There is a curious anomaly around today. When we discuss our weight we invariably refer to the number of kilograms we ‘weigh’. But this is a measurement of mass, not weight! So, if someone claim a weight of 100 kg, they are really referring to their mass. This is where it gets interesting. To… Continue reading What is your weight on Mars? Or other planets???
All of the sun’s photons are generated through nuclear reactions within it. If a photon is generated at the centre of the sun it can take anywhere between 2 days and 200,000 years to escape the body of the sun. That’s because the path of the photon is purely probabilisitic. At the centre of the… Continue reading How long does it take a new photon to reach us from its creation in the sun?
So, just the other day, I was thinking about how much energy we need to destroy hair follicle and blood vessels. Typically we talk about 1 or 2 joules per pulse. Then I thought, what is 1 joule of energy? I had no idea what this actually meant in the ‘real’ world! So, I… Continue reading How much energy does it take to heat a cup of coffee or tea?