The North Pole

[scottyp]

Rather than derail Ray's awesome Edwards 5 build thread, I figured I'd throw my off-topic comments here.
As previously posted:

"The earths north pole has a polarity of south that is why the compass needle that has a north polarity is attracted to it. I removed all the magnets and reinstalled them the correct way around and everything works fine.

From Wikipedia, the free encyclopedia
"Because opposite poles attract, this means that as a physical magnet, the magnetic north pole of the earth is actually on the southern hemisphere.""


Here is my take:

Could it be that the magnetic pole at the "top" of the earth (the one near Canada) IS actually North and the end of the compass needle that is attracted to and points to this pole is South polarized and someone happened to paint it RED and stamp an N on it to indicate where North is?

Somewhat rhetorical, it is a matter of perspective and labeling. What came first, the Earth or the Compass?

 

[Rdean33422]

It is an interesting question so I did some more research and found this.

"The north and south pole of a magnet aligns with the Earth's geographical north and south pole respectively. Since unlike poles attract, the north pole of the magnet must align with the Earth's magnetic south pole. Similarly the south pole of the magnet would align with Earth's magnetic north pole. Hence, the magnetic north and south poles of the Earth must be situated at geographical south and north poles of the Earth respectively."​

How does a person determine the polarity of a magnet?


Ray

 

[scottyp]

OK - How one determines the polarity of a permanent magnet is by where the magnetic field lines run from/to. They run from the magnetic north to the magnetic south. And in Earth's case they run from the Antarctic end to the Arctic end of the Earth. I am now sold on the magnetic north being at the south pole. Crazy. I suppose that is assuming we are talking about conventional magnetic field flow.

If we look at electronics, there are the conventional flow vs. electron flow perspectives. Now, if we apply this to magnetic fields, is north still south?

 

[Rdean33422]

Now I have not found an answer to my question as to how out in the shop and not using a compass or dangling the magnet from a string how do you determine the north or south pole.
I have found an app that you can install on your smart phone that tells you but I don't have a smart phone and it is potentially dangerous to your phone as well.
I also found several pencil like devices that can indicate the poles at a push of a button but at around $88.00 I'm not up for that.

Anyone have an idea.

Ray

 

[kf2qd]

So, you are certain that the compass that you have is correct and the earths poles are wrong... How very arrogant of you. And what difference does it make. North Pole, South Pole are just names we have given them for our convenience. Could have just as easily said the "north pole" is really the positive pole.

 

[Charles Lamont]

The red end of your compass needle will be attracted to the South pole of your magnet.

 

[cdn flyr]

The answer is pbvious. You have a Tates compass. They marked their needles backward; which gave rise to the expression "He who has a Tates is lost".

 

[mklotz]

Make yourself a solenoid. Then, use the right hand rule on the (conventional) current to identify the North pole. Then use that to identify the polarity of the compass needle.

More here...

https://physics.stackexchange.com/questions/337822/direction-of-magnetic-field-in-a-solenoid

 

[Rdean33422]

Thanks all for the ideas.

I think I have it figured out now.
Ray

 

[Rdean33422]

The answer is pbvious. You have a Tates compass. They marked their needles backward; which gave rise to the expression "He who has a Tates is lost".

Now that's funny
Ray

 

[RM-MN]

Now that's funny
Ray

Not when you are navigating at night with someone else's compass. I went farther into the woods when I thought I was exiting.

 

[scottyp]

Once you are halfway into the woods, you are exiting.

 

[L98fiero]

Once you are halfway into the woods, you are exiting.

Just to be pedantic, if you are halfway into the woods you are still entering, if you're halfway through, with your next step, you'll be exiting.

 

[ccolby]

The answer is pbvious. You have a Tates compass. They marked their needles backward; which gave rise to the expression "He who has a Tates is lost".

LOL. Probably old, but still most excellent!

 

[ccolby]

Now I have not found an answer to my question as to how out in the shop and not using a compass or dangling the magnet from a string how do you determine the north or south pole.
I have found an app that you can install on your smart phone that tells you but I don't have a smart phone and it is potentially dangerous to your phone as well.
I also found several pencil like devices that can indicate the poles at a push of a button but at around $88.00 I'm not up for that.

Anyone have an idea.

Ray

Go outside on a sunny morning and drive a slender stake in a level area of ground. Make sure that the stake is long enough to cast a decent shadow on the ground. At noon local standard time, as noted by your watch or handheld digital annoyance, the shadow will be pointing geometrically (not magnetically) exactly north and south. Of course, you will also have to know in which hemisphere you are standing to know which end of the shadow is pointing north. This will also work indoors as long as the sun can shine through a window onto the floor at noon and you have something that holds the stake in a vertical orientation.

If for some reason, you need better accuracy, you will also have to consult a magnetic pole declination chart to know how much deviation to expect between true north and magnetic north. For logic that escapes me, the owners manual for my 2014 Volkswagen contains that declination chart.

 

[kf2qd]

The stake in the ground thing doesn't work so well down here in south Texas. We are so close to the Tropic of Cancer that the sun is almost straight overhead. And in the summer months, anyone south of us has the shadow pointing south at mid day.

 

[ccolby]

The stake in the ground thing doesn't work so well down here in south Texas. We are so close to the Tropic of Cancer that the sun is almost straight overhead. And in the summer months, anyone south of us has the shadow pointing south at mid day.

I agree. I apologize for my narrow thinking up here on the 40th parallel. You're stuck with either using a Google Maps satellite image of your shop or borrowing one of those Tates compasses from a migrant.

 

[terryd]

I agree. I apologize for my narrow thinking up here on the 40th parallel. You're stuck with either using a Google Maps satellite image of your shop or borrowing one of those Tates compasses from a migrant.

Hi,
If you can't create a simple sun dial (stick in the ground ) or it's not sunny I then use my Apple watch compass app. It's not super accurate - but neither is a magnetic compass if there's metal around - But it's enough for me. Of course on a clear night you could stand out in a place visible from your window and paint a line on the ground, lay a stick embedded in the ground or a row of bricks pointing at the North Star. Then you merely have to peer out of your window at your lovely consruction pointing directly to thr pole.
If you are down in Texas you can use the stick method and paint a line before the sun passes to the North, I did this on my concrete driveway in the (UK 52nd parallel) when I built my sundial for the Mars Rover 'Two Planets, One Sun' project under the auspisces of Bill Nye abd NASA At his suggestion a few of us made sundials with local highlights decorating the dials which wee individuall live sreame to a Nasa website.
By the way, the stick and shadow method is most accurate for the actual pole but you need to know your longitude to correct for the magnetic pole Magnetic compasses can be seriously affected by the presence of some metals especially ferrous ones, even ferrous ores in the ground.

Regards,
TerryD

 

[JohnBDownunder]

Seems to me that nobody has yet mentioned that the sun rises in the east - sets in the west so facing 90deg away will be near enough north - south even on the equator.
Just to give you a clue?
Oh, here at Latitude: -38° 08' 49.60" S it rises over the left end of my neighbour's roof peak in summer, right end mid winter.

 

[Steamchick]

In the northern hemisphere , where it is wet enough, check trees for the mossy side. Half-way around the mossy patch is about north...
Dandelions flower at or above 13 degrees C.
Lots of "old" knowledge tells you about your environment.
But division of the compass to give accurate navigation, division of the sun's shadow on a sundial, etc. are true engineering solutions to expand human endeavour.
K2