Twilight
The things one learns while attempting to garner a little information is just astounding.
Since tonight is the night we set our clocks back, I was curious as to how this would effect my bike riding. It had been getting darker sooner, and with the upcoming change it appears it will be practically impossible to ride after work for a while. I have a headlight and a tail light, but I don't really feel comfortable riding at night. They're more useful for twilight and/or dusk type situations.
I found the times for sunrise and sunset here. Once you enter in the data, it gives you not only the above-mentioned times but also the beginning and ending times for "civil twilight." Of course, I fully realize that the moment the sun goes down all is not dark, but I'd never heard the term "civil twilight" before. So I did a little research.
On this page I got my answer. Civil twilight is the moment the center of the sun is six degrees below the horizantal plane of the horizon line. In layman's terms, it means that after that time, you probably need a flashlight. There's still some ambient light, but not much.
I'd never knew such things were so defined. There's also a nautical twilight, which is where you can still see silhouettes. Astronomical twilight begins when the ambient light reflecting off the upper atmosphere is imperceptible, apparently.
What this means is that I'll probably begin riding my bike in the mornings before school. Where I live, civil twilight begins at 5:50 a.m., which is plenty of time to go for a 45-minute bike ride and still make it in plenty of time for class. As winter moves on, however, the days grow shorter, so the calendar is going to quickly compress on itself.
Sigh. I never knew bike riding involved the study of celestial objects.
Since tonight is the night we set our clocks back, I was curious as to how this would effect my bike riding. It had been getting darker sooner, and with the upcoming change it appears it will be practically impossible to ride after work for a while. I have a headlight and a tail light, but I don't really feel comfortable riding at night. They're more useful for twilight and/or dusk type situations.
I found the times for sunrise and sunset here. Once you enter in the data, it gives you not only the above-mentioned times but also the beginning and ending times for "civil twilight." Of course, I fully realize that the moment the sun goes down all is not dark, but I'd never heard the term "civil twilight" before. So I did a little research.On this page I got my answer. Civil twilight is the moment the center of the sun is six degrees below the horizantal plane of the horizon line. In layman's terms, it means that after that time, you probably need a flashlight. There's still some ambient light, but not much.
I'd never knew such things were so defined. There's also a nautical twilight, which is where you can still see silhouettes. Astronomical twilight begins when the ambient light reflecting off the upper atmosphere is imperceptible, apparently.
What this means is that I'll probably begin riding my bike in the mornings before school. Where I live, civil twilight begins at 5:50 a.m., which is plenty of time to go for a 45-minute bike ride and still make it in plenty of time for class. As winter moves on, however, the days grow shorter, so the calendar is going to quickly compress on itself.
Sigh. I never knew bike riding involved the study of celestial objects.
I'd never heard of civil twilight. Does that imply there is also an uncivil twilight? In fact, what is the source of the word twilight? I always considered twilight to mean the time between the setting,(or rising) of the sun, and total darkness.
You might have to get one of those stationary bikes and ride at home. They're not much fun though. Boring scenery.
Posted by
Fish-2 |
8:11 AM
My best guess is that it's a shortening of the phrase "betwixt the light," but that's just a wild guess. I'll do some research.
I'm actually searching for a device that I can hook to my back tire, so that I can convert my bike into a stationary one for exactly that purpose. I may have to invent something, but I would imagine somone sells it.
Posted by
Yorick |
10:50 PM