Variation in tides

According to a local old sea dog, there is a 50 year cycle to the height of
tides superimposed on the usual new/full moon / sun distance, cyclic
variation.
If there is indeed such an influence , would any one know what it is -
earth's precession ?

It's not the earth's precession, that has a cycle of about 26000 years. (I
think)

Regards

Colin Dawson
www.cjdawson.com

"n cook" wrote in message
...
According to a local old sea dog, there is a 50 year cycle to the height
of
tides superimposed on the usual new/full moon / sun distance, cyclic
variation.
If there is indeed such an influence , would any one know what it is -
earth's precession ?

Hello
This has prompted a question I have not worked out the answer but is
probably a very easy one and everybody else probably knows the answer.
If the moon goes round the earth once about 25 hours and is the main effect
on the tides why do we get 2 high tides in 25 hours and not one
regards Paul
"n cook" wrote in message
...
According to a local old sea dog, there is a 50 year cycle to the height
of
tides superimposed on the usual new/full moon / sun distance, cyclic
variation.
If there is indeed such an influence , would any one know what it is -
earth's precession ?

p forsdick wrote in message
. uk...
Hello
This has prompted a question I have not worked out the answer but is
probably a very easy one and everybody else probably knows the answer.
If the moon goes round the earth once about 25 hours and is the main
effect
on the tides why do we get 2 high tides in 25 hours and not one
regards Paul
"n cook" wrote in message
...
According to a local old sea dog, there is a 50 year cycle to the height
of
tides superimposed on the usual new/full moon / sun distance, cyclic
variation.
If there is indeed such an influence , would any one know what it is -
earth's precession ?





Tidal effects not travelling at 1000 mph (1000 times 24 = earth
circumference) is probably something to do with that effect

"p forsdick" wrote in message
. uk...
Hello
This has prompted a question I have not worked out the answer but is
probably a very easy one and everybody else probably knows the answer.
If the moon goes round the earth once about 25 hours and is the main
effect on the tides why do we get 2 high tides in 25 hours and not one
regards Paul
It is wrong to think of the tides as being caused by the Moon 'pulling'.
The key is that the whole 'Earth-Moon' system, is orbiting around their
common mass centre (actually inside the Earth). In it's simplest form, the
bit of the Earth closest to the Moon, gets pulled more, and bulges upwards
towards the Moon, but at the same time, the part furthest away, gets
pulled less, and with the centripetal effect, bulges up in the opposite
direction. Worse, the actual 'tides', lag the pull, and can get
accelerated/decelerated by the local geography, so (for example), there
are places that actually get four tides (or more!) a day, as the water
takes different routes round the local land masses.

Best Wishes

"Roger Hamlett" wrote in message
...

"p forsdick" wrote in message
. uk...
Hello
This has prompted a question I have not worked out the answer but is
probably a very easy one and everybody else probably knows the answer.
If the moon goes round the earth once about 25 hours and is the main
effect on the tides why do we get 2 high tides in 25 hours and not one
regards Paul
It is wrong to think of the tides as being caused by the Moon 'pulling'.
The key is that the whole 'Earth-Moon' system, is orbiting around their
common mass centre (actually inside the Earth). In it's simplest form, the
bit of the Earth closest to the Moon, gets pulled more, and bulges upwards
towards the Moon, but at the same time, the part furthest away, gets
pulled less, and with the centripetal effect, bulges up in the opposite
direction. Worse, the actual 'tides', lag the pull, and can get
accelerated/decelerated by the local geography, so (for example), there
are places that actually get four tides (or more!) a day, as the water
takes different routes round the local land masses.

Best Wishes



Damn it!

The first message i actually had an accurate answer to and someone beat me
to it ):

"Robert Geake" wrote in message
...
"Roger Hamlett" wrote in message
...

"p forsdick" wrote in message
. uk...
Hello
This has prompted a question I have not worked out the answer but is
probably a very easy one and everybody else probably knows the
answer.
If the moon goes round the earth once about 25 hours and is the main
effect on the tides why do we get 2 high tides in 25 hours and not
one
regards Paul
It is wrong to think of the tides as being caused by the Moon
'pulling'.
The key is that the whole 'Earth-Moon' system, is orbiting around their
common mass centre (actually inside the Earth). In it's simplest form,
the
bit of the Earth closest to the Moon, gets pulled more, and bulges
upwards
towards the Moon, but at the same time, the part furthest away, gets
pulled less, and with the centripetal effect, bulges up in the opposite
direction. Worse, the actual 'tides', lag the pull, and can get
accelerated/decelerated by the local geography, so (for example), there
are places that actually get four tides (or more!) a day, as the water
takes different routes round the local land masses.

Best Wishes



Damn it!

The first message i actually had an accurate answer to and someone beat
me
to it ):
Your reference, was much more complete though. :-)

Best Wishes

Roger Hamlett wrote:

It is wrong to think of the tides as being caused by the Moon 'pulling'.
The key is that the whole 'Earth-Moon' system, is orbiting around their
common mass centre (actually inside the Earth). In it's simplest form, the
bit of the Earth closest to the Moon, gets pulled more, and bulges upwards
towards the Moon, but at the same time, the part furthest away, gets
pulled less, and with the centripetal effect, bulges up in the opposite
direction. Worse, the actual 'tides', lag the pull, and can get
accelerated/decelerated by the local geography, so (for example), there
are places that actually get four tides (or more!) a day, as the water
takes different routes round the local land masses.

Where can I see a page or two on this non Newtonian physics that shows
how a mass 1/4 of a million miles away can have more effect on tiny
particulates than a mass 81 times greater and no distance at all? Got a
link?

p forsdick wrote:
If the moon goes round the earth once about 25 hours and is the main
effect on the tides why do we get 2 high tides in 25 hours and not one

http://astunit.com/tutorials/tides.htm

Best,
Stephen

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"n cook" wrote in message
...
According to a local old sea dog, there is a 50 year cycle to the height
of
tides superimposed on the usual new/full moon / sun distance, cyclic
variation.
If there is indeed such an influence , would any one know what it is -
earth's precession ?



A good reference::

http://home.hiwaay.net/~krcool/Astro/moon/moontides/