Physicists

Measurers of all things

The requirements for ‘Use of apparatus and techniques’ are common to all A-level specifications. Here Nicky Robinson discusses: ‘5. Use callipers and micrometers for small distances, using digital or vernier scales’. She explains the operation of analogue and digital instruments for measuring small sizes, gives you a guide in best practice in using these pieces of equipment and shows how to calculate the uncertainty in their measurements

Measurement is an integral part of human nature; we like to compare the sizes of things. Even when you were too young really to comprehend mathematics I bet you would have compared the sizes of toys, sweets and especially yourselves. Similarly, one of the first things a physicist does when thinking about a new object or idea is to try to put a size to it, or attach a sense of scale to it.

Physicists like to understand how everything works, so there is an enormous range of sizes to get to grips with, from the absolutely tiny (around 10−18m for the upper limit of a quark) to the unimaginably large (approximately 10 27m for the observable universe).