Screwing Around With SDR

A few weeks ago, I pointed a camera at the East River to take pictures of the ships as they pass by. I wanted to know more. Every sufficiently large ship is constantly broadcasting information about itself via the Automatic Information System (AIS). It is, roughly speaking, a digital signal broadcast on the ship’s short range VHF radio. Anyone can receive it. So, I decided I wanted to learn all about AIS and read the signals for myself.
Read more →

Measuring memory utilization in Go

A long while back, I experimented with making a Go web server behave differently based on its heap utilization. I used runtime.ReadMemStats, but I didn’t run ReadMemStats on every request because it stops the world. More recently, I started getting curious about logging memory utilization, against a production system, where we found that it was important to see the memory in use for each and every web request. I thought back to my old friend ReadMemStats, but I was frightened of stopping the world.
Read more →

Using command line tools to analyze a crash

At Nautilus Labs, we’re advancing the efficiency of maritime transportation by collecting data and recognizing patterns. An interesting side effect of this is that we have insight into a ships' actions, not just day-by-day, but second-by-second. It’s not as simple as dots on a map either; engine power, wind, rate-of-turn, it’s all important. We worked with one of our clients to take advantage of this recently. A few days ago, one of their ships struck a jetty during a berthing maneuver.
Read more →

Rubens' Tube

Hey, check out this Rubens' Tube! What’s a Rubens' Tube? It’s a tube filled with flammable gas with a transducer on one end and holes drilled in the top. You light the gas on fire. When you play a sound into the tube that is a harmonic of the tube’s resonant frequency, you get patterns in the flame! I built this one at South Side Hackerspace: Chicago with the help of my friends Dmitriy and Josef.
Read more →

End Grain Cutting Board

I made an end-grain cutting board, and it’s about the coolest thing. It’s 1 3/4" thick and made from white maple. I’ll take you through the steps I followed. I’ve been a metal guy for years now. I love welding, I love machining, but recently I discovered that glued wood joints can be far stronger than I ever thought. We kinda needed a second cutting board, so I watched a few videos and read a few guides and decided I could probably build one.
Read more →