27 May 2009

Finding our way – through a fog of confusion!

A discussion that began with the question ‘What is a map?’ threw up all kinds of interesting ideas and conceptions; certainly plenty of food for thought (and we thrive on that kind of food in Class 2i!)

Tatiana: A map is like a big paper with places on it.

Virginia: A map is a paper who (sic) shows places around the world.

Sharukh: A map is a big piece of paper with the names of roads and the names of areas and you use it to see how you go to the other areas.  And there are maps on the Internet.

Meghna:  If you are lost you can just take a map and it tells you where to go.  (Now wouldn’t that be wonderful!)

jd finds the way

Sivert: In museums maps tell you where to go in them.

Martin:  It helps you to go where the right place is so you don’t go to the wrong place.

Shahrbano: When you want to go somewhere you can see the map and it tells you where to go.

Harrison: If you don’t know where a place is you can buy a TomTom that shows you where to go.  (A true sign of the times!)

Tommy: Or you can use a compass.  (That was one large mouthful of ‘food for thought’.)

Right.  Let’s home in on what Tommy suggested; namely that a compass can help you find your way.  And ask a supplementary question or two; How does a compass help you find your way?  What does a compass do?  What is a compass?


“If you have a compass you see, if it shows north you have to continue,” said Dylan.

“North is up,” ‘corrects’ Virginia, pointing skywards.

Sharukh, standing, “If I face this way, north is here.  If I turn, north is the way I face.”  A murmur of agreement here.

OK; where is north then.  Can you point to north?  And, perhaps unsurprisingly, a forest of fingers point in my general direction.  But also somewhat unsurprisingly, there are also murmurs when I, facing them, wonder if north for me can be in the opposite direction.  Is north in front of me or behind me?  Can north be in two different directions at the same time?

“No; north is a certain way,” concludes Amelia. 

“What certain way?” asks Ryoma.  Good question.

And a compass; what does it actually do?  Well, it points north.  North and only north.  In a certain way.  Anyone know why?

Dylan again.  “It is because of the treasure buried.”  Hmm.  Too many computer games perhaps!

"It is because of something in the earth,” confirms Sharukh.  But definitely not treasure!

"There is a magnet in there,” Tommy tells us emphatically.

And so, in a very roundabout fashion, we make our way via TomToms and museum guides, past street maps and buried treasure to the magnetic core of the Earth and the fact that a compass is a tiny weak magnet that is attracted to the huge magnet that is our planet.  And that this fact can help us find our way.

And we set out to show it.  By remembering firstly, something we had learned about magnets in our unit on materials.  That a magnet has a ‘south’ end (or pole) and a ‘north’ end.  And that these two opposite ends stick (or are attracted) to one another.  And it wasn’t too far a step needed to link the North and South Poles of the Earth to the north and south poles of magnets, and work out that maybe the tiny weak magnet in a compass would be attracted by and point towards the opposite pole of the huge magnet that is our planet.  Let’s not here get bogged down by the confusion of the fact that a magnet’s north end points to the North Pole (no, no, no!)

Instead let’s get our hands on some tiny weak magnets that are compasses as well as some somewhat stronger plastic-coated magnets and investigate how they work.  Let’s find out, for example, that even though it might appear that this compass is pointing towards the west…..


when we swivel the compass around towards the letter N, the needle stays in place (my goodness how exciting that was!)


Let’s suspend a somewhat stronger plastic-coated magnet from a piece of string…..


to see if that too will point towards the north (which we confirm for ourselves is indeed in a certain direction).


And just for fun, let’s think about what might happen if we were to put different ends of a somewhat stronger plastic-coated magnet near (but not too close to) a tiny weak magnet that is a compass.  And then let’s check to see if we were right.

And now that we are ‘experts’ on how they work, let us plan a map-following trip where we can put them to use.  More of which later.

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