No, I'm trying to get people to think about the relationship between
altitude and period between rise and set for a fixed lunar orbital period.

Cheers

Jeff Morris wrote:

"Navigator" wrote in message
...


Wally wrote:

Navigator wrote:


What location has moon rise and set 12 hours apart?


Virtually anywhere, I'd guess - just had a look at moon rise and set for
some random locations (Glasgow, Jerusalem and Canberra), for today, and
they're all a shade over 12 hours apart. If rise/set are close to due
east/west, then the time for the moon to traverse the sky will be about 12
hours - think about the solar equinoxes, where the sun rises/sets due
east/west. I dare say this princple won't hold at extreme latitudes. The
moon passes the due east/west points twice in its mo(o)nthly cycle.



The devil _is_ in the detail and is it ever 12 hours????



Why not? What's the problem? Or are you making the sophomoric argument that
its very unlikely to be "precisely" 12 hours? It certainly isn't hard to find
places and times where its within a couple of minutes. Certain latitudes are
more favorable than others for this situation to exist, but there's nothing the
precludes it.

Have a go with:
http://aa.usno.navy.mil/ select "Data Services" and then "Table of
sunrise/sunset ..."

Bart Senior wrote:

Moonrise 4 pm local time
Moonset 4 am local time

Approximately when is high tide? [ 1 pt ]

Are we right on the ocean, or somewhere up a coastal bay? On the Ocean
the high tide will occur around lunar noon (when the moon is at it's
highest point in the sky) and again about twelve hours and 25 minutes
later. So let's say about 10pm and then about 10:30am the next day.

On a basin like, say, Rehoboth Bay tides can lag by several hours.
Check the local tide charts.

--
//-Walt
//
// Sigs suck. Oh, the irony.

"Bart Senior" wrote in message
. net...
Moonrise 4 pm local time
Moonset 4 am local time

Approximately when is high tide? [ 1 pt ]

I've no idea!


Cherbourg is almost due south of Portsmouth, by about 70 miles. Their
Moonrise/set times will be almost identical. However, there is a 3 hour
difference in their HW times.

One lash for asking a silly question.


Regards


Donal
--

"Donal" wrote in message
...

"Bart Senior" wrote in message
. net...
Moonrise 4 pm local time
Moonset 4 am local time

Approximately when is high tide? [ 1 pt ]

I've no idea!


Cherbourg is almost due south of Portsmouth, by about 70 miles. Their
Moonrise/set times will be almost identical. However, there is a 3 hour
difference in their HW times.

One lash for asking a silly question.

Its not a "silly question," its a trick question, which can't be answered with
one more piece of information. The key is that every sailor should know the
Establishment (or Lunitidal Interval) for their home port, and others they
frequent. Do you know yours?

"Jeff Morris" wrote in message
...
"Donal" wrote in message
One lash for asking a silly question.

Its not a "silly question," its a trick question, which can't be answered
with
one more piece of information. The key is that every sailor should know
the
Establishment (or Lunitidal Interval) for their home port, and others they
frequent. Do you know yours?


I'm not sure that there is only one piece of information missing!!


All I need to know is that when there is a full, or new, moon the HW will be
around 13:00.



Regards


Donal
--

"Donal" wrote in message
...

"Jeff Morris" wrote in message
...
"Donal" wrote in message
One lash for asking a silly question.

Its not a "silly question," its a trick question, which can't be answered
with
one more piece of information. The key is that every sailor should know
the
Establishment (or Lunitidal Interval) for their home port, and others they
frequent. Do you know yours?


I'm not sure that there is only one piece of information missing!!


All I need to know is that when there is a full, or new, moon the HW will be
around 13:00.

Well, there are a few other details that aren't stated, like the presumption the
tides are semi-diurnal.

If you know the times of moonrise/moonset then the relationship between lunar
noon (the midpoint of rise and set) and high tide is relatively fixed. Thus,
the relationship you observe about the time of high tide and the state of the
moon can be used throughout the month.

I'm assuming you're talking about Portsmouth. If so, you should double check
your understanding of the tides. Full Moon last occurred on about 5 hours ago,
May 4 at 9:35 pm BST. High tide was at 12:06 am on May 5.

"Jeff Morris" wrote in message
news
"Donal" wrote in message
...
All I need to know is that when there is a full, or new, moon the HW
will be
around 13:00.

Well, there are a few other details that aren't stated, like the
presumption the
tides are semi-diurnal.

If you know the times of moonrise/moonset then the relationship between
lunar
noon (the midpoint of rise and set) and high tide is relatively fixed.
Thus,
the relationship you observe about the time of high tide and the state of
the
moon can be used throughout the month.

I'm assuming you're talking about Portsmouth. If so, you should double
check
your understanding of the tides. Full Moon last occurred on about 5 hours
ago,
May 4 at 9:35 pm BST. High tide was at 12:06 am on May 5.

Fair enough! I should have said that springs were at 13:00.



Regards


Donal
--

"Donal" wrote in message ...
"Bart Senior" wrote in message
. net...
Moonrise 4 pm local time
Moonset 4 am local time

Approximately when is high tide? [ 1 pt ]

I've no idea!


Cherbourg is almost due south of Portsmouth, by about 70 miles. Their
Moonrise/set times will be almost identical. However, there is a 3 hour
difference in their HW times.


Dont feel bad, Clearlake varies from 6-8 hours difference from
Galveston only 35 mile from here, then tayor lake cut is an hour or so
off of the clearlake cut. And the differences change all the time.
Lucky we usually only have one high and one low a day.

Joe


One lash for asking a silly question.


Regards


Donal
--