Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Featured Stargazing U.S. Solar Eclipse of Aug. 21, 2017

  1. Jul 16, 2017 #151
    Might try, http://www.cambridgeincolour.com/
     
  2. Jul 17, 2017 #152

    OmCheeto

    User Avatar
    Gold Member

    I checked.
    I could not find a "How to photograph white cows in a blizzard" article, but did see that "UV filters" used to be used for that purpose. I still have all of my old "film" developing junk, and found a UV filter.
    In the one article I read, it stated that digital cameras don't suffer from the "UV light confusing" the camera.
    After taking a couple of images with and without the filter, I can't tell a difference.
    I may have to read the manual for my camera. Please don't tell collinsmark. It's been over a year.....

    [edit: Nada. The camera has no special features in "movie" mode]

    ps. That linked thread is actually a setup for my next question.
     
    Last edited: Jul 17, 2017
  3. Jul 20, 2017 #153
  4. Jul 20, 2017 #154

    jim hardy

    User Avatar
    Science Advisor
    Gold Member

    I read someplace that a #12 or #14 welder's helmet lens is a suitable filter.

    Hasn't been easy finding a table of attenuation vs shade number
    here's best i could do, from https://photo.stackexchange.com/que...-translate-to-stops-when-used-as-an-nd-filter
    weldingshade.jpg

    but the higher numbers are hard to find.

    My guess from transmittance numbers is that two #10's together will be not far from a #14... for visible that is
    transmittance of 0.0139 ^2 = 0.000193, which is 71% of a #14's nominal 0.00027
    UV is better by an order or two of magnitude ?
    so
    I bought two pair of #10's, with tax they cost me about five bucks each
    upload_2017-7-20_15-22-24.png



    when get a minute will see what they do to the sun.

    I figured it's safer than something home-made.
    If there's a welding optics guy in the house i welcome corrections .

    old jim
     
  5. Jul 20, 2017 #155

    OmCheeto

    User Avatar
    Gold Member

    That is seriously interesting.

    "If you don’t think the danger is real, read this amazing recent interview with an optometrist on Space.com, where he states you can actually see the crescent Sun burned into the backs of patient’s eyes who stared too long at a partial solar eclipse (!) It’s a permanent souvenir you don’t want to have."

    But that brings up the question; "How long can you stare at the sun without getting a 'souvenir'?"

    After some googling, it looks as though there have not been enough volunteers for such a study, but;

    "Eclipse watching is the commonest cause of solar retinopathy..." [ref: British Journal of Ophthalmology]​

    :oldsurprised:

    Sunglasses, stained or smoked glass, and old film negatives do not protect against retinal damage following deliberate observation of the sun.
     
  6. Jul 20, 2017 #156

    OmCheeto

    User Avatar
    Gold Member

    Ok. This looks like a reasonable answer.

    "...read this amazing recent interview with an optometrist on Space.com"

    While official recommendations by NASA and the American Astronomical society say you shouldn't look directly at the sun when any part of it is showing, experienced eclipse watchers like Chou say it's safe to remove your eclipse glasses during the 2-3 seconds before and after totality to see the so-called diamond ring effect, or "Baily's beads." During this phase of the eclipse, the light of the crescent sun forms points of light on the edge of the disk for just a few seconds.
     
  7. Jul 20, 2017 #157

    jim hardy

    User Avatar
    Science Advisor
    Gold Member

    Two #10's make the afternoon sun just a pale yellow circle in a black field. It's so dim as to be barely visible so i'll have to rig some sort of face shield to block light from the sides. I think i'll look at welder's helmets .......

    One #10 is NOT enough .

    old jim

    Late entry

    got a welding helmet with #10 lens. Another lens taped on should work, will try it tomorrow..

    Hobart 770264 , $33 at Amazon $25 at Tractor Supply..
    upload_2017-7-20_21-42-11.png
     
  8. Jul 21, 2017 #158

    anorlunda

    Staff: Mentor

    Uh oh. I just read this article about eclipse mania. They make it sound like this scene from the movie Contact.

    fIMfPvD.png

    It makes me fear that I may have seriously underestimated the logistics of seeing the totality. My wife and I are departing Vermont in the beginning of August for a 6 week car+tent tour of the US Northwest & Canada. The high point of the trip would be the eclipse. It is not our habit to plan anything in advance when we tour. We just follow our noses.

