Democritus – an Ancient Greek philosopher – was born nearly 2,500 years ago, but his legacy in the world of science lives on today. He is known as the person who first formulated the theory of the atom. His foresight and intelligence still inspires people of all ages today.
The development of science and technology depends upon a deepening understanding of the minutiae of life. But how is this achieved? The width of a human hair is a common comparative point of reference in many fields, but how is it possible to measure at this scale?
Measuring the Width of a Human Hair
You can measure the width of a human hair in the comfort of your own home. And counter-intuitively, there’s no need for expensive technology are equipment to do so. There are three things you need to carry out the experiment: cardboard, tape and a laser pointer – oh, and a hair too of course. Also, it’s best to have another person involved to help with the measuring…
- Prepare Your Hair – You’ll need to make a small ‘frame’ of cardboard. Tape the hair tightly across the hole in the middle.
- Dim the Lights – In a darkened room, stand at least one meter from a blank wall, and hold the cardboard frame up. Shine the laser ‘through’ the hair and towards the wall.
- Light Will Scatter across the wall if you’ve completed the above steps correctly. The pattern created by the scattering of the light is relative to the size of the hair.
- Mathtastic– We can deduce the width of the hair by making some measurements and using mathematical formulae.
- Measure the distance from the wall to the hair incentimetres
- Find out what the wavelength of the laser’s light is. The measurement used is nanometers, and it can usually be found on the side of the laser pointer.
- Measure the breadth of the light scatter, from the ‘dot’ to where the light runs out.
So at this point, you have all the information you need to calculate the width of your hair!
Follow this link for help in making your final calculation.
Ensure you use the same units when making your calculation. For this purpose, 100 nanometers = 0.00001 centimeters.
This simple experiment illustrates how we can make further sense of our world using fairly rudimentary, everyday objects. However, given the units used in this experiment (centimetres) and the opportunities for human error, the resulting figure is only an approximation. This can be useful to gain a sense of an object’s scale – rough figures can serve a purpose, but in many instances even ‘pinpoint precision’ isn’t fine enough.
Scientifically Specific
Even Democritus would struggle to believe the scale to which modern science and mathematics is able to operate. Technology has been developed to enable incredibly precise measurements to be made and without the influence of external factors. Modern equipment is designed tominimise the possibility of human error – or that produced by a condition out of the user’s control. They use state-of-the-art sensors which produce results that are both accurate and reliable.
Given the continuing advancement of technology, the world of science will benefit from enhanced levels of precision when testing out a hypothesis or conducting an experiment.
