Talking Physics

A great trick to show students is using a glass rod. Write CARBON in red and DIOXIDE

If you roll a glass rod over the the text and look through it. You can see how the frequency dependence on refraction and how red light refracts less than blue so is upside down.

You can also show this with the stem of a wine glass.

Of course my explanation is wrong. Those astute students you have will notice that both are flipped and that DIOXIDE has mirror image symmetry about the horizontal axis

 

I was recently asked for my thoughts on developing an investigation for primary students to do with either rainbows or colour perception.

Being a primary age investigation I thought that Jelly Lenses may be a good thing to investigate.

 

 

Before I made jelly lenses I tried showing how optical density affects refraction with a petri dish and different liquids, water, golden syrup

The light dependant resistor connected to a resistance meter was just to show the intensity of the light

 

Double refraction  in a transparent plastic moulding Clear plastic phone case_1

Image of the case between crossed polars, see powerpoint in earlier post for detail

Hi Steve this is a great demonstration. We have a plastic shaped hook for adding weights to and seeing how the stress changes.

I like showing retardation with different layers of sellotape. In this video I just scrunch it up.

It is a great demonstration to get the students to think about what is happening to the different frequencies of the light.

A lot of insects use polarisation and waterboatmen us it to find water. They often mistake dark metallic car paint  for a lovely puddle and drop out of the sky only to ping off the metal surface!

This article is good for showing students how materials in the environment can trigger insect sensors.
https://www.newscientist.com/article/dn16380-wildlife-confused-by-polarised-light-pollution/

 

[Author]

Posts