Category Archives: Science

Small advances in literacy

History, Mathematics, Reading, Science, , ,

Here are a couple of things we’re going to be working on that I think will be a help to Antonia’s literacy in the long-term.

Greek letters.  They’re used in a lot of mathematical and scientific contexts, they’re easy and fun to learn when you’re young, and if you don’t learn them you will one day finding yourself reading passages like: “(shape) over d (unknown symbol) (other shape) equals the ultimate answer; where (shape) is the Infinity Constant  and (other shape) is the hypotenuse of the space-time continuum”.   In other words, you will have enough problems to be going on with, without having to keep shape and other shape straight in your mind.

I found the Open University’s set of applets for learning the Greek letters to be very nice and efficient.  The one on trying to put together Greek words at the end is just a bonus for our current purposes.

Roman numerals.   These might be a mere curiosity in some cultures.  True, they often appear decoratively on clocks, but in the end, most of us go by position, rather than reading the numbers.  In France though, it’s customary to express the centuries in Roman numerals.  ‘XVIIeme siecle’ is the 17th Century and so on.  That’s a nice little addition to the already pressing need to keep straight the idea that the17th Century belongs with the 1600s.  Antonia has nearly reached the age where she will find it helpful to have instant recognition of all the numerals up to XXI.

I was surprised that I couldn’t find any nice applets for teaching kids the Roman numerals from scratch so I’m resorting to good old-fashioned flashcards.  The first 8 have the individual numerals I, V, X, L, C, D and M.  The next set have I to XXI with the range of years corresponding to the century on the back.  The last set are more individual numerals for building numbers with.

Strewing the Periodic Table

Science

Here’s the part of the science curriculum I’ve come up with so far, a modern icon, the Periodic Table.  There’s only one I know of that’s pretty enough to hang on the wall.  It comes from Theodore Gray’s site.  I must say that I although I think the poster is amazing and the site is (was?) brilliant, it seems to have suffered from a sudden proliferation of advertising for this same poster which drags it down a bit.  Here I was, planning to buy the poster anyway, and now I would like to get some extra information about all the elements and enjoy the pictures.  There is lots of information, photographs and other wonderful stuff.  And, at a rate of about three times per page, there are lots more adverts for this poster.  Nobody, but nobody, who visits this site will be left in any doubt that there is a poster for sale.  That, I suppose, is the idea, but I’m sure there must be more refined ways of achieving the same end. Maybe it’s just me, but this does not breed in me an earnest desire to buy further posters for everyone from my third cousin to my neighbour’s budgie.  It breeds in me a certain irritation.

periodic-table-poster.JPG

Currently, we’re having a small problem with our poster because the US postal service have decided to mangle it, but I’m confident we can sort that out.  With the Periodic Table goes a certain amount of vocabulary, which will hopefully emerge from our idle chitchat around it:

  • parts of the table: period, group, atomic number, atomic mass number,chemical symbol
  • some groups whose names are worth knowing: alkali metals, alkaline earth metals, transition metals, chalcogens, halogens, noble gases
  • some other ways of describing elements: metal, metalloid, non-metal, radioactive, stable, unstable
  • elements and their names: Mike’s view is that we should all learn Tom Lehrer’s Elements song off by heart.  This probably will work quite well as we are all big fans of Lehrer, even though he’s rarely suitable for children.  Antonia’s favourite song is called Poisoning Pigeons in the Park.  That’s possibly because she can not understand so many of the others (I hope).

Anyway, we already know chunks of the Elements song.  And thanks to Theodore Gray we will be able to know that our big favourite ‘Fooly-em’ (Thulium) has “very few applications” and that “some people consider it the most useless of all naturally occuring elements”.  We might have guessed that from its name.

PS.  In case you hadn’t gathered, Theodore Gray is selling posters like the one above ; )

Science Experiment: ye olde rede cabbage acid/base indicator

Science

So we got round to it.  After a little review (20 minutes or so) of what happens when you add bicarbonate of soda to vinegar, we knocked up some purple cabbage juice in the blender and applied it to various substances.  The results:

  • Our water is distinctly alkaline,
  • You can make all kinds of pretty colours with this stuff,

acid-base-indicator.jpg


After that, the chemistry lesson slowly merged into full-blown potions lab…

potions-class.jpg

During which we discovered that kitchen towel is so incredibly alkaline that it turns the cabbage juice a pretty cyan.

I have also learned a couple of things lately.  The first and most important is that I’d really better review my chemistry before I teach it.  They’ve changed one or two little things in the last 25 years (darn ’em).  The other is that anthropomorphic explanations trap ideas in the six-year old mind like honey traps flies:  all those mean hydrogen ions zooming around like pirates looking for electrons to steal, whilst the wretched alkalis have more than they know what to do with. Antonia: ¨I bet they’re glad to get rid of them really!¨

Candy-making for beginners

Life skills, Science,

 Antonia and I are planning to learn to make sweets of all kinds.  And we will be calling it chemistry.  We started with crystallised violets, which can only be done at this time of year of course.

crystallised-violets.jpg

Crystallised violets are very retro.  I suppose we must be in that kind of mood.  By the time I was a kid they had already morphed into artificial purple blobs.  Now they’ve disappeared completely, presumably because the purple food colouring turned out to be carcinogenic.  I can see why the real ones aren’t mass marketed.  If we want to improve them next time, we will paint each one with egg white individually using a small paintbrush, as the recipe suggests, instead of just dunking them.  And I would go with the ultra-refined, pure white, finely crystallised sugar instead of the earthy, organic stuff we usually use.

