Hackaday Forced Into Light Mode

April 1, 2021 by Elliot Williams 95 Comments

Hackaday has always been dark mode. Gray10 is less jarring when you’re burning the midnight oil on a project, so we give you a lot of it. Fifteen years ago, it was called “reverse video” or “trog mode“, and we were the freaks. We were doing it wrong. We had the colors “backwards”. Dark mode used to be edgy, outré, but dare we say it, a bit sexy.

Hackaday … QuickBooks. Just sayin’.
They even ripped our highlight yellow!

Flash forward, and everyone has come over to the dark side. Facebook has a dark mode. Google has dark mode. Across the Microsoft empire, from Windows 10 to GitHub, you can live your life in the dark. Heck, even the White House has a dark mode! (They call it high-contrast mode, but they’re not fooling anyone.)

Dark mode here, dark mode there. It’s mainstream. Dark mode has become corporate cool which is nobody’s idea of cool.

We’re not saying that all of the aforementioned institutions are biting the Hackaday style, but, well, they’re all biting our style. Where were they when we were the only website on the whole darn Internet with a sensible background color? Huh? Dark-mode-come-latelys!

But Hackaday doesn’t rest on its laurels. We have our fingers on the pulse on the modern hacker. Where previously you would be up late at night researching Hackaday for juicy nuggets of communal wisdom to help out with your current hack, you’re probably “telecommuting” these days — a euphemism for working on your private projects even while the fiery ball is still in the sky. (Wink, wink, nudge, nudge.) It’s only natural that you’d want a lighter background color to match your new lifestyle. We hear you!

So we present you, Hackaday Light Mode™. Enjoy!

[Editor’s note: For historical accuracy, we had phosphor green headings in the very beginning, in place of the jarring white. If you want to relive those glory days of yore, or just to go back to Hackaday in dark mode, there’s always CSS scripting.]

The Difference Between 4WD And AWD

March 31, 2021 by Zoe Skyforest 102 Comments

Car manufacturers will often tout a vehicle’s features to appeal to the market, and this often leads to advertisements featuring a cacophony of acronyms and buzzwords to dazzle and confuse the prospective buyer. This can be particularly obvious when looking at drivelines. The terms four-wheel drive, all-wheel drive, and full-time and part-time are bandied about, but what do they actually mean? Are they all the same, meaning all wheels are driven or is there more to it? Let’s dive into the technology and find out.

Part-Time 4WD

Part-time four-wheel drive is the simplest system, most commonly found on older off-road vehicles like Jeeps, Land Cruisers and Land Rovers up to the early 1990s, as well as pickup trucks and other heavy duty applications. In these vehicles, the engine sends its power to a transfer case, which sends an equal amount of torque to the front and rear differentials, and essentially ties their input shafts together. This is good for slippery off-road situations, as some torque is provided to both axles at all times. However, this system has the drawback that it can’t be driven in four-wheel drive mode at all times. With the front and rear differentials rotating together, any difference in rotational speed between the front and rear wheels — such as from turning a corner or uneven tyre wear — would cause a problem. The drive shaft going to one differential would want to turn further than the other, a problem known as wind-up.

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Hershey Fonts: Not Chocolate, The Origin Of Vector Lettering

March 30, 2021 by Chris Lott 57 Comments

Over the past few years, I kept bumping into something called Hershey fonts. After digging around, I found a 1967 government report by a fellow named Dr. Allen Vincent Hershey. Back in the 1960s, he worked as a physicist for the Naval Weapons Laboratory in Dahlgren, Virginia, studying the interaction between ship hulls and water. His research was aided by the Naval Ordnance Research Calculator (NORC), which was built by IBM and was one of the fastest computers in the world when it was first installed in 1954.

The NORC’s I/O facilities, such as punched cards, magnetic tape, and line printers, were typical of the era. But the NORC also had an ultra-high-speed optical printer. This device had originally been developed by the telecommunications firm Stromberg-Carlson for the Social Security Administration in order to quickly print massive amounts of data directly upon microfilm.

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Google Calls It Quits With VR, But Cardboard Lives On

March 30, 2021 by Tom Nardi 16 Comments

Google giving up on one of their projects and leaving its established userbase twisting in the wind hardly counts as news anymore. In fact, it’s become something of a meme. The search giant is notorious for tossing out ideas just to see what sticks, and while that’s occasionally earned them some huge successes, it’s also lead to plenty of heartache for anyone unlucky enough to still be using one of the stragglers when the axe falls.

So when the search giant acknowledged in early March that they would no longer be selling their Cardboard virtual reality viewer, it wasn’t exactly a shock. The exceptionally low-cost VR googles, literally made from folded cardboard, were a massive hit when they were unveiled back in 2014. But despite Google’s best efforts to introduce premium Cardboard-compatible hardware with their Daydream View headset two years later, it failed to evolve into a profitable business.

Of course if you knew where to look, the writing had been on the wall for some time. While the Daydream hardware got a second revision in 2017, and Google even introduced a certification program to ensure phones would work properly with the $100 USD headset, the device was discontinued in 2019. On the software side, Android 7 “Nougat” got baked-in VR support in 2016, but it was quietly removed by the time Android 11 was released in the fall of 2020.

With Cardboard no longer available for purchase, Google has simply made official what was already abundantly clear: they are no longer interested in phone-based virtual reality. Under normal circumstances, anyone still using the service would be forced to give it up. Just ask those who were still active on Google+ or Allo before the plug was pulled.

