: Have the Earth's Poles Flipped?



SwampeastMike
08-04-13, 02:53 PM
Anyone have a problem with their inside rear-view mirror reading 180 degrees out of whack? A week or so ago my mirror displayed "C" for "Calibration" (it's done it before) and when it came back, north was south and east west. I figured out that holding down the "Compass" button for a while after the declination setting step will force it into calibration mode, but I've done it three times since and it's still in reverse.

Checking the lensatic compass I keep in the glove box showed that the poles didn't flip and that UFOs weren't messing with the local magnetic field, so I guess there must be some sort of reasonable answer and maybe some way to correct it. Oddly, the problem did occur on or about the day when I read that a "Carrington Level Event" (a coronal discharge from the sun supposedly sufficient to bring down the electric grid on a continental if not global basis) narrowly missed the earth.

JimD
08-04-13, 03:26 PM
The potentially simple fix is to locate an empty big box parking lot away from overhead utility lines/transformers and slowly drive the car in tight 360 degree turns until the compass mechanism sees enough changing flux to figure out the ambiguity.

As for the earth's poles flipping (again), that is not scheduled for any time soon.

Submariner409
08-04-13, 04:05 PM
I think this is reproduced in some owner's manuals........... so you see what happens to a magnetic compass as we drive significant distances, especially east/west. If you look at the dotted lines - change in declination per year - you can calculate how fast the north magnetic pole is moving. The north magnetic pole currently is moving across the Canadian arctic ice shelf, headed NNW at just under 40 miles a year.

The-Dullahan
08-05-13, 05:35 AM
^So much this. I have experienced this in the past with other people and done research on it myself.

I personally do not use a compass (I own a really "fancy" archaic one) and rely on my personal sense of direction and ability to determine the four compass directions. It is really not difficult at all.

Fun Fact: Men have a better sense of direction than women, due to an iron deposit in their nose, which helps them detect direction utilizing the magnetic north as a beacon. While one cannot spin in a random circle until determining which direction is north, it DOES give them a subconscious point of reference, allowing them to determine which direction they came from, even after spinning and turning in all sorts of ways and directions on their journey.

The More You Know...

70eldo
08-05-13, 05:41 AM
Check if you carry anything magnetic in your car that could interfere with your compass. Like headphones, mobile phone, electric motor. I don't know where the actual compass is located in the car, but it might be somewhere else than in your mirror?

Submariner409
08-05-13, 09:59 AM
These compasses are electric/electronic - in the mirror - a fluxgate module, using N-S and E-W sensing coils, calculates changes in the earth's magnetic pattern as the car's heading changes.

Fluxgate compasses are somewhat less susceptible to interference that is a standard magnetic compass. A gyrocompass and its associated controls is just too much to stick in a car, but they are practically immune to outside interference.

When I was in USS SKIPJACK (SSN585) back in the mid-60's we did some really neat high-latitude gyrocompass work with Sperry during under-ice and North Pole runs. A gyro is almost unusable at or near the geodetic poles......... practically no inertial reference.

bwv565
08-05-13, 12:05 PM
Mike, that happened to me last night while driving home. I was going due west on the highway, but the mirror was 'stuck' in NE. I tried the hold power button, waiting for it to hopefully reset but nothing happened. Then, about 20 minutes later I was travelling SE and the mirror said S but not SE, which is almost always accurate on the mirror. It didn't self-adjust to be better, and even when it changed to S it wasn't simultaneous with the direction change.

Out of curiosity, do you have a dash- or windshield-mounted GPS? I was using my Garmin GPS mounted to my windshield last night when this happened. I wonder if there's some interference/incompatibility between the RVM and the GPS. Will be an interesting experiment. In response to a comment above re: other devices, I actually also did have my cell phone charging but was not using the Nav (Maps) app. However, have done so successfully in the past (use the phone as a GPS) without it affecting the display on the mirror.

Let me know if you find out anything.

dkozloski
08-05-13, 11:19 PM
Did you hear about the anemic guy that got his iron pills mixed up with his Viagra? Now every time a girl walks by he points North.

