The Amazing Maser

January 28, 2026 by Al Williams 30 Comments

While it has become a word, laser used to be an acronym: “light amplification by stimulated emission of radiation”. But there is an even older technology called a maser, which is the same acronym but with light switched out for microwaves. If you’ve never heard of masers, you might be tempted to dismiss them as early proto-lasers that are obsolete. But you’d be wrong! Masers keep showing up in places you’d never expect: radio telescopes, atomic clocks, deep-space tracking, and even some bleeding-edge quantum experiments. And depending on how a few materials and microwave engineering problems shake out, masers might be headed for a second golden age.

Simplistically, the maser is — in one sense — a “lower frequency laser.” Just like a laser, stimulated emission is what makes it work. You prepare a bunch of atoms or molecules in an excited energy state (a population inversion), and then a passing photon of the right frequency triggers them to drop to a lower state while emitting a second photon that matches the first with the same frequency, phase, and direction. Do that in a resonant cavity and you’ve got gain, coherence, and a remarkably clean signal.

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Zombie Netscape Won’t Die

January 27, 2026 by Lewin Day 21 Comments

The very concept of the web browser began with a humble piece of software called NCSA Mosaic, all the way back in 1993. It was soon eclipsed by Netscape Navigator, and later Internet Explorer, which became the titans of the 1990s browser market. In turn, they too would falter. Navigator’s dying corpse ended up feeding what would become Mozilla Firefox, and Internet Explorer later morphed into the unexceptional browser known as Edge.

Few of us have had any reason to think about Netscape Navigator since its demise in 2008. And yet, the name lingers on. A zombie from a forgotten age, risen again to haunt us today.

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One Hundred Years Of Telly

January 26, 2026 by Jenny List 12 Comments

Today marks an auspicious anniversary which might have passed us by had it not been for [Diamond Geezer], who reminds us that it’s a hundred years since the first public demonstration of television by John Logie Baird. In a room above what is today a rather famous Italian coffee shop in London’s Soho, he had assembled a complete mechanical TV system that he demonstrated to journalists.

Television is one of those inventions that owes its genesis to more than a single person, so while Baird was by no means the only one inventing in the field, he was the first to demonstrate a working system. With mechanical scanning and just 30 lines, it’s hardly HD or 4K, but it does have the advantage of being within the reach of the constructor.

Perhaps the saddest thing about Baird and his system is that while he was able to attract the interest of the BBC in it, when the time came for dedicated transmissions at a higher resolution, his by then partly mechanical system could not compete and he faded into relative obscurity. Brits instead received EMI’s 405 line system, which persisted until the very start of the 1980s, and eventually the German PAL colour system in the late 1960s.

So head on down to Bar Italia if you can to raise a coffee to his memory, and should you wish to have a go at Baird-style TV for yourself, then you may need to print yourself a disk.

Header image: Matt Brown, CC BY 2.0.

Ancient Egyptian Flatness

January 24, 2026 by Al Williams 37 Comments

Making a truly flat surface is a modern engineering feat, and not a small one. Even making something straight without reference tools that are already straight is a challenge. However, the ancient Egyptians apparently made very straight, very flat stone work. How did they do it? Probably not alien-supplied CNC machines. [IntoTheMap] explains why it is important and how they may have done it in a recent video you can see below.

The first step is to define flatness, and modern mechanical engineers have taken care of that. If you use 3D printers, you know how hard it is to even get your bed and nozzle “flat” with respect to each other. You’ll almost always have at least a 100 micron variation in the bed distances. The video shows how different levels of flatness require different measurement techniques.

The Great Pyramid’s casing stones have joints measuring 0.5 mm, which is incredible to achieve on such large stones with no modern tools. A stone box in the Pyramid of Seostris II is especially well done and extremely flat, although we can make things flatter today.

The main problem with creating a flat surface is that to do a good job, you need some flat things to start with. However, there is a method from the 19th century that uses three plates and multiple lapping steps to create three very flat plates. In modern times, we use a blue material to indicate raised areas, much as a dentist makes you chomp on a piece of paper to place a crown. There are traces of red ochre on Egyptian stonework that probably served the same purpose.

Lapping large pieces is still a challenge, but moving giant stones at scale appears to have been a solved problem for the Egyptians. Was this the method they used? We don’t know, of course. But it certainly makes sense.

