Teaching almost everything through astrophysics

2015-11-25 17:52


Stephanie Grant, Subject Genius, astrophysics

Christmas is coming – the John Lewis advert is out after all and it is all about looking through telescopes! (That is my interpretation at least, we’ll gloss over the fact it claims a small refracting telescope can enable someone on the Moon to see a child waving on Earth…). Space is by far my favourite topic to teach and one of the reasons I have always had a keen interest in astrophysics is its breadth – you can be analysing wavelengths of light one minute, then thinking about nuclear reactions, then calculating the mechanics of orbits. It is the ultimate synoptic topic. In this way it is really useful to bring it into everything you teach. Part of the reason for this is that I don’t think enough astrophysics is in GCSE and A-level  specifications, but also that students get really engaged. They see why wavelengths of light, for example, can be useful, beautiful and staggeringly informative when looking at stars or nebulae. I was fortunate enough to have a like-minded Head of Department in a previous school and he resourced many topics at all levels with great images and video clips linking things to space, and the highlights are below.

I start the electromagnetic spectrum lesson at GCSE by using www.chromoscope.net, a fantastic resource. H-alpha filters are probably something to gloss over except with a top set, but seeing the different areas which are giving out different frequencies of light is fascinating. What does this mean about the energy of the objects visible?

I don’t talk about weight without showing some clips of moonwalking from the Apollo 11 missions, but even more interesting is a discussion about the clips showing the Apollo missions leaving Earth compared to the module on the Moon leaving.  It is only going to rendezvous with its orbiter of course, but there is still so much to talk about here – less g on the Moon but also the way that, as there is less fuel there is less ‘m’ too, so in terms of Newton’s second law less ‘F’ is needed for the same ‘a’.

I teach convection by showing a video clip of the ‘bubbling’ seen on the surface of the Sun in UV (and there is a discussion to be had here about why SOHO is looking at UV instead of visible). Density leads to a discussion about neutron stars – some of the most incredibly dense objects in the universe; or the fact that Saturn’s average density is less than water’s so in a big enough pool of water it would float.

My favourite fact recently from the partial solar eclipse was that as the Sun then becomes a smaller source of light, shadows actually become sharper. At A-level, the diffraction effects in images of stars are also interesting.

When teaching magnetism, it would be crazy not to mention the Earth’s magnetic field and how it causes the aurorae (depending on the level this can lead to a discussion about de-excitation in different gases). And why stop at considering Earth? There are some great images of aurorae spotted on other planets with magnetic fields.

The Mars Curiosity rover has a lot of amazing physics on board – the nuclear battery for instance. It is also fascinating that the time delay for signals to reach it from Earth (a great speed, distance and time calculation) mean that it would be dangerous if it moved very quickly as obstacles could not be avoided. In terms of energy resources, the solar panels on the International Space Station being as big as a football pitch to generate all the energy required to run the station is a great fact too.

Picking things that are in the news like the Philae landing last year (I put together a whole talk on Physics to unsuspecting Primary PGCE students based on this news item), are brilliant things to try to weave into lessons. This brings me back again to the International Space Station – Tim Peake is the first British astronaut to be going there soon as part of the Principia mission. How this mission can be used in lessons across the curriculum in your schools is a topic for another day, and one which I am very excited about.

Stephanie Grant teaches physics in Norwich and is an Ogden Trust Physics Teaching Fellow