If you're coming to this blog looking for evidence against home educators, add this

Here is Shark, outside BHS in Milton Keynes Shopping Centre.


You can say Evidence! This home educator humiliated her poor daughter by forcing her to face the wall in a public place to complete her homework!

Proof. Home ed should be banned, to protect the vulnerable.

My fantastic list of crimes, misdeeds and madnesses is coming along nicely, isn't it? I might do unicorn horn chopping next, or driving round Leicester, naked.

Well, it's a better line than saying this is a geology lesson.

This BHS wall is faced with marble, which you all know is a building material also used for gravestones, ornaments and worksurfaces. And it's a metamorphic rock, which is mainly why we're here, looking at the patterns and talking about heat and pressure under the earth and what that does to all the minerals and chemicals and fantastic bits that make up rock.

Not as exciting a story as driving round Leicester, naked, huh?

For me, the most wonderful rock is Travertine. Here it is.


Imagine a huge bubbling bath that you're going to leave for thousands of years. Every so often the water is just the lovely right temperature for lots of algae to grow, and they're joined by great gloopy lumps of bacteria and little creatures, having a fantastic time swimming about in that lovely warm bath.

Then someone turns on the tap, and out pours a load more water, mud, silt, and tiny carbonate particles like bits of melted pearl or crushed up snail shell.

That tapload bashes the surface, ripping up and killing off the algae, and lays down a new top layer of mud and silt.

But don't worry, after a few more thousand years the algae's grown back. Then you can turn on the tap again.

Give it long enough, and the whole lot solidifies. And now you can see it in Milton Keynes Shopping Centre. It's called Travertine. It's a sedimentary rock, and here it's all over the floors and walls. Can you see those layers? The darker lines are mud and the lighter lines are algae. It's fantastic. I love it.


When we've done with Travertine, we go off and look at Gabbro, and a pretty pink granite and a blood-red granite.


It's all thanks to one of those experts we know from this education world, fantastically filled with opportunity, should you take it. So a public thanks to Jill Eyers for one of her walking guides, Rocks Afoot.

But I know a geology lesson is not a crime. And if you've come here looking for that evidence of our sordid lifestyle, then this is bound to be a disappointment. Sorry. I promise to do better with the madness and naked driving thing.

But look on the bright side. You can always accuse me of being a smugbastard highhorsed granolaeating homeeducator who definitely lives on the fringes of society because we went all that way to CMK and never even bought an acrylic jumper.