Wednesday, 16 February 2011

Plant Science 1 and Potato guns (and other scientific adventures)

Plant science.
Yep, that's what we appear to be doing. After our venture into cells here it seemed logical to carry on.

It all arose out of a desire (mine) to take our everyday-as-it-happens science up a notch or two.

My hunt for a one-stop suitable book or resource - something between text book and popular science, with sequential and relevant experiments, clear diagrams and a host of other requirements - has, not surprisingly, been unsuccessful.

And so we have resorted to our usual mish-mash of resources, researched, cribbed and squidged together as a higgledy piggledy selection of podcasts, old pre-curriculum science books, webpage printouts and BBC video clips.

First we looked at transpiration and the flow of water up plant stems. The conversation went something like this:

Dh: "Celery? But I thought you didn't like celery?"
me: "I don't. It's for science."
Dh: "Oh. Right."
He looks at me strangely. This is the man who made gunpowder in our back garden for ds1's 7th birthday. Who used liquid nitrogen and orange juice to make orange sorbet for our barbecue. Nuff said.

Anyway, the old 'celery in a glass of coloured water trick' (btw only one stick is required, not the whole blooming lot).

Et voila! Blue dye seen in celery slice. Now that was worth £1.15 at the greengrocers.

Then we look at osmosis. You know, the passage of water through a selectively-permeable membrane from a place of low solute concentration to high solute concentration. [Just look it up in wikipedia]

ds2 cuts 2 potato slices:

Yep, like that.

One slice is added to plain old water.
The other slice is added to water with a big load of salt dissolved in it.
After an hour or so, the slice in the salty water should go floppy as water passes from the potato into the water, and the slice in the normal water should go hard as water passes into the potato. Or something like that. You get the gist.

And what to do with all that leftover potato? An impromptu opportunity for potato sculptures, of course.

And ammunition for weapons
If you make the mess, you clear it up dear eldest.
Like a shoot-out on CSI, but with only small lumps of starch left as evidence (all over my conservatory floor as it happens).
More plant science.
We finally get around to planting those Spring bulbs bought in October.
Some of them were even trying to flower in the bulb bag (on 1cm stalks) Oops.
Ah well. As my father always said - they have two chances: live or die. I'm not sure what he was talking about at the time. (It might have been rather tactless if it was people.)

More science.
Have you ever seen a more characterful photo of a 12-yr-old?
...with a bicarbonate of soda rocket in his hand.

More science. Ds1 makes one of those wiggly buzzy wire things, except this one lights up a bulb instead. Made out of a rolled up piece of aluminium foil, a large battery, an empty chocolate box, a bulb and some wire (I guess). All his own work. He obviously doesn't trust me to have any useful input into these technical things whatsoever.

Bird feeders and nuts.
I suppose that counts as science...natural history or something, if you want to tick a box.

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