Sir Winston Churchill often spoke of World War 2 as the “Wizard War”. Both the Allies and Axis powers were in a race to gain the electronic advantage over each other on the battlefield. Many technologies were born during this time – one of them being the ability to decipher coded messages. The devices that were able to achieve this feat were the precursors to the modern computer. In 1946, the US Military developed the ENIAC, or Electronic Numerical Integrator And Computer. Using over 17,000 vacuum tubes, the ENIAC was a few orders of magnitude faster than all previous electro-mechanical computers. The part that excited many scientists, however, was that it was programmable. It was the notion of a programmable computer that would give rise to the idea of artificial intelligence (AI).
As time marched forward, computers became smaller and faster. The invention of the transistor semiconductor gave rise to the microprocessor, which accelerated the development of computer programming. AI began to pick up steam, and pundits began to make grand claims of how computer intelligence would soon surpass our own. Programs like ELIZA and Blocks World fascinated the public and certainly gave the perception that when computers became faster, as they surely would in the future, they would be able to think like humans do.
But it soon became clear that this would not be the case. While these and many other AI programs were good at what they did, neither they, or their algorithms were adaptable. They were ‘smart’ at their particular task, and could even be considered intelligent judging from their behavior, but they had no understanding of the task, and didn’t hold a candle to the intellectual capabilities of even a typical lab rat, let alone a human.
Continue reading “A Short History of AI, and Why It’s Heading in the Wrong Direction”
A geophone is a specially built microphone for listening to the Earth. [JTAdams] found them at a reasonable price so bought some to play with. A geophone is used to detect vibrations from earthquakes, explosions, rumbling trucks, and vibroseis vehicles. To be useful it needs an amplifier and a recording device to capture the signals.
[JTAdams] used a standard amplifier design for an LT1677 op-amp, fed the signal to an MCP3008 A/D converter, and read the output using a Raspberry Pi. A Python script records the data to a CSV file for processing. The Pi worked well because the entire setup needs to be portable to take into the field. Another Python script plots the data which is made available from a web page. A neat simple way of presenting the raw data. [JTAdams] promises more information in the future on post-processing the data. You don’t need a geophone to detect seismic waves if you build your own, but a real ‘phone will be more rugged.
Oh, what’s a vibroseis? It’s a truck with a big flat plate underneath it. The plate is hydraulically lowered to the ground until the weight of the truck is on it. The truck then causes the plate to vibrate, usually sweeping from around 10 hz to 100 hz. This infrasound pass through the ground until it is reflected back by underlying rock layers. A long string of geophones, think 1,000s of feet, detects the waves, which are recorded. In practice, many trucks are used to generate a synchronized signal of sufficient strength. Or, you can set off an explosion which is the technique used in water. Typically the information is used for oil and gas exploration. A video of one of the trucks in action after the break.
Continue reading “Listening to the Sounds of the Earth”
[Matthias Wandel] is the preeminent YouTube woodworker, with dozens of machines constructed from wooden gears, amazing machines that produce perfect mortise and tenons, and home-built table saws and jointers. Actually building something instead of buying it is a hallmark of [Matthias]’ channel, and he’s at it again, building his own woodworking machines. This time it’s a 1″ wide belt sander. Of course anyone can go out and simply buy one of these sanders for under $100, but what’s the point in that when you can build one out of plywood and a motor you picked out of the trash?
The design of this belt sander – just like the commercial version he’s improving upon – uses three wheels to guide the 42″ long strip of sandpaper around its course. [Matthias] is using rollerblade wheels for the front wheels. Rollerblade wheels aren’t the best shape for bearings, this can be fixed by using a table saw as a lathe. Yes, [Matthias] lathes with a table saw. He’s just that good.
The rest of the frame was carefully constructed out of plywood and powered by a 1/3 horsepower furnace fan motor pulled from the trash. There are a few interesting features that make this belt sander exceptionally useful: a rounded platen behind the belt makes sanding interior corners very easy, and is something that isn’t usually found on commercial belt sanders.
You can check out [Matthias]’ video below.
Continue reading “Matthias Builds A Belt Sander”