Flagging Down Aliens With World’s Biggest Laser Pointer

November 20, 2018 by Tom Nardi 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.

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The Electric Imp Sniffs Out California Wildfires

November 20, 2018 by Tom Nardi 13 Comments

The wildfires in California are now officially the largest the state has ever seen. Over 50,000 people have been displaced from their homes, hundreds are missing, and the cost in property damage will surely be measured in the billions of dollars when all is said and done. With a disaster of this scale just the immediate effects are difficult to conceptualize, to say nothing of the collateral damage.

While not suggesting their situation is comparable to those who’ve lost their homes or families, Electric Imp CEO [Hugo Fiennes] has recently made a post on their blog calling attention to the air quality issues they’re seeing at their offices in Los Altos. To quantify the problem so that employees with respiratory issues would know the conditions before they came into work, they quickly hacked together a method for displaying particulate counts in their Slack server.

The key to the system is one of the laser particle sensors that we’re starting to see more of thanks to a fairly recent price drop on the technology. A small fan pulls air to be tested into the device, where a very sensitive optical sensor detects the light reflected by particles as they pass through the laser beam. The device reports not only how many particles are passing through it, but how large they are. The version of the sensor [Hugo] links to in his blog post includes an adapter board to make it easier to connect to your favorite microcontroller, but we’ve previously seen DIY builds which accomplish the same goal.

[Hugo] then goes on to provide firmware for the Electric Imp board that reads the current particulate counts from the sensor and creates a simple web page that can be viewed from anywhere in the world to see real-time conditions at the office. From there, this data can be plugged into a Slack webhook which will provide an instantaneous air quality reading anytime a user types “air” into the channel.

We’ve covered a number of air quality sensors over the years, and it doesn’t look like they’re going to become any less prevalent as time goes on. If anything, we’re seeing a trend towards networks of distributed pollution sensors so that citizens can collect their own data on their air they’re breathing.

[Thanks to DillonMCU for the tip.]

Hackaday Links: November 18, 2018

November 18, 2018 by Brian Benchoff 18 Comments

The greatest bit of consumer electronics is shipping and the reviews are out: Amazon’s Alexa-enabled microwave is a capable microwave, but befuddling to the voice-controlled-everything neophyte. Voice controlled everything is the last hope we have for technological innovation; it’s the last gasp of the consumer electronics industry. This is Amazon’s first thing with a built-in voice assistant, and while this is a marginally capable microwave at only 700 Watts — fine for a college dorm, but it’s generally worth shelling out a bit more cash for a 1000 Watt unit — the controls are befuddling. The first iteration is always hard, and we’re looking forward to the Amazon Alexa-enabled toaster, toothbrush, vacuum cleaner, and Bezos shrine.

Need a laser cutter, like crowdfunding campaigns, and know literally nothing about laser cutters? Have we got something for you. The Etcher Laser crowdfunding campaign has been pinging my email non-stop, and they’ve got something remarkable: a diode laser ~~cutter~~ engraver for $500. It comes in a neat-looking enclosure, so it’s sure to raise a lot of money.

A while back [Paulusjacobus] released an Arduino-based CNC controller for K40 laser cutters. There were a few suggestions to upgrade this to the STM32, so now this CNC controller is running on a Blue Pill. Yes, it’s great and there’s more floating points and such and such, so now this project is a Kickstarter project. Need a CNC controller based on the STM32? Boom, you’re done. It’s also named the ‘Super Gerbil’, which is an awesome name for something that is effectively a GRBL controller. Naming things is the hardest problem in computer science, after all.

The Gigatron computer is a ‘home computer’ without a microprocessor or microcontroller. How does it do this? A metric butt-load of ROM and look-up tables. This is cool and all, but now the Gigatron logo is huge. we’re talking 18 μm by 24 μm. This was done by etching a silicon test wafer with electron beam lithography.

The How And Why Of Laser Cutter Aiming

November 9, 2018 by Tom Nardi 16 Comments

Laser aficionado [Martin Raynsford] has built up experience with various laser cutters over the years and felt he should write up a blog post detailing his first-hand findings with an often overlooked aspect of the machines: aiming them. Cheap diode laser cutters and engravers operate in the visible part of the spectrum, but when you get into more powerful carbon dioxide lasers such as the one used in the popular K40 machines, the infrared beam is invisible to the naked eye. A secondary low-power laser helps to visualize the main laser’s alignment without actually cutting the target. There are a couple of ways to install an aiming system like this, but which way works better?

[Martin] explains that there are basically two schools of thought: a head-mounted laser, or a beam combiner. In both cases, a small red diode laser (the kind used in laser pointers) is used to indicate where the primary laser will hit. This allows the user to see exactly what the laser cutter will do when activated, critically important if you’re doing something like engraving a device and only have one chance to get it right. Running a “simulation” with the red laser removes any doubt before firing up the primary laser.