It would be a long time before modern people could make things as flat. While we can do even better now, we also have better measuring tools.

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How Accurate Is A 125 Year Old Resistance Standard?

January 16, 2026 by Maya Posch 43 Comments

Internals of the 1900 Evershed & Vignoles Ltd 1 ohm resistance standard. (Credit: Three-phase, YouTube)

Resistance standards are incredibly useful, but like so many precision references they require regular calibration, maintenance and certification to ensure that they stay within their datasheet tolerances. This raises the question of how well a resistance standard from the year 1900 performs after 125 years, without the benefits of modern modern engineering and standards. Cue the [Three-phase] YouTube channel testing a genuine Evershed & Vignoles Ltd one ohm resistance standard from 1900.

With mahogany construction and brass contacts it sure looks stylish, though the unit was missing the shorting pin that goes in between the two sides. This was a common feature of e.g. resistance decade boxes of the era, where you inserted pins to connect resistors until you hit the desired total. Inside the one ohm standard is a platinoid resistor, which is an alloy of copper, nickel, tungsten, and zinc. Based on the broad arrow mark on the bottom this unit was apparently owned by the UK’s Ordnance Board, which was part of what was then called the War Office.

After a quick gander at the internals, the standard was hooked up to a Keithley DMM7510 digital bench meter. The resistance standard’s ‘datasheet’ is listed on top of the unit on the brass plaques, including the effect of temperature on its accuracy. Adjusting for this, the measured ~1.016 Ω was within 1.6% tolerance, with as sidenote that this was with the unit not having been cleaned or otherwise having had maintenance performed on it since it was last used in service. Definitely not a bad feat.

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Clone Wars: IBM Edition

January 14, 2026 by Al Williams 51 Comments

If you search the Internet for “Clone Wars,” you’ll get a lot of Star Wars-related pages. But the original Clone Wars took place a long time ago in a galaxy much nearer to ours, and it has a lot to do with the computer you are probably using right now to read this. (Well, unless it is a Mac, something ARM-based, or an old retro-rig. I did say probably!)

IBM is a name that, for many years, was synonymous with computers, especially big mainframe computers. However, it didn’t start out that way. IBM originally made mechanical calculators and tabulating machines. That changed in 1952 with the IBM 701, IBM’s first computer that you’d recognize as a computer.

If you weren’t there, it is hard to understand how IBM dominated the computer market in the 1960s and 1970s. Sure, there were others like Univac, Honeywell, and Burroughs. But especially in the United States, IBM was the biggest fish in the pond. At one point, the computer market’s estimated worth was a bit more than $11 billion, and IBM’s five biggest competitors accounted for about $2 billion, with almost all of the rest going to IBM.

So it was somewhat surprising that IBM didn’t roll out the personal computer first, or at least very early. Even companies that made “small” computers for the day, like Digital Equipment Corporation or Data General, weren’t really expecting the truly personal computer. That push came from companies no one had heard of at the time, like MITS, SWTP, IMSAI, and Commodore. Continue reading “Clone Wars: IBM Edition” →

The Time Clock Has Stood The Test Of Time

January 8, 2026 by Kristina Panos 32 Comments

No matter the item on my list of childhood occupational dreams, one constant ran throughout: I saw myself using an old-fashioned punch clock with the longish time cards and everything. I now realize that I have some trouble with the daily transitions of life. In my childish wisdom, I somehow knew that doing this one thing would be enough to signify the beginning and end of work for the day, effectively putting me in the mood, and then pulling me back out of it.

But that day never came. Well, it sort of did this year. I realized a slightly newer dream of working at a thrift store, and they use something that I feel like I see everywhere now that I’ve left the place — a system called UKG that uses mag-stripe cards to handle punches. No it was not the same as a real punch clock, not that I have experience with a one. And now I just want to use one even more, to track my Hackaday work and other projects. At the moment, I’m torn between wanting to make one that uses mag-stripe cards or something, and just buying an old punch clock from eBay.

I keep calling it a ‘punch clock’, but it has a proper name, and that is the Bundy clock. I soon began to wonder how these things could both keep exact time mechanically, but also create a literal inked stamp of said time and date. I pictured a giant date stamper, not giant in all proportions, but generally larger than your average handheld one because of all the mechanisms that surely must be inside the Bundy clock. So, how do these things work? Let’s find out.

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