Future Foundry (by alaric)

My father Lionel and stepmother Lynn were here to stay for a day again, so while Lynn took Sarah shopping, Lionel sorted out the little garage I am planning to make into my metalwork shop.

He did such a great job:

...that there's more space than I had hoped for, so I will instead make it into my full metal workshop. I was planning on just doing the forging and casting in here, and shouldering the metal machining into my grandfather's old workshop - but that can now stay as a wood workshop.

I just need to wait for the rest of my tools and the foundry stuff to arrive - hopefully not before I finish my backlog of work, because it would be frustrating to have it all there waiting to be set up when I don't have the time...

Lionel also found time to enjoy feeding Jean:

Whereas I, in an honest effort to (in one stroke) keep her warm, absorb any more partially-digested milk that should come out, and keep her sitting upright (which she likes, and cmplains if laid down when she's feeling inquisitive), managed to make her look like a Boohbah:

Transistors (by alaric)

Now, my knowledge of electronics really centers around digital stuff, so transistors have always remained a bit of a mystery to me. Sure, I know the gate or base input controls stuff flowing between the other two oddly-named pins, but I've never really known how this works out in practice - if a 12v battery is placed betwixt the collector and emitter of an NPN transistor, and the base is supplied from the +12v rail via a 10KΩ resistor, what would happen? Read more »

Avalanche functions (by alaric)

One way of looking at the design of a cipher is that you are taking a small fixed-block-size cipher of known good design, and finding a way to extend the security of that small block cipher to a larger block, potentially variable sized.

For example, stream ciphers (and their close cousins, 'cipher modes' like OFB, CFB, and so on) work by splitting the message into smaller blocks and applying the mini-cipher to each block in turn; but if they did that with the same key each time, the result would not be particularly secure for various reasons - weaker than the mini-cipher - so they use various means of causing interrelationships between the mini-blocks.

This brings about a property known as "avalanche"; namely, changing a single bit of the input should cause 'cascading changes' such that (on average) half of the output bits are changed, meaning that the new output is as related to the old output as two independently chosen random bit strings.

Bubble woman (by alaric)

http://www.izpitera.ru/lj/tetka.swf

This thing is interesting, yet sincerely odd.

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Future Foundry (by alaric)

Last weekend, we went to visit the Mill and take the first load of boxes up to the Bakery, which is now unoccupied (except for being used to put guests up) until we move in.

There is a single garage on the end of the Bakery that I'd never given much thought to, since it was always full of junk and for some reason I remembered it being made of wood. However, it turns out to all be very obviously made of stone (my powers of observation are just great!), and whats more, it had been used by the tenants in the Bakery and was, therefore, now empty. In fact, it's where we put our boxes of books we'd taken up there.

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