"Joe" wrote


| Bwahahahaha lubber!

OK! You got me. Your not a farmer. (blush, I guess I blew my sailing test debut)

Cheers,
Ellen

Ellen MacArthur wrote:

OK! You got me. Your not a farmer. (blush, I guess I blew my sailing
test debut)

For someone that moans about lack of sailing content in what is widely seen
as a virtual yacht club bar (where the patrons also talk about stuff other
than sailing), you have a lot to yet contribute.

The clue is in the 12ths part...

hour change as a fraction of tidal range
1 1/12
2 2/12
3 3/12
4 3/12
5 2/12
6 1/12

Say the tide drops 5" over the first hour. Since you know that that 5" is
one twelfth of the total range, you can calculate that the tide will have
dropped 5"x12 = 60" = 5 feet when it gets to low water. Of course, 5' is a
girly tidal range. Here, it's a proper, manly 5 metres (or more).


--
Capt Scumbalino

"Capt. Scumbalino" wrote

| The clue is in the 12ths part...
|
| hour change as a fraction of tidal range
| 1 1/12
| 2 2/12
| 3 3/12
| 4 3/12
| 5 2/12
| 6 1/12

Thanks for the explanation. So what's the difference between the rule of 12ths
and the rule of thirds. In the rule of thirds the first two hours it goes down 1/4
which is the same as your 3/12th. The second two hours it goes down 1/2 which is the
same as your 6/12th and the third two hours it goes down 1/4 which is the same as
your 3/12th. See I got it right in spite of myself.

Not a lubber, not a lubber, not a lubber... Yippee!

Cheers,
Ellen

Ellen MacArthur wrote:

Thanks for the explanation. So what's the difference between the
rule of 12ths and the rule of thirds. In the rule of thirds the first
two hours it goes down 1/4 which is the same as your 3/12th. The
second two hours it goes down 1/2 which is the same as your 6/12th
and the third two hours it goes down 1/4 which is the same as your
3/12th. See I got it right in spite of myself.

It's based on the pretty-much universal fact that the time for the tide to
change from high to low water, and vice-versa, is pretty close to six hours.
Since we humans deal with time in chunks of one hour, the question we ask
is: "how much does the tide change in one hour?". Since the smallest
fraction is one twelfth, just before and just after slack water, it's
natural to refer to the tidal change during other hours in terms of the same
denominator. One twelfth in the first hour leads us to express the change
during the second as two twelfths, etc.

Also, the larger the time slot, the greater the granularity. Imagine you're
waiting for the tide to rise enough to clear a sandbar. The rule of thirds
would have you waiting in chunks of two hours before you sail. The rule of
12ths would keep you at anchor for chunks of one hour. Of course, plot the
heights on a graph over time, and you can pinpoint your departure time
(rather, the time at which you can safely cross the sandbar) much more
finely.

Whilst your 'rule of thirds' (which, incidentally, isn't exclusive to
photography, but is a general principle used in many forms of visual art)
may be mathematically correct at its junctures, it doesn't fit with how
people think of time (ie, we think in days of 24 hours, not days of 12
bi-hours).


--
Capt Scumbalino

Everybody should read your post...

Very erudite of you, Capt. And you didn't lose your temper. And you didn't call
me names. Your a good example for how newsgroup discussion should be done.