We also made fudge, but as we didn’t have a sugar thermometer at the time we undercooked it.  The mixture sat around the kitchen for, errrm…, several weeks while it dried to a suitable consistency.  Now it tastes just right.

fudge.jpg

We are fairly expert at origami by now, so making the box to keep the sweets in was a singe.  I love making boxes, plates, envelopes and folders, which must be one of the most useful and easy branches of origami.

Wild about honey bees

Homeschooling in general, Nature Study, Science, ,

bees-book.jpgI bought this book just as a treat, because the pictures in it are too beautiful. Now the passion for honeybees is growing on me and Antonia. In another life, a life in which my husband was not allergic to honey and I traveled less, I think I would be a beekeeper. I’m fascinated by their senses, their communication, their life cycles and their castes. I’m blown away that they have five eyes of two different types, and two kinds of ‘ears’. And that the workers cycle through a series of tasks during their life, from comb maintenance to brood nursing, guarding to gathering, and that they develop the appropriate organs accordingly. And the stuff that they collect and produce is so attractive to the senses: pollen, nectar, honey, wax, propolis. They’re so furry, I could cuddle them if they didn’t sting, and they have such a hypnotic hum.

In my dreams, I would have a natural observation hive, in which I could just watch the bees do their own thing, and maybe pinch one of their smaller combs from time to time. In fact, the hive I want is this one, below. Maybe I could get those people to swap houses with me! The wild combs are so beautiful, I just can’t help wanting to reach up and steal one, and munch straight into it. They look like galettes, and they must be appealing to some very primitive instinct in me. I don’t think the manmade combs are pretty at all.

beehive.jpg

Taken by Max xx, a fellow Brit in France, apparently, from Flickr with a CC licence.

Poor bees. They have been having such a hard time lately. It would practically be a civic duty to let some live behind my shutters. Can you just hear me talking myself into something here? In my obsession, I’ve been reading everything I can find about bees. Some proponents of natural bee-keeping like this one, think the bees will do better in more natural conditions. Standard bee-keeping encourages them to build bigger cells and bigger bodies, produce more honey and less wax than they might choose, get moved around so that they produce honey from single plants, refrain from their usual reproductive activities if possible, and live off sugar syrup once the results of their labour has been harvested. When you look at it like that, it’s no wonder they’re struggling. And those nasty artificial combs don’t look nearly so hygienic, safe or well-ventilated as the natural ones, to me.

I was musing on this today, and it suddenly struck me as a pretty good metaphor of homeschooling versus schooling. Like the standard hives, schools provide a ‘safe’, prepared environment that’s designed to draw out some human characteristics further than they might otherwise go while repressing others, and train kids in the habit of over-productivity. Turns out the environment isn’t as safe as all that, and the kids end up weakened in various ways. Then lots of us go on to live adult lives that are much the same. Too much working to produce honey/knowledge/money and the honey ends up too thin, too purified and easily diverted to other people’s ends. Not enough wax, the relationships and life skills that hold people’s lives together in the first place. Bzzzzzz…. I imagine this metaphor will only make sense to me.

Science experiment: make your own ‘fossil’

Science

make-your-own-fossil.jpgAntonia chose this science experiment from her magazine. One of the cool things about homeschooling is we actually have time to do the magazine’s activities if she wants to. My childhood memories are filled with the input of good ideas from many sources and not time to carry them out.

This is one of those experiments to make something that looks a bit like a fossil. Basically, you fill a snail shell with plaster, set it in a plaster base, then dissolve the shell with vinegar. I was somewhat dubious as to whether this would work well. Actually, the incomplete form we ended up with is probably more realistic.

Homeschooling for adults: microscopy

Science

Mike and I are getting to grips with our microscope before we let Antonia loose with it. She is pushing for a go, but this morning we had problems with a dodgy switch on the light. I was sad because I had managed to prepare an almost decent section of the hyacinth stem using nothing but a craft knife. This evening we got the thing working, and we’re delighted to find we can take reasonable photographs without paying a huge sum for a camera adapter.

When I compared the pictures, I discovered the tripod hardly made any difference over a handheld camera. The focusing is not totally brilliant, but it will do.

There we go… with practice, we might get some nice pictures! Now, I don’t know what that spiral structure in the picture is. I want to believe it is contamination from dust but there are lots of them all over the stem section, and none on other parts of the slide. If anyone wants to enlighten me, please leave a comment.