Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > rec.arts.sf.written > #450409 > unrolled thread
| Started by | jdnicoll@panix.com (James Nicoll) |
|---|---|
| First post | 2016-08-31 19:59 +0000 |
| Last post | 2016-09-02 07:50 -0700 |
| Articles | 20 on this page of 126 — 31 participants |
Back to article view | Back to rec.arts.sf.written
Young People Read Old SFF: Nightfall by Isaac Asimov jdnicoll@panix.com (James Nicoll) - 2016-08-31 19:59 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Lynn McGuire <lynnmcguire5@gmail.com> - 2016-08-31 15:54 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov news{@bestley.co.uk (Mark Bestley) - 2016-08-31 22:43 +0100
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Lynn McGuire <lynnmcguire5@gmail.com> - 2016-08-31 18:30 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-08-31 19:00 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Greg Goss <gossg@gossg.org> - 2016-09-01 03:10 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov jdnicoll@panix.com (James Nicoll) - 2016-09-01 13:41 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov jdnicoll@panix.com (James Nicoll) - 2016-09-01 03:58 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Lynn McGuire <lynnmcguire5@gmail.com> - 2016-09-01 12:37 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2016-09-01 18:07 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-01 11:34 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Lynn McGuire <lynnmcguire5@gmail.com> - 2016-09-01 15:15 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov tsbrueni@gmail.com - 2016-09-01 13:48 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "Michael F. Stemper" <michael.stemper@gmail.com> - 2016-09-01 16:24 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-01 15:45 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-01 15:47 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-02 00:40 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov tsbrueni@gmail.com - 2016-09-01 18:18 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-01 20:20 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-01 19:46 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-01 21:09 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Dimensional Traveler <dtravel@sonic.net> - 2016-09-01 20:47 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-02 03:13 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-02 03:25 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov hamish.laws@gmail.com - 2016-09-01 20:48 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-02 04:34 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Robert Woodward <robertaw@drizzle.com> - 2016-09-01 22:16 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-02 07:32 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-02 07:33 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-03 00:22 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-02 21:39 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "Brian M. Scott" <b.scott@csuohio.edu> - 2016-09-02 22:57 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-02 21:28 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2016-09-03 05:33 +0200
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-02 23:39 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-02 21:25 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Paul Colquhoun <newsposter@andor.dropbear.id.au> - 2016-09-03 18:22 +1000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-03 10:10 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-04 00:38 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov tsbrueni@gmail.com - 2016-09-03 20:23 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-03 08:31 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-03 10:14 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-03 08:25 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-03 08:31 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-02 16:21 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-02 10:39 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-02 13:17 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Jaimie Vandenbergh <jaimie@sometimes.sessile.org> - 2016-09-02 23:03 +0100
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-02 17:54 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-03 00:03 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-02 21:35 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov tsbrueni@gmail.com - 2016-09-02 16:08 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David DeLaney <daviddelaney@earthlink.net> - 2016-09-02 21:16 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov 103134.3516@compuserve.com - 2016-09-07 12:56 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Robert Carnegie <rja.carnegie@excite.com> - 2016-09-07 19:05 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "Brian M. Scott" <b.scott@csuohio.edu> - 2016-09-07 22:21 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-08 04:53 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Jaimie Vandenbergh <jaimie@sometimes.sessile.org> - 2016-09-09 00:12 +0100
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Dimensional Traveler <dtravel@sonic.net> - 2016-09-08 17:00 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Greg Goss <gossg@gossg.org> - 2016-09-08 22:36 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Jaimie Vandenbergh <jaimie@sometimes.sessile.org> - 2016-09-09 08:34 +0100
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David DeLaney <daviddelaney@earthlink.net> - 2016-09-09 04:41 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov tsbrueni@gmail.com - 2016-09-09 03:31 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Jaimie Vandenbergh <jaimie@sometimes.sessile.org> - 2016-09-09 16:36 +0100
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Peter Trei <petertrei@gmail.com> - 2016-09-09 09:11 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Joe Bernstein <joe@sfbooks.com> - 2016-09-09 09:45 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-09 09:52 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-09 11:18 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-09 10:29 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Peter Trei <petertrei@gmail.com> - 2016-09-09 12:17 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Peter Trei <petertrei@gmail.com> - 2016-09-09 12:20 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov scott@slp53.sl.home (Scott Lurndal) - 2016-09-09 19:59 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-09 14:14 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-09 14:44 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-09 15:35 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-09 16:00 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-09 14:34 