Last week I was asked by some school students about the nature of gravity. What is it? Isaac Newton, and a whole pile of textbooks following him, treat gravity as an attractive force between two objects. It’s a force that is proportional to the product of the masses of the two objects, and is inversely […]
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I’ve just given a couple of lectures on special relativity to a class of first years. It’s clear that grasping the key ideas is going to take some time. The results are so far removed from everyday experience that there is a certain air of bewilderment in the classroom. Here’s an example of what I […]
Continue readingBenjamin is now two-and-two-thirds, or near enough. As ever, his grasp of physics continues to improve. In the last few weeks, he has been picking up the idea of time. We have a large (more accurately, LARGE) analogue clock on the wall of our lounge. He's watched me take it off the wall, change the […]
Continue readingWith the recent undiscovery of Sandy Island I’ve begun wondering what other things might be ripe for undiscovery. Wasps, for example. Wouldn’t it be great if we realized that there wasn’t actually any evidence for the existence of wasps after all. Their discovery had been just a mistake made by an entomologist back in the […]
Continue readingHere’s a thorny problem that no doubt every physics teacher has grappled with. In a space-station, orbiting the earth, are you weightless? There are at least two ways of answering this: 1. Yes, you are. Let’s face it, you float around inside the space-station, water forms large blobs, some plants don’t know which way up […]
Continue readingLast night we went to the movies. We had free passes that needed using by the end of the week, so we turned up at Chartwell early evening without knowing what was showing. Not wishing to see a film about adultery, we decided against ‘Water for Elephants’ (or whatever it’s called) and picked Thor. If […]
Continue readingI’ve just been perusing CERN’s Twitter site http://www.twitter.com/cern for some of their latest news. While the Higgs is still hiding inside some time-travelling baguette, there’s still some really nice physics arising. This example is one that caught my attention – it’s the detection of a bound state made up of a beauty (or bottom) quark […]
Continue readingPhysicsStop is one today! That means I’m a year older than I was when I wrote the first entry, give or take a few nanoseconds as a result of special and general relativistic effects while on aircraft journeys. Eeek.
Continue readingThere are some lovely physics demonstrations that get repeatedly wheeled-out for things like Open Day and visits from school groups. Things like holding a spinning bike wheel on a rotating chair (flip it over and you start rotating – conservation of angular momentum) and levitating a piece of superconductor above a magnet at liquid nitrogen […]
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One of my undergraduate students has been researching gravitational waves this year. Last Friday, he gave a nice presentation on the subject. Gravitational waves are one of the many examples of waves in physics. We are perhaps more used to waves on the surface of water, or waves along a guitar string, or electromagnetic waves […]
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