TL;DR: Demo here. Hit the button at the top to start.

I recently tried out a bunch of different Javascript accelerometer demos that claimed to able to access the sensor in-browser. It was usually a simple demo: dots rolling across a screen due to gravity, or perspective shifting a 3D scene based on what your orientation was. However, none of these demos worked at all — no popup asking about permissions or anything. What gives?

In iOS 13, Apple added an option under Safari to allow webpages to request accelerometer access. However, the webpage couldn’t just spam you with a “Please Let Us Use Your Accelerometer” screen until you responded yes — Instead, the user had to purposefully trigger the request, by hitting a button or performing an action to allow the site to request access. …

Hi, Andy here. I want to bring your attention to the depressing fact that there are really only two ways to sell software. Well, three, but hardly anybody uses the third. I am, of course, talking of subscription services (SaaS) and advertisement/data driven.

Software as a Business Model

Before people could write software for a living, you had to sell things. Tangible objects that performed a certain function, whose parts cost money, which further cost more money to assemble into a product.

Two people exchanging a bag of money for a house
Two people exchanging a bag of money for a house
Transactions before software

After computers became widespread people began writing software, and realized that other people would pay real money to buy your software. And best of all, software sales were essentially free — simply copy the file onto a new disc and send it over to them. Nowadays, the cost has become even lower, with free online file hosting and storing and sharing, to the point where the only cost of sending software is the thirty seconds it takes to email the link. …

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It happened again. You didn’t notice the gloomy skies as you pulled out of your driveway to go to Home Depot, and now you’re umbrella-less and sitting in their parking lot, watching the raindrops bead up and flow down your windshield. Worse yet, their New Grill November sale has summoned every dad within a 25 mile radius to the store, forcing you to park in the back of the lot. You didn’t even bring your rain jacket, because it’s new and you didn’t want to dirty it while carrying your new oak floorboards.

As you sit there feeling sorry for yourself, you notice that the sound of the rain has changed. From the time you pulled in to the moment you searched Amazon for oak flooring, the intensity of the rain has changed, and with it, the sound. That’s it! All you have to do is pick the right time to make a mad dash for the those automatic doors, and you’ll get minimally wet, despite making no preparations. You listen closely, and think back to a familiar math…

“Waking up one morning, a student of Zen realized he was going to be late to meet his teacher. He quickly got up and rushed out to his teacher’s hut. Upon arriving, he took off his shoes outside and greeted him.

Noticing his shortness of breath, his master asked ‘Which shoe did you put on first this morning?’ Ashamed that he did not know, the student realized he was not ready for his lessons and went home.”

Every time I’m late, I’ve always been working on something. I see the time, throw my shoes on and rush out. Along the way, I walk as quickly as possible, one foot in front of the other, driving myself to minimize the time that I’m tardy. Along the way, I only look forward; after all, that is the direction I’m headed. …

Bear with me. I’m going to try to explain something slightly abstract but incredibly interesting.

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Apparently you can’t embed a mirror in a blog post

You, the brain reading this

Look at your hands. Admire your reflection in a mirror. That’s you, right?

Wrong. That is not you. You are the brain inside that person. You are a chunk of meat piloting a bone-armored meatsuit, using your limbs as tools to let you interact with the physical world. And they’re our best tools because they’re so generalizable; I’m currently using the fingers on mine to hit my keyboard in specific combinations to write the words you’re reading.

However, their generality leads us to create more specialized tools to make certain tasks easier for us. Hammers allow us to piece together pieces of wood with bits of metal. Pianos make it easy to create specific sounds reliably. Keyboards enable precise electron changes on tiny, tiny silicon chips. We use our general tools to create and harness more specialized ones. …

Hello! This is Andy. I’m about to tell you about something way cooler than implanting a chip in the brain to control robot arms, which is a very hard subject to top.

You can read brain activity by just shooting lasers into your skull and seeing how much of it comes back out. Introducing fNIRS, or functional near-infrared spectroscopy.

The basic principle of fNIRS is that blood changes shade as it becomes more oxygenated. Since deoxygenated blood absorbs more red light than oxygenated, it appears darker.

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Not so blue, right?

You can think of fNIRS as shining a flashlight onto the brain. Since groups of neurons firing will exhaust their blood supply, more active regions of the brain will have less oxygenated blood. By picking a laser in the right dark-red region, we can shoot it at brain tissue and look at how it scatters. By the Law of Large Numbers, some of the photons we inject will bounce back from the brain and make it out to a sensitive photodetector we placed near the laser source. Depending on how much of the brain in that region was active, we’ll see greater or fewer numbers of photons coming back out. …

We’re going to explore the simpler uses of machine learning.

Hello, this is Andy. There is an underlying perception that people new to the topic of machine learning have, and that is this: when a model isn’t doing too hot, you need either more data or more hidden layers with more neurons between them. This misconception isn’t their fault; it seems everyone in the news is talking about these huge neural networks trained on terabytes of data to decide whether to advertise an eco-friendly backpack or water bottle to an unsuspecting consumer based on their heart rate variance. However, more neurons != …

Hello, this is Andy. I’me here to tell you about a minor problem in the way the world is. Humor me, your well-adjusted benevolent author, and take a moment to look at the following pictures of shapes.

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Triangles neatly covering a plane

Hello! I’m Andy. I’ll be showing you a simple DIY instrument that is incredibly easy to make anywhere you are, and can also be played obnoxiously loudly. All you need is some kind of can, aluminum or steel, tall boy or normal soda can. You likely have one nearby you’re already sipping on, and you can follow this tutorial once you’ve finished it!

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All the supplies you need for a DIY orchestra

Imagine this. It’s summertime. You’re in a park. There’s people playing frisbee nearby. You have just finished off the dregs of your favorite drink, held safely in an aluminum can. While you were sipping from your modern beverage container, you were also harking back to the drinks of the good old days. …


Andy Kong

Hi! I’m Andy. I try to make things that haven’t been made before. Check out my personal projects at

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