Magnetic Pole Shift causing Armageddon!

[SeanPatrick]

Originally Posted by boatman61

Invent a compass that shows true N and you can buy the best boat money can buy..

Isn't that what a gyrocompass does?

[Cheechako]

What's a compass?

[boatman61]

Originally Posted by SeanPatrick

Isn't that what a gyrocompass does?

Do they make them for small boats.?? and how accurate are they in compensating for Earth wobble..

[Montanan]

Originally Posted by Cheechako

What's a compass?

Latin: Com = together.

Latin: passus = a step or pace.


Alternatively, a tool used to draft circles or arc segments.

[Gaia]

[
At present this is not a great worry, the only place that has seen shifts measured in degree rather than decimals or min's is Alaska, It is the uncertainty that is causing concern. Evidence from the geological record shows that when the field flips it does so very quickly. So if that is what is happening we could shortly see changes in degrees anywhere, possibly even 10's of degrees and you may get to see the Northern Lights while sailing in the trades which would be kind of cool![/QUOTE]

Quick on a geological scale. Not to worry me thinks.

Jim

[rsn48]

Some one here said just keep up with variations but if I'm using a chart dated 1999 and take the degree adjustment from the chart, won't it be out a bit as the key point is "speed up" if I read it correctly.

[boatman61]

Originally Posted by rsn48

Some one here said just keep up with variations but if I'm using a chart dated 1999 and take the degree adjustment from the chart, won't it be out a bit as the key point is "speed up" if I read it correctly.

That's among the reasons why your supposed to update your charts annually..
However once your Government opens again you can use this facility to help you out..
https://www.thecompassstore.com/decvar.html#

[jmschmidt]

They already have invented such a compasses one is call an initial navigation system. Today they are run by solid state, ring-laser gyros, no spinning mechanical gyros.

The other is called GPS. Both systems can be set up disregard magnetic. No more using grid navigation to navigation over the poles.

[Jenneau Owner]

I was told that the mag N Pole is moving at the moment at about 15NM per annum.
Here in the UK in my sailing career since the late 60’s I have seen a significant change. There was then approx 7deg W and decreasing. I now sail in the E Med with constantly increasing E variation.
I once sailed with a Ocean Sceintist from Plymouth university who told me that eventually the Poles would flip and that would be the end of the planet as we know it.
Don’t panic we have a few million years to go yet.

As far as paper charts are concearned. I would not sail without them !

[Jenneau Owner]

Ps The reason why charts should be updated or even renewed every five years is that the Scientific info re variation can not be accurately forecast for any period of time longer than that.

[jmschmidt]

It doesn't matter how fast the magnetic pole is moving as long as currently accurate variation data is available to calculate your DR working position. If the old chart makers used accurate variation data and if the new mariners use currently accurate variation data and plot their DRs with that data like they are supposed to, in theory it should all work out fine.

[Wotname]

Originally Posted by SailFastTri

.........

Another interesting thing is that Direct Current flows out from the negative terminal of a battery and the positive terminal is the return point. So why do we fuse the positive side? Answer: IMHO Blindly follows stupid conventions. We could fuse either side and it doesn’t matter so long as we fuse close to the battery.

OK, how about getting the facts correct. Conventional current flow states DC flows from the positive terminal of the supply externally to the negative terminal of the supply. Internally (inside the source), it flows from the negative terminal to the positive terminal. Electron current flow states the opposite. Both are correct and non-contradictorary.

The positive side is fused when the circuit is located in a system that has a metal chassis that is connected to the negative terminal of the source. In systems where the positive terminal is connected to the metal chassis, the negative side is fused. In circuits without any metal chassis, either or both sides are fused. Recreational fibreglass boats has just (blindly IMO) followed the automobile practice.

Originally Posted by jmschmidt

........ Airplanes today don't even have whiskey compasses anymore but aviation charts and runway markings are still in magnetic. But if enter "N Pole" in the airplane's navigation system and hit execute if gives me the magnetic heading, time and distance to the actual physical north pole not the magnetic one. Whereas mariners, at least when you take the USCG exam, are required to work initially in magnetic and convert to TRUE on their charts. Go figure.

Most (all??) aircraft still have a magnetic compass (often called either a standby or a landing compass) and they are swung regularly. Aircraft navigation is usually determined in magnetic headings as the gyro (or remote) compass systems read and display magnetic heading.

Originally Posted by jmschmidt

They already have invented such a compasses one is call an initial navigation system. Today they are run by solid state, ring-laser gyros, no spinning mechanical gyros.

.........

Assuming you meant Inertial Navigation System (INS). This is not a compass system, rather it is a navigational system and very rare on aircraft. Last time I checked, there were no civilian aircraft in Australia using INS and very few elsewhere. Of course, things change so there might be an occasional INS is use somewhere in aircraft but not many. They were (are?) popular in submarines .

Most aircraft gyros (of all types) are referenced to magnetic north by using an onboard magnetic flux detector which aligns the gyro reading to the earth's magnetic field that exists in the vicinity of the aircraft. If a magnetic flux detector is not fitted, the pilot has to manually adjust the gyro compass about every 15 minutes (by referencing the standby compass) as the gyro precesses (when compared to the earths rotation).

In essence, your statements regarding aircraft navigational are mostly in error.

Originally Posted by jmschmidt

It doesn't matter how fast the magnetic pole is moving as long as currently accurate variation data is available to calculate your DR working position. If the old chart makers used accurate variation data and if the new mariners use currently accurate variation data and plot their DRs with that data like they are supposed to, in theory it should all work out fine.

I don't understand what you mean by DR positions. Usually a DR position is an estimated position based on historical (and sometimes doubtful) data. A position based on accurate current data is known as a Fix, not a DR position.

[Wotname]

Originally Posted by Montanan

Latin: Com = together.

Latin: passus = a step or pace.


Alternatively, a tool used to draft circles or arc segments.

Ahh, you mean compasses or a pair of compasses or a bow compass; completely different animal to a compass.

A compass is the thing that points north while the drawing tool is a pair of compasses (or commonly just compasses).

[Alan Mighty]

Originally Posted by Wotname

Ahh, you mean compasses or a pair of compasses or a bow compass; completely different animal to a compass.

A compass is the thing that points north while the drawing tool is a pair of compasses (or commonly just compasses).

Hmm ...

1. compass, the instrument for drawing a circle, is the older term in English. OED cites usage examples in written English from about 1340.

2. compass in the sense of a mariner's compass, is a more recent term by just less than 200 years. OED cites usage examples from about 1515.

And the key point is that compass (mariner's compass) is named after compass the drawing instrument. The origin of 'compass' for the circular card and the magnetised needle is unexplained other than, as already noted, it is named after the drawing instrument.

[StuM]

Originally Posted by Wotname

Ahh, you mean compasses or a pair of compasses or a bow compass; completely different animal to a compass.

A compass is the thing that points north while the drawing tool is a pair of compasses (or commonly just compasses).

https://en.oxforddictionaries.com/definition/compass


Middle English: from Old French compas (noun), compasser (verb), based on Latin com- ‘together’ + passus ‘a step or pace’. Several senses (‘measure’, ‘artifice’, ‘circumscribed area’, and ‘pair of compasses’) which appeared in Middle English are also found in Old French, but their development and origin are uncertain. The transference of sense to the magnetic compass is held to have occurred in the related Italian word compasso, from the circular shape of the compass box.