Galileo and the telescope

Revised  6 April 2021 Telescopes are instruments which use multiple lenses to produce magnified images of distant objects. It is unclear who invented the first telescope: lenses had been widely used in Europe to correct poor eyesight since the fourteenth century and I expect that, over time, the telescope was actually invented many times by… Continue reading Galileo and the telescope

196-an unsolved problem

For my latest post I'll move away from my usual topics of astronomy and space travel and I'll talk about an interesting unsolved problem in mathematics which is: 'Is the number 196 a Lychrel number?'. What is a Lychrel number? There is a simple mathematical operator called reverse and add where you take a number… Continue reading 196-an unsolved problem

Satellite navigation – the next ten years

Satellite navigation is such a vital part of day-to-day life that other countries of the world are planning to build up their own network of navigation satellites and move away from total reliance on the American system, GPS. America As mentioned in my previous post, the GPS system is operated and funded by the US government. The first… Continue reading Satellite navigation – the next ten years


The Global Positioning System, better known as GPS, has come to affect countless aspects of our daily lives, from directing our holiday aeroplanes to enabling us to drive round an unfamiliar city without any map other than the one on our mobile phone.  At the risk of making myself sound like a scary stalker, I… Continue reading GPS.


Watching the Sun set below the horizon and the sky gradually get darker and darker is an almost magical experience.  Twilight is that period of the day when the sky is not completely dark, and it can be used to describe the period either just after sunset, or just before sunrise.  It is valued by photographers because of… Continue reading Twilight