But this time, things are a little different. Between Google’s decision to spin it off into an open source project and the legions of third party viewers on the market, Cardboard isn’t going down without a fight. The path ahead might be different from what Google originally envisioned, but the story certainly isn’t over.

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A Few Of My Favorite Things: Pens

March 29, 2021 by Kristina Panos 111 Comments

Pens! They just might be the cheapest, most important piece of technology ever overlooked by a large group of people on a daily basis. Pens are everywhere from your desk to your car to your junk drawer, though they tend to blink out of existence when you need one. Where would we be without them? Probably still drawing on cave walls with dandelions and beets.

Photo of a Pilot Metropolitan by Aaron Burden on Unsplash

Why do I think pens are so great? Well, they’re a relatively cheap tool depending on the pen you get, but whatever you spend, you’re getting a lot for your money. Pens are possibility, pure and simple, and they’re even conveniently packaged in a portable device.

Aesthetically speaking, I like pens because of how different they can be both inside and out. Some of them make thick lines, some make thin lines, and in the case of flexible nibs, some alternate between thick and thin lines depending on pressure. I use pens for a number of reasons, most notably for writing. Everything you read here that bears my name began life as pen marks on paper.

Pens are revolutionary because they can be used to make ideas permanent and/or illustrate any concept. It’s up to you to use the pen wisely. You can use other, better tools later, but pens are always a great first tool. If you’re not encumbered by an uncomfortable grip, ink that skips, or a scratchy, draggy contact point, your ideas will flow more freely. When you find the right pen for you, you aren’t hindered by your tool — you’re elevated by it. Continue reading “A Few Of My Favorite Things: Pens” →

The $50 Ham: WSPR-ing Around The World

March 25, 2021 by Dan Maloney 18 Comments

Everybody has a bucket list, things to be accomplished before the day we eventually wake up on the wrong side of the grass. Many bucket-list items are far more aspirational than realistic; very few of us with “A trip to space” on our lists are going to live to see that fulfilled. And even the more realistic goals, like the trip to Antarctica that’s been on my list for ages, become less and less likely as your life circumstances change — my wife hates the cold.

Luckily, instead of going to Antarctica by myself — and really, what fun would that be? — I’ve recently been getting some of the satisfaction of world travel through amateur radio. The last installment of “The $50 Ham” highlighted weak-signal digital modes using WSJT-X; in that article, I mentioned a little about the Weak Signal Propagation Reporter, or WSPR. It’s that mode that let me test what’s possible with very low-power transmissions, and allowed me to virtually visit six continents including Antarctica and Sweden-by-way-of-Alaska.

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How Fast Is The Universe Expanding? The Riddle Of Two Values For The Hubble Constant

March 25, 2021 by Moritz v. Sivers 44 Comments

In the last decades, our understanding of the Universe has made tremendous progress. Not long ago, “precision astronomy” was thought to be an oxymoron. Nowadays, satellite experiments and powerful telescopes on earth were able to measure the properties of our Universe with astonishing precision. For example, we know the age of the Universe with an uncertainty of merely 0.3%, and even though we still do not know the origin of Dark Matter or Dark Energy we have determined their abundance with a precision of better than 1%.

There is, however, one value that astronomers have difficulty in pinning down: how fast our universe is expanding. Or, more precisely, astronomers have used multiple methods of estimating the Hubble constant, and the different methods are converging quite tightly on two different values! This clearly can’t be true, but nobody has yet figured out how to reconcile the results, and further observations have only improved the precision, deepening the conflict. It’s likely that we’ll need either new astronomy or new physics to solve this puzzle.

The Discovery of the Expanding Universe

In the 1920s Edwin Hubble used the newly built telescope at Mount Wilson Observatory to study fuzzy objects known as nebulae. Back then, astronomers were arguing whether these nebulae are clouds of stars within our Milky Way or if they are whole different galaxies. Hubble discovered stars within these nebulae whose brightness slowly fades in and out. These were known as Cepheids and previously studied by Henrietta Levitt who showed that there was a tight relationship between the star’s intrinsic brightness and the period of its variation. This means Cepheids could be used as so-called standard candles which refers to objects whose absolute brightness is known. Since there is a simple relationship between how the brightness of an object decreases with distance, Hubble was able to calculate the distance of the Cepheids by comparing their apparent and intrinsic brightness. He showed that the Cepheid stars were not located within our galaxy and that nebulae are actually distant galaxies.

Hubble also measured the velocity at which these distant galaxies are moving away from us by observing the redshifts of spectral lines caused by the Doppler effect. He found that the further away the galaxy is located, the faster it is moving away from us described by a simple linear relationship.

$\bf v = H_0 d$

The parameter H₀ is what is known as the Hubble constant. Later the Belgian priest and physicist Georges Lemaître realized that the velocity-distance relationship measured by Hubble was evidence for the expansion of the Universe. Since the expansion of space itself causes other galaxies to move away from us we are not in any privileged location but the same effect would be measured from any other place in the Universe. An effect that is sometimes illustrated by drawing points on a balloon, when it is inflated the points move away from each other at a speed that depends on their distance. It is also better not to think of the cosmological redshift as being caused by a real velocity as the parameter v in the above equation can easily exceed the speed of light. Continue reading “How Fast Is The Universe Expanding? The Riddle Of Two Values For The Hubble Constant” →