Choose Your Paradox – the downside of the Axiom of Choice

Bill Wadge's Blog

And He took the five loaves and the two fish, and looking up to heaven, He blessed and broke and gave the loaves to the disciples; and the disciples gave to the multitudes. So they all ate and were filled, and they took up twelve baskets full of the fragments that remained. – Matthew 14.

The logician Willard Quine defined a paradox as an “absurd” statement backed up by an argument.

The famous result of Banach and Tarski definitely counts as a paradox by this definition. They proved that it is possible to take a unit sphere (a ball with radius 1), divide it into five pieces, then by rotations and translations reassemble it into two unit spheres.

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WebGL Basics 3 – Rotating triangle

The Blog-o-Ben

We continue this pure WebGL tutorial with animation.

Introduction

The previous post was dedicated to all the function calls necessary to render a simple triangle. In this post, we will animate this triangle and make it rotate around the three axes. The web page used in the previous post must be changed as following:

  • Addition of a mechanism to periodically refresh the canvas and manually control the rotation
  • Modification of the shader code to include a matrix-based transformation of vertices
  • Creation of a function used to pre-compute the transformation matrix

The part about the transformation matrix necessitates some basic linear algebra but should be understandable with high-school level mathematics knowledge.

Refactoring the code

First of all, in order to make the program more readable, we move some code around. The code of the shaders is placed at the beginning of the Javascript part:

Note that the vertex shader code above…

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What is Windows *doing* while hogging that lock

Random ASCII

Earlier this month I wrote about how Windows 10 holds a lock during too much of process destruction, which both serializes this task and causes mouse-cursor hitches and UI hangs (because the same lock is used for these UI tasks).

I thought I’d use this as an excuse to dig slightly deeper into what is going on using a clunky-but-effective ETW profiling technique. This technique shows that a 48 instruction loop is consuming a huge chunk of the CPU time while the lock is held – the 80/20 rule is alive and well. And, thanks to some discussion on hacker news I know have an idea of what that function does and why it got so much more expensive in Windows 10 Anniversary Edition.

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How to create a private Ethereum network

Musings of a Meta-physician

Objectives:

  1. To create a private Ethereum network
  2. To deploy a simple contract to your private Ethereum network
  3. To interact with a contract on your private Ethereum network

Target audience:  

Ethereum developers.

Necessity: 

The need for this tutorial arises from outdated Ethereum documentation, resulting in hair-pulling, heartburn, and insomnia.

Precautions:

Isolate your development environment, and your private Ethereum network, from any real Ether you might have. It’s easy to compromise your machine and lose real money if you slip up.

Step 1: Set up a virtual server and install Ethereum command-line tools

Many tutorials guide you through deploying contracts using the Ethereum wallet GUI. I’m using the Go Ethereum client (geth) and encourage others to learn how to use the command line interface (CLI). The better you understand the Ethereum client’s internal workings and the anatomy of a blockchain, the more power to you. It doesn’t matter which hostingservice you…

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Why We Eloped

Words of Lizdom

liz wedding 185

In 2015, couples spent an average of $32,641 on their wedding. 

I don’t know about you, but a price tag like this gives me anxiety. This is one of several reasons we eloped.

Yes, we eloped. It was a lovely, teeny-tiny ceremony in October 2013 in Woodinville, WA.

When it comes up, I get a lot of questions. There are several reasons we made this choice, and I don’t regret it.

If your dream is to have a huge ceremony, that’s fine. However, I bring this up because I’ve had conversations with brides-to-be admitting they never wanted a huge ceremony and feel completely overwhelmed.

I’m here to tell you it doesn’t have to be this way.

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