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Robert Carnegie <rja.carnegie@excite.com> - 2016-09-09 19:19 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-10 04:40 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-10 08:21 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-10 07:09 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-10 10:49 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Dimensional Traveler <dtravel@sonic.net> - 2016-09-10 08:19 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-10 12:27 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Greg Goss <gossg@gossg.org> - 2016-09-10 10:47 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-10 12:49 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-10 17:15 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Dimensional Traveler <dtravel@sonic.net> - 2016-09-10 14:20 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-10 10:29 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-10 12:47 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-10 10:55 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-10 12:51 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "J. Clarke" <j.clarke.873638@gmail.com> - 2016-09-10 17:18 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-11 05:45 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Don Kuenz <g@crcomp.net> - 2016-09-12 00:06 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Robert Carnegie <rja.carnegie@excite.com> - 2016-09-10 11:22 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-10 10:33 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-09 14:33 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Kevrob <kevrob@my-deja.com> - 2016-09-09 15:13 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-09 16:00 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-09 16:08 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Cryptoengineer <treifamily@gmail.com> - 2016-09-10 10:36 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-09 16:06 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-09 16:10 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "Brian M. Scott" <b.scott@csuohio.edu> - 2016-09-10 12:49 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Charles Bishop <ctbishop@earthlink.net> - 2016-09-10 14:43 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov "Brian M. Scott" <b.scott@csuohio.edu> - 2016-09-10 17:57 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Tom Kratman <tomkratman@gmail.com> - 2016-09-10 20:20 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-10 20:27 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Tom Kratman <tomkratman@gmail.com> - 2016-09-11 19:51 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-11 21:16 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Tom Kratman <tomkratman@gmail.com> - 2016-09-12 18:08 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-12 19:40 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Tom Kratman <tomkratman@gmail.com> - 2016-09-14 17:31 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov TB <tsbrueni@dcn.davis.ca.us> - 2016-09-14 18:16 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2016-09-14 22:26 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-11 05:38 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Greg Goss <gossg@gossg.org> - 2016-09-12 21:55 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov 103134.3516@compuserve.com - 2016-09-16 12:06 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-11 05:30 -0700
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David Johnston <Davidjohnston29@yahoo.com> - 2016-09-02 00:12 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov David DeLaney <daviddelaney@earthlink.net> - 2016-09-02 08:53 -0500
Re: Young People Read Old SFF: Nightfall by Isaac Asimov jdnicoll@panix.com (James Nicoll) - 2016-09-02 01:33 +0000
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Greg Goss <gossg@gossg.org> - 2016-09-01 21:53 -0600
Re: Young People Read Old SFF: Nightfall by Isaac Asimov wdstarr@panix.com (William December Starr) - 2016-09-01 20:11 -0400
Re: Young People Read Old SFF: Nightfall by Isaac Asimov Quadibloc <jsavard@ecn.ab.ca> - 2016-09-02 07:50 -0700
Page 3 of 7 — ← Prev page 1 2 [3] 4 5 6 7 Next page →
| From | "J. Clarke" <j.clarke.873638@gmail.com> |
|---|---|
| Date | 2016-09-03 08:31 -0400 |
| Message-ID | <MPG.32341ae4b11fbd0598a503@news.eternal-september.org> |
| In reply to | #450639 |
In article <XnsA677E6946FCBBmelchizedek@216.166.97.131>, treifamily@gmail.com says... > > Don Kuenz <g@crcomp.net> wrote in news:20160902c@crcomp.net: > > > > > TB <tsbrueni@dcn.davis.ca.us> wrote: > >> If our Moon was seven times larger than it is, how long would a solar > >> eclipse last? > > > > That's a good, interesting question, as are your other questions. > > Unfortunately, my knowledge of celestial mechanics is just about nil. > > The length of 'normal' solar eclipses can range up to just over 7 > minutes. If everything else was equal, a 7x larger Moon could > allow an eclipse up to 49 minutes. That's totality, not the partial > covering at start and end. But 7 times larger by what measure? Diameter? Volume? Mass? If the diameter is seven times larger and the density remains constant then the mass will be about 4 times that of Earth, which moves the barycenter of the system to the vicinity of the Moon, which will have an effect on orbital speeds which in turn will alter the duration of the eclipse. Also with it that large totality will not require that the centers of the three bodies be quite as closely aligned, so total eclipses will be of varying lengths.
[toc] | [prev] | [next] | [standalone]
| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-03 10:14 -0500 |
| Message-ID | <XnsA67872564E21Amelchizedek@216.166.97.131> |
| In reply to | #450675 |
"J. Clarke" <j.clarke.873638@gmail.com> wrote in news:MPG.32341ae4b11fbd0598a503@news.eternal-september.org: > In article <XnsA677E6946FCBBmelchizedek@216.166.97.131>, > treifamily@gmail.com says... >> >> Don Kuenz <g@crcomp.net> wrote in news:20160902c@crcomp.net: >> >> > >> > TB <tsbrueni@dcn.davis.ca.us> wrote: >> >> If our Moon was seven times larger than it is, how long would a >> >> solar eclipse last? >> > >> > That's a good, interesting question, as are your other questions. >> > Unfortunately, my knowledge of celestial mechanics is just about >> > nil. >> >> The length of 'normal' solar eclipses can range up to just over 7 >> minutes. If everything else was equal, a 7x larger Moon could >> allow an eclipse up to 49 minutes. That's totality, not the partial >> covering at start and end. > > But 7 times larger by what measure? Diameter? Volume? Mass? > > If the diameter is seven times larger and the density remains constant > then the mass will be about 4 times that of Earth, which moves the > barycenter of the system to the vicinity of the Moon, which will have > an effect on orbital speeds which in turn will alter the duration of > the eclipse. > > Also with it that large totality will not require that the centers of > the three bodies be quite as closely aligned, so total eclipses will > be of varying lengths. Odd. I'd thought of the changing relative mass issue, but somehow didn't get it into the post. But Paul made the point that I'd totally missed - that 'totality' is now short since the leading edge of the Sun appear from behind the only minutes from when the trailing edge dissapears, a larger moon would greatly increase that period. pt
[toc] | [prev] | [next] | [standalone]
| From | Quadibloc <jsavard@ecn.ab.ca> |
|---|---|
| Date | 2016-09-03 08:25 -0700 |
| Message-ID | <914e2d46-45b6-4bb9-8d41-283608134482@googlegroups.com> |
| In reply to | #450639 |
On Friday, September 2, 2016 at 8:39:57 PM UTC-6, Cryptoengineer wrote: > Don Kuenz <g@crcomp.net> wrote in news:20160902c@crcomp.net: > > TB <tsbrueni@dcn.davis.ca.us> wrote: > >> If our Moon was seven times larger than it is, how long would a solar > >> eclipse last? > > That's a good, interesting question, as are your other questions. > > Unfortunately, my knowledge of celestial mechanics is just about nil. > The length of 'normal' solar eclipses can range up to just over 7 > minutes. If everything else was equal, a 7x larger Moon could > allow an eclipse up to 49 minutes. That's totality, not the partial > covering at start and end. The thing is, the Sun is about the same apparent size as our present Moon, it isn't a point. So what gets multiplied by seven for a total eclipse is either the time between first contact and totality or the time between totality and fourth contact. With the Moon seven times larger, for a central eclipse, the time of totality would be six times what we have now for the time between first contact and totality (which time stays the same, as the Sun is the same size). John Savard
[toc] | [prev] | [next] | [standalone]
| From | Quadibloc <jsavard@ecn.ab.ca> |
|---|---|
| Date | 2016-09-03 08:31 -0700 |
| Message-ID | <fa2c62b6-3bb4-4837-bacf-ece9498e33bf@googlegroups.com> |
| In reply to | #450680 |
On Saturday, September 3, 2016 at 9:25:50 AM UTC-6, Quadibloc wrote: > On Friday, September 2, 2016 at 8:39:57 PM UTC-6, Cryptoengineer wrote: > > Don Kuenz <g@crcomp.net> wrote in news:20160902c@crcomp.net: > > > TB <tsbrueni@dcn.davis.ca.us> wrote: > > >> If our Moon was seven times larger than it is, how long would a solar > > >> eclipse last? > > > > That's a good, interesting question, as are your other questions. > > > Unfortunately, my knowledge of celestial mechanics is just about nil. > > > The length of 'normal' solar eclipses can range up to just over 7 > > minutes. If everything else was equal, a 7x larger Moon could > > allow an eclipse up to 49 minutes. That's totality, not the partial > > covering at start and end. > The thing is, the Sun is about the same apparent size as our present Moon, it > isn't a point. > So what gets multiplied by seven for a total eclipse is either the time between > first contact and totality or the time between totality and fourth contact. > With the Moon seven times larger, for a central eclipse, the time of totality > would be six times what we have now for the time between first contact and > totality (which time stays the same, as the Sun is the same size). So instead of taking 49 minutes, the length of a total eclipse in that case would be roughly six hours... plus the original seven minutes, but the error in my "six hours" is more than that. John Savard
[toc] | [prev] | [next] | [standalone]
| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-02 16:21 +0000 |
| Message-ID | <20160902a@crcomp.net> |
| In reply to | #450563 |
Robert Woodward <robertaw@drizzle.com> wrote:
> In article <20160901c@crcomp.net>, Don Kuenz <g@crcomp.net> wrote:
>
>> hamish.laws@gmail.com wrote:
>> > On Friday, September 2, 2016 at 1:25:43 PM UTC+10, Don Kuenz wrote:
>> >> David Johnston <Davidjohnston29@yahoo.com> wrote:
>> >> > On 9/1/2016 6:40 PM, Don Kuenz wrote:
>
> <SNIP>
>> >>
>> >> This thread finally prodded me into a re-read of the whole story.
>> >> Michael got it right up thread. This story requires a complete lack of
>> >> knowledge of celestial mechanics.
>> >>
>> >> One way to achieve "a total darkness all over" Lagash is to change the
>> >> story and have the red dwarf Beta eclipse Alpha and the two distant
>> >> companion pairs. And then have a moon eclipse Beta.
>> >>
>> >> Unfortunately, the story has the other five suns setting. It just
>> >> doesn't work unless you stretch "a total darkness all over" to mean that
>> >> Lagash eventually experiences "a total darkness all over" as each
>> >> longitudinal slice of the planet rotates into the total eclipse.
>> >>
>> > It's been a fair while since I read the story but is it possible that
>> > there's only one small landmass on the planet?
>>
>> My first re-read was too fast by half. A far more careful re-read of
>> pertinent parts revealed this essential bit:
>>
>> Beta is alone in its hemisphere and at maximum distance, at
>> which time the moon is invariably at minimum distance. The
>> eclipse that results, with the moon seven times the apparent
>> diameter of Beta, covers all of Lagash and lasts well over
>> half a day, so that no spot on the planet escapes the effects.
>>
>> That's my second scenario. The one where the whole planet of Lagash
>> eventually experiences darkness as each longitudinal slice rotates
>> into the eclipse. The celestial mechanics work out after all.
>
> IIRC, nobody ever noticed the eclipsing object. That will require an
> albedo significantly less than the Moon's (which is pretty low).
It's a shame that your useful world "albedo" is missing from the story.
Regardless, here's how the story explains the heretofore hidden moon:
"What if there were another non-luminous planetary body
such as Lagash? If there were, you know, it would shine only
by reflected light, and if it were composed of bluish rock,
as Lagash itself largely is, then, in the redness of the sky,
the eternal blaze of the suns would make it invisible - drown
it out completely."
How about that upcoming total eclipse of the sun that passes over
America? It happens on August 21 2017. My residence is about one mile
away from the center line.
http://www.eclipse2017.org/2017/path_through_the_US.htm
BTW Dave, the Shakespeare section of _Bartlett's Familiar Quotations_
is probably the largest section in the book. It begins on page 171 and
ends on page 231. And now it's time to squeeze yet another eclipse quote
out of _Bartlett's_. :0)
Thank you,
--
Don Kuenz KB7RPU
Not mine own fears, nor the prophetic soul
Of the wide world dreaming on things to come,
Can yet the lease of my true love control,
Suppos'd as forfeit to a confin'd doom.
The mortal moon hath her eclipse endur'd,
And the sad augurs mock their own presage;
Incertainties now crown themselves assur'd,
And peace proclaims olives of endless age.
-Shakespeare
[toc] | [prev] | [next] | [standalone]
| From | TB <tsbrueni@dcn.davis.ca.us> |
|---|---|
| Date | 2016-09-02 10:39 -0700 |
| Message-ID | <a39668cf-74c8-48ca-aebc-7fa5d638e763@googlegroups.com> |
| In reply to | #450590 |
On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote: > How about that upcoming total eclipse of the sun that passes over > America? It happens on August 21 2017. My residence is about one mile > away from the center line. At the center line, how long does the total eclipse sequence take (from first contact to last contact)? If the Moon were 7 times larger, how long would the eclipse sequence take? > > http://www.eclipse2017.org/2017/path_through_the_US.htm >
[toc] | [prev] | [next] | [standalone]
| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-02 13:17 -0500 |
| Message-ID | <XnsA6779162266D5melchizedek@216.166.97.131> |
| In reply to | #450598 |
TB <tsbrueni@dcn.davis.ca.us> wrote in news:a39668cf-74c8-48ca-aebc-7fa5d638e763@googlegroups.com: > On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote: > >> How about that upcoming total eclipse of the sun that passes over >> America? It happens on August 21 2017. My residence is about one mile >> away from the center line. > > At the center line, how long does the total eclipse sequence take > (from first contact to last contact)? > > If the Moon were 7 times larger, how long would the eclipse sequence > take? >> >> http://www.eclipse2017.org/2017/path_through_the_US.htm >> > My current (tentative) plan is to combine an eclipse viewing trip with a visit to Yellowstone. pt
[toc] | [prev] | [next] | [standalone]
| From | Jaimie Vandenbergh <jaimie@sometimes.sessile.org> |
|---|---|
| Date | 2016-09-02 23:03 +0100 |
| Message-ID | <mltjsb9fnfll3ohut2obidc8rhcgot4am8@4ax.com> |
| In reply to | #450605 |
On Fri, 02 Sep 2016 13:17:20 -0500, Cryptoengineer <treifamily@gmail.com> wrote: >TB <tsbrueni@dcn.davis.ca.us> wrote in >news:a39668cf-74c8-48ca-aebc-7fa5d638e763@googlegroups.com: > >> On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote: >> >>> How about that upcoming total eclipse of the sun that passes over >>> America? It happens on August 21 2017. My residence is about one mile >>> away from the center line. >> >> At the center line, how long does the total eclipse sequence take >> (from first contact to last contact)? >> >> If the Moon were 7 times larger, how long would the eclipse sequence >> take? >>> >>> http://www.eclipse2017.org/2017/path_through_the_US.htm >>> >> > >My current (tentative) plan is to combine an eclipse viewing trip >with a visit to Yellowstone. I'd suggest that you try and be somewhere fairly arid for the eclipse. The two I've attempted to view, both in western European countryside, I was foiled by instant clouds appearing from a clear sky as the sun started to be covered. The temperature change alone caused the condensation. Cheers - Jaimie -- 'The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents' - H.P.Lovecraft, "The Call of Cthulhu"
[toc] | [prev] | [next] | [standalone]
| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-02 17:54 -0500 |
| Message-ID | <XnsA677C0605F2C0melchizedek@216.166.97.131> |
| In reply to | #450627 |
Jaimie Vandenbergh <jaimie@sometimes.sessile.org> wrote in news:mltjsb9fnfll3ohut2obidc8rhcgot4am8@4ax.com: > On Fri, 02 Sep 2016 13:17:20 -0500, Cryptoengineer > <treifamily@gmail.com> wrote: > >>TB <tsbrueni@dcn.davis.ca.us> wrote in >>news:a39668cf-74c8-48ca-aebc-7fa5d638e763@googlegroups.com: >> >>> On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote: >>> >>>> How about that upcoming total eclipse of the sun that passes over >>>> America? It happens on August 21 2017. My residence is about one >>>> mile away from the center line. >>> >>> At the center line, how long does the total eclipse sequence take >>> (from first contact to last contact)? >>> >>> If the Moon were 7 times larger, how long would the eclipse sequence >>> take? >>>> >>>> http://www.eclipse2017.org/2017/path_through_the_US.htm >>>> >>> >> >>My current (tentative) plan is to combine an eclipse viewing trip >>with a visit to Yellowstone. > > I'd suggest that you try and be somewhere fairly arid for the eclipse. > The two I've attempted to view, both in western European countryside, > I was foiled by instant clouds appearing from a clear sky as the sun > started to be covered. The temperature change alone caused the > condensation. There's a reason I'm going to Wyoming rather than somewhere closer. Other criteria include 'long lonely highways in various directions, especially along the path of totality'. The idea is to drive out from under approaching clouds. The drawback of meeting the previous criteria is that cell data service may be dodgey, which makes getting cloud coverage data a little harder (though eyeballing it would work, at shorter range). pt
[toc] | [prev] | [next] | [standalone]
| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-03 00:03 +0000 |
| Message-ID | <20160902b@crcomp.net> |
| In reply to | #450629 |
Cryptoengineer <treifamily@gmail.com> wrote:
> Jaimie Vandenbergh <jaimie@sometimes.sessile.org> wrote in
> news:mltjsb9fnfll3ohut2obidc8rhcgot4am8@4ax.com:
>
>> On Fri, 02 Sep 2016 13:17:20 -0500, Cryptoengineer
>> <treifamily@gmail.com> wrote:
>>
>>>TB <tsbrueni@dcn.davis.ca.us> wrote in
>>>news:a39668cf-74c8-48ca-aebc-7fa5d638e763@googlegroups.com:
>>>
>>>> On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote:
>>>>
>>>>> How about that upcoming total eclipse of the sun that passes over
>>>>> America? It happens on August 21 2017. My residence is about one
>>>>> mile away from the center line.
