December 16, 2013

Advent Chemistry: Titration

Titration is, like most of the concepts I’ve covered this year, basically quite a simple trick. You take an unknown amount of something, and you add somethig it reacts with in small, known amounts, until the reaction stops. Then you know how much of the...

December 15, 2013

Memory: what matters

Advent Computing: Memory: what matters

We know our computers store numbers, but the only way we’ve talked about how to store those numbers was that infinitely long piece of tape the Turing machine had. I want to spend a bit of time talking about how computers actually store data. Before...

Advent Chemistry: Dropwise

Sometimes – often – there are no shortcuts. If you wan to get the best results, you have to take time over them. You have to let your mixture reflux for long enough. You have to dry it off in the oven until it’s properly...

December 14, 2013

Atomics and locks

Advent Computing: Atomics and locks

When writing a simple program, you will normally only have a single “thread of execution”. That means that you’ll write a series of instructions for the computer, and the computer will follow them one-after-another. There might be jumps and loops (“do this five times” or...

December 13, 2013

Advent Chemistry: Magnetic balances

One of the more curious devices in a chemistry lab is the magnetic balance. This is an extremely precise balance – as in, accurate to the nearest hundred thousandth of a gram or closer – with an electromagnet underneath. The balance lives in a nearly...

A green steam train

Advent Computing: Threads, trains and tortured analogies

Imagine you’re running the train network. You have a whole bunch of train tracks, a whole bunch of people to get from one place to another, and just one train to do it with. Simple, right? Move your train from place to place, and let...

December 12, 2013

Making things faster

Advent Computing: Making things faster

Back to something a bit more practical. When you’re working with a computer, it’s pretty common to want it to go faster. It’s pretty rare that going to fast is a problem. So how can you make your computer go faster? How can computer manufacturers...

Advent Chemistry: Piping hot

I’ve mentioned concepts like making things hot before, but I haven’t gone into detail about how. The rather charming image of a chemist in a dark laboratory, tending to a bunsen flame, while the varnish on the wooden bench gleams in the light, and green...

December 11, 2013

A black-and-white photograph of two women operating a large computer. The computer has two large sections, both taler than the women, with a control panel visible in the left one, vacuum tubes visible on both, and a large paper tape reel on the right of the machine.

Advent Computing: A historical divergence: Wartime advances

The key idea from Babbage’s analytical engine was that of a single computer which could solve multiple problems. Previous devices were built to solve a single problem, and at best would need to be disassembled and rearranged before they could be used for anything else....

Advent Oil & Gas: Pipes and tankers

So we have all this useful stuff… but how do we get it to people who will pay for it?  The answer is, simply enough, “in bulk”.  Oil and gas are valuable commodities but it still makes sense to save as much as possible by...

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