Have you ever wondered how light seems to illuminate a room as soon as the switch is pressed? Does that mean that light spreads out instantly throughout the whole room at once? Or does light actually travel over a period of time just like everything else?
It was Italian physicist and astronomer Galileo Galilee who was one of the first to think that light travelled at a fixed speed rather than travelling instantly. During the 17th Century Galileo tried to measure the speed of light by placing lanterns on various hilltops and, with the help of a few colleagues, timing how long it took him to see them after they were uncovered. Unsurprisingly, his measurements were not great because light travels way too fast to be measured like this.
Later in that Century a Danish astronomer, Ole Roemer, became the first person to actually prove that light travels at a fixed speed. He did this by studying the way that eclipses of Jupiter’s moons took place either later or earlier than expected according to whether the distance between Jupiter and Earth was longer or shorter than average. Using this method, Roemer calculated a light speed of 200,000,000 metres per second.
Since then, a number of other scientists have made improvements to measurement techniques and have produced increasingly accurate calculations. However, it wasn’t until 1983 that the speed of light was announced to be the 299,792,458 metres per second that we use today. A speed which would allow light to travel just over 7 times round the entire Earth in a single second.
It is truly amazing, then, that Yr12 students at Bicester Technology Studio this week were able to measure the speed of light to be 300,000,000 metres per second, accurate to within 0.1% of the currently accepted value with equipment no more technical than that which most of us have in our homes.
Does that make our students better than Galileo Galilei? I wonder how they are at the Fandango?
Assistant Principal – Director of STEAM