Differential equations: how does separation of variables really work?

There's no shortage of guidance on writing English that people will want to read. In science and technology, however, can we apply the same guidelines without losing information?

As part of my campaign to eliminate wall-warts and external power supplies that don't have on/off switches, I've built a USB charger that has a mains switch. Why? Because nobody seems to sell one.

In a market dominated by the Amazon Kindle, it's easy to forget that Sony, not Amazon, made the first commercially-successful e-book reader.

How worried should we be, that we're wasting electrical energy for no benefit?

How a non-existent English village ended up on maps, and the implications this has for how we handle information.