Rotating Out of the Imaginary Plane

Commentary: Let’s get real about alternative energy

Lots of good stuff, including some tips that quantify some suggestions for efficiency,

Take, for example, the idea that one of the top 10 things you should do to make a difference to your energy consumption is to unplug your cell-phone charger when you are not using it. The truth is that leaving a phone charger plugged in uses about 0.01 kWh per day, 1/100th of the power consumed by a lightbulb.

This means that switching the phone charger off for a whole day saves the same energy as is used in driving an average car for one second. Switching off phone chargers is like bailing the Titanic with a teaspoon. I’m not saying you shouldn’t unplug it, but please realize, when you do so, what a tiny fraction it is of your total energy footprint.

as well as putting the alternative power generation options into perspective. Fossil fuels are used because they have a high energy density and they are transportable. Alternatives will have shortcomings.

There’s also a comment about hydrogen — one must realize that hydrogen is a storage medium, not a source. i.e. you have to make hydrogen, so hydrogen = battery

Before I close, I would like to say a few words about the idea that “the hydrogen economy” can magically solve our energy problems. The truth is that, in energy terms, today’s hydrogen-powered vehicles don’t help at all. Most prototype hydrogen-powered vehicles use more energy than the fossil-fuel vehicles they replace. The BMW Hydrogen 7, for example, uses 254 kWh per 100 km, but the average fossil car in Europe uses 80 kWh per 100 km.

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It's All Greek to Me

Easy as α β γ ?

The brilliant young PhD student Ralph Alpher working with his advisor George Gamow were about to publish a major work about the origins of the elements after the Big Bang. In a burst of inspiration, Gamow invited the physicist Hans Bethe to include his name on the paper, even though he had not contributed to it at all. That way the paper would have been authored by Alpher, Bethe, Gamow, a play on the first three letters of the Greek alphabet alpha, beta, and gamma. It was a delightful pun, and their one page paper serendipitously ran in the April 1st issue of Physical Review Letters.

Random Laser

The Laser Glow of an Atom Cloud

A normal laser is essentially a gain medium inside a reflective cavity. The light is amplified by the medium as it bounces back and forth between the cavity’s mirrors. A random laser has no cavity. Instead, tiny “mirrors,” or scatterers, are added to the gain medium, causing photons to bounce around and become amplified by the medium, before escaping in all directions. For example, a container of micron-sized particles floating in water in which a laser dye has also been dissolved can emit laser light if pumped with external light. Random lasers do not require the same precise manufacturing as normal lasers, so they could be inexpensive to produce. Potential applications include digital displays, light emitting paints, and temperature sensors.