Low tech practicals

Today I’m celebrating the low tech practical. Practical where the equipment looks basic. Then put together it shows off an amazing effect. Last week I made telescopes with year 11. They needed 2 lenses, 2 lens holders, blu tack and a metre ruler. They were underwhelmed when they saw the equipment, but all of them made it work and ended up really enjoying the lesson AND seeing the theory behind how a telescope works in action.

Book on a string and a straw to show resonance: 

The benefits of keeping it simple: it works for all students.  The basic physics concept doesn’t get lost in the complication of the experiment. It’s easy to set up and run too and helps build basic practical skills, but the most important benefit is the first one: it works.

Force on a conductor in a magnetic field:                                      

There are other reasons for keeping things basic. I taught a year 13 class recently and we were looking at magnetism. In the first lesson it emerged they hadn’t ever looked at the magnetic field around a bar magnet with iron filings. This practical (usually completed in year 8) had been skipped for some reason. So the next lesson we got out the bar magnets and iron filings. They found it very valuable, and fun and I had just assumed it was too basic. I’d forgotten it’s the easiest way of visualising a field and was helpful even after we’d already studied gravitational and electric fields.

Field between bar magnets:                                      

Sometimes a simple practical has to become a simple demo due to equipment restrictions. For example, using a laser to show interference fringes in Young’s double slit experiment. Also, making the room into a giant pin hole camera (I’ll try this again in summer! Though it did work! ). I only needed duct tape and black sugar paper for that one and best of all, one of my students recreated it at home and said it worked brilliantly. He had a better view though and I’m sure that helped (the beautiful sea front compared to the building next to my lab).

resonance wine glasses:                                              

I’m not against complicated practicals, or ones using a lot more modern technology. These have their place and I’m not suggesting they should be replaced with simpler alternatives. Just don’t underestimate the power of a simple, low tech practical. 🙂