70eldo
08-06-13, 04:09 AM
Mike, that happened to me last night while driving home. I was going due west on the highway, but the mirror was 'stuck' in NE. I tried the hold power button, waiting for it to hopefully reset but nothing happened. Then, about 20 minutes later I was travelling SE and the mirror said S but not SE, which is almost always accurate on the mirror. It didn't self-adjust to be better, and even when it changed to S it wasn't simultaneous with the direction change.

Out of curiosity, do you have a dash- or windshield-mounted GPS? I was using my Garmin GPS mounted to my windshield last night when this happened. I wonder if there's some interference/incompatibility between the RVM and the GPS. Will be an interesting experiment. In response to a comment above re: other devices, I actually also did have my cell phone charging but was not using the Nav (Maps) app. However, have done so successfully in the past (use the phone as a GPS) without it affecting the display on the mirror.

Let me know if you find out anything.

Mind you anything magnetic near your car's compass with a stronger magnetic field than the earth magnetic field will mess it up. One thing you learn flying and sailing. Thanks Submariner409!
When you start up the gyro compass you need to set north in reference to a magnetic compass. After that there will be no interference from external magnetic influence. But indeed if the earth magnetic field is weak or off (like near the poles; thanks Sub) the setting of the gyro cannot be done correctly. BTW, how often do you reset the gyro compass in a sub?
In an airplane you do it after engine start of course. And I presume the sub has at least a set of 2 gyro compasses like an airplane as well?

bwv565
08-06-13, 12:57 PM
Well, maybe this has some truth to it after all:

http://ca.news.yahoo.com/blogs/geekquinox/sun-magnetic-field-preparing-flip-124130717.html

Submariner409
08-06-13, 02:02 PM
Not only do submarines carry 2 or 3 different gyrocompasses (and they're all self-leveling and self-heading now) but also they carry some of the most sophisticated inertial navigation systems on earth. Too long-winded to go into - Google "inertial navigation systems".

The compasses supply heading readouts for steering, navigation, and torpedo fire control inputs while the inertial navigators supply (in addition to scary-accurate ship's position) roll, pitch and yaw for submerged ship control and missile programming at the instant of launch.

My heading gyro (in addition to a small, compensated magnetic compass) in the single and twin engined aircraft I owned were either electrical or vacuum (venturi) driven and needed constant checking - there was a mechanical pull-out knob - similar to a watch crown - that you pulled out, set the proper heading, and pushed back in. Nowadays I would suppose that most heading info is supplied by an 8-channel GPS unit while larger aircraft would be far more sophisticated. The numeric markings on the runway ends - that's the magnetic heading of the runway - as you turned onto the runway for takeoff you checked your compass and gyro and did a quick gyro set if needed. "27 R" would be the right runway, heading 270 - West magnetic. "09 R" would be heading the opposite way - 090 or east. Which way you take off - land is determined by where the wind is blowing from.

Many airports, worldwide, have just re-numbered their runways to account for the rapid changes in magnetic pole location over the last 100 years.

EDIT: In the 60's the diesel subs carried another compass - the forerunner of today's fluxgate units - called a "MagneSyn". A remote heading sensor (~ 60 feet "remote") was cabled to one or more repeaters, located as needed.

Self-serving "I love me" picture EDIT. Polaroid shot, me, staring into a dead reckoning plotter and gyroscope readout about 60 miles from the North Pole (300 feet down) during ICEX operations in mid-1963 - SKIPJACK. This was during one of the "test runs" for Sperry described earlier. Hard to believe that was 50 years ago last June. Time flies when you're having fun.

talismandave
08-07-13, 12:20 AM
Very cool info and even better photo!

Lookin' pretty studdly there Sub!:thumbsup:

Ranger
08-07-13, 10:27 AM
I think he may still be driving in circles.

Submariner409
08-07-13, 10:34 AM
Hard to do: At the North Pole every possible direction is South.

Ranger
08-07-13, 10:49 AM
Not you Sub, I was talking about Swampeast.