Schoolbook question

[Alderman Barnes]

My daughter came home with a book from the school library yesterday - a little American book explaining how magnets work.

It was nice, informative little book with some interesting experiments in it - for example how to make a compass - but there was one thing in it which struck me as odd.

Talking about magnetite, it said that the rocks had been in the earth for thousands of years and had become magnetised by the earth's magnetic field.

That's thousands of years, not millions.

Is this a sop to creationism, or is there some innocent explanation to this? Perhaps they suppose that small children might not understand the concept of millions, or might it be something to do with the occasional reversal of the earth's magnetic poles?

Maybe I've become oversensitised because of the "kick in the teeth" debates on here, but it just seemed weird to me.

[JtS]

Schoolbook question

Maybe it only takes thousands of years rather than millions

[Alderman Barnes]

Schoolbook question

Well yeah, it's a genuine question. I don't know how long it takes to magnetise the rocks, but it did say they had been in the earth for thousands of years.

[Bruno]

Schoolbook question

When was the book first published, and by whom?

[Ginger Yellow]

Schoolbook question

Well, magnetite is often found in igneous rocks (presumably because the atoms in the crystals get aligned when the rock is molten), so it wouldn't be too surprising if a lot of it was geologically young. It's also found though in sedimentary rock, from biological sources, which necessarily be old.

[Alderman Barnes]

Schoolbook question

I don't know how old the book is, but it didn't look very old or particularly recent. I'll have a look. It was published by Scholastic. The rocks in questions were the lodestones that were found in Magnetos.