    I thought loosely that if we went to any remote area of Wyoming or Idaho or Oregon that we would have clear skies with no crowds. I did not plan to find a camp site within the zone of totality. But I thought we might be able to tent within 100 miles of the zone, and then drive in for the event and drive out again before dark. But in the remote areas, highways are also scarce. The approach roads might be jammed solid, and one can't find a private place behind a bush to pee. In short, my planning might be woefully inadequate.

    Counting only the American West. It seems like infinite wide open space, but not really. Let me do a little Drake equation.

    There are about 5 billion square meters of surface in the totality zone within 1000 miles of the Pacific. Optimistically, 1% of that is is within 200 m of a road. Figure 5 square meters per person including their car and chairs. There is room for only 10 million people, whereas 100 million people might be interested. Ay ay ay, it may get very crowded indeed.

    10 million people also need about 3 million toilet visits per hour. My wife and I are 72, we're no longer like Woodstock hippies.

    USA-WDSTK-2-1A.jpg

    One thing we won't do is to cancel. This is a chance of three lifetimes. I just hope that the news reports are greatly exaggerated.

     
    Last edited: Jul 21, 2017
  9. Jul 21, 2017 #159
    Quoting from the article, it's no wonder volunteers have been in short supply. (You would think a trained psychologist would know better than staring at the Eclipse long enough to blind himself.)
    "Don’t be like 18th century psychologist Gustav Fechner who blinded himself staring at the Sun, mesmerized by the glare of lingering afterimages."
     
  10. Jul 21, 2017 #160

    OmCheeto

    User Avatar
    Gold Member

    If only it would be that peaceful. Just to be safe, I'm planning for a "Zombie Apocalypse":



    This has been me, every day, for quite some time.
    Just two weeks ago, I ran into a guy at our local renaissance faire. He was lugging around a $6000 camera/tripod setup. (He claimed the tripod cost more than his camera.)
    After about 5 minutes of conversation, I asked him where he was going for the "Eclocalypse".
    He said; "Fossil".
    Which is where I was planning on being.
    :oldcry:

    One glimmer of light is that I've found a multi-thousand acre ranch very near where I wanted to be, and they are only charging $150 per person, for a Thursday-Monday camp spot, and they only have 268 followers on Facebook. Which makes me suspicious, that they might be Russian hackers.
    http://www.mountaincreekeclipse2017.com/

    But I'm still going to wait on the weather report. I just discovered yesterday that I'm only a 19 mile bicycle ride away from the edge of totality.

    Furthest I'm willing to drive: 700 miles, Idaho Falls, Old Jim's place. Major cost: gas (≈$120)
    Middling place I'm willing to drive to: Mitchell Oregon, 200 miles. Cost: Ehr mehr gerd. 5 days of supplies, with self supplied solar heating & cooling, etc.... ≈$1000
    Bicycling distance: 19 miles. Might have to get up and leave by 5 am. Cost: New inner tubes. (guessing $10)

    [preemptive edit: Ehr mehr gerd......]



    These [russian hacker] kids might have a media agent.
    [/preemptive edit]
     
  11. Jul 21, 2017 #161

    Janus

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Just double checked, and our reservation in Lincoln City that we made back in early September is still good and for the same price as when we booked. Now its just a matter of good weather :cool:. (and no Hag fish spilled on the road. We spent three nights in Depoe Bay last week, and got caught in the traffic jam caused by that accident for better than an hour. If that wasn't bad enough, we were on a fairly steep incline and I have a stick shift. It was clutch and brake, clutch and brake the entire time.)
     
  12. Jul 21, 2017 #162

    OmCheeto

    User Avatar
    Gold Member

    My next door neighbors parents own a bar in Depoe Bay. I mentioned the "Hag Fish" incident to him yesterday, saying; "That reminded me of you!"

    Good thing he has a sense of humour.

    ps. My brother owns a house in Waldport, where he says he'll be for the eclipse, with my grand-nephew. It's on the VERY southern edge of totality, meaning; 1 second of totality......

    I did some interpolative [aka bad] maths the other day, and it appears that eclipse durations are kind of like Einstein's Lorentzian mass maths:

    2017.07.21.eclipse.lorentz.png

    All they have to do, is walk for an hour northward, and it will be... Wow......

