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Old 2017-08-15, 22:07   #67
cuBerBruce
 
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Quote:
Originally Posted by Xyzzy View Post
We plan to be in Perryville, MO for the eclipse.

If anyone else is in that area let us know!

I'm tentatively planning to go to the Columbia/Boonville area in Missouri, It looks like Perryville is about a 3+ hours drive from there. Plans may change depending on weather forecasts.
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Old 2017-08-16, 02:54   #68
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Quote:
Originally Posted by richs View Post
I received my eclipse glasses in two days using Amazon Prime. But be sure that they are ISO approved to be safe:

http://www.skyandtelescope.com/astro...m_medium=email
Hmm, since I and my friends will be in the area of maximum totality duration... perhaps I'll skip them? Hmmm
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Old 2017-08-16, 03:19   #69
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Quote:
Originally Posted by Dubslow View Post
Hmm, since I and my friends will be in the area of maximum totality duration... perhaps I'll skip them? Hmmm
Please don't "play chicken" with the sun. A moment too soon or too late could scar your retinas, as I am sure you know.

I'm just expressing concern. Try to get some glasses!
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Old 2017-08-16, 05:46   #70
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Quote:
Originally Posted by kladner View Post
Please don't "play chicken" with the sun. A moment too soon or too late could scar your retinas, as I am sure you know.

I'm just expressing concern. Try to get some glasses!
I have stared at the sun, directly, for a few seconds, occasionally before -- perhaps 3 or 4 times total in my life, for maybe a total of ~6 seconds... and my eyes are still fine? Obviously I would be sacrificing the before and after, which is significantly longer than totality, but... totality will be pretty hard to miss lol.

On a different note, just how many people will be in the Carbondale area (say, to within a ~10-20km tolerance)?
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Old 2017-08-16, 06:07   #71
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Quote:
Originally Posted by Dubslow View Post
I have stared at the sun, directly, for a few seconds, occasionally before -- perhaps 3 or 4 times total in my life, for maybe a total of ~6 seconds... and my eyes are still fine? Obviously I would be sacrificing the before and after, which is significantly longer than totality, but... totality will be pretty hard to miss lol.
An astronomer surveyed the literature.
Galileo, solar observing, and eye safety
The sun near the horizon is safer as many sunset watchers have experienced but it is still scary business.
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Old 2017-08-16, 06:26   #72
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Quote:
Originally Posted by only_human View Post
An astronomer surveyed the literature.
Galileo, solar observing, and eye safety
The sun near the horizon is safer as many sunset watchers have experienced but it is still scary business.
Could it also be related to non-solar visual acuity? As in, I have remarkably good vision, perhaps that's related?
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Old 2017-08-16, 06:32   #73
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Quote:
Originally Posted by Dubslow View Post
Could it also be related to non-solar visual acuity? As in, I have remarkably good vision, perhaps that's related?
His survey goes into considerable detail but I would not like to excerpt any portion out of context. Thermal damage is not the primary factor. Short wavelength photochemical retina damage is worse.

edit: I will add this excerpt after all because eye damage at near totality is the worst.
Quote:
Statistical evidence

Evidence that the normal eye is (marginally) able to look briefly at the Sun without harm is shown by the statistical distribution of solar injuries. After all, the near-total eclipses at which eye injury occasionally occurs are visible only a few minutes per century at any given location on Earth; the unobscured Sun is available for viewing every clear day. If we suppose the Sun is up (on the average) for 12 hours a day, that's about 440,000 hours or over 26 million minutes per century that the Sun is up outside of eclipse, compared to a few minutes of dangerous time near totality. So you'd expect eye injuries from unprotected Sun-viewing to be roughly a million times more common than injuries during eclipses.

But in fact, according to the review of such injuries published by Istock in 1985, “the vast majority of solar retinal injuries occur as a result of viewing a solar eclipse without adequate protection.” So it usually requires the special conditions of an eclipse near totality, in which the low level of general illumination allows the pupil to open up instead of contracting (as it normally does when looking at the Sun), to push the visual system over the threshold for damage in a brief exposure.

Last fiddled with by only_human on 2017-08-16 at 06:42
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Old 2017-08-16, 12:11   #74
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Brian and I saw the total eclipse in 1999 from a field in France.
As the eclipse started, there was no obvious dimming of the sun. A few minutes before totality, it at last got a little darker and the birds stopped singing. Then suddenly, as total eclipse was reached, the light dropped away. In the distance, however, you could still see some light.

Afterwards, we discovered that the field was very muddy, and our shoes were a mess!
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Old 2017-08-16, 16:55   #75
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Quote:
Originally Posted by Dubslow View Post
Could it also be related to non-solar visual acuity? As in, I have remarkably good vision, perhaps that's related?
An article I caught yesterday said that if you look at the unobscured sun your eyes "slide around" avoiding the sun, as evidenced by multiple afterimages that gradually clear. If the sun is in partial eclipse, the visual reference points give your eyes/mind something to focus on that may increase the risk of localized retinopathy.

Bottom line: if you're young, as in less than 35, say, don't take any chances. In another article about the 1979 eclipse there was someone in Oregon who had a classmate say that the hurt went away if you stared long enough at the partial; 38 years later, he's got a "pea sized" blind spot in his visual field. You should have glasses right up until totality...
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Old 2017-08-17, 05:28   #76
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I have started my trip to see the eclipse. Currently I am still a distance away. On the road I saw vehicles marked indicating that they are traveling to see it. Doing some sight seeing in a different area on Thursday. Heading to meet my family member that evening. Will do some things local to them Friday. Saturday will travel up to the hotel. Sunday will scope out locations.

Not currently planning on pointing any camera at it.
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Old 2017-08-18, 20:23   #77
chalsall
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Quote:
Originally Posted by only_human View Post
An astronomer surveyed the literature.
Galileo, solar observing, and eye safety The sun near the horizon is safer as many sunset watchers have experienced but it is still scary business.
So, 2017.08.21 should be interesting...

I have warned everyone I know not to look directly at the eclipse (we're only going to get ~73% coverage here in Bim).

I have suggested they teach their kids how to make a pin hole camera. And perhaps teach them a little bit about how light works. This is a wonderful opportunity for education.

Several people have said to me that they had heard that looking at the sun through a CD would be safe, and that they had done it before without damage. Luckily for them it was overcast at the time. If it is a clear day only 12 grade welding glasses are safe.

Using a "smart phone" with a camera, and watching the eclipse on the screen, would also be safe.
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