That’s the idea, anyway. In his experience, both methods have their issues. Head-mounted lasers are easier to install and maintain, but their accuracy changes with movement of the machine’s Z-axis: as the head goes up and down, the red laser dot moves horizontally and quickly comes out of alignment. Using the beam combiner method should, in theory, be more accurate, but [Martin] notes he’s had quite a bit of trouble getting both the red and IR lasers to follow the same course through the machine’s mirrors. Not only is it tricky to adjust, but it’s also much more complex to implement and may even rob the laser of power due to the additional optics involved.

In the end, [Martin] doesn’t think there is really a clear winner. Neither method gives 100% accurate results, and both are finicky, though in different scenarios. He suggests you just use whatever method your laser cutter comes with from the factory, as trying to change it probably isn’t worth the effort. But if your machine doesn’t have anything currently, the head-mounted laser is certainly the easier one to retrofit.

In the past, we’ve covered a third and slightly unconventional way of aiming the K40, as well as a general primer for anyone looking to pick up eBay’s favorite laser cutter.

Vibrosight Hears When You Are Sleeping. It Knows When You’re Awake.

October 22, 2018 by Tom Nardi 16 Comments

No matter how excited you are to dive headfirst into the “Internet of Things”, you’ve got to admit that the effort and expense of going full-on Jetsons is a bit off-putting. To smarten up your home you’ve generally got to buy all new products (and hope they’re all compatible) or stick janky after-market sensors on the gear you’ve already got (and still hope they’re all compatible). But what if there was a cheap and easy way to keep tabs on all your existing stuff? The answer may lie in Cold War era surveillance technology.

As if the IoT wasn’t already Orwellian enough, Vibrosight is a project that leverages a classic KGB spy trick to keep tabs on what’s going on inside your home. Developed by [Yang Zhang], [Gierad Laput] and [Chris Harrison], the project uses retro-reflective stickers and a scanning laser to detect vibrations over a wide area. With this optical “stethoscope”, the system can glean all kinds of information; from how long you’ve been cooking something in the microwave to whether or not you washed your hands.

The project takes its inspiration from the optical eavesdropping system developed by Léon Theremin in the late 1940’s. By bouncing a beam of light off of a window, Theremin’s gadget was able to detect what people inside the room were saying from a distance. The same idea is applied here, except now it uses an automated laser scanner and machine learning to turn detected vibrations into useful information that can be plugged into a home automation system.

For Vibrosight to “listen” to objects, the user needs to place retro-reflective tags on whatever they want to include in the system. The laser will periodically scan around the room looking for these tags. Once the laser finds a new tag, will add it to a running list of targets to keeps an eye on. From there Vibrosight is able to take careful vibration measurements which can provide all sorts of information. In the video after the break, Vibrosight is shown differentiating between walking, jogging, and running on a treadmill and determining what kind of hand tools are being used on a workbench. The team even envisions a future where Vibrosight-ready devices would “hum” their IP address or other identifying information to make device setup easier.

If all this talk of remote espionage at a distance has caught your interest, we’ve covered Theremin’s unique surveillance creations in the past, and even a way to jam them if you’re trying to stay under the radar.

Continue reading “Vibrosight Hears When You Are Sleeping. It Knows When You’re Awake.” →

This Year’s Nobel Prizes Are Straight Out Of Science Fiction

October 10, 2018 by Steven Dufresne 22 Comments

In the 1966 science fiction movie Fantastic Voyage, medical personnel are shrunken to the size of microbes to enter a scientist’s body to perform brain surgery. Due to the work of this year’s winners of the Nobel Prize in Physics, laser tools now do work at this scale.

Arthur Ashkin won for his development of optical tweezers that use a laser to grip and manipulate objects as small a molecule. And Gérard Mourou and Donna Strickland won for coming up with a way to produce ultra-short laser pulses at a high-intensity, used now for performing millions of corrective laser eye surgeries every year.

Here is a look at these inventions, their inventors, and the applications which made them important enough to win a Nobel.

Continue reading “This Year’s Nobel Prizes Are Straight Out Of Science Fiction” →

Laser Noob: Getting Started With The K40 Laser

September 27, 2018 by Adam Fabio 77 Comments

Why spend thousands on a laser cutter/engraver when you can spend as little as $350 shipped to your door? Sure it’s not as nice as those fancy domestic machines, but the plucky K40 is the little laser that can. Just head on down to Al’s Laser Emporium and pick one up. Yes, it sounds like a used car dealership ad, but how far is it from the truth? Read on to find out!

Laser cutting and engraving machines have been around for decades. Much like 3D printers, they were originally impossibly expensive for someone working at home. The closest you could get to a hobbyist laser was Epilog laser, which would still cost somewhere between $10,000 and $20,000 for a small laser system. A few companies made a go with the Epilog and did quite well – notably Adafruit used to offer laptop laser engraving services.

Over the last decade or so things have changed. China got involved, and suddenly there were cheap lasers on the market. Currently, there are several low-cost laser models available in various power levels. The most popular is the smallest – a 40-watt model, dubbed the K40. There are numerous manufacturers and there have been many versions over the years. They all look about the same though: A blue sheet metal box with the laser tube mounted along the back. The cutting compartment is on the left and the electronics are on the right. Earlier versions came with Moshidraw software and a parallel interface.