You may well ask, what is the point of an SI unit that measures “amount”? Surely if we want to know an amount then we simply count whatever it is that we need to quantify. That’s fine until we get to VERY large numbers. How large? We’re talking here about numbers that are massively bigger … Continue reading Magnificent moles
Farewell to Hunterston B
As was announced back in August 2020, the second reactor at Hunterston B nuclear power station is being "switched off" today (7th January 2022). Interestingly, one UK newspaper reported this as an "early" closure as the plant's owner, EDF, had originally hoped to keep it running until 2023, but this has to be put into … Continue reading Farewell to Hunterston B
Heisenberg and Sheldon; speed and uncertainty
In my very last Y11 lesson of last term I did a 15-minute dash through some of the weirder bits of physics, including Heisenberg's uncertainty principle. This says that, for example, you cannot know the exact values of an object's position and speed (actually its momentum). More excitingly, you cannot know the exact energy of … Continue reading Heisenberg and Sheldon; speed and uncertainty
Kinetic Theory
Scientific theories are constructs (models) that we use to explain our observations. They are different from scientific laws, which are rules that have to be obeyed and which can be applied across a wide variety of situations. The best known example is the Big Bang Theory but we'll be looking at a theory that relates … Continue reading Kinetic Theory
Non-binary electrons
On the final day of term, a member of my form tested me with a series of science jokes, the first of which was; “Why does a beef burger have less energy than a steak?” Pause here if you want to come up with your own solution. I must admit that I didn’t guess the … Continue reading Non-binary electrons
Thawing a frozen balloon
The pressure, volume and temperature of a gas are all linked so it makes sense to keep one of them constant when investigating the interdependence of the other two. But we didn't do that when we watched the effect of liquid nitrogen on a partially-inflated balloon - as shown in the animation below. Before viewing … Continue reading Thawing a frozen balloon
Phase-change diagrams
The concepts of specific heat capacity and specific latent heat are nicely illustrated in phase-change diagrams. But how realistic are the diagrams that are commonly seen online? The answer, perhaps surprisingly, is "not very". The phase-change diagram shown below is useful in terms of the amount of information it provides but, in common with many … Continue reading Phase-change diagrams
Absolute Zero
Where does the idea of "absolute zero" come from? In part it stems from a need to avoid negative temperatures but a better explanation can be found by thinking about the kinetic theory of gases. When a gas is heated, its particles gain kinetic energy. This in turn means that the particles have a higher … Continue reading Absolute Zero
Energy: the biggest “big idea”
Physics, let alone all the sciences put together, covers such a vast range of knowledge that it's useful to identify a small number of "big ideas" that link across a greater number of concepts. And energy is undoubtedly the biggest of these "big ideas". When it comes to revising energy, the breadth of its impact … Continue reading Energy: the biggest “big idea”
Auto-electric?
We all know that fossil fuels are bad for the environment and that their use in cars is being phased out but how much do you know about the alternatