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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 |
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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
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| From | David Johnston <Davidjohnston29@yahoo.com> |
|---|---|
| Date | 2016-09-01 21:09 -0600 |
| Message-ID | <nqaqhv$88b$1@dont-email.me> |
| In reply to | #450546 |
On 9/1/2016 8:46 PM, TB wrote: > On Thursday, September 1, 2016 at 7:20:16 PM UTC-7, David Johnston wrote: >> On 9/1/2016 6:40 PM, Don Kuenz wrote: >>> David Johnston <Davidjohnston29@yahoo.com> wrote: >>>> On 9/1/2016 3:24 PM, Michael F. Stemper wrote: >>>>> On 2016-09-01 15:48, tsbrueni@gmail.com wrote: >>>>>> Every 2050 years, on a day when all but one of the planet's 6 suns has >>>>>> set, a moon gets in front of that sun, leading to a multi-hour eclipse >>>>>> which allows the people to see a very large number of stars. The >>>>>> combination of the darkness and the stars drives everyone mad. >>>>>> >>>>>> How is the planet able to hang onto a satellite that is so far away >>>>>> that it takes 2050 years to complete an orbit? >>>>> >>>>> Thanks to a complete lack of knowledge of celestial mechanics. >>>>> >>>> >>>> Wait...it doesn't take 2050 years to complete an orbit. It's just 2050 >>>> years between an eclipse that happens when all except the smallest suns >>>> are on the other side of the planet. Of course in order for this to >>>> work the planet would have to have a very small land mass. >>> >>> It's also my understanding that it takes about 2050 years for the Alpha >>> sun and the two distant companion pairs to simultaneously set. At that >>> point the Beta sun is left alone in the sky so darkness ensues when a >>> non-luminous planetary body eclipses Beta. >> >> I'm not sure how that's different from what I said. >> >>> >>> The non-luminous planet may very well eclipse Beta every day but it only >>> causes a black out on the planet Lagash when the other five suns are >>> antipodal to Saro City. An antipodal event that occurs approximately >>> every 2050 years. >>> >>> What if Lagash and another planet of equal size rotate about each other? >>> Do the celestial mechanics work any better? >> >> It doesn't change the problem that the eclipse is just not going to >> black out the whole planet. > > A big Moon covering a small sun. > Nothing changes the reality that the other side of the planet would have five suns shining down on it.
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| From | Dimensional Traveler <dtravel@sonic.net> |
|---|---|
| Date | 2016-09-01 20:47 -0700 |
| Message-ID | <nqaso6$ch5$1@dont-email.me> |
| In reply to | #450547 |
On 9/1/2016 8:09 PM, David Johnston wrote: > On 9/1/2016 8:46 PM, TB wrote: >> On Thursday, September 1, 2016 at 7:20:16 PM UTC-7, David Johnston wrote: >>> On 9/1/2016 6:40 PM, Don Kuenz wrote: >>>> David Johnston <Davidjohnston29@yahoo.com> wrote: >>>>> On 9/1/2016 3:24 PM, Michael F. Stemper wrote: >>>>>> On 2016-09-01 15:48, tsbrueni@gmail.com wrote: >>>>>>> Every 2050 years, on a day when all but one of the planet's 6 >>>>>>> suns has >>>>>>> set, a moon gets in front of that sun, leading to a multi-hour >>>>>>> eclipse >>>>>>> which allows the people to see a very large number of stars. The >>>>>>> combination of the darkness and the stars drives everyone mad. >>>>>>> >>>>>>> How is the planet able to hang onto a satellite that is so far away >>>>>>> that it takes 2050 years to complete an orbit? >>>>>> >>>>>> Thanks to a complete lack of knowledge of celestial mechanics. >>>>>> >>>>> >>>>> Wait...it doesn't take 2050 years to complete an orbit. It's just >>>>> 2050 >>>>> years between an eclipse that happens when all except the smallest >>>>> suns >>>>> are on the other side of the planet. Of course in order for this to >>>>> work the planet would have to have a very small land mass. >>>> >>>> It's also my understanding that it takes about 2050 years for the Alpha >>>> sun and the two distant companion pairs to simultaneously set. At that >>>> point the Beta sun is left alone in the sky so darkness ensues when a >>>> non-luminous planetary body eclipses Beta. >>> >>> I'm not sure how that's different from what I said. >>> >>>> >>>> The non-luminous planet may very well eclipse Beta every day but it >>>> only >>>> causes a black out on the planet Lagash when the other five suns are >>>> antipodal to Saro City. An antipodal event that occurs approximately >>>> every 2050 years. >>>> >>>> What if Lagash and another planet of equal size rotate about each >>>> other? >>>> Do the celestial mechanics work any better? >>> >>> It doesn't change the problem that the eclipse is just not going to >>> black out the whole planet. >> >> A big Moon covering a small sun. >> > > Nothing changes the reality that the other side of the planet would have > five suns shining down on it. Yabut only barbarians live on the other side of the planet. ;) -- Now taking submissions for the rec.arts.TV Channels Watched Survey for Summer 2016
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| From | TB <tsbrueni@dcn.davis.ca.us> |
|---|---|
| Date | 2016-09-02 03:13 -0700 |
| Message-ID | <6dad7110-b41a-4986-b2f0-73f9553d0be4@googlegroups.com> |
| In reply to | #450547 |
On Thursday, September 1, 2016 at 8:09:53 PM UTC-7, David Johnston wrote: > On 9/1/2016 8:46 PM, TB wrote: > > On Thursday, September 1, 2016 at 7:20:16 PM UTC-7, David Johnston wrote: > >> On 9/1/2016 6:40 PM, Don Kuenz wrote: > >>> David Johnston <Davidjohnston29@yahoo.com> wrote: > >>>> On 9/1/2016 3:24 PM, Michael F. Stemper wrote: > >>>>> On 2016-09-01 15:48, tsbrueni@gmail.com wrote: > >>>>>> Every 2050 years, on a day when all but one of the planet's 6 suns has > >>>>>> set, a moon gets in front of that sun, leading to a multi-hour eclipse > >>>>>> which allows the people to see a very large number of stars. The > >>>>>> combination of the darkness and the stars drives everyone mad. > >>>>>> > >>>>>> How is the planet able to hang onto a satellite that is so far away > >>>>>> that it takes 2050 years to complete an orbit? > >>>>> > >>>>> Thanks to a complete lack of knowledge of celestial mechanics. > >>>>> > >>>> > >>>> Wait...it doesn't take 2050 years to complete an orbit. It's just 2050 > >>>> years between an eclipse that happens when all except the smallest suns > >>>> are on the other side of the planet. Of course in order for this to > >>>> work the planet would have to have a very small land mass. > >>> > >>> It's also my understanding that it takes about 2050 years for the Alpha > >>> sun and the two distant companion pairs to simultaneously set. At that > >>> point the Beta sun is left alone in the sky so darkness ensues when a > >>> non-luminous planetary body eclipses Beta. > >> > >> I'm not sure how that's different from what I said. > >> > >>> > >>> The non-luminous planet may very well eclipse Beta every day but it only > >>> causes a black out on the planet Lagash when the other five suns are > >>> antipodal to Saro City. An antipodal event that occurs approximately > >>> every 2050 years. > >>> > >>> What if Lagash and another planet of equal size rotate about each other? > >>> Do the celestial mechanics work any better? > >> > >> It doesn't change the problem that the eclipse is just not going to > >> black out the whole planet. > > > > A big Moon covering a small sun. > > > > Nothing changes the reality that the other side of the planet would have > five suns shining down on it. But in half a day, the other side would be in darkness! All we need is an eclipse lasting more than half a day!
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| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-02 03:25 +0000 |
| Message-ID | <20160901b@crcomp.net> |
| In reply to | #450539 |
David Johnston <Davidjohnston29@yahoo.com> wrote:
> On 9/1/2016 6:40 PM, Don Kuenz wrote:
>> David Johnston <Davidjohnston29@yahoo.com> wrote:
>>> On 9/1/2016 3:24 PM, Michael F. Stemper wrote:
>>>> On 2016-09-01 15:48, tsbrueni@gmail.com wrote:
>>>>> Every 2050 years, on a day when all but one of the planet's 6 suns has
>>>>> set, a moon gets in front of that sun, leading to a multi-hour eclipse
>>>>> which allows the people to see a very large number of stars. The
>>>>> combination of the darkness and the stars drives everyone mad.
>>>>>
>>>>> How is the planet able to hang onto a satellite that is so far away
>>>>> that it takes 2050 years to complete an orbit?
>>>>
>>>> Thanks to a complete lack of knowledge of celestial mechanics.
>>>>
>>>
>>> Wait...it doesn't take 2050 years to complete an orbit. It's just 2050
>>> years between an eclipse that happens when all except the smallest suns
>>> are on the other side of the planet. Of course in order for this to
>>> work the planet would have to have a very small land mass.
>>
>> It's also my understanding that it takes about 2050 years for the Alpha
>> sun and the two distant companion pairs to simultaneously set. At that
>> point the Beta sun is left alone in the sky so darkness ensues when a
>> non-luminous planetary body eclipses Beta.
>
> I'm not sure how that's different from what I said.
>
>>
>> The non-luminous planet may very well eclipse Beta every day but it only
>> causes a black out on the planet Lagash when the other five suns are
>> antipodal to Saro City. An antipodal event that occurs approximately
>> every 2050 years.
>>
>> What if Lagash and another planet of equal size rotate about each other?
>> Do the celestial mechanics work any better?
>
> It doesn't change the problem that the eclipse is just not going to
> black out the whole planet.
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.
Thank you,
--
Don Kuenz KB7RPU
The sun . . .
In dim eclipse, disastrous twilight sheds
On half the nations, and with fear of change
Perplexes monarchs.
-Milton
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| From | hamish.laws@gmail.com |
|---|---|
| Date | 2016-09-01 20:48 -0700 |
| Message-ID | <30ab5c6a-041c-4ead-96d6-69c9c0fbb442@googlegroups.com> |
| In reply to | #450548 |
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: > >> David Johnston <Davidjohnston29@yahoo.com> wrote: > >>> On 9/1/2016 3:24 PM, Michael F. Stemper wrote: > >>>> On 2016-09-01 15:48, tsbrueni@gmail.com wrote: > >>>>> Every 2050 years, on a day when all but one of the planet's 6 suns has > >>>>> set, a moon gets in front of that sun, leading to a multi-hour eclipse > >>>>> which allows the people to see a very large number of stars. The > >>>>> combination of the darkness and the stars drives everyone mad. > >>>>> > >>>>> How is the planet able to hang onto a satellite that is so far away > >>>>> that it takes 2050 years to complete an orbit? > >>>> > >>>> Thanks to a complete lack of knowledge of celestial mechanics. > >>>> > >>> > >>> Wait...it doesn't take 2050 years to complete an orbit. It's just 2050 > >>> years between an eclipse that happens when all except the smallest suns > >>> are on the other side of the planet. Of course in order for this to > >>> work the planet would have to have a very small land mass. > >> > >> It's also my understanding that it takes about 2050 years for the Alpha > >> sun and the two distant companion pairs to simultaneously set. At that > >> point the Beta sun is left alone in the sky so darkness ensues when a > >> non-luminous planetary body eclipses Beta. > > > > I'm not sure how that's different from what I said. > > > >> > >> The non-luminous planet may very well eclipse Beta every day but it only > >> causes a black out on the planet Lagash when the other five suns are > >> antipodal to Saro City. An antipodal event that occurs approximately > >> every 2050 years. > >> > >> What if Lagash and another planet of equal size rotate about each other? > >> Do the celestial mechanics work any better? > > > > It doesn't change the problem that the eclipse is just not going to > > black out the whole planet. > > 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?
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| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-02 04:34 +0000 |
| Message-ID | <20160901c@crcomp.net> |
| In reply to | #450551 |
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:
>> >> David Johnston <Davidjohnston29@yahoo.com> wrote:
>> >>> On 9/1/2016 3:24 PM, Michael F. Stemper wrote:
>> >>>> On 2016-09-01 15:48, tsbrueni@gmail.com wrote:
>> >>>>> Every 2050 years, on a day when all but one of the planet's 6 suns has
>> >>>>> set, a moon gets in front of that sun, leading to a multi-hour eclipse
>> >>>>> which allows the people to see a very large number of stars. The
>> >>>>> combination of the darkness and the stars drives everyone mad.
>> >>>>>
>> >>>>> How is the planet able to hang onto a satellite that is so far away
>> >>>>> that it takes 2050 years to complete an orbit?
>> >>>>
>> >>>> Thanks to a complete lack of knowledge of celestial mechanics.
>> >>>>
>> >>>
>> >>> Wait...it doesn't take 2050 years to complete an orbit. It's just 2050
>> >>> years between an eclipse that happens when all except the smallest suns
>> >>> are on the other side of the planet. Of course in order for this to
>> >>> work the planet would have to have a very small land mass.
>> >>
>> >> It's also my understanding that it takes about 2050 years for the Alpha
>> >> sun and the two distant companion pairs to simultaneously set. At that
>> >> point the Beta sun is left alone in the sky so darkness ensues when a
>> >> non-luminous planetary body eclipses Beta.
>> >
>> > I'm not sure how that's different from what I said.
>> >
>> >>
>> >> The non-luminous planet may very well eclipse Beta every day but it only
>> >> causes a black out on the planet Lagash when the other five suns are
>> >> antipodal to Saro City. An antipodal event that occurs approximately
>> >> every 2050 years.
>> >>
>> >> What if Lagash and another planet of equal size rotate about each other?
>> >> Do the celestial mechanics work any better?
>> >
>> > It doesn't change the problem that the eclipse is just not going to
>> > black out the whole planet.
>>
>> 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.
It's a good thing that everything finally got settled. My _Bartlett's_
is running low on eclipse quotes. :0)
Thank you,
--
Don Kuenz KB7RPU
It was that fatal and perfidious bark,
Built in th' eclipse, and rigg'd with curses dark,
That sunk so low that sacred head of thine.
-Milton
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| From | Robert Woodward <robertaw@drizzle.com> |
|---|---|
| Date | 2016-09-01 22:16 -0700 |
| Message-ID | <robertaw-B43616.22162701092016@news.individual.net> |
| In reply to | #450559 |
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).
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| From | TB <tsbrueni@dcn.davis.ca.us> |
|---|---|
| Date | 2016-09-02 07:32 -0700 |
| Message-ID | <c0db6e15-9a93-4cb7-818b-3a6655c6d396@googlegroups.com> |
| In reply to | #450563 |
On Thursday, September 1, 2016 at 10:16:33 PM UTC-7, Robert Woodward 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 could be that the moon normally appears small (being at greater than its minimum distance) in the sky, and gets drowned out by the lights of the planet's suns.
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| From | TB <tsbrueni@dcn.davis.ca.us> |
|---|---|
| Date | 2016-09-02 07:33 -0700 |
| Message-ID | <9804364b-7edb-4e15-a46d-b93e009bdf47@googlegroups.com> |
| In reply to | #450563 |
If our Moon was seven times larger than it is, how long would a solar eclipse last?
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| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-03 00:22 +0000 |
| Message-ID | <20160902c@crcomp.net> |
| In reply to | #450587 |
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. Thank you, -- Don Kuenz KB7RPU It will be the Eclipse first, the rest nowhere. -O'Kelly
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| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-02 21:39 -0500 |
| Message-ID | <XnsA677E6946FCBBmelchizedek@216.166.97.131> |
| In reply to | #450635 |
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. pt
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| From | "Brian M. Scott" <b.scott@csuohio.edu> |
|---|---|
| Date | 2016-09-02 22:57 -0400 |
| Message-ID | <10ywta6yrtu5u$.15hmr659gszhg.dlg@40tude.net> |
| In reply to | #450639 |
On Fri, 02 Sep 2016 21:39:50 -0500, Cryptoengineer <treifamily@gmail.com> wrote in<news:XnsA677E6946FCBBmelchizedek@216.166.97.131> in rec.arts.sf.written: > 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. Or approximately 18.5 minutes, or approximately 13.4 minutes, depending on whether the moon’s linear dimensions, cross-section, or volume have been multiplied by 7. 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.
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| From | TB <tsbrueni@dcn.davis.ca.us> |
|---|---|
| Date | 2016-09-02 21:28 -0700 |
| Message-ID | <bb000d6b-a156-4e94-a055-1cb1659f365a@googlegroups.com> |
| In reply to | #450641 |
On Friday, September 2, 2016 at 7:57:22 PM UTC-7, Brian M. Scott wrote: > On Fri, 02 Sep 2016 21:39:50 -0500, Cryptoengineer > <treifamily@gmail.com> wrote > in<news:XnsA677E6946FCBBmelchizedek@216.166.97.131> in > rec.arts.sf.written: > > > 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. > > Or approximately 18.5 minutes, or approximately 13.4 > minutes, depending on whether the moon’s linear dimensions, > cross-section, or volume have been multiplied by 7. I am multiplying the linear dimensions of the Moon by 7, and keeping it in the same orbit as now. I am keeping the Sun the same apparent size.
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| From | Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> |
|---|---|
| Date | 2016-09-03 05:33 +0200 |
| Message-ID | <57ca446f$0$20639$e4fe514c@textnews.kpn.nl> |
| In reply to | #450639 |
On 03.09.16 4:39, 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. > > pt > A 7 times sized moon weights 7*7*7*current moon. About 350 moons, earth would not survive that.
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| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-02 23:39 -0500 |
| Message-ID | <XnsA6786A837421melchizedek@216.166.97.131> |
| In reply to | #450643 |
Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> wrote in news:57ca446f$0$20639$e4fe514c@textnews.kpn.nl: > On 03.09.16 4:39, 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. >> >> pt >> > A 7 times sized moon weights 7*7*7*current moon. > About 350 moons, earth would not survive that. > Assuming unchanged densities, the Earth would orbit the Moon, instead of the other way around, but aside from higher tides, and some initial earthquakes, I don't see it as 'unsurvivable'. pt
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| From | TB <tsbrueni@dcn.davis.ca.us> |
|---|---|
| Date | 2016-09-02 21:25 -0700 |
| Message-ID | <96f82e17-9b21-42bb-8657-41ec8c8a2b38@googlegroups.com> |
| In reply to | #450639 |
On Friday, September 2, 2016 at 7:39:57 PM UTC-7, 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. I'm assuming that the Sun is the same size as it is now. The apparent size of the Moon is about the same as that of the Sun. Thus, the period of totality would only be a small fraction of the total eclipse sequence (which would include the partial coverings at the start and end. If the apparent size of the Moon were 7 time that of the Sun, than the eclipse would be total for most of the eclipse sequence!
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| From | Paul Colquhoun <newsposter@andor.dropbear.id.au> |
|---|---|
| Date | 2016-09-03 18:22 +1000 |
| Message-ID | <slrnnsl21m.1gr.newsposter@andor.dropbear.id.au> |
| In reply to | #450639 |
On Fri, 02 Sep 2016 21:39:50 -0500, Cryptoengineer <treifamily@gmail.com> 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.
I think it would be longer than that.
Say the apparent width of the Sun is 'S',
and the apparent width of the Moon is 'M'
If S = M then the total eclipse period would be zero, as the leading
edge of the sun would appear on one side just as the trailing edge
dissapreaed on the other.
If M = S + X, then the period of totality is the time it takes the moon
to move distance X.
Now X isn't that big, and it varies a bit since sometimes we get annular
eclipses where X is actually negative. Call it 5% of S.
So the moon traveling 1/20 * S takes 7 the minutes of totality.
If M was suddenly 7 * S, traveling the extra 6 * S would take
20 * 6 * 7 = 840 minutes = 14 hours.
Making X be 10% gives a more manageable 7 hours.
Of course, all this assumes that a 7 times larger moon still takes a
month to orbit the earth. However, now that the moon is 25 times as
massive as the earth, it will be the earth orbiting the moon, and if the
distance is the same, the orbital period will be much shorter, and thus
the period of totality will be much shorter.
According to http://www.calctool.org/CALC/phys/astronomy/planet_orbit
the orbital period would be ~5.38 days, so ~5.2 times faster, giving
a totality period of 1.3 to 2.6 hours (depending on the 5% or 10%
assumptions for X above).
--
Reverend Paul Colquhoun, ULC. http://andor.dropbear.id.au/
Asking for technical help in newsgroups? Read this first:
http://catb.org/~esr/faqs/smart-questions.html#intro
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| From | Cryptoengineer <treifamily@gmail.com> |
|---|---|
| Date | 2016-09-03 10:10 -0500 |
| Message-ID | <XnsA67871B3F55FFmelchizedek@216.166.97.131> |
| In reply to | #450671 |
Paul Colquhoun <newsposter@andor.dropbear.id.au> wrote in news:slrnnsl21m.1gr.newsposter@andor.dropbear.id.au: > On Fri, 02 Sep 2016 21:39:50 -0500, Cryptoengineer > <treifamily@gmail.com> 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. > > > I think it would be longer than that. > > Say the apparent width of the Sun is 'S', > and the apparent width of the Moon is 'M' > > If S = M then the total eclipse period would be zero, as the leading > edge of the sun would appear on one side just as the trailing edge > dissapreaed on the other. > > If M = S + X, then the period of totality is the time it takes the > moon to move distance X. > > Now X isn't that big, and it varies a bit since sometimes we get > annular eclipses where X is actually negative. Call it 5% of S. > > So the moon traveling 1/20 * S takes 7 the minutes of totality. > > If M was suddenly 7 * S, traveling the extra 6 * S would take > 20 * 6 * 7 = 840 minutes = 14 hours. > > Making X be 10% gives a more manageable 7 hours. You're right. Thanks. pt
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| From | Don Kuenz <g@crcomp.net> |
|---|---|
| Date | 2016-09-04 00:38 +0000 |
| Message-ID | <20160903b@crcomp.net> |
| In reply to | #450671 |
Paul Colquhoun <newsposter@andor.dropbear.id.au> wrote:
> On Fri, 02 Sep 2016 21:39:50 -0500, Cryptoengineer <treifamily@gmail.com> 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.
>
>
> I think it would be longer than that.
>
> Say the apparent width of the Sun is 'S',
> and the apparent width of the Moon is 'M'
>
> If S = M then the total eclipse period would be zero, as the leading
> edge of the sun would appear on one side just as the trailing edge
> dissapreaed on the other.
>
> If M = S + X, then the period of totality is the time it takes the moon
> to move distance X.
>
> Now X isn't that big, and it varies a bit since sometimes we get annular
> eclipses where X is actually negative. Call it 5% of S.
>
> So the moon traveling 1/20 * S takes 7 the minutes of totality.
>
> If M was suddenly 7 * S, traveling the extra 6 * S would take
> 20 * 6 * 7 = 840 minutes = 14 hours.
>
> Making X be 10% gives a more manageable 7 hours.
>
>
> Of course, all this assumes that a 7 times larger moon still takes a
> month to orbit the earth. However, now that the moon is 25 times as
> massive as the earth, it will be the earth orbiting the moon, and if the
> distance is the same, the orbital period will be much shorter, and thus
> the period of totality will be much shorter.
>
> According to http://www.calctool.org/CALC/phys/astronomy/planet_orbit
> the orbital period would be ~5.38 days, so ~5.2 times faster, giving
> a totality period of 1.3 to 2.6 hours (depending on the 5% or 10%
> assumptions for X above).
Thank you Paul for your very informative post. Allow me to change tack
away from the story and into natural philosophy.
S ~ M during a solar eclipse when the Sun, Earth, and Moon align to
become a precision optical instrument that provides a teachable moment
to curious people. The Sun's corona, for instance, remains visible,
which enabled people to discover spectral lines.
It's my understanding that the teachable moment requires an optical
alignment with at least a 10% or greater precision. Increase or
decrease the the Moon's diameter by 10% and no coronal spectral lines
are visible. Increase or decrease the Sun's diameter by 10% and again,
no visible corona. Increase or decrease the distance from the Earth to
the Sun, and no corona. And so on and so forth.
Thank you,
--
Don Kuenz KB7RPU
I have always read that the world, both land and water, was
spherical, as the authority and researches of Ptolemy and all the others
who have written on the subject demonstrate and prove, as do the
eclipses of the moon and other experiments that are made from east to
west, and the elevation of the North Star from north to south.
- Columbus
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| From | tsbrueni@gmail.com |
|---|---|
| Date | 2016-09-03 20:23 -0700 |
| Message-ID | <1607ba92-c219-451d-b438-c50a0475c340@googlegroups.com> |
| In reply to | #450712 |
On Saturday, September 3, 2016 at 5:38:59 PM UTC-7, Don Kuenz wrote: > Paul Colquhoun <newsposter@andor.dropbear.id.au> wrote: > > On Fri, 02 Sep 2016 21:39:50 -0500, Cryptoengineer <treifamily@gmail.com> 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. > > > > > > I think it would be longer than that. > > > > Say the apparent width of the Sun is 'S', > > and the apparent width of the Moon is 'M' > > > > If S = M then the total eclipse period would be zero, as the leading > > edge of the sun would appear on one side just as the trailing edge > > dissapreaed on the other. > > > > If M = S + X, then the period of totality is the time it takes the moon > > to move distance X. > > > > Now X isn't that big, and it varies a bit since sometimes we get annular > > eclipses where X is actually negative. Call it 5% of S. > > > > So the moon traveling 1/20 * S takes 7 the minutes of totality. > > > > If M was suddenly 7 * S, traveling the extra 6 * S would take > > 20 * 6 * 7 = 840 minutes = 14 hours. > > > > Making X be 10% gives a more manageable 7 hours. > > > > > > Of course, all this assumes that a 7 times larger moon still takes a > > month to orbit the earth. However, now that the moon is 25 times as > > massive as the earth, it will be the earth orbiting the moon, and if the > > distance is the same, the orbital period will be much shorter, and thus > > the period of totality will be much shorter. > > > > According to http://www.calctool.org/CALC/phys/astronomy/planet_orbit > > the orbital period would be ~5.38 days, so ~5.2 times faster, giving > > a totality period of 1.3 to 2.6 hours (depending on the 5% or 10% > > assumptions for X above). > > Thank you Paul for your very informative post. Allow me to change tack > away from the story and into natural philosophy. > > S ~ M during a solar eclipse when the Sun, Earth, and Moon align to > become a precision optical instrument that provides a teachable moment > to curious people. The Sun's corona, for instance, remains visible, > which enabled people to discover spectral lines. > > It's my understanding that the teachable moment requires an optical > alignment with at least a 10% or greater precision. Increase or > decrease the the Moon's diameter by 10% and no coronal spectral lines > are visible. Increase or decrease the Sun's diameter by 10% and again, > no visible corona. Increase or decrease the distance from the Earth to > the Sun, and no corona. And so on and so forth. My interest in growing the Moon 7 fold is to produce an eclipse that covers the entire Earth, and lasts long enough for the entire surface to experience darkness, as per the "Nightfall" story.
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