Ion Thrusters: Not Just For TIE Fighters Anymore

March 3, 2022 by Lewin Day 42 Comments

Spacecraft rocket engines come in a variety of forms and use a variety of fuels, but most rely on chemical reactions to blast propellants out of a nozzle, with the reaction force driving the spacecraft in the opposite direction. These rockets offer high thrust, but they are relatively fuel inefficient and thus, if you want a large change in velocity, you need to carry a lot of heavy fuel. Getting that fuel into orbit is costly, too!

Ion thrusters, in their various forms, offer an alternative solution – miniscule thrust, but high fuel efficiency. This tiny push won’t get you off the ground on Earth. However, when applied over a great deal of time in the vacuum of space, it can lead to a huge change in velocity, or delta V.

This manner of operation means that an ion thruster and a small mass of fuel can theoretically create a much larger delta-V than chemical rockets, perfect for long-range space missions to Mars and other applications, too. Let’s take a look at how ion thrusters work, and some of their interesting applications in the world of spacecraft!

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Researchers Build Neural Networks With Actual Neurons

March 1, 2022 by Lewin Day 21 Comments

Neural networks have become a hot topic over the last decade, put to work on jobs from recognizing image content to generating text and even playing video games. However, these artificial neural networks are essentially just piles of maths inside a computer, and while they are capable of great things, the technology hasn’t yet shown the capability to produce genuine intelligence.

Cortical Labs, based down in Melbourne, Australia, has a different approach. Rather than rely solely on silicon, their work involves growing real biological neurons on electrode arrays, allowing them to be interfaced with digital systems. Their latest work has shown promise that these real biological neural networks can be made to learn, according to a pre-print paper that is yet to go through peer review.
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It’s Official! The Raspberry Pi Is Now 10!

February 28, 2022 by Jenny List 100 Comments

In any given field there are epoch-defining moments, those events after which nothing was quite the same as it had been before. It’s been a decade since the launch of the first Raspberry Pi single board computer. This was by no means the first inexpensive computer board, nor was it the first to support the GNU/Linux operating system, but it was among the first to promise a combination of those two. Coupled with support from a crop of British 8-bit alumni meant that from when it first gained publicity in early 2011 it garnered a huge buildup of interest.

We were first teased with a USB stick style prototype, which morphed into a much larger Raspberry Pi alpha board and finally into pre-production boards much closer to the model launched at the end of February ten years ago.

How To Disappoint Every Single British Geek At 6 AM

An array of Pi prototype boards pictured on display at the Cambridge University Computer Laboratory.

Pedants will claim that the 10th birthday of the Pi is technically not yet upon us because those first Model B boards went on sale on the 29th of February 2012, a leap day. The two distributors, RS and Farnell, were both putting them on sale with the expectation of selling around 10,000 units — a prediction that proved woefully inadequate, with both websites collapsing under the weight of would-be Pi-purchasers within seconds of opening up at 6 AM.

I was ready to order at 6 AM, and was only able to order mine halfway through the day. That short wait would be just the beginning — because they received so many more orders than anticipated, the bulk of the orders weren’t fulfilled until May. Nobody had imagined how wildly successful the Pi boards would become. Continue reading “It’s Official! The Raspberry Pi Is Now 10!” →

Big Chemistry: From Gasoline To Wintergreen

February 22, 2022 by Dan Maloney 18 Comments

Most of us probably have some vivid memories of high school or college chemistry lab, where the principles of the science were demonstrated, and where we all got at least a little practice in experimental methods. Measuring, diluting, precipitating, titrating, all generally conducted under safe conditions using stuff that wasn’t likely to blow up or burn.

But dropwise additions and reaction volumes measured in milliliters are not the stuff upon which to build a global economy that feeds, clothes, and provides for eight billion people. For chemistry to go beyond the lab, it needs to be scaled up, often to a point that’s hard to conceptualize. Big chemistry and big engineering go hand in hand, delivering processes that transform the simplest, most abundant substances into the things that, for better or worse, make life possible.

