22 July 2014

Going solar, part 2: Economics and hardware

Costing a solar system is complicated; there’s just no getting away from that. So I’m not going to present a detailed cost breakdown; instead, I’ll outline a few of the complexities. First of all, solar panels vary in efficiency. Higher efficiency panels generate more power per unit area, but they also cost more. So do you buy more panels, buy better panels, or aim to use less electricity? Similarly, the inverter which turns DC electricity from the panels into AC has a certain capacity and efficiency, and there are lots of companies making them to all kinds of specifications. ... Read more

21 July 2014

Going solar, part 1: History and practicalities

The first working solid state solar cell was developed in 1883 by Charles Fritts. Just 1% of the solar energy hitting the cell would be converted to electricity, and the cell was made from selenium with a thin layer of gold, making it far too expensive. It wasn’t until the development of silicon semiconductor junctions in the 1950s that solar cells started to become economically practical. Bell Labs developed a silicon-based solar cell with about 6% efficiency in 1954. ... Read more

19 July 2014

Apple’s iOS spyware

iOS hacker Jonathan Zdziarski has put together a presentation about the deliberate backdoors Apple maintains in iOS. Firstly, the iOS data encryption uses a hardware-determined encryption key to protect SMS, photos, videos, contacts, audio recording, and call history, no matter what passcode you choose. This key is referred to in code as “NSProtectionNone”, suggesting that the programmers understood the implications and picked the internal label as a snarky way of saying so. ... Read more

9 July 2014

Life of pie

Recently I’ve suffered some sort of viral infection that left me with pounding headaches for almost two weeks. I’m currently fighting off the last of it, which mostly manifests as dizziness but is amenable to regular doses of aspirin. During my long days of laying in bed dosed up on hydrocodone and still aching, my mind naturally turned to trepanation, a controversial elective surgery often performed by amateurs, and featured in the movie π. ... Read more

15 June 2014

The rat

We were sitting in a neighborhood café when I saw her. Someone had lost interest in their lunch, and had dumped a plate half-full of food onto the top of the gray plastic tub where the used coffee cups go. She was sitting nearby, nibbling at a piece of pita bread she had grabbed from the plate, her whiskers glinting in the afternoon sunlight. I sipped my iced coffee and watched. ... Read more

© mathew 2017