>>>>
>>>> At the center line, how long does the total eclipse sequence take
>>>> (from first contact to last contact)?
>>>>
>>>> If the Moon were 7 times larger, how long would the eclipse sequence
>>>> take?
>>>>>
>>>>> http://www.eclipse2017.org/2017/path_through_the_US.htm
>>>>>
>>>>
>>>
>>>My current (tentative) plan is to combine an eclipse viewing trip
>>>with a visit to Yellowstone.
>>
>> I'd suggest that you try and be somewhere fairly arid for the eclipse.
>> The two I've attempted to view, both in western European countryside,
>> I was foiled by instant clouds appearing from a clear sky as the sun
>> started to be covered. The temperature change alone caused the
>> condensation.
>
> There's a reason I'm going to Wyoming rather than somewhere closer.
> Other criteria include 'long lonely highways in various directions,
> especially along the path of totality'. The idea is to drive out
> from under approaching clouds.
>
> The drawback of meeting the previous criteria is that cell data
> service may be dodgey, which makes getting cloud coverage data
> a little harder (though eyeballing it would work, at shorter
> range).
Cell phones tend to continually drop offline on the way to Yellowstone.
Jamie makes a good point in regards to aridity. IMHO the
Teton/Yellowstone corner of Wyoming is greener, wetter, and colder when
compared to the rest of the state.
One of my colleagues is lobbying local government to build an outdoor
amphitheater to offer families the opportunity to stargaze on their way
to/from Yellowstone. Most of Wyoming is arid high desert. Note the lack
of trees in this over-sized photo:
http://projects.aljazeera.com/2014/charlie-hardy/images/charlie_hardy_running.jpg
The town of Casper's situated in a valley between the photographer and
the mountain. That valley's packed with deciduous trees because the
Platte River runs through it. Glamour shots of Casper nearly always show
that valley with its deciduous trees.
Casper Mountain is in the background. It's loaded with evergreens and
aspens. Its elevation is about 8,000 feet above sea level. A majority of
nights are crystal clear and you can very easily see the entire expanse
of the Milky Way after you get away from the city lights.
A Total Eclipse of the Sun
A total eclipse of the Sun has to be one of the most
spectacular and awe-inspiring events of the natural world.
We see dozens of pictures of these eclipses in the news and
on the web, but for those who witness a total eclipse, it
is - AN EXPERIENCE. You can feel the shadow approaching.
The wildlife becomes quiet. The temperature drops. The
light becomes ghostly and strange. Then an eerie darkness
engulfs you. You feel awe and anxiety all at the same time.
You literally feel the shadow. You are living the experience
of a total solar eclipse.
To help celebrate the total eclipse of the sun on Monday,
August 21st, 2017, the Astronomica League will hold its
annual national convention in the days leading up to the
event. Casper Wyoming will host the conference as the
eclipse path goes right through the city. ...
https://astrocon2017.astroleague.org/
Thank you,
--
Don Kuenz KB7RPU
With hue like that when some great painter dips
His pencil in the gloom of earthquake and eclipse.
-Shelley
[toc] | [prev] | [next] | [standalone]
| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-02 21:35 -0500 |
| Message-ID | <XnsA677E5D934AE7melchizedek@216.166.97.131> |
| In reply to | #450634 |
Don Kuenz <g@crcomp.net> wrote in news:20160902b@crcomp.net: > > Cryptoengineer <treifamily@gmail.com> wrote: >> Jaimie Vandenbergh <jaimie@sometimes.sessile.org> wrote in >> news:mltjsb9fnfll3ohut2obidc8rhcgot4am8@4ax.com: >> >>> On Fri, 02 Sep 2016 13:17:20 -0500, Cryptoengineer >>> <treifamily@gmail.com> wrote: >>> >>>>TB <tsbrueni@dcn.davis.ca.us> wrote in >>>>news:a39668cf-74c8-48ca-aebc-7fa5d638e763@googlegroups.com: >>>> >>>>> On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote: >>>>> >>>>>> How about that upcoming total eclipse of the sun that passes over >>>>>> America? It happens on August 21 2017. My residence is about one >>>>>> mile away from the center line. >>>>> >>>>> At the center line, how long does the total eclipse sequence take >>>>> (from first contact to last contact)? >>>>> >>>>> If the Moon were 7 times larger, how long would the eclipse >>>>> sequence take? >>>>>> >>>>>> http://www.eclipse2017.org/2017/path_through_the_US.htm >>>>>> >>>>> >>>> >>>>My current (tentative) plan is to combine an eclipse viewing trip >>>>with a visit to Yellowstone. >>> >>> I'd suggest that you try and be somewhere fairly arid for the >>> eclipse. The two I've attempted to view, both in western European >>> countryside, I was foiled by instant clouds appearing from a clear >>> sky as the sun started to be covered. The temperature change alone >>> caused the condensation. >> >> There's a reason I'm going to Wyoming rather than somewhere closer. >> Other criteria include 'long lonely highways in various directions, >> especially along the path of totality'. The idea is to drive out >> from under approaching clouds. >> >> The drawback of meeting the previous criteria is that cell data >> service may be dodgey, which makes getting cloud coverage data >> a little harder (though eyeballing it would work, at shorter >> range). > > Cell phones tend to continually drop offline on the way to > Yellowstone. Jamie makes a good point in regards to aridity. IMHO the > Teton/Yellowstone corner of Wyoming is greener, wetter, and colder > when compared to the rest of the state. > > One of my colleagues is lobbying local government to build an outdoor > amphitheater to offer families the opportunity to stargaze on their > way to/from Yellowstone. Most of Wyoming is arid high desert. Note the > lack of trees in this over-sized photo: > > http://projects.aljazeera.com/2014/charlie-hardy/images/charlie_hardy_r > unning.jpg > > The town of Casper's situated in a valley between the photographer and > the mountain. That valley's packed with deciduous trees because the > Platte River runs through it. Glamour shots of Casper nearly always > show that valley with its deciduous trees. > > Casper Mountain is in the background. It's loaded with evergreens and > aspens. Its elevation is about 8,000 feet above sea level. A majority > of nights are crystal clear and you can very easily see the entire > expanse of the Milky Way after you get away from the city lights. > > A Total Eclipse of the Sun > > A total eclipse of the Sun has to be one of the most > spectacular and awe-inspiring events of the natural world. > We see dozens of pictures of these eclipses in the news and > on the web, but for those who witness a total eclipse, it > is - AN EXPERIENCE. You can feel the shadow approaching. > The wildlife becomes quiet. The temperature drops. The > light becomes ghostly and strange. Then an eerie darkness > engulfs you. You feel awe and anxiety all at the same time. > You literally feel the shadow. You are living the experience > of a total solar eclipse. > > To help celebrate the total eclipse of the sun on Monday, > August 21st, 2017, the Astronomica League will hold its > annual national convention in the days leading up to the > event. Casper Wyoming will host the conference as the > eclipse path goes right through the city. ... > > https://astrocon2017.astroleague.org/ Casper is certainly a candidate. But Idaho Falls is closer to Yellowstone, but the directions of the major highways aren't as good (I'd probably drive up to Sugar City). pt
[toc] | [prev] | [next] | [standalone]
| From | tsbrueni@gmail.com |
|---|---|
| Date | 2016-09-02 16:08 -0700 |
| Message-ID | <d353927b-1729-4f68-a4f1-73045c8a8c85@googlegroups.com> |
| In reply to | #450590 |
On Friday, September 2, 2016 at 9:21:09 AM UTC-7, Don Kuenz wrote: > Robert Woodward <robertaw@drizzle.com> wrote: > > In article <20160901c@crcomp.net>, Don Kuenz <g@crcomp.net> wrote: > > > >> hamish.laws@gmail.com wrote: > >> > On Friday, September 2, 2016 at 1:25:43 PM UTC+10, Don Kuenz wrote: > >> >> David Johnston <Davidjohnston29@yahoo.com> wrote: > >> >> > On 9/1/2016 6:40 PM, Don Kuenz wrote: > > > > <SNIP> > >> >> > >> >> This thread finally prodded me into a re-read of the whole story. > >> >> Michael got it right up thread. This story requires a complete lack of > >> >> knowledge of celestial mechanics. > >> >> > >> >> One way to achieve "a total darkness all over" Lagash is to change the > >> >> story and have the red dwarf Beta eclipse Alpha and the two distant > >> >> companion pairs. And then have a moon eclipse Beta. > >> >> > >> >> Unfortunately, the story has the other five suns setting. It just > >> >> doesn't work unless you stretch "a total darkness all over" to mean that > >> >> Lagash eventually experiences "a total darkness all over" as each > >> >> longitudinal slice of the planet rotates into the total eclipse. > >> >> > >> > It's been a fair while since I read the story but is it possible that > >> > there's only one small landmass on the planet? > >> > >> My first re-read was too fast by half. A far more careful re-read of > >> pertinent parts revealed this essential bit: > >> > >> Beta is alone in its hemisphere and at maximum distance, at > >> which time the moon is invariably at minimum distance. The > >> eclipse that results, with the moon seven times the apparent > >> diameter of Beta, covers all of Lagash and lasts well over > >> half a day, so that no spot on the planet escapes the effects. > >> > >> That's my second scenario. The one where the whole planet of Lagash > >> eventually experiences darkness as each longitudinal slice rotates > >> into the eclipse. The celestial mechanics work out after all. > > > > IIRC, nobody ever noticed the eclipsing object. That will require an > > albedo significantly less than the Moon's (which is pretty low). > > It's a shame that your useful world "albedo" is missing from the story. > Regardless, here's how the story explains the heretofore hidden moon: > > "What if there were another non-luminous planetary body > such as Lagash? If there were, you know, it would shine only > by reflected light, and if it were composed of bluish rock, > as Lagash itself largely is, then, in the redness of the sky, > the eternal blaze of the suns would make it invisible - drown > it out completely." If the Moon is blue, and the sky is red, shouldn't the Moon stand out like a sore thumb?
[toc] | [prev] | [next] | [standalone]
| From | David DeLaney <daviddelaney@earthlink.net> |
|---|---|
| Date | 2016-09-02 21:16 -0500 |
| Message-ID | <bIadnae7_YsVr1fKnZ2dnUU7-dmdnZ2d@earthlink.com> |
| In reply to | #450630 |
On 2016-09-02, tsbrueni@gmail.com <tsbrueni@gmail.com> wrote: > If the Moon is blue, and the sky is red, shouldn't the Moon stand out like a > sore thumb? Nope. If the sky is red, it's not because it's _reflecting_ red light (the way a cloud that was red would be). It's because it's ABSORBING blue light. Thus light that was blue, reflected from a blue Moon, wouldn't get through. You may wish to look into why _our_ sky is generally blue in the daytime. (It involves Rayleigh scattering, if I remember right.) Dave, much the same reason as the difference between combining paint to get a color and combining spotlights to get a color -- \/David DeLaney posting thru EarthLink - "It's not the pot that grows the flower It's not the clock that slows the hour The definition's plain for anyone to see Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK> website on VIC is down, probably for good - oh well/ I WUV you in all CAPS! --K.
[toc] | [prev] | [next] | [standalone]
| From | 103134.3516@compuserve.com |
|---|---|
| Date | 2016-09-07 12:56 -0700 |
| Message-ID | <82fabbe2-3c83-4fb5-93c9-0246eb7d79d1@googlegroups.com> |
| In reply to | #450637 |
On Friday, September 2, 2016 at 10:16:47 PM UTC-4, David DeLaney wrote: > > You may wish to look into why _our_ sky is generally blue in the daytime. > (It involves Rayleigh scattering, if I remember right.) Really, it's simply because blue is the color of air. Very light clear blue, of course: it takes miles of air before the color becomes evident. But it works looking horizontally at distant mountains just as well as it does looking vertically upward: distant objects take on a bluish cast, like looking through a blue filter. The reason why the color of air is blue is what has to do with Rayleigh scattering. JimboCat -- People tell me one thing and out the other.
[toc] | [prev] | [next] | [standalone]
| From | Robert Carnegie <rja.carnegie@excite.com> |
|---|---|
| Date | 2016-09-07 19:05 -0700 |
| Message-ID | <091898f9-09dc-41a7-86df-2f83c7d95882@googlegroups.com> |
| In reply to | #450925 |
On Wednesday, 7 September 2016 20:56:35 UTC+1, 10313...@compuserve.com wrote: > On Friday, September 2, 2016 at 10:16:47 PM UTC-4, David DeLaney wrote: > > > > You may wish to look into why _our_ sky is generally blue in the daytime. > > (It involves Rayleigh scattering, if I remember right.) > > Really, it's simply because blue is the color of air. Very light clear blue, of course: it takes miles of air before the color becomes evident. But it works looking horizontally at distant mountains just as well as it does looking vertically upward: distant objects take on a bluish cast, like looking through a blue filter. > > The reason why the color of air is blue is what has to do with Rayleigh scattering. If air was naturally coloured blue then the moon would appear blue. (I think sea water actually is blue, or was it green...) The appearance of distant objects in daytime is more to do with weather conditions, but it may be better (or may not be) to say that the air /glows/ blue when there is sunlight, and that blue glow is overlaid on distant objects. I suppose the moonlight must be scattered as well. But we don't see the night sky as blue, perhaps for approximately the same reason that you don't see a not-quite-black television screen producing colours all the way down to not-quite-black, although logically it does that; it is (usually) a small difference that you don't notice.
[toc] | [prev] | [next] | [standalone]
| From | "Brian M. Scott" <b.scott@csuohio.edu> |
|---|---|
| Date | 2016-09-07 22:21 -0400 |
| Message-ID | <zn4n1i5u9b3n$.li4p0728tove.dlg@40tude.net> |
| In reply to | #450943 |
On Wed, 7 Sep 2016 19:05:33 -0700 (PDT), Robert Carnegie <rja.carnegie@excite.com> wrote in<news:091898f9-09dc-41a7-86df-2f83c7d95882@googlegroups.com> in rec.arts.sf.written: > On Wednesday, 7 September 2016 20:56:35 UTC+1, > 10313...@compuserve.com wrote: >> On Friday, September 2, 2016 at 10:16:47 PM UTC-4, David >> DeLaney wrote: >>> You may wish to look into why _our_ sky is generally >>> blue in the daytime. (It involves Rayleigh scattering, >>> if I remember right.) >> Really, it's simply because blue is the color of air. >> Very light clear blue, of course: it takes miles of air >> before the color becomes evident. But it works looking >> horizontally at distant mountains just as well as it >> does looking vertically upward: distant objects take on >> a bluish cast, like looking through a blue filter. >> The reason why the color of air is blue is what has to >> do with Rayleigh scattering. > If air was naturally coloured blue then the moon would > appear blue. No doubt it does -- once in a blue moon. [...] Brian -- It was the neap tide, when the baga venture out of their holes to root for sandtatties. The waves whispered rhythmically over the packed sand: haggisss, haggisss, haggisss.
[toc] | [prev] | [next] | [standalone]
| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-08 04:53 +0000 |
| Message-ID | <20160907c@crcomp.net> |
| In reply to | #450944 |
Brian M. Scott <b.scott@csuohio.edu> wrote:
> On Wed, 7 Sep 2016 19:05:33 -0700 (PDT), Robert Carnegie
> <rja.carnegie@excite.com> wrote
> in<news:091898f9-09dc-41a7-86df-2f83c7d95882@googlegroups.com>
> in rec.arts.sf.written:
>
>> On Wednesday, 7 September 2016 20:56:35 UTC+1,
>> 10313...@compuserve.com wrote:
>
>>> On Friday, September 2, 2016 at 10:16:47 PM UTC-4, David
>>> DeLaney wrote:
>
>>>> You may wish to look into why _our_ sky is generally
>>>> blue in the daytime. (It involves Rayleigh scattering,
>>>> if I remember right.)
