aspect of chirality is causing significant concerns in the field of synthetic biology. The prospect of so-called mirror organisms is leading to calls from a group of prominent scientists for research in the field to be curtailed due to the risks they would present.

Chirality is baked into all life; our DNA is formed of right-handed molecules while our proteins are left handed. The “mirror” organisms would reverse either or both of these, and could in theory be used to improve biochemical production processes. The concern is that these organisms would evade both the immune systems of all natural life forms, and any human defences such as antibiotics, thus posing an existential risk to life. It’s estimated that the capacity to produce such a life form lies more than a decade away, and the scientists wish to forestall that by starting the conversation early. They are calling for a halt to research likely to result in these organisms, and a commitment from funding bodies not to support such research.

Warnings of the dangers from scientific advances are as old as science itself, and it’s safe to say that many such prophecies have come from dubious sources and proved not to have a basis in fact. But this one, given the body of opinion behind it, is perhaps one that should be heeded.

Header: Original: Unknown Vector: — πϵρήλιο, Public domain.

Use Your RTL, In The Browser

The web browser started life as a relatively simple hypertext reading application, but over the 30+ years since the first one displayed a simple CERN web page it has been extended to become the universal platform. It’s now powerful enough to run demanding applications, for example a full software-defined radio. [Jtarrio] proves this, with an application to use an RTL-SDR, in HTML5.

It’s a fork of a previous Google-Chrome-only FM receiver, using the HTML5 WebUSB API, and converted to TypeScript. You can try it out for yourself if you have a handy RTL dongle lying around, it provides an interface similar to the RTL apps you may be used to.

The Realtek digital TV chipset has been used as an SDR for well over a decade now, so we’re guessing most of you with an interest in radio will have one somewhere. The cheap ones are noisy and full of spurious peaks, but even so, they’re a bucket of fun. Now all that’s needed is the transmit equivalent using a cheap VGA adapter, and the whole radio equation could move into the browser.

Automated Rig Grows Big, Beautiful Crystals Fast

We haven’t seen [Les Wright] in a while, and with the release of his new video, we know why — he’s been busy growing crystals.

Now, that might seem confusing to anyone who has done the classic “Crystal Garden” trick with table salt and laundry bluing, or tried to get a bit of rock candy out of a supersaturated sugar solution. Sure, growing crystals takes time, but it’s not exactly hard work. But [Les] isn’t in the market for any old crystals. Rather, he needs super-sized, optically clear crystals of potassium dihydrogen phosphate, or KDP, which are useful as frequency doublers for lasers. [Les] has detailed his need for KDP crystals before and even grown some nice ones, but he wanted to step up his game and grow some real whoppers.

And boy, did he ever. Fair warning; the video below is long and has a lot of detail on crystal-growing theory, but it’s well worth it for anyone taking the plunge. [Les] ended up building an automated crystal lab, housing it in an old server enclosure for temperature and dust control. The crystals are grown on a custom-built armature that slowly rotates in a supersaturated solution of KDP which is carefully transitioned through a specific temperature profile under Arduino control. As a bonus, he programmed the rig to take photographs of the growing crystals at intervals; the resulting time-lapse sequences are as gorgeous as the crystals, one of which grew to 40 grams in only a week.

We’re keen to see how [Les] puts these crystals to work, and to learn exactly what a “Pockels Cell” is and why you’d want one. In the meantime, if you’re interested in how the crystals that make the whole world work are made, check out our deep dive into silicon.

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A Look Back At Google’s 2015 Chromecast

Google’s Chromecast was first released in 2013, with a more sophisticated follow-up in 2015, which saw itself joined by the Chromecast Audio dongle. The device went through an additional two hardware generations before the entire line of products was discontinued earlier this year in favor of Google TV.

Marvell's Armada 88DE3006 dual-core Cortex-A7 powers the second-generation ChromeCast. (Credit: Brian Dipert, EDN)
Marvell’s Armada 88DE3006 dual-core Cortex-A7 powers the second-generation Chromecast. (Credit: Brian Dipert, EDN)

In addition to collecting each generation of Chromecast, [Brian Dipert] over at EDN looked back on this second-generation dongle from 2015 while also digging into the guts of a well-used example that got picked up used.

While not having any of the fascinating legacy features of the 2nd-generation Ultra in his collection that came with the Stadia gaming controller, it defines basically everything that Chromecast dongles were about: a simple dongle with a HDMI & USB connector that you plugged into a display that you wanted to show streaming content on. The teardown is mostly similar to the 2015-era teardown by iFixit, who incidentally decided not to assign any repairability score, for obvious reasons.

Most interesting about this second-generation Chromecast is that the hardware supported Bluetooth, but that this wasn’t enabled until a few years later, presumably to fix the wonky new device setup procedure that would be replaced with a new procedure via the Google Home app.

While Google’s attention has moved on to newer devices, the Chromecast isn’t dead — the dongles in the wild still work, and the protocol is supported by Google TV and many ‘smart’ appliances including TVs and multimedia receivers.

British Spooks Issue Yearly Teaser

As a British taxpayer it’s reassuring to know that over in Cheltenham there’s a big round building full of people dedicated to keeping us safe. GCHQ is the nation’s electronic spying centre, and just to show what a bunch of good eggs they are they release a puzzler every year to titillate the nation’s geeks. 2024’s edition is out if you fancy trying it, so break out your proverbial thinking caps.

The puzzle comes in several stages each of which reveals a British landmark, and we’re told there’s a further set of puzzles hidden in the design of the card itself. We know that Hackaday readers possess fine minds, so you’ll all be raring to have a go.

Sadly GCHQ would for perfectly understandable reasons never let Hackaday in for a tour, but we’ve encountered some of their past work. First the Colossus replica codebreaking computer at Bletchley Park was the progenitor of the organisation, and then a few years ago when they had an exhibition from their archive in the London Science Museum.

Good Lighting On A Budget With Cordless Tool Batteries

It’s perhaps not fair, but even if you have the best idea for a compelling video, few things will make people switch off than poor lighting. Good light and plenty of it is the order of the day when it comes to video production, and luckily there are many affordable options out there. Affordable, that is, right up to the point where you need batteries for remote shoots, in which case you’d better be ready to open the purse strings.

When [Dane Kouttron] ran into the battery problem with his video lighting setup, he fought back with these cheap and clever cordless tool battery pack adapters. His lights were designed to use Sony NP-F mount batteries, which are pretty common in the photography trade but unforgivably expensive, at least for Sony-branded packs. Having access to 20 volt DeWalt battery packs, he combined an off-the-shelf battery adapter with a 3D printed mount that slips right onto the light. Luckily, the lights have a built-in DC-DC converter that accepts up to 40 volts, so connecting the battery through a protection diode was a pretty simple exercise. The battery pack just slots right in and keeps the lights running for portable shoots.

Of course, if you don’t already have DeWalt batteries on hand, it might just be cheaper to buy the Sony batteries and be done with it. Then again, there are battery adapters for pretty much every cordless tool brand out there, so you should be able to adapt the design. We’ve also seen cross-brand battery adapters which might prove useful, too.

The Disappearing Capacitor

As part of a phosphorescence detector, [lcamtuf] has been working with photodiodes. The components, like all diodes, have some capacitance at the junction, and this can limit performance. That’s why [lcamtuf] turned to bootstrapping to make that parasitic capacitance almost disappear.

The technique appears in several Analog Devices datasheets that presents a mystery. An op amp circuit that would normally limit changes to about 52 kHz has an unusually-placed JFET and claims to boost the bandwidth to 350 kHz.

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