The Mostly Forgotten Story Of Atmospheric Railway

August 17, 2020 by Jenny List 58 Comments

It doesn’t matter whether you know it as a railway, a railroad, a chemin de fer, or a 铁路, it’s a fair certainty that the trains near where you live are most likely to be powered either by diesel or electric locomotives. Over the years from the first horse-drawn tramways to the present day there haven’t been many other ways to power a train, and since steam locomotives are largely the preserve of museums in the 21st century, those two remain as the only two games in town.

But step back to the dawn of the railway age, and it was an entirely different matter. Think of those early-19th-century railway engineer-barons as the Elon Musks and Jeff Bezos’ of their day, and instead of space and hyperloop startups their playground was rail transport. Just as some wild and crazy ideas are spoken about in the world of tech startups today, so it was with the early railways. One of the best-known of these even made it to some real railways, I’m speaking of course about the atmospheric railway.

These trains were propelled not by a locomotive, but by air pressure pushing against a piston in a partially evacuated tube between the tracks.

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Smashing The Atom: A Brief History Of Particle Accelerators

July 29, 2020 by Moritz v. Sivers 28 Comments

When it comes to building particle accelerators the credo has always been “bigger, badder, better”. While the Large Hadron Collider (LHC) with its 27 km circumference and €7.5 billion budget is still the largest and most expensive scientific instrument ever built, it’s physics program is slowly coming to an end. In 2027, it will receive the last major upgrade, dubbed the High-Luminosity LHC, which is expected to complete operations in 2038. This may seem like a long time ahead but the scientific community is already thinking about what comes next.
Recently, CERN released an update of the future European strategy for particle physics which includes the feasibility study for a 100 km large Future Circular Collider (FCC). Let’s take a short break and look back into the history of “atom smashers” and the scientific progress they brought along. Continue reading “Smashing The Atom: A Brief History Of Particle Accelerators” →

MP3 Is 25 Years Old!

July 27, 2020 by Lewin Day 127 Comments

In the streaming era, music is accessed from a variety of online services, ephemeral in nature and never living on board the device. However, the online audio revolution really kicked off with the development of one very special format. The subject of bitter raps and groundbreaking lawsuits, this development from Germany transformed the music industry as we know it. Twenty-five years on from the date the famous “.mp3” filename was chosen, we take a look back at how it came to be, and why it took over the world.

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Jan Czochralski And The Silicon Revolution

July 22, 2020 by Dan Maloney 39 Comments

If you were to travel back in time to the turn of the previous century and try to convince the average person that the grains of sand on just about any beach would be the basis of an industry worth hundreds of billions of dollars within 100 years, they’d probably have thought you were crazy. Aside from being coarse, rough, and irritating, sand is everywhere, and convincing anyone of its value would be a hard sell, unless your interlocutor was a real estate visionary with an appreciation of the future value of seaside property and a lot of patience.

Fast forward to our time, and we all know the value of the material that comes from common quartz sand: silicon, specifically the ultra-purified crystals of silicon that end up as the wafers we depend on to build the circuitry of life. The trip from beach to chip foundry is a long and non-obvious one which would not have been possible without the insights of an undistinguished Polish student and one-time druggist who discovered the process that made the Information Age possible: Jan Czochralski.

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How Early Radio Receivers Worked

July 10, 2020 by Al Williams 43 Comments

If you’ve ever built a crystal radio, there’s something magical about being able to pull voices and music from far away out of thin air. If you haven’t built one, maybe you should while there’s still something on the AM band. Of course, nowadays the equivalent might be an SDR. But barring a computer solution, there are not many ways to convert radio waves into intelligence. From a pocket radio to advanced RADAR to a satellite in orbit, receiving a radio wave is accomplished in pretty much the same way.

There are, however, many ways to modulate and demodulate that radio wave. Of course, an AM radio works differently than an FM radio. A satellite data downlink works differently, too. But the process of capturing the radio wave from the air and getting them into a form ready for further processing hasn’t changed much over the years.

In this article, I’ll talk about the most common radio receiver architectures you may have seen in years past, and next week I’ll talk about modern architectures. Either way, understanding receiver architectures will help you design new radios or troubleshoot them.

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Why Are Digital Cameras Still Boring?

July 1, 2020 by Jenny List 102 Comments

In the matter of technological advancement, we are as a species, mostly insatiable. The latest toy, the fastest silicon, the largest storage, the list goes on. Take digital cameras as an example, what was your first one? Mine was a Casio QV200 in about 1997, I still have it somewhere though I can’t immediately lay my hands on it, and it could hold a what was for its time a whopping 64 VGA-resolution pictures in its 4Mb of onboard memory.

The QV200 showing off its VGA photography capabilities. It’s March 1998, and this is a brand-new PlayStation that I’m about to install a mod chip inside.

It’s a shock to realise that nearly a quarter century has passed since then, and its fixed-focus 640×480 camera module with a UV-sensitive CMOS sensor that gave everything a slight blue tint would not even grace the cheapest of feature phones in 2020. Every aspect of a digital camera has improved beyond measure since the first models in the 1980s and early 1990s that started to resemble what we’d know today as a standalone digital camera, they have near-limitless storage, excellent lenses, huge and faithfully-reproducing sensors, and broadcast-quality video capability.

But how playful have camera manufacturers been with the form factor? We see reporters in sci-fi movies toting cameras that look nothing like their film-based ancestors. What do our real-life digital cameras have on offer as far as creative body design goes?

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Loading Coils, The Heaviside Condition, And Pupin Coils

June 19, 2020 by Al Williams 27 Comments

When we draw schematics, we have the luxury of pretending that wire is free. There are only a few cases where you have to account for the electrical characteristics of wire: when the wire is very long or the frequency on the wire is relatively high.

This became apparent after the first transatlantic cable went into service for telegraph communications. Even though the wire was linear, there was still distortion on the line so severe that dots and dashes would overlap each other. The temporary solution was to limit speeds so slow that operators had trouble sending and receiving at those speeds. How slow? An average character took two minutes to send! That’s not a typo. Two minutes per character. By custom, Morse code assumes a word is five characters, so you could send a word every 10 minutes.

The first transatlantic cable went into service in 1858 and was virtually the moon landing of its day. Frustrated with how slow the communications were, an electrician by the name of Whitehouse decided to crank up the voltage to over 1,000 volts which caused the cable to fail after only three weeks in service. Whoops. Later analysis showed the cable was probably going to fail quickly anyway, but Whitehouse took the public blame.

The wire back then wasn’t as good as what we have today, which led to some of the problems. The insulation was made from multiple coats of a natural latex, gutta percha, which is what dentists use to fill root canals. The jackets were made from tarred hemp and bound with iron wire. There was no way to build an underwater amplifier in 1858, so the cables were just tremendous wires laying on the ocean floor between Newfoundland and Ireland.

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