>
>>> Really, it's simply because blue is the color of air.
>>> Very light clear blue, of course: it takes miles of air
>>> before the color becomes evident. But it works looking
>>> horizontally at distant mountains just as well as it
>>> does looking vertically upward: distant objects take on
>>> a bluish cast, like looking through a blue filter.
>
>>> Really, it's simply because blue is the color of air.
>>> Very light clear blue, of course: it takes miles of air
>>> before the color becomes evident. But it works looking
>>> horizontally at distant mountains just as well as it
>>> does looking vertically upward: distant objects take on
>>> a bluish cast, like looking through a blue filter.
>
>>> The reason why the color of air is blue is what has to
>>> do with Rayleigh scattering.
>
>> If air was naturally coloured blue then the moon would
>> appear blue.
>
> No doubt it does -- once in a blue moon.
That's out of the blue.
--
Don Kuenz KB7RPU
I think no innocent species of wit or pleasantry should be
suppressed; and that a good pun may be admitted among the smaller
excellencies of lively conversation. - Boswell
[toc] | [prev] | [next] | [standalone]
| From | Jaimie Vandenbergh <jaimie@sometimes.sessile.org> |
|---|---|
| Date | 2016-09-09 00:12 +0100 |
| Message-ID | <iqr3tbpgi8fvi8n8eo1squu0qajltfdkef@4ax.com> |
| In reply to | #450943 |
On Wed, 7 Sep 2016 19:05:33 -0700 (PDT), Robert Carnegie <rja.carnegie@excite.com> wrote: >On Wednesday, 7 September 2016 20:56:35 UTC+1, 10313...@compuserve.com wrote: >> On Friday, September 2, 2016 at 10:16:47 PM UTC-4, David DeLaney wrote: >> > >> > You may wish to look into why _our_ sky is generally blue in the daytime. >> > (It involves Rayleigh scattering, if I remember right.) >> >> Really, it's simply because blue is the color of air. Very light clear blue, of course: it takes miles of air before the color becomes evident. But it works looking horizontally at distant mountains just as well as it does looking vertically upward: distant objects take on a bluish cast, like looking through a blue filter. >> >> The reason why the color of air is blue is what has to do with Rayleigh scattering. > >If air was naturally coloured blue then the moon would >appear blue. It probably would, if the light at night wasn't generally too faint to be triggering your retinal cones - the colour receptors. It's only in the very brightest of full moons that you can see any colour under moonlight at all. >(I think sea water actually is blue, or was it green...) Sea water is all sorts of colours, depending what's in it. http://www.bbc.co.uk/earth/story/201505226-is-the-sea-really-blue Cheers - Jaimie -- Growing old is mandatory, growing up is optional.
[toc] | [prev] | [next] | [standalone]
| From | Dimensional Traveler <dtravel@sonic.net> |
|---|---|
| Date | 2016-09-08 17:00 -0700 |
| Message-ID | <nqsu3p$dqj$2@dont-email.me> |
| In reply to | #450967 |
On 9/8/2016 4:12 PM, Jaimie Vandenbergh wrote: > On Wed, 7 Sep 2016 19:05:33 -0700 (PDT), Robert Carnegie > <rja.carnegie@excite.com> wrote: > >> On Wednesday, 7 September 2016 20:56:35 UTC+1, 10313...@compuserve.com wrote: >>> On Friday, September 2, 2016 at 10:16:47 PM UTC-4, David DeLaney wrote: >>>> >>>> You may wish to look into why _our_ sky is generally blue in the daytime. >>>> (It involves Rayleigh scattering, if I remember right.) >>> >>> Really, it's simply because blue is the color of air. Very light clear blue, of course: it takes miles of air before the color becomes evident. But it works looking horizontally at distant mountains just as well as it does looking vertically upward: distant objects take on a bluish cast, like looking through a blue filter. >>> >>> The reason why the color of air is blue is what has to do with Rayleigh scattering. >> >> If air was naturally coloured blue then the moon would >> appear blue. > > It probably would, if the light at night wasn't generally too faint to > be triggering your retinal cones - the colour receptors. It's only in > the very brightest of full moons that you can see any colour under > moonlight at all. > >> (I think sea water actually is blue, or was it green...) > > Sea water is all sorts of colours, depending what's in it. > > http://www.bbc.co.uk/earth/story/201505226-is-the-sea-really-blue > Don't drink the yellow water. -- Now taking submissions for the rec.arts.TV Channels Watched Survey for Summer 2016
[toc] | [prev] | [next] | [standalone]
| From | Greg Goss <gossg@gossg.org> |
|---|---|
| Date | 2016-09-08 22:36 -0600 |
| Message-ID | <e3esi0FkeoiU1@mid.individual.net> |
| In reply to | #450967 |
Jaimie Vandenbergh <jaimie@sometimes.sessile.org> wrote: >>If air was naturally coloured blue then the moon would >>appear blue. > >It probably would, if the light at night wasn't generally too faint to >be triggering your retinal cones - the colour receptors. It's only in >the very brightest of full moons that you can see any colour under >moonlight at all. I saw a very-long-exposure starlight picture once. It looked like a perfectly ordinary day. -- We are geeks. Resistance is voltage over current.
[toc] | [prev] | [next] | [standalone]
Page 3 of 7 — ← Prev page 1 2 [3] 4 5 6 7 Next page →
Back to top | Article view | rec.arts.sf.written
csiph-web