h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

My 5 year old has just started talking about symmetry. Can anyone suggest some household objects that would be good for exploring symmetry further?
Are there interesting things I could point out about symmetry?


Alex.

I always thought that symmetry was such a simple idea, it was ridiculous what a big deal the mathematicians made of it!

Can your 5-year old read? You could show her the symmetry in the capital letters. Some of them have vertical symmetry, some horizontal, some both, some rotational. You can even put together words that are the same upside down or in a mirror, or spell something different. Write TOYOTA and PEUGEOT vertically and look at them in a mirror.

Show her symmetry in nature: "higher" animals tend to be bilateral symmetry - a cat, a bird. Jellyfish, starfish and sea-urchins have four and five-fold symmetry. Plants often have five-fold symmetry.

Are you in the UK, Alex? Examine a 50p coin.

Don't start on the question of why a mirror reverses left-right and not up-down until she's much older! And even then, only when you are sure of it yourself. The answer involves the bilateral symmetry of "higher" animals.

Excellent! These are great ideas.

He (sorry, should have specified) is learning to read and knows the letters well. Looking at their symmetry is a interesting way of exploring their shapes.

Yes. I must get a small plane mirror.

Have you ever had a look at ambigrams (I don't think I'll show him them yet)? Hoo showed me them and you can create one for your own name. E.g. http://www.01101001.com/ambigrams/

Thanks


Alex.

PS. Yes, UK.

Yes. I must get a small plane mirror.

No. Get two! Then you can play about with reflection angles and images when she's old enough. You could even make a periscope. Kids love periscopes.

B

Afraid I borrowed 2 right angled prisms from school.

Apparently I had promised him that we would make glasses that would let him see his toes (after he had tripped up about a month ago).

Anyway. We made a periscope with those.

Hmmm, maybe I should have started with mirrors?



Alex

If you have digital camera and photoshop similar you could demonstrate how unsymmetrical - and I'll word this tactfully - people's faces can be. Take a picture, split it down the middle and mirror one half over to the other side. Unless of course you and your son have perfect faces you will be surprised at how different you look.

Yes, that's a good idea.

In fact his own example of symmetry was a face. That will be interesting to do.

Thanks.

Darn the face things has been mentioned!

You could use a various things for him to prove that he understands symmetry i.e. a teapot is (normally) symmetrical from the front and top but not the side. And more marks for your son if he says the top is not symmetrical due to the hole in the top to let the steam out.

Slight topic jump:

You do know that Johnny Ball organises Science theatre events not sure whether they are still going? What 30something who is now an engineer/scientist did NOT watch him when they were younger? Wish I hadn't I might be doing something that makes lots of cash!