NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Reality Check: Navigating Around Hill and Dips
From: David Hoyte
Date: 2003 Aug 30, 10:12 EDT
>> I wrote, 8/13/2003:
>> Gravity anomalies cause the geodic heigh of the ocean's
>> surface to vary around the world by up to 200 meters, 650 feet. Ref:
http://www.csr.utexas.edu/grace/publications/press/03-07-21-ggm01-nasa.html
>> I heard as far back as 1975 that a large ship will use
>> significantly more fuel if it passes down into a gravitational dip
>> and climbs the other side, rather than following a longer path
>> around the dip which will keep it more "on the level".
=========
> Response from George Huxtable, george@HUXTABLE.U-NET.COM:
> I am a natural sceptic about most matters, and here's another to be
> sceptical about.
> I just don't believe it. On the ocean surface there are no
> gravitational dips.
=========
George,
Being loath to abandon a little-know fact, after it had been
imparted to me with all the 110% confidence of a former officer of
HM Royal Navy, in my briefing to transfer technology to the then
USSR, I have carried out a "Reality Check" on your assertions.
Not just a single mariner, who would doubtless have just as
much confidence in his reply as that former Naval officer: I consulted
the team responsible for instructing the captains of a fleet of 25
tankers and other ships of a major oil company on the courses they
are to follow as they traverse today's oceans, week by week.
This oil company has an active Research Department, where I
worked some 50 years ago. I felt sure that at least one of their
highly-competitive scientists, sometime in the last 25 years that the
gravitational hill-and-dip phenomenon had been known, would have made
his mark on the company by saving their tanker fleet vast sums of
money in time and fuel by having their ships skirt the anomalies.
And I was right about the place to ask. The answer came back
loud and clear by return of email:
The seagoing fleet of this major oil company pays no attention
whatever to the gravitational hills and dips in the oceans as they
navigate the oceans of the world. To a ship's captain, knowledge of
these gravitational rises and falls in the ocean's surface are clearly
superfluous: they affect neither the time nor the fuel used in a sea
journey.
George, I must thank you (in particular) for your patience in
explaining the physics of the matter in such an understandable way.
Interestingly, a friend tells me the question of the sea level
being higher in an area of high 'g', was used as a physics-class
problem in his Canadian college courses, some 20 years ago.
On the matter of complex cycles in tidal movements: I was
at one time involved with computer programs to identify cyclic
interactive processes, such as a cement kiln. The program gave the
plot of amplitude-vs.-frequency for each variable in the process:
cause and effect could be identified by their similar frequencies.
Programs of this type were in an advanced state of develpment
by Prof. Ashikaga at University of Tokyo, in 1985.
Tidal movements in the ocean were commonly used as a test for
these programs: Are these same programs now used as the primary
method for the analysis of tides, do you know?
George, Thank you again for helping to educate me.
Take care, David. (DavidHoyte@aol.com)
From: David Hoyte
Date: 2003 Aug 30, 10:12 EDT
>> I wrote, 8/13/2003:
>> Gravity anomalies cause the geodic heigh of the ocean's
>> surface to vary around the world by up to 200 meters, 650 feet. Ref:
http://www.csr.utexas.edu/grace/publications/press/03-07-21-ggm01-nasa.html
>> I heard as far back as 1975 that a large ship will use
>> significantly more fuel if it passes down into a gravitational dip
>> and climbs the other side, rather than following a longer path
>> around the dip which will keep it more "on the level".
=========
> Response from George Huxtable, george@HUXTABLE.U-NET.COM:
> I am a natural sceptic about most matters, and here's another to be
> sceptical about.
> I just don't believe it. On the ocean surface there are no
> gravitational dips.
=========
George,
Being loath to abandon a little-know fact, after it had been
imparted to me with all the 110% confidence of a former officer of
HM Royal Navy, in my briefing to transfer technology to the then
USSR, I have carried out a "Reality Check" on your assertions.
Not just a single mariner, who would doubtless have just as
much confidence in his reply as that former Naval officer: I consulted
the team responsible for instructing the captains of a fleet of 25
tankers and other ships of a major oil company on the courses they
are to follow as they traverse today's oceans, week by week.
This oil company has an active Research Department, where I
worked some 50 years ago. I felt sure that at least one of their
highly-competitive scientists, sometime in the last 25 years that the
gravitational hill-and-dip phenomenon had been known, would have made
his mark on the company by saving their tanker fleet vast sums of
money in time and fuel by having their ships skirt the anomalies.
And I was right about the place to ask. The answer came back
loud and clear by return of email:
The seagoing fleet of this major oil company pays no attention
whatever to the gravitational hills and dips in the oceans as they
navigate the oceans of the world. To a ship's captain, knowledge of
these gravitational rises and falls in the ocean's surface are clearly
superfluous: they affect neither the time nor the fuel used in a sea
journey.
George, I must thank you (in particular) for your patience in
explaining the physics of the matter in such an understandable way.
Interestingly, a friend tells me the question of the sea level
being higher in an area of high 'g', was used as a physics-class
problem in his Canadian college courses, some 20 years ago.
On the matter of complex cycles in tidal movements: I was
at one time involved with computer programs to identify cyclic
interactive processes, such as a cement kiln. The program gave the
plot of amplitude-vs.-frequency for each variable in the process:
cause and effect could be identified by their similar frequencies.
Programs of this type were in an advanced state of develpment
by Prof. Ashikaga at University of Tokyo, in 1985.
Tidal movements in the ocean were commonly used as a test for
these programs: Are these same programs now used as the primary
method for the analysis of tides, do you know?
George, Thank you again for helping to educate me.
Take care, David. (DavidHoyte@aol.com)
