The pages of ThinkGeek teem with techno-tees fitted with LEDs, speakers, DIY artwork, virtual instruments and WiFi meters. Meanwhile, companies vie to gin up greener charging methods for cell phones.
Is it time for a mashup? A cellphone-charging tee? Maybe – but good luck wearing one through airport security.
If the back of your entertainment system looks like a cross between mission control and a 1960s Manhattan switchboard, you could probably use a little help separating your composite from your component video. In this article, I’ll explain the oxymoronic mystery that is optical audio, with stops along the way to explore the evolution of inputs, outputs, standards and jacks that led to it. I’ll also tell you how this fiberoptic system stacks up against HDMI.
Photography is all about light; it’s right there in the name: photo (“light”) + graph (“means of recording”). So how do you shoot in the gloom between the golden hours? Well, you have a few options. You can pop in a flashbulb. You can try your hand at painting with light – that is, fiddling with f-stops and shutter speeds to let more light in over a longer period. Unfortunately, flashbulbs tend to wash out photos, and setting up longer exposures tends to limit your photographic freedom.
Night-vision cameras and attachments get around these problems, either by amplifying existing light or working with a different kind of ambient “light” – aka infrared radiation, either from body heat (thermal IR) or from an active IR illuminator attached to the camera. Today, infrared and ultraviolet cameras also make useful tools for inspections and field work. But how do they work, and what is their history?
There’s an old run of Peanuts in which Charlie Brown is repeatedly confronted by girls skipping “hi-fi” jump ropes or wearing “hi-fi” bracelets. Each strip ends with Charlie Brown loudly questioning how such an object can be hi-fi, but of course we know the answer: marketing.
Magnetic soap has that sort of ring to it, too. But there are actually good reasons for making surfactants – the group of surface-tension reducing substances to which soap belongs – stick to magnets. Imagine cleaning up an environmental disaster like the Deepwater Horizon oil spill without leaving any of your cleanup materials behind, and you’ll begin to see what I mean.
Of course, that doesn’t exampling how soap can be magnetic in the first place. For that, you’ll have to read on.
One of the unwritten rules of physics says you can’t get something for nothing; at best, you can swing a fair exchange rate between energy in and energy out. The problem is heat: Like an energy embezzler, it skims off the top of chemical reactions, physical systems and electrical circuits (which is why we can’t have perpetual motion machines).
Superconductors don’t break the laws of thermodynamics, but they do manage to find some fairly large loopholes. Send current through a superconducting wire, and it loses no energy to resistance. Bend the wire into a loop, and it will hold charge indefinitely. Levitate it above a magnet, and the sun will devour the Earth before it will fall.
Plus, it can levitate a frog.
What is Superconductivity?
Quiz: How Super are Superconductors?