Cheers,
Ellen



"Capt. Scumbalino" wrote in message ...
| Ellen MacArthur wrote:
|
| Thanks for the explanation. So what's the difference between the
| rule of 12ths and the rule of thirds. In the rule of thirds the first
| two hours it goes down 1/4 which is the same as your 3/12th. The
| second two hours it goes down 1/2 which is the same as your 6/12th
| and the third two hours it goes down 1/4 which is the same as your
| 3/12th. See I got it right in spite of myself.
|
| It's based on the pretty-much universal fact that the time for the tide to
| change from high to low water, and vice-versa, is pretty close to six hours.
| Since we humans deal with time in chunks of one hour, the question we ask
| is: "how much does the tide change in one hour?". Since the smallest
| fraction is one twelfth, just before and just after slack water, it's
| natural to refer to the tidal change during other hours in terms of the same
| denominator. One twelfth in the first hour leads us to express the change
| during the second as two twelfths, etc.
|
| Also, the larger the time slot, the greater the granularity. Imagine you're
| waiting for the tide to rise enough to clear a sandbar. The rule of thirds
| would have you waiting in chunks of two hours before you sail. The rule of
| 12ths would keep you at anchor for chunks of one hour. Of course, plot the
| heights on a graph over time, and you can pinpoint your departure time
| (rather, the time at which you can safely cross the sandbar) much more
| finely.
|
| Whilst your 'rule of thirds' (which, incidentally, isn't exclusive to
| photography, but is a general principle used in many forms of visual art)
| may be mathematically correct at its junctures, it doesn't fit with how
| people think of time (ie, we think in days of 24 hours, not days of 12
| bi-hours).
|
|
| --
| Capt Scumbalino
|
|
|

Bull. He one of the worst examples. If he happens to occasionally say
something useful, it's mostly drowned out by his other common behavior. We
don't need any more sockpuppets, certainly not like him.

--
"j" ganz @@
www.sailnow.com

"Ellen MacArthur" wrote in message
reenews.net...
Everybody should read your post...

Very erudite of you, Capt. And you didn't lose your temper. And you
didn't call
me names. Your a good example for how newsgroup discussion should be done.

Cheers,
Ellen



"Capt. Scumbalino" wrote in message
...
| Ellen MacArthur wrote:
|
| Thanks for the explanation. So what's the difference between the
| rule of 12ths and the rule of thirds. In the rule of thirds the first
| two hours it goes down 1/4 which is the same as your 3/12th. The
| second two hours it goes down 1/2 which is the same as your 6/12th
| and the third two hours it goes down 1/4 which is the same as your
| 3/12th. See I got it right in spite of myself.
|
| It's based on the pretty-much universal fact that the time for the tide
to
| change from high to low water, and vice-versa, is pretty close to six
hours.
| Since we humans deal with time in chunks of one hour, the question we
ask
| is: "how much does the tide change in one hour?". Since the smallest
| fraction is one twelfth, just before and just after slack water, it's
| natural to refer to the tidal change during other hours in terms of the
same
| denominator. One twelfth in the first hour leads us to express the
change
| during the second as two twelfths, etc.
|
| Also, the larger the time slot, the greater the granularity. Imagine
you're
| waiting for the tide to rise enough to clear a sandbar. The rule of
thirds
| would have you waiting in chunks of two hours before you sail. The rule
of
| 12ths would keep you at anchor for chunks of one hour. Of course, plot
the
| heights on a graph over time, and you can pinpoint your departure time
| (rather, the time at which you can safely cross the sandbar) much more
| finely.
|
| Whilst your 'rule of thirds' (which, incidentally, isn't exclusive to
| photography, but is a general principle used in many forms of visual
art)
| may be mathematically correct at its junctures, it doesn't fit with how
| people think of time (ie, we think in days of 24 hours, not days of 12
| bi-hours).
|
|
| --
| Capt Scumbalino
|
|
|

Capt. JG wrote:
Bull. He one of the worst examples. If he happens to occasionally say
something useful, it's mostly drowned out by his other common
behavior. We don't need any more sockpuppets, certainly not like him.

Nonsense. I'm the pink fluffy bunny of sockpuppetry.

Well, I would be if I was a sockpuppet, but I'm not a sockpuppet (unlike a
certain poster here who has more socks than a sock shop on National Sock
Day).


--
Capt Scumbalino

Ellen MacArthur wrote:


Very erudite of you,

Katy is that you?

Joe

Joe wrote:
Ellen MacArthur wrote:

Very erudite of you,

Katy is that you?

Joe

Nope...have never played the sock puppet game....

Capt. Scumbalino wrote:

It's based on the pretty-much universal fact that the time for the tide to
change from high to low water, and vice-versa, is pretty close to six hours.

Universal, if your universe consists of only places with semi-diurnal
tides. That's the majority, granted, but not everywhere has
semi-diurnal tides.

You might want to get out more.

//Walt