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Longform articles, the best of what the Hackaday writing crew has to offer.

Creating Black Holes: Division By Zero In Practice

November 21, 2018 by 31 Comments

Dividing by zero — the fundamental no-can-do of arithmetic. It is somewhat surrounded by mystery, and is a constant source for internet humor, whether it involves exploding microcontrollers, the collapse of the universe, or crashing your own world by having Siri tell you that you have no friends.

It’s also one of the few things gcc will warn you about by default, which caused a rather vivid discussion with interesting insights when I recently wrote about compiler warnings. And if you’re running a modern operating system, it might even send you a signal that something’s gone wrong and let you handle it in your code. Dividing by zero is more than theoretical, and serves as a great introduction to signals, so let’s have a closer look at it.

Chances are, the first time you heard about division itself back in elementary school, it was taught that dividing by zero is strictly forbidden — and obviously you didn’t want your teacher call the cops on you, so you obeyed and refrained from it. But as with many other things in life, the older you get, the less restrictive they become, and dividing by zero eventually turned from forbidden into simply being impossible and yielding an undefined result.

And indeed, if a = b/0, it would mean in reverse that a×0 = b. If b itself was zero, the equation would be true for every single number there is, making it impossible to define a concrete value for a. And if b was any other value, no single value multiplied by zero could result in anything non-zero. Once we move into the realms of calculus, we will learn that infinity appears to be the answer, but that’s in the end just replacing one abstract, mind-boggling concept with another one. And it won’t answer one question: how does all this play out in a processor? Continue reading “Creating Black Holes: Division By Zero In Practice” →

Flagging Down Aliens With World’s Biggest Laser Pointer

November 20, 2018 by 86 Comments

As you’re no doubt aware, humans are a rather noisy species. Not just audibly, like in the case of somebody talking loudly when you’re in a movie theater, but also electromagnetically. All of our wireless transmissions since Marconi made his first spark gap broadcast in 1895 have radiated out into space, and anyone who’s got a sensitive enough ear pointed into our little corner of the Milky Way should have no trouble hearing us. Even if these extraterrestrial eavesdroppers wouldn’t be able to understand the content of our transmissions, the sheer volume of them would be enough to indicate that whatever is making all that noise on the third rock orbiting Sol can’t be a natural phenomena. In other words, one of the best ways to find intelligent life in the galaxy may just be to sit around and wait for them to hear us.

Of course, there’s some pesky physics involved that makes it a bit more complicated. Signals radiate from the Earth at the speed of light, which is like a brisk walk in interstellar terms. Depending on where these hypothetical listeners are located, the delay between when we broadcast something and when they receive it can be immense. For example, any intelligent beings that might be listening in on us from the closest known star, Proxima Centauri, are only just now being utterly disappointed by the finale for “How I Met Your Mother“. Comparatively, “Dallas” fans from Zeta Reticuli are still on the edge of their seats waiting to find out who shot J.R.

But rather than relying on our normal broadcasts to do the talking for us, a recent paper in The Astrophysical Journal makes the case that we should go one better. Written by James R. Clark and Kerri Cahoy,  “Optical Detection of Lasers with Near-term Technology at Interstellar Distances” makes the case that we could use current or near-term laser technology to broadcast a highly directional beacon to potentially life-harboring star systems. What’s more, it even theorizes it would be possible to establish direct communications with an alien intelligence simply by modulating the beam.

Continue reading “Flagging Down Aliens With World’s Biggest Laser Pointer” →

How The Xbox Was Hacked

November 19, 2018 by 38 Comments

The millennium: a term that few had any use for before 1999, yet seemingly overnight it was everywhere. The turning of the millenium permeated every facet of pop culture. Unconventional popstars like Moby supplied electronica to the mainstream airwaves while audiences contemplated whether computers were the true enemy after seeing The Matrix. We were torn between anxiety — the impending Y2K bug bringing the end of civilization that Prince prophesied — and anticipation: the forthcoming release of the PlayStation 2.

Sony was poised to take control of the videogame console market once again. They had already sold more units of the original PlayStation than all of their competition combined. Their heavy cloud of influence over gamers meant that the next generation of games wasn’t going to start in until the PS2 was on store shelves. On the tail of Sony announcing the technical specs on their machine, rumors of a new competitor entering the “console wars” began to spread. That new competitor was Microsoft, an American company playing in a Japanese company’s game.
Continue reading “How The Xbox Was Hacked” →

Supercon: Designing Your Own Diffractive Optics

November 16, 2018 by 15 Comments

Kelly Peng is an electrical and optical engineer, and founder of Kura AR. She’s built a fusion reactor, a Raman spectrometer, a DIY structured light camera, a linear particle accelerator, and emotional classifiers for likes and dislikes. In short, we have someone who can do anything, and she came in to talk about one of the dark arts (pun obviously intended): optics.

The entire idea of Kura AR is to build an immersive augmented reality experience, and when it comes to AR glasses, there are two ways of doing it. You could go the Google Glass route and use a small OLED and lenses, but these displays aren’t very bright. Alternatively, you could use a diffractive waveguide, like the Hololens. This is a lot more difficult to manufacture, but the payoff will be a much larger field of view and a much more immersive experience.

Continue reading “Supercon: Designing Your Own Diffractive Optics” →

Choosing Cell Modems: The Drama Queen Of Hardware Design

November 15, 2018 by 20 Comments

So you went to a tradeshow and heard about this cool new idea called the Internet Of Things; now it’s time to build an IoT product of your own. You know that to be IoT, your Widget D’lux® has to have a network connection but which to choose?

You could use WiFi or Bluetooth but that would be gauche. Maybe LoRaWAN? All the cool kids are using LoRa for medium or long range wireless these days, but that still requires a base station and Widget D’lux® will be a worldwide phenomenon. Or at least a phenomenon past your bedroom walls. And you know how much user’s hate setting things up. So a cell modem it is! But what do you have to do to legally include one in your product? Well that’s a little complicated.

Continue reading “Choosing Cell Modems: The Drama Queen Of Hardware Design” →

Alice Evans: Brucellosis, Or Why We Pasteurize Milk

November 13, 2018 by 51 Comments

It’s easy to forget how much illness and death was caused by our food and drink just one hundred years ago. Our modern food systems, backed by sound research and decent regulation, have elevated food safety to the point where outbreaks of illness are big news. If you get sick from a burger, or a nice tall glass of milk, it’s no longer a mystery what happened. Instead we ask why, and “who screwed up?”

In the early 20th century though, many food-borne illnesses were still a mystery, and microbiology was a scientific endeavor that was just getting started. Alice Catherine Evans was an unlikely figure to make a dent in this world at the time, but through her research at the United States Department of Agriculture’s (USDA), and later at the Hygienic Laboratory (now the National Institute of Health) she had a huge impact on the field of bacteriology, the dairy industry, and consumer safety. Continue reading “Alice Evans: Brucellosis, Or Why We Pasteurize Milk” →

Hello, And Please Don’t Hang Up: The Scourge Of Robocalls

November 12, 2018 by 113 Comments

Over the last few months, I’ve noticed extra calls coming in from local numbers, and if you live in the US, I suspect maybe you have too. These calls are either just dead air, or recordings that start with “Please don’t hang up.” Out of curiosity, I’ve called back on the number the call claims to be from. Each time, the message is that this number has been disconnected and is no longer in service. This sounds like the plot of a budget horror movie, how am I being called from a disconnected number? Rather than a phantom in the wires, this is robocalling, combined with caller ID spoofing.

Continue reading “Hello, And Please Don’t Hang Up: The Scourge Of Robocalls” →