Today, January 5, came the latest sunrise, 7:22 AM – as seen from 40 degrees north, the latitude of Philadelphia or Salt Lake city.
From my present latitude of about 51, this happened back on December 31 and the time was more like 8. But I can tell you that it still feels drearily dark to get up when I feel compelled to, at or before 6, and go out under the cold and often damp sky. It feels more like midwinter than it did back on December 22, the solstice and shortest day, or Dec. 12, the earliest sunset for my latitude, or Dec. 8, earliest sunset for latitude 40.
It’s all very well to argue, as Howard Wilk does and I, inspired by him, do in the “Latest and Earliest Sunrise and Sunset” bit on page 31 of Astronomical Calendar 2016, that December 8 is the beginning of the end of winter because from then on the evenings start getting longer and so the days, in that sense, seem to be getting longer and spring is a first twinkle at the end of a long tunnel and we can almost hear the first crocus bulb beginning to swell somewhere underground or the first bud trying to break through the gray bark of a grapevine or the first bloodroot readying itself to open on an Appalachian mountainside
and therefore we should celebrate the day as Seculus. The idea is benevolent; one flaw in it is that business of the date being different for different latitudes. The other is my statement that “Most people in urban cultures are oblivious of sunrise and aware of sunset.” Yes, I may be more often conscious at sunset (I can’t recall an instance of having been passed out) than at sunrise (I sometimes sleep in) but there’s a difference between conscious and aware. In our lives as nomads or gardeners we saw the sunsets but in our lives in rooms and streets we seldom do.
I think cataracts come from too much light.
The medical books say that cataracts have an unknown cause. But logic tells me that if you need clear vision to see in dim light, the body’s wisdom responds by keeping the proteins in the lens clear. Similar to the way the body makes muscles stronger to suit your exercise routine, or the way the brain develops neural pathways as your practice a musical instrument. The body responds to your request for performance.
Another cause of cataracts is reading glasses. Forcing your eyes to focus on small print exercises the ciliaris muscle. The ciliaris muscle contracts to make the lens more convex so you can see close up. When you use reading glasses the ciliaris muscle doesn’t have to work so hard. The lens doesn’t have to change size so it becomes static. Things that don’t move in the body become calcified. In the case of the lens, i it becomes cloudy.
To prevent cataracts, I never use artificial light until it gets too dark to see. I only use reading glasses or a magnifying glass if the print is way too small. For example, I can read the definition in my dictionary without glasses, but to read the italic print that gives the root of the word, I have to use reading glasses.
Furthermore, I think any kind of eyeglasses are bad for your eyes. They are just crutches. I know that some people have to use them but for the most part they are overused. Sorry, Ben Franklin.
You must take care of your eyes if you are an astronomer. It’s one of your best tools.
You are lucky to have got only so far in the deterioration of your eyes.
I don’t think it’s luck. I think my vision is holding out because I limit use of reading glasses. Of course, I am only 57.
Inverted yoga poses are also good for the eyes. Inverted poses are upside down poses, like headstand, shoulder stand, down dog, etc.
Those are useful tips, for those who still have time to make use of them. What I gently meant was that a point will be passed, sooner or later and of course preferably later, and probably by you too, when the choice will be between the artificial means you deprecate – spectacles, magnification, illumination – and ceasing to see anything with precision, thus having to cut such things as reading and astronomy out of your life. After the onset of macular degeneration, for example, which is incurable and for which spectacles are no mitigation; the only help is from magnitfication and illumination and self-training in averted vision. Your advance precautions are no doubt excellent, but a more important one to alert people to is defence against short-wavelength light, by not living outside unprotected against the sun.
Thanx for your info. I knew that infrared rays cause heat cataracts, but I’d forgotten about the UV damage.
Quality eyeglasses (that block 99% of UV light) would be useful if you work in the sun.
Cheap eyeglasses should never be used. They dim the light which dilates the pupil, but since they don’t block UV rays the dilated pupils allow even more UV penetration.
I love this post, it speaks to me of my observations of sunset/sunrise times (locally) in Boone, NC. And waiting for the bloodroot to bloom.
I have a small personal altar in my home. When it gets dark in the evening I light a votive candle on the altar and leave it burning until I go to bed. I refrain from turning on electric lights until after I’ve lit the candle, and beeswax candles are not cheap, so I don’t light the candle until I can’t see what I’m doing. This little habit helps me notice twilight. In the winter one candle usually lasts three nights. In the summer one candle lasts over a week, and during the longest days I need to ceremoniously light a candle even before dusk.
If I get up during the night or before dawn I don’t turn on the lights. Just by opening the curtains, there’s enough light to find my way around. I keep red flashlights and headlamps scattered around my flat in case I need more light for something in particular.
If the sky is clear I’ll usually spend at least a few minutes in the evening and the morning out in the back yard looking at the sky. Even though I live in the middle of a city, the back yard is shielded from streetlights, and my immediate neighbors are all considerate enough to refrain from leaving outdoor lights on when they’re not using them. But I always know exactly when each of them goes to bed and when they get up, because the last thing they do in the evening is turn off their indoor lights, and the very first thing they do in the morning is turn the lights back on. I feel a bit sorry for people who live their whole lives in bright light.
That is something beneficial to think about: a candle that measures the minutes between the onset of dark (the end of “practical light”?) and bedtime. Doesn’t it correspond to what everyone had to do in medieval monasteries and cottages?
I sometimes think I would have been happier living in earlier times. But then I remember that “I” only exist at this moment in history, and that my forebears were poor, uneducated peasants, and that the binoculars I use to look at the sky would have been a marvel to Galileo.
I’m doing an operation on the blog, which happened to bring me back past Anthony’s comment of back in January, mentioning abstaining from switching lights on when walking around at night; it reminded me of a short story I wrote not long ago about walking around with the eyes shut, I may post it here sometime.