mersenneforum.org  

Go Back   mersenneforum.org > Extra Stuff > Hobbies > Astronomy

Reply
 
Thread Tools
Old 2019-11-11, 19:07   #12
xilman
Bamboozled!
 
xilman's Avatar
 
"π’‰Ίπ’ŒŒπ’‡·π’†·π’€­"
May 2003
Down not across

29×3×7 Posts
Default Sic transit gloria Monday,

Completely clouded out.

Exactly what one should expect in this ${DEITY}-forsaken country.
xilman is offline   Reply With Quote
Old 2019-11-11, 20:05   #13
Dr Sardonicus
 
Dr Sardonicus's Avatar
 
Feb 2017
Nowhere

10010001000112 Posts
Default

Quote:
Originally Posted by xilman View Post
Completely clouded out.

Exactly what one should expect in this ${DEITY}-forsaken country.
Edmond Halley had a similarly gloomy view of the weather on the island of St. Helena, where he spent two years observing the heavens. In Return to St Helena we find
Quote:
In November 1677 Halley wrote to Jonas Moore that:
such hath been my ill fortune, that the Horizon of this Island is almost always covered with a Cloud, which sometimes for some weeks together hath hid the Stars from us, and when it is clear, is of so small continuance, that we cannot take any number of Observations at once; so that now, when I expected to be returning, I have not finished above half my intended work; and almost despair to accomplish what you ought to expect from me.
He was, however, able to observe the transit of Mercury on 28 October 1677.
Dr Sardonicus is offline   Reply With Quote
Old 2019-11-11, 22:47   #14
Spherical Cow
 
Spherical Cow's Avatar
 
Nov 2004

22×33×5 Posts
Default

Quote:
Originally Posted by xilman View Post
Completely clouded out.

Exactly what one should expect in this ${DEITY}-forsaken country.
Partially clouded out here in desert, but the best pictures were the ones with the clouds, actually, as there were no interesting sunspots. Nor any uninteresting sunspots, even. Cellphone camera again, so I'm sure you'll see many higher resolution images on the internet.

Better than waiting until 2032.

Norm
Attached Thumbnails
Click image for larger version

Name:	20191111_084320shrp-crop-v2smallrsz.jpg
Views:	146
Size:	829.2 KB
ID:	21299  
Spherical Cow is offline   Reply With Quote
Old 2019-11-12, 02:47   #15
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

2·5·312 Posts
Default

Quote:
Originally Posted by xilman View Post
Sic transit gloria Monday
Correct is: sic transit Gloria Gaynor. Or, in this case, sic transit gloria alien, aaa... sorry, mercurian...

LaurV is offline   Reply With Quote
Old 2019-11-12, 02:55   #16
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

2×5×312 Posts
Default

Quote:
Originally Posted by Spherical Cow View Post
the best pictures were the ones with the clouds,
That photo is not good, because the sun has a black dot in the middle....
I somehow imagine some communist censor publishing it in a scientific magazine, or a newspaper, but not before fixing the inaccuracy of the film...

Now, joking apart, assuming I have an infinite-resolution of that photo, could I guess/calculate your exact location on earth, where the photo was taken, without knowing the time it was taken at? (In theory this would be possible, I think)

Last fiddled with by LaurV on 2019-11-12 at 03:01
LaurV is offline   Reply With Quote
Old 2019-11-12, 12:56   #17
Spherical Cow
 
Spherical Cow's Avatar
 
Nov 2004

10000111002 Posts
Default

Quote:
Originally Posted by LaurV View Post
That photo is not good, because the sun has a black dot in the middle....
I somehow imagine some communist censor publishing it in a scientific magazine, or a newspaper, but not before fixing the inaccuracy of the film...

Now, joking apart, assuming I have an infinite-resolution of that photo, could I guess/calculate your exact location on earth, where the photo was taken, without knowing the time it was taken at? (In theory this would be possible, I think)
Hmmm. Interesting; I'll have to think that through- my first guess would have been that we would need to know the time to calculate the location on earth. Plus, we would probably have to make assumptions about distortion of the image. The optics are not likely perfectly aligned- this is a cellphone mounted tentatively over the eyepiece, with cellophane tape and rubber washers as spacers; a "Rube Goldberg" approach (. (Although the cellophane tape has been carefully calibrated...). Guess I better measure the solar image first, to see if its actually circular.

Norm
Spherical Cow is offline   Reply With Quote
Old 2019-11-12, 13:08   #18
retina
Undefined
 
retina's Avatar
 
"The unspeakable one"
Jun 2006
My evil lair

2×19×163 Posts
Default

Quote:
Originally Posted by LaurV View Post
Now, joking apart, assuming I have an infinite-resolution of that photo, could I guess/calculate your exact location on earth, where the photo was taken, without knowing the time it was taken at? (In theory this would be possible, I think)
I think the best you could expect is to narrow it down to a line crossing the Earth. To pinpoint the precise position on the line you need the exact time. Fortunately the exif metadata does have the time (but it doesn't have the GPS coords), and assuming the time is suitably accurate then you could compute the position.
retina is online now   Reply With Quote
Old 2019-11-12, 16:25   #19
PhilF
 
PhilF's Avatar
 
Feb 2005
Colorado

22·7·23 Posts
Default

Quote:
Originally Posted by LaurV View Post
That photo is not good, because the sun has a black dot in the middle....
I somehow imagine some communist censor publishing it in a scientific magazine, or a newspaper, but not before fixing the inaccuracy of the film...

Now, joking apart, assuming I have an infinite-resolution of that photo, could I guess/calculate your exact location on earth, where the photo was taken, without knowing the time it was taken at? (In theory this would be possible, I think)
Because of the principle of the diffraction of light, there isn't any such thing as infinite resolution.
PhilF is offline   Reply With Quote
Old 2019-11-12, 19:39   #20
xilman
Bamboozled!
 
xilman's Avatar
 
"π’‰Ίπ’ŒŒπ’‡·π’†·π’€­"
May 2003
Down not across

29×3×7 Posts
Default

Quote:
Originally Posted by PhilF View Post
Because of the principle of the diffraction of light, there isn't any such thing as infinite resolution.
Are you sure about that?

I'm not.
xilman is offline   Reply With Quote
Old 2019-11-12, 20:31   #21
PhilF
 
PhilF's Avatar
 
Feb 2005
Colorado

22·7·23 Posts
Default

Quote:
Originally Posted by xilman View Post
Are you sure about that?

I'm not.
A good discussion of diffraction limit can be found here:

https://books.google.com/books?id=1g...ion%22&f=false
PhilF is offline   Reply With Quote
Old 2019-11-12, 20:56   #22
bsquared
 
bsquared's Avatar
 
"Ben"
Feb 2007

3×1,171 Posts
Default

Video from NASA's SDO:
https://vimeo.com/372671661
bsquared is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mercury Transit Spherical Cow Astronomy 8 2016-05-20 04:53
windows 10 , transit or not? firejuggler Lounge 41 2015-08-17 09:09
Live NASA Webcast of Venus Solar Transit Dubslow Lounge 4 2012-06-13 19:28

All times are UTC. The time now is 13:13.


Fri Jul 16 13:13:23 UTC 2021 up 49 days, 11 hrs, 2 users, load averages: 2.87, 2.38, 1.97

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.