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17th October 2020, 04:38 AM
#1
Basic Information for the Reasons and Causes of Tides.
Whilst not wanting to raise again the topic of Climate Change and so called rising sea levels. I think it right that everyone whether seaman or not should be aware of the reason for their occurrence , maybe it will give some a better idea of the world we inhabit.
Tides are fluctuations in the mean level of the sea by the gravitational attractions of the Moon and Sun. It should be remembered that the attractions act not only on the waters directly beneath the Sun and Moon, but all waters up to 90 degrees away. The tangential pull , together with the gravitational lift , is usually termed the " tractive effort".
the body having the greatest pull is the Moon which exerts about 2.25 times the attractive force of the Sun. This is because the Moon is about 400 times nearer the Earth than the Sun.
When the Sun and Moon are over the same meridian their attractions are combined and we get a maxinum height of tide called a Spring Tide. To do this the Sun and Moon must be in conjunction both having the same Right Ascension and the moon will be new or changing.
Whenever a tide is raised under the sun or moon , or both, a tide of similar height is raised at the opposite point on the earth.
if the moon moved at the same speed as the sun we would always have a spring tide.. But she moves farther away from the sun every day by 12.5 degrees ..
Without going further and discussing other tides such as Neaps etc. incidently the sun is about 400 times bigger than the earth, just another bit of useless knowledge.
The earth since it was formed consisted initially of total water, and went through its changes of life unassisted by man and to my mind is still doing so. So differences of opinion about mans being the cause of todays changes cannot be totally his. As many would have us believe. However this post is the basics on Tides for those who dont already know. Cheers JS
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17th October 2020, 04:44 AM
#2
Re: Basic Information for the Reasons and Causes of Tides.
Your knowledge is valuable , and well taken JS
Man of the World not only the Seas!
Cheers
Senior Site Moderator-Member and Friend of this Website
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17th October 2020, 08:14 AM
#3
Re: Basic Information for the Reasons and Causes of Tides.
Originally Posted by
Doc Vernon
Your knowledge is valuable , and well taken JS
Man of the World not only the Seas!
Cheers
he knows a bit about beer as well...lol cappy
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17th October 2020, 08:40 AM
#4
Re: Basic Information for the Reasons and Causes of Tides.
Still waiting for that case of whiskey which never arrived. That Rusty Rita is not to be trusted. Are you still living in the shed. ? JS
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17th October 2020, 08:49 AM
#5
Re: Basic Information for the Reasons and Causes of Tides.
yer still living in the shed but am tunneling like a mole....how are you settling in your new abode and regards to gwen old mate ....cappy
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18th October 2020, 08:38 AM
#6
Re: Basic Information for the Reasons and Causes of Tides.
#1. Reading myself #1. It may appear different to some. I must point out that when reference is made to heavenly bodies and their apparent motion through the heavens, it should be remembered that only the Earth and the Moon have orbital paths. The sun is a star and does not have an orbit as we know it . It is stationary in the heavens like all the millions of other stars. The Planets in our solar system like Mars, Jupiter, Saturn etc etc. all have orbital paths. Other solar systems as yet unknown Astronomers will have their work cut out during many lifetimes to come to advance the knowledge of the human race , assuming it still exists, by then. Cheers
ps a good example of how to work out how far a star is away is to work out mentally ?? That Light travels at 186,000 miles a second , and when someone says something like did you know Aldebaran is 101 light years away , you can turn round and say that my present vision of the star is X number of years old then ! JS
Last edited by j.sabourn; 18th October 2020 at 10:24 AM.
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19th October 2020, 05:22 AM
#7
Re: Basic Information for the Reasons and Causes of Tides.
Cappy, welcome home where the bloody hell you been?
I hope you have a note to cover your abscence young man!!
AS to the tides, as a young lad at school we were taught about the lunar effect on the tides, would have though more would be aware.
But another factor today which I think has as much effect on the atmospheric temperatures as anything is the effect of La Nina, which we are in now and
El Nino which we had last year.
The effect of La Nina is now becoming obvious this year, cooling of the Southern Ocean will see a wetter and somewhat more humid weather pattern in the southern hemisphere.
The Northern one can expect much colder weather patterns over the coming winter.
Happy daze John in Oz.
Life is too short to blend in.
John Strange R737787
World Traveller
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cappy thanked for this post
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19th October 2020, 08:08 AM
#8
Re: Basic Information for the Reasons and Causes of Tides.
well the story of my missing the ship is unbelievable.....but i seek the 12th amendment at this time ......but a bloke from perf is involved......nuff said....regards cappy
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19th October 2020, 10:04 AM
#9
Re: Basic Information for the Reasons and Causes of Tides.
John Cappy thinks La Nina is an old girlfriend from Liverpool. JS
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20th October 2020, 04:49 AM
#10
Re: Basic Information for the Reasons and Causes of Tides.
Originally Posted by
j.sabourn
John Cappy thinks La Nina is an old girlfriend from Liverpool. JS
John, got to keep it quiet or the other girls will be after him.
She no doubt is just one of many, he must be super fit at his age to keep that up.
Happy daze John in Oz.
Life is too short to blend in.
John Strange R737787
World Traveller
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