I knew that more economic development tends to mean smaller families, and I knew that people were having fewer children in many developing countries. But I hadn't grasped how quickly that shift was happening until I read this comparison from last Thursday's issue of The Economist:

The transition from a [birth] rate of five [births per woman] to that of two, which took 130 years to happen in Britain--from 1800 to 1930--took just 20 years--from 1965 to 1985--in South Korea. Mothers in developing countries today can expect to have three children. Their mothers had six. In some countries the speed of decline in the fertility rate has been astonishing. In Iran, it dropped from seven in 1984 to 1.9 in 2006--and to just 1.5 in Tehran. That is about as fast as social change can happen.

But, while it's easy to assume that slowing population growth means a more sustainable future, it's not really as cut and dry as all that. Like The Economist points out: With development, you also get more people living the fossil-fuel heavy American lifestyle. Their argument: The problem of creating a sustainable future isn't really tied to birth rate. That's taking care of itself and couldn't go much faster without China-like impositions on personal freedom. Instead, the focus needs to be on the technology and policies that will help those children grow up in sustainable, energy efficient societies.

The Economist--"Demography, Growth and the Environment", via Follow the Energy blog.

Light can't escape a black hole. Some people look at this fact and get the shudders. Others think, "Hey, that would make a really effective solar panel!"

Or, rather, it might if not for that whole "massive, crushing force of gravity" problem. MIT's Technology Review has a neat piece about scientists trying get around that minor hiccup. They're working with light-distorting metamaterials, the stuff you frequently see written up in stories about the coming of futuristic cloaking devices, alongside references to Harry Potter's invisibility cloak. But instead of bending light around the metamaterial, these researchers are focusing on a weirder--and, in my opinion, much cooler--goal.

...a metamaterial that distorts space so severely that light entering it (in this case microwaves) cannot escape.Their black hole consists of 60 layers of printed circuit board arranged in concentric circles (see picture below). The printed circuit boards are coated in a thin layer of copper from which Qiang and Tie have etched two types of pattern that either resonate at microwave frequency or do not. They've measured microwaves at 18 GHz going in and none coming out. And the circular symmetry of their metamaterial means that the microwaves are absorbed in all directions at once.

There you have it: The light-capturing power of a black hole, without the teeny inconvenience of being smooshed. Incorporate the material in solar collectors, and you could end up with a much more efficient way of harnessing the sun for energy.

Let's start this off with a quick clarification. When I say "LED light", I'm not talking about the nifty, little blinky things that are frequently part of the ingredients list in Make projects. I'm talking about the Big Show: An LED light that can replace the incandescent bulbs and/or CFLs you have lighting up your home right now. To do it right, you don't just need a single LED that works, you need an array of them...and you need them to produce enough light, and the right color of light, reliably enough that people can buy an LED bulb and know what they're getting into.That ain't easy. But it is getting easier.

Trouble is, they're being oversold, like whoa. For about two-and-a-half years, I've been reporting on LED lighting for a trade magazine called Architectural SSL*. During that time, I've watched mainstream press and enviro blogs tout LEDs as the green energy miracle light. Often, with a level of enthusiasm seldom seen outside rooms full of puppies. Don't get me wrong. LEDs are pretty cool. There are places where they're useful now, and places they probably will be soon. But if you're just hearing about the awesome, you aren't getting the full story. And, as more LED products start showing up on store shelves, that really starts to matter.

Join me, won't you, as we put on our Sober Assessment Goggles and take a peek at the current state of light bulb of the tomorrow...

*The glamorous life of a freelance writer, everybody. That said, if you are thinking about freelance, I recommend convincing a trade magazine or two to love you. The work is steady, the pay is decent and the people are good. And that is a better situation than you'll get from a lot of things you could do to pay the bills. /unsolicitedwriteradvice

A century ago, farmers relied on these big, steampunk-y contraptions called threshing machines to bring in the harvest. The machines were portable, and expensive--they were usually owned by a third party, or by a cooperative of farmers. The threshers traveled from farm to farm, region to region, separating grain from stalk and turning crops into commodities.

Now, researchers from the University of Minnesota are hoping to repeat history with a portable machine that could turn prairie grasses, small trees and corn stalks into liquid biofuel. It's a nifty idea that could be great for both the environment and rural economies...provided the boys in the back room can work out a few bugs.

As a huge fan of FlowingData, NPR and electricity, I'm super excited about this interactive map that gives you a clear view of the structure of the U.S. power grid. Clicking through, you'll see how areas of the country currently are (and aren't) connected to one another, what's in the works to improve the system, and why that matters (a lot) when you start talking about alternative energy sources. Good stuff.

In this picture, you can see the yellow lines that really seem to do a good job of efficiently linking up the whole country. Those power lines haven't been built yet. In the interactive part, you can take those off, revealing a clearer view of our current transmission infrastructure that looks more like a series of occasionally connected river systems than a grid.