    Hopefully, my sister-in-law got my "Eclipses destroy Eyes!" message yesterday.
    My brother, although well meaning, is, IMHO, a bit daft.
     
  13. Jul 21, 2017 #163

    OmCheeto

    User Avatar
    Gold Member

    :oldlaugh:

    Just checked out the wiki entry on "Mitchell Oregon", trying to determine the average night time temperature[44 - 52°F. Bring warm night time clothing!], and saw this at the end:

    In popular culture
    In the novel World War Z[as in... Zombie!], by Max Brooks, the people of Mitchell are almost entirely infected and turned into zombies. Instead of being cleared, the town is sealed and is turned into the K-9 Urban Warfare school, where military dogs are trained with live zombies.

    ps. I've never actually seen the movie.
     
  14. Jul 22, 2017 #164

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

    upload_2017-7-22_11-13-32.png

    My spot..... I'll be driving home from Texas to see the eclipse....
     
  15. Jul 22, 2017 #165

    anorlunda

    Staff: Mentor

    The web site that gave you numbers for the spot you clicked looks useful. Do you have a link for it?
     
  16. Jul 22, 2017 #166

    Dr Transport

    User Avatar
    Science Advisor
    Gold Member

  17. Jul 22, 2017 #167

    jim hardy

    User Avatar
    Science Advisor
    Gold Member

    That's likely near where i'll wind up. That's only a three hour drive for me.
    Things are just not falling in to place for a run way out west, family complications ...

    Tried my welder's helmet on the noonday sun. It has a #10 lens and i just duct-taped another #10 in front of it. Sun is a nice yellow disc .
    Helmet needs a blocking cloth in back , ambient light makes reflections on inside of lens..
     
  18. Jul 22, 2017 #168
  19. Jul 22, 2017 #169

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    I expect that this site underestimates the number of visitors, especially in the west, far away from the 2024 eclipse path:
     
  20. Jul 22, 2017 #170
    I believe the "stat" page I linked was only concerned with the event on the 21st, The 2024 show will be "Full House" over almost it's entire path due to the populated area it's covering, vastly different demographics from this years Eclipse. I have Family in both Lincoln City, Oregon and Thermopolis, Wyoming, after seeing the odds of favorable weather at both locations I've decided on being a little south of Thermopolis unless the weather goes to hell. Contingency spot is Mt. Borah, although my wife and I have hiked that area many times we won't be trying the peak due to her health. (Isn't it ironic how the edge of the Eclipse just brushes the northern part of "Craters of the moon". :smile:
     
  21. Jul 22, 2017 #171

    OmCheeto

    User Avatar
    Gold Member

    Twas a similar video of Mt. Jefferson, that made me sad I'm so old.



    I was actually devising plans of buying bolt cutters to get through forestry service gates, camping at just below the peak the night before, etc, etc. Fortunately, the logistical problems nipped that idea in the butt.
     
  22. Jul 22, 2017 #172
    Most people just hook on a stout chain and take off in low gear. (Not that I'm advocating vandalism of forest service gates) Actually the best hiking is behind those gates due to the lack of traffic.
    Don't get me started.:frown:
    All said that Mt. Jefferson looks awesome. :thumbup:
     
  23. Jul 22, 2017 #173

    OmCheeto

    User Avatar
    Gold Member

    Just found another video of climbing the mountain made around this time last year.

    Ehr mehr gerd......



    Near the end, you can see it's "above the clouds".

    Love his quote at the end; "If you want to experience fantastic things, you need to put yourself, in fantastic places."
     
  24. Jul 22, 2017 #174

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    Sure, and I think they underestimate the number of people interested in it.

    I mentioned the 2024 eclipse because someone close to the line of totality then has a smaller incentive to see the eclipse next month.
     
  25. Jul 22, 2017 #175

    BillTre

    User Avatar
    Science Advisor

    I was reading an article about photographing the eclipse that pointed out the following:

    If you are at a relatively high vantage point, you might be able to see the shadow of the moon as it is sweeping across lower areas, before and after the eclipse occurs at your specific location.
    I would like to make a video of this but I feel I will be lucky to find such a high vantage place since they are not obvious on maps.
    Maybe a butte or cliff next to a river.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted