North vs. South

panic mode

Joined Oct 10, 2011
1,788
When in doubt about character of Earths poles... make a solenoid and power it from a DC source. Then you know which side is N/S and can test your collection of magnets if they they are attracted or repelled by the solenoid. :rolleyes:
 

Thread Starter

Wendy

Joined Mar 24, 2008
21,914
I may be wrong, wouldn't be the fist time. I always thought it was part of the GPS function.The movement direction would determine which way you were facing, that and it can be derived from constellation of satellites, which is how I assumed it was done.

Looks like I hit a nerve with what I thought was a simple question. Now to find out if their is a compass feature on my Samsung smart phone.
 

joeyd999

Joined Jun 6, 2011
4,287
I may be wrong, wouldn't be the fist time. I always thought it was part of the GPS function.The movement direction would determine which way you were facing, that and it can be derived from constellation of satellites, which is how I assumed it was done.

Looks like I hit a nerve with what I thought was a simple question. Now to find out if their is a compass feature on my Samsung smart phone.
Go to dial keypad, type:

*#0*#

Select "Sensors".
 

Thread Starter

Wendy

Joined Mar 24, 2008
21,914
I googled it, the compass app(which I would have to download) is referred to as GPS based.

I'll take that as confirmation of my GPS hypothesis.
 

BR-549

Joined Sep 22, 2013
4,938
The magnetic field direction is referenced from S to N at the dipole. So, a magnet, a loop of wire, a current meter and the left hand generator rule........should indicate which pole of a magnetic is approaching loop.
 

Thread Starter

Wendy

Joined Mar 24, 2008
21,914
My current thought involves a chunk of a Styrofoam cup and a bowl of tap water. doable given my current state of disability. There are many times I wish God had just ended me rather than put me through this. I have kids and grand kids, they anchor me from doing any thing stupid. Sorry for writing this, but feeling helpless is hard for me. So I'll keep on muddling through, and try to keep it in my blog in off Topic "All About Wendy". Meanwhile I'll bug my friends here and elsewhere with my stupid questions. It's something to do.

For the record I tried dialing, the codes in post #25, Nada. Maybe I just did it wrong.
 

Thread Starter

Wendy

Joined Mar 24, 2008
21,914
It is neater than bear poo. Got lucky in placing the magnet, compass still works with it attached!I looked for place on the phone where the magnet was least attracted too, didn't want to mess with the speaker or microphone. The magnet is superglued on a removable case on the phone.

Figures a trickster would know about this trick. Offer a lot of practical jokes I don't think I'll ever use, like turning on the vibrate mode and discharging the phone. Thanks Joey, It is something a techie nerdette like me would love.
 
Last edited:

MrAl

Joined Jun 17, 2014
6,784
Hi,

Yes the north pole of a magnet points to the north pole of the earth at least for the time being.

The simplest compass is made by taking any magnet and gluing the end of a sewing thread to the magnet with super glue or maybe hot glue. Hold the string up with one hand and wait for the thread to unravel a little. Then the magnet stops turning, the side that points north is the north pole.
A couple notes though:
1. The magnet has to be suspended such that the two poles face outward.
2. The thread must be long enough to avoid any torsion from affecting the rotation after some seconds of untwisting.
3. If the magnet swings back and forth a little you can dampen this with your other hand, then wait for the untwisting to stop.
4. Stay clear of any large metal objects.

It's so easy. I actually used this idea once when going to a new place on foot where i took a bus to get there and had a map but needed to know where north was so i could use the map effectively to walk down the right streets to get there. It was a little fun really but i was lucky there was no wind because that would have made it too hard to use i think unless i went indoors.

There is another interesting way to find the north pole if you have a CRT oscilloscope.
If you bring the north pole of the magnet close to the SIDE of the scope (perpendicular to the electron beam) the beam will deflect downward. The south pole will cause the beam to deflect upward.
You should adjust the scope such that there is just a dot in the middle of the screen before this.
 

Thread Starter

Wendy

Joined Mar 24, 2008
21,914
Again, my goal was not to make a compass, but to identify the N/S poles on an unknown magnet. I now have several techniques (including the phone) to do this with. Sheesh, throwing a problem like this to bunch of problem solvers is like throwing a steak to a pack of ravenous wolves!
 

MrAl

Joined Jun 17, 2014
6,784
Hi,

Yes but when you make a compass you make a way to find the north pole of a magnet. That's why so many suggestions to make a compass.
You dont need the compass itself, you just need to identify the N pole of the magnet, then you have a way to find the N pole of any magnet after that by just using your known magnet. You mark the N pole, remove the thread, then you have the magnet with known poles to use from then on.

The CRT scope is easier if you have one around but most people have LCD scopes now :)
With every new technology we lose something in return.
 

MrChips

Joined Oct 2, 2009
19,728
Again, a compass is off topic.
I think you miss the point.
We all know that you know which way is geographic north.
I have a compass. Its red needle points north. Hence the red end is a north pole.




Now I can use the compass to identify which end of an unknown magnet is a south pole.



If you are not careful you can inadvertently reverse the polarity of the compass and then you will be totally confused just like in one of the videos. I wouldn't post it because it will confuse a lot of people. Don't believe everything you see on the internet.
 

MrChips

Joined Oct 2, 2009
19,728
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