Reading it gives you academic knowledge in as much as "This aught to work in theory"

Actually experimenting with it gives you a physical aspect  in "This feels right"

Together they take you to a point where you have a better chance of a working knowledge.

Highlight each of these drawings and print them - preferably on card, if your printer can handle it.

Then stick them together with sticky tape.

Super accuracy is not the aim. We just need to use them.

In true Blue Peter style, you will need a tray with sides on and a bag of sugar or salt.


Er...Not sure why this one has the crease in the wrong place...


You need to tape two sheets of paper together and do enough housework that you can actually get it flat on a worktop or table. Putting it on the carpet is a no no.

Then you need to tip some sugar on it. Salt will do. It has to be dry.

The ripples on the paper is the sugar. Should have found some yellow sugar so it would photo better.

Set the square ended boat shape down at one end of the sugar

Put your fingers in it to stop it riding up and then push it along....

This creates a wave in front of the boat and a line down each side....

If that was in water, you would be pushing that wave along and moving the rest of the water out to the sides as you pass.

This is the equivalent to dragging a long a barrel of water and of trying to push gallons sideways by half the width of the boat each yard you move. The water would come back after you pass, but you still have to pay the energy to move it in the first place.

Note that the sugar wave also built up high enough to come over the front of the boat. We will look more at that later.

Have a go with the round nosed one - having smoothed out the 'water' first.

This one still builds a little wave in front, but nothing like as much as the square nose...

It still makes a massive wave beside the boat....

Looks like my thumb modified it a bit.

Hopefully you are more careful than me.

Smoothing the water ready for the next boat lol.

Ready... Set....

No bow wave...

The side wave isnt as big. I think thats because I accidentally made this one slightly narrower than the other two. All the sugar that was in the boats path ended up pushed to either side as with the other two

However, not having the bow wave makes a pointy boat easier to move through water.

Please try it yourself so that you are absolutely sure.

You might want to do it when the kids arnt lurking..

It took a while before I got my toys back and most of the sugar managed to jump on the floor.

Pigging kids.

Of course, you might also want to check if the water resists blunt objects more than sharp ones as it doesnt actually look much like sugar.

To do this you will need some water in a bowl or bath or whatever.

And a wooden pencil.

Put the pencil in the bowl and try flicking it sideways. It jumps, but only a little.

Try flicking it lengthways and it will travel some distance.

This is with the same pencil, same mass, same water. The only difference is the area offered to the water...

The amount of water being moved out of the way makes a massive difference to the boat as to the pencil.