Lights, Spectrometer, Action! (emf2026)

Come and watch me point a spectrometer at a load of things, and teach you about how light interacts with stuff. What’s a spectrometer, you ask? Well it’s a device that measures light and produces a graph of the brightness of the light at each wavelength. I inherited one last year, and this talk will mainly consist of live demos of the spectrometer, along with explanations of what we’re seeing and how it works. The talk will be accessible to almost anyone - you don't need a lot of science knowledge to be able to enjoy it! I’ll start with looking at some different light sources (incandescent bulbs, fluorescent bulbs, LEDs, sunlight, LCD displays) and then take a look at how a spectrometer works and what is inside the box. I’ll then introduce some other useful bits of kit, including a very expensive sheet of white plastic and a ‘sphere’ that has a surprisingly cuboid shape. My background is in satellite imaging - which basically uses spectrometers mounted on satellites - so we’ll do a live look at the reflectance graphs we get for things we might be able to see from a satellite, like vegetation, soil and water and try to understand what causes these specific spectra. We’ll link these to real satellite images and cover some of the problems with doing spectroscopy from space - and even explain why a friend of mine did a whole PhD on the reflectance spectra of a concrete runway in the UK. Finally we’ll try a few experiments that may or may not work, looking at the uses of spectroscopy in chemistry and measuring aerosols. Licensed to the public under https://creativecommons.org/licenses/by-sa/4.0/ about this event: https://www.emfcamp.org/schedule/2026/51-lights-spectrometer-action