Thursday, March 23, 2017

Letter in support of proposed wind turbine sound rules

To the Clerk of the Vermont Public Service Board:

I support the proposed wind turbine sound rules as a first step to protect the aural environment of our mountains.

As you know, a quiet rural night in Vermont is likely to have a sound level of only 25 dBA or even less. An increase in ambient noise of 5 dB is recognized as a cause of widespread complaints. So limiting the sound level at night to 35 dBA is not severe but actually rather lenient.

The proposed rule does not address low-frequency noise, which Denmark (the world's leader in wind energy technology and implementation) since 2011 has limited to 20 dBA indoors (10-160 Hz).

Infrasound (which is not heard but instead felt) is also a concern, with many acoustic engineers determining that a C-weighted indoor limit of 50 dB is necessary to protect health.

Nor does the proposed rule address amplitude modulation, the distinct "swish" or "thump" of large wind turbines. In the UK, planning permission for the Den Brook project included a rule to limit amplitude modulation: A 125-ms pulse of 3 dBA or greater (3 dB being the difference in noise level detectable by the human ear) can not occur in any 2-second period five or more times in six or more minutes of any hour, when those minute-long average noise levels are 28 dBA or more.

While these limits, as well as the proposed setback of 10 times the total height from residences (which should be at least 15 times the height, and from property lines, so that people can enjoy all of their property), begin to protect human neighbors, they do nothing to protect the wildlife of the mountains, who in most cases are much more sensitive to sound than humans.

[See also:  Proposal and comments for implementing a rule regarding sound from wind generation projects, by Stephen Ambrose]

Monday, March 20, 2017

Devils take you.

Irish curse:  Go mbeire an dhá dhiabhal dhéag leo thú.

Pronunciation:  Guh mairuh un gaw yeewul yayug luh hoo.

Translation:  May the twelve devils take you with them.

Actual word order:  That carry the two devils ten with them you.

Wednesday, March 15, 2017

Jet lag, depression, and the circadian rhythm

From “The Sleeping Cure”, by Richard A. Friedman, New York Times, March 12, 2017:

When you quickly cross several time zones, your circadian rhythm remains stuck in the city you left behind. Arriving in Rome with your New York City brain is what produces the unpleasant symptoms of jet lag: fatigue, malaise, poor concentration and mood changes.

When you leave New York at 6 p.m., the Italians are probably in bed asleep. But you won’t feel ready for sleep until around 11 [p.m. New York time, or around 5 a.m. in Rome]. To make the right adjustment, you need to shift your internal clock earlier by six hours.

Unfortunately, exposure to light in the middle of the night will do the opposite. Instead of shifting you earlier to Italian time, it makes you feel it’s even later — that the night is over and it’s already morning.

If you’re ever in that situation, close the shades and put on dark sunglasses. Keep the glasses on until lunchtime in Rome — or 7 a.m. back home. Then go out into the sun, have an espresso and enjoy the splendor of the ancient city. This will shift your clock closer to Roman time.

The clock in your brain doesn’t just take cues from light, but from the hormone melatonin as well. Every night, about two to three hours before you conk out, your brain starts to secrete melatonin in response to darkness. Taking a melatonin supplement in the evening will advance your internal clock and make it possible to fall asleep earlier; taking it in the morning will do the opposite. (You might assume this would make you even more tired during the day but it won’t; you could think of it as tricking your brain into believing you slept longer.)

So now you know the fix for jet lag: Travel east and you’ll need morning light and evening melatonin; go west and you’ll need evening light and morning melatonin.

...

Researchers have developed a limited form of sleep deprivation that is euphemistically called wake therapy. It has been shown to have sustained antidepressant benefit in patients with bipolar disorder and major depression. The idea is to get up for the day halfway through the usual sleep period, which shifts the circadian clock to an earlier time. It’s thought that this works by realigning the sleep cycle with other circadian rhythms, like changes in levels of body temperature and the stress hormone cortisol, that are also out of sync with each other in depression.

Studies show that it is possible to make wake therapy even more powerful by incorporating two additional interventions: early morning light therapy and what’s called sleep phase advance, in which the patient goes to bed about five to six hours earlier than usual and sleeps for about seven hours. This combination of treatments is called triple chronotherapy, and the typical course involves one night of complete sleep deprivation followed by three nights of phase-advanced sleep and early morning light.