The Andromeda galaxy

More lesson ideas on magnitude and scale

Getting to grips with scale is a major challenge when exploring space biology

You could be dealing with the vastness of space one moment, measuring distances in light years, and considering the precursors of life at the molecular level the next. Recording size in standard form helps but it’s still difficult to conceptualise or visualise. What does 10–11 or 1026 actually mean? It’s all about understanding the relative scale.

Our activity on relative size is a useful plenary, but there are many other ways you can explore this idea further.

The pH scale measuring the number of hydrogen ions in a litre of solution is probably the first scale that students encounter in science representing numbers on a logarithmic scale.

Test this simulation model to understand more about the concentration of H+ and OH- ions, and convert between linear and logarithmic scales.

An essential starting-point is to see how orders of magnitude compare when using standard units. See this quick guide from the Royal Society.

You can challenge your students’ understanding of size from nano to macro with this quiz too, or download our sorting activity to get them discussing relative sizes – what knowledge can they use to place items in size order?

Further external links to developing understanding of orders of size and magnitude

Universcale – linear representation

The scale of the universe – zoom in and out to explore the scale of the universe

Powers of ten – classic film that takes the viewer on a journey of magnitudes

Units of measurement – great explanations of different types of measurement

Lead image:

The Andromeda galaxy seen through a telescope in the night sky.

joeltonyan/Flickr CC BY NC ND

Downloadable resources

About this resource

This resource was first published in ‘Space Biology’ in June 2015.

Statistics and maths, Ecology and environment
Space Biology
Education levels:
16–19, Continuing professional development