http://www.miniclip.com/games/space-hopper/en/

You have a little spaceman and you have to collect stars. After the first level there are different density planets which you can tell from the height you can jump - and it's fun!

http://www.rapidonline.com/searchresults.aspx?style=0&kw=dent+puller

 The 110cm ones are £1.95 each and two make great Magdeburg hemispheres. With p & p under a fiver, that's still less than a tenner!

http://www.physiol.ucl.ac.uk/ashmore/

..oh and there's some video or other that's with it. 

 http://www.dr-jordan-design.de/signalgen.htm

 Does up to 20kHz and has different wave shapes and fine and coarse control.

I have decided to try and add something each week that makes them think outside the current curriculum - maybe a 'wow' moment, maybe a 'why does it do that' moment, maybe an image ......

So this week I did the marshmallows (thanks to Neil Gupta for this)

It drew suitable oohs and has - so that by Friday older sisters were asking when they were going to see it as their younger sisters had already seen it.

Th eonly trouble was if I did it at the beginning, the valuable ensuing discussion ran on and we struggled to do the meat of the lesson.

I now have to collect many more so that there is a different one every week for 5 years!

And just at the right time Paul Nugent drew my attention to David Featonby's article. 

Next week the colour change ducks I bought in Sainsbury's in the post-Christmas sale. 

The Special Theory of Relativity

A learned man, Galileo by name,
Once said that all physics should be the same,
For everyone in an inertial frame,
Moving at constant velocity.

Then a Scott called Maxwell caused a schism,
With his theory: Electromagnetism,
That predicts many things with precision,
But says light's speed's a constant.

So what is the light travelling through?
And if it's a constant, then for who?
It must, it was reasoned, be with reference too,
A medium that they called The Aether.

Quickly they rushed to their chalk and their boards,
A difference if moving away and towards,
The Aether - if measured would reap great rewards,
But Michelson / Morley found nothing.

So a great contradiction in physics remained,
To preconceptions, the experts were chained,
‘Til a mind such as Einstein's, that unconstrained,
Offered a simple solution.

What if light travels the same speed for all?
The Aether's a fiction, a cerebral shawl,
We can't treat light like a stone or a ball,
Velocities don't add and subtract.

And what follows on from this idea sublime?
All the dimensions distort and combine,
Contraction for space; dilation for time,
Energy and mass conflate.

It doesn't stop there, I hope you will see,
That's just the Special Theory of Relativity,
Acceleration and gravity,
Are left for another poem.

By James Sheils

http://www.amazon.co.uk/gp/product/0316366951/ref=sib_rdr_dp

I shall add it to my list for next year.

At the Amazon site you can search through some of the content.

Happy New Year! 

Here's how to make it:

1] Get a clean empty pop bottle, some glitter, permanent ohp marker pens, a bit of white plastic from an ice cream tub or similar, a bendy straw and a paperclip, some white acrylic paint and a brush.

2]  Mark a thick line around the bottom of the bottle, 3-4 cm up, all the way around.

3] Paint the bottom of the bottle on the outside with the white paint up to this line. Trying to paint inside the bottle doesn't seem to work well as the paint doesn't dry. 

4] When the paint is dry draw Xmas iconic images, snowmen, reindeers, Christmas tree and most importantly a chimney on the outside of the bottle.

5] On a bit of white plastic small enough to fit through the hole in the bottle draw a Santa.

6] Put the water in the bottle almost to the top.

7] Bend the bendy straw and cut off the excess so that you have two even lengths coming off from the bend.  

8] Hold the ends together with the paperclip and also keep the plastic Santa in place with it.

9] In a dish of water get the straw/paperclip/Santa combination to just float by making sure there's just enough trapped air in the bend of the straw to keep everything afloat.

10] Carefully but quickly put the Santa diver in the bottle.

11] Put the top on the bottle and squeeze and make sure the Santa dives. (If he doesn't fish him out and adjust - putting your mouth over the undone top and sucking will sometimes make him float if he's sunk)

12] Finally add the glitter for the snowstorm effect.

(There are more detailed instruction here:  http://www.sciencetoymaker.org/diver/assembl.html.)

Squeeze the bottle to get Santa to drop down the chimney! 

Have you seen these in Hawkins Bazaar?

They call them  switch ball

When you throw it up in the air, with a bit  of spin, it opens out so it is neither green nor orange, then when you catch it, it decides which to be.

In other words, you can only tell which state it is in when you have stopped it!

[Thanks go to Michael Brimicombe for this one] 

The website is here: http://www.powerballs.com/