So Noory is shoveling out more of his crap…
One of my “poll” questions a while back asked whether airport runways are lined up with “rotational north” (aka True North) or “magnetic north”. Another question asked what North on your compass points to.
The correct answer is that runways are aligned relative to rotational/True north, not magnetic north. Your compass does not point to either the magnetic pole or True north.
Think of the planet as a spinning top with an invisible string through the middle. That string through the middle is the rotational axis and if you followed it into outer space would be close to the North Star.
Barring something like a collision with the moon, the Axis doesn’t change, only on a very long time scale. About every 20,000 years the Earth wobbles, so the North Star will move very slowly in a circle, but for a 100 years, the amount of motion is very tiny. This change was enough to be measured 500 years ago and is not speculation.
The earth magnetically is a big ball of molten iron with a hard shell – kind of like an M&M. Magnetic poles are the point at which the magnetic lines of force originate. Magnetic poles wander over short times by a relatively significant distance – right now the South pole is actually in the ocean, nowhere near the rotational South Pole – the North Pole is 450 miles away from the rotational pole – keep this in mind when Algore talks about no ice at the pole – I really doubt he knows the difference, nor the reporters who should challenge his assertions if they weren’t scientific illiterates themselves.
Because airplanes partly rely on compasses to navigate (before GPS), the fact that latitude and longitude and runway alignments are based on rotational north, means that you can’t just follow the compass to your destination. You have to adjust your direction with a correction factor based on the deviation in angle between magnetic north and “True” North, which is constantly changing as you move.
That’s not even the whole story. The Earth’s magnetic field is not even – the molten iron in the core moves around over time and local variations happen due to iron deposits close to the surface. That angle deviation varies wildly based on the local conditions. A compass is only useful for relative reckoning over relatively short distances.
GPS (as long as it keeps working) solves the problem – your location is based on the location of orbiting satellites and not based on the erratic behavior of a compass…..
One of the answers to the poll is “So that’s why I keep crashing in the flight simulator” – that’s probably a correct answer – if you thought “North” was “North” and made no adjustments for Magnetic Declination, you’ll never line up with the runway….
http://www.magnetic-declination.com/what-is-magnetic-declination.php
Now the “corrections” that people arriving from RSS who have no idea of anything I’ve ever written but feel a need to “correct” my mistakes then vanish…
If you think back to science class, the same poles on magnetic repel each other. It’s actually the “South Pole” of your compass that points to the North.
Pre-GPS, the compass is only one of the navigation tools – in addition to dealing with the constantly changing magnetic declination over a long journey, the plane is being moved by the winds it is flying through. Even if you started flying straight at your destination and there was no magnetic variation, you would still miss the target. On top of that, the Earth is a round sphere that bulges in the middle, not a flat map. Flying around the planet, you’re need to fly along an arc in order to “fly straight”.
non-GPS Navigation relies mostly on ground based navigation aids at fixed known locations. You generally fly relative to a “radial” – an imaginary line coming from the fixed location. You also have a map showing the terrain and match that up with what you’re seeing out the windows (unless you’re above the clouds). However, if you’re flying over an ocean, you have no visual references and have few fixed navigation aids…. once you appreciate all of that, it becomes easier to understand how the KAL-007 airplane got off course while flying over the Pacific Ocean because it was accidentally navigating only on Magnetic compass headings
*** tosses out hook ***.
http://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007
“The correct answer is that runways are aligned relative to rotational/True north, not magnetic north. Your compass does not point to either the magnetic pole or True north.”
Actually, most US runways are numbered relative to magnetic north, unless the local magnetic declination (the angle between true north and magnetic north) is so large that it would cause confusion. For example, my local general aviation airport was constructed in the 1930s by the Navy. When it was built the north-south runway was aligned pretty close to N-S (according to the magnetic compass). Thus the runway was numbered 36-18. However over time the magnetic pole has drifted a little and that same north-south runway is now numbered 1-19. From old topographic maps we can tell that in the 1930s the magnetic declination at the airport location was almost zero. Now the declination is about 4 degrees west.
I’m usually reluctant to reference Wikipedia but it has the best explanation I could find quickly:
http://en.wikipedia.org/wiki/Runway
This is a lot of work to land one fish.
Tampa just had to redesignate their runway due to the the declination change. Congress should just pass a law to outlaw magnetic north moving and fund research into preventing global magnetic change.
ROTFL! But, seriously, don’t give them any ideas. These are the same folks who expressed concern that an island might capsize if you put too many soldiers on it.
Did a little more reading today…. it turns out the sun switching poles is part of the normal cycle – every 11 years (more or less) North and South change ends – which just happened a short time ago – pointing out even more so that the alignment of the Earth has nothing to do with the magnetic force.
The other interesting thing was what will happen when the poles do shift (probably in about 1000 years) – it’s a very complex process, and the speculation is that for a period of time (probably measured in years or decades) “poles” would pop up around the planet at different places and come and go frequently. Good thing we have GPS now.
Haven’t you heard? All compasses now point to “The One.” It’s in all papers.
Fascinating!
Never realized the “attraction” of the compass needle was due to the “South” pole.
The reason for my Art’s science lesson is Noory and now Alex Jones (and Drudge) are trying to scare people who don’t know better that a “pole shift” is gonna happen any day now because the North Pole is movIng. It’s always moving – a lot. I was hoping to find an animation that shows it over the past few hundred years where we have accurate records.
This pole shift stuff is more of the crap from the Father of the Global Warming Hoax, Art Bell – who is busy laughing his ass off at how stupid Americans are. Nobody told Al Gore that Chupacabras aren’t real either. Art portrayed a pole reversal as the rotational poles would switch ends and a 1000 mike an hour wind would destroy everything
That’s utter nonsense. Even if the magnetic poles reverse (not good for your compass), the Earth isn’t going anywhere. If the magnetic pull (not to be confused with gravitational pull) was that significant, the earth wouldn’t be on the permanent tilt that causes the seasons. The inertial force of the planet rotating once a day is absolutely huge. A three year old who has balanced a gyroscope on a string or tries to turn a spinning bicycle tire knows that.
Tap tap tap… Maybe I forgot to bait the hook.
And everyone knows what happens to a spinning top when it starts to wobble – soon the wobbling makes it loose it’s inertia, and it wobbles more, and ultimately it’ll stop spinning. So soon we’ll be hearing how the Earth is starting to slow down and will ultimately stop. We’ll become like the moon – always facing the same side to the sun, with a hot side and a cold side. A light side and a dark side.
The Great Global De-Spinning Theory. You heard it here first.
Or did Art Bell already do it?