Monday, 24 November 2014

Science Posters

Okay, thought I'd dig these out of the digital attic. The following are links to two science posters I made some time ago.
They are licenced under Creative Commons (Attribution and Share Alike) so feel free to print share.

Wednesday, 16 April 2014


These are some great biology videos from Harvard University.

Biovisions - Inner Life of a Cell

Biovisions - Powering the Cell: Mitochondria

and a lot more available at:

The Youtube versions are better for a projector screen than the ones you can get on the Harvard site. (Larger and clearer).

Inner Life of a Cell is a great way to introduce cell parts, either for juniors and seniors.

Sunday, 2 June 2013

Alternative Conceptions

One of the basic facts of science and mathematical education is that you have to deal with Alternative Conceptions in your students.
Basically humans are very good at finding patterns in the world, but we're very reluctant to give up on discovered patterns, even with plenty of evidence that they don't work. We also have a weird tendency to only seek evidence that confirms our theory, and discount or dismiss evidence that rules our theory out.
The following link lists a series of common Alternative Conceptions.

Van Der Graaf Machine - Preparation and Safety

Van Der Graaf machines are awesome - impressive as all hell, and allow you to investigate and demonstrate a large varieties of electrical physics concepts.

Typically I'm very much against the inductive-learning-good, deductive-learning-bad philosophy that has seemed to invade modern scientific theory. It takes too much time if done every lesson, it does little to correct pervasive alternative conceptions and it ignores half of how science works.

But a mixture of inductive and deductive learning works for Van Der Graaf machines. At the bottom of this post are some investigations that can be done. With good timing and a dollop (5 minutes) of deductive-style learning, you can complete most of them in a single one hour lesson.

Van Der Graaf - Miniature Lightning Bolts.

This earlier post outlines what you need to consider before doing any Van Der Graaf experiments.

This current post is the second in a series that describes some demonstrations that can be done with Van Der Graaf machines, including theoretical explanations.

The first demonstration is the simplest, throwing miniature lightning bolts.

Hair Club for Van Der Graaf Machines and Einstein Hair

This is the third post on Van Der Graaf demonstrations, and serves as an important theory point before you discuss charge distribution in hollow objects and air discharge and lightning rods.

Van Der Graaf Demonstrations - Induced Charge

It's demonstrations like this that really show the limits of Inductive-only learning in Science. Don't get me wrong, inductive teaching is a powerful tool under certain circumstances, but how the hell do you design an activity to inductively derive all the complexities of induced charge? Even if you can come up with one, it won't have as much impact or be as quick to do as the mixed-method demonstration discussed below.