sglines writes "Over the last couple of years I've been slowly getting deaf. Too much loud rock and roll I suppose. After flubbing a couple of job interviews because I couldn't understand my inquisitors, I had a hearing test which confirmed what I already knew: I'm deaf. So I tried on a set of behind-the-ear hearing aids. Wow, my keyboard makes clacks as I type and my wife doesn't mumble to herself. Then I asked how much: $3,700 for the pair. Hey, I'm unemployed. The cheapest digital hearing aids they had were $1,200 each. If you look at the specs they are not very impressive. A digital hearing aid has a low-power A-to-D converter. Output consists of D-to-A conversion with volume passing through an equalizer that inversely matches your hearing loss. Most hearing loss, mine included, is frequency dependent, so an equalizer does wonders. The 'cheap' hearing aids had only four channels while the high-end one had twelve. My 1970 amplifier had more than that. I suppose they have some kind of noise reduction circuitry, too, but that's pretty much it. So my question is this: when I can get a very good netbook computer for under $400 why do I need to pay $1,200 per ear for a hearing aid? Alternatives would be welcome."

New Scientist has an update on the so-called "gigantic jets" first discovered in 2003 — these are lightning bolts that reach from cloud tops upward into the ionosphere, as high as 90 kilometers. (There's a video at the link.) What's new is that researchers from Duke University have managed to measure the electrical discharge from a gigantic jet and confirm that they carry as much energy skyward as ordinary lightning strikes carry to the ground. According to the article, "Gigantic jets are one of a host of new atmospheric phenomena discovered in recent years. Other examples are sprites and blue jets."