To get a better idea of how big chemistry does that, we’re going to take a look at one simple molecule that we’ve probably all used at one time or another: the common artificial flavoring wintergreen. It’s an innocuous ingredient in a wide range of foods and medicines, but the infrastructure required to make it and all its precursors is a snapshot of just how important big chemistry really is.

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The Electrifying Debate Around Where Lightning Comes From

February 17, 2022 by Maya Posch 26 Comments

Along with many other natural phenomena, lightning is probably familiar to most. Between its intense noise and visuals, there is also very little disagreement that getting hit by a lightning strike is a bad thing, regardless of whether you’re a fleshy human, moisture-filled plant, or conductive machine. So it’s more than a little bit strange that the underlying cause of lightning, and what makes certain clouds produce these intense voltages along ionized air molecules, is still an open scientific question.

Many of us have probably learned at some point the most popular theory about how lightning forms, namely that lightning is caused by ice particles in clouds. These ice particles interact to build up a charge, much like in a capacitor. The only issue with this theory is that this process alone will not build up a potential large enough to ionize the air between said clouds and the ground and cause the lightning strike, leaving this theory in tatters.

A recent study, using data from Earth-based radio telescopes, may now have provided fascinating details on lightning formation, and how the charge may build up sufficiently to make us Earth-based critters scurry away to safety when dark clouds draw near.

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Teardown: Alcatel Telic 1 Minitel Terminal

February 16, 2022 by Jenny List 34 Comments

For British teenagers in the 1980s, the delights of 8-bit computers such as the Sinclair Spectrum, Commodore 64, or BBC Micro were firmly restricted to the offline arena. We would read about the BBS scene on the other side of the Atlantic, but without cheap local calls and with a modem costing a small fortune, the chances of us ever experiencing one was zero. When we took the British school rite of passage of a trip to France though, we were astounded to see that every French person was not merely online, but that they were doing so with a neat little all-in-one terminal. We’d just been introduced to the French Minitel system, and in that minute shared a glimpse of the future.

Un Réseau Trés Français

The Minitel terminal is a small CRT monitor with a fold-down alphanumeric keyboard. — My Alcatel Minitel terminal

In the 1970s and 1980s, so-called videotext systems, terminal-based phoneline access to information services on central computers, were seen as an obvious next step for telephone network operators with an interest in profitable new products. In most countries this resulted in services such as the UK’s Prestel, a subscription service relying on costly hardware, but France Télécom instead pursued the bold path of making the terminals free to subscribers with free access to phone listings and yellow pages, but a business model based on pay-to-use premium services.

Thus, through the 1980s all French households had a Minitel terminal beside the phone, and the service became a runaway success. Ever since seeing Minitel terminals as a tourist I’d been fascinated by the service, so here in the 2020s when a friend was visiting their family in France I asked whether he could pick up an old Minitel terminal for me. Thus I found myself parting with around $25 and being rewarded with a slightly battered Minitel cardboard box containing one of the familiar brown Alcatel terminals. I certainly wasn’t expecting one in its original packaging. Continue reading “Teardown: Alcatel Telic 1 Minitel Terminal” →

Hair Today Gone Tomorrow: Four Men Go To Fix A Wafer Prober

February 8, 2022 by Dave Rowntree 43 Comments

I’ve had a fairly varied early part of my career in the semiconductors business: a series of events caused me to jump disciplines a little bit, and after one such event, I landed in the test engineering department at Philips Semiconductors. I was tasked with a variety of oddball projects, supporting engineering work, fixing broken ATE equipment, and given a absolute ton of training: Good times! Here’s a story that comes straight off the oddball pile.

We needed to assemble a crack team of experts and high-tail it to deepest darkest Wales, and sort out an urgent production problem. The brief was that the wafer probe yield was disastrous and the correlation wafer was not giving the correct results. Getting to the punch line is going to require some IC fabrication background, but if you like stories about silicon, or red-bearded test engineers, it’s worth it. Continue reading “Hair Today Gone Tomorrow: Four Men Go To Fix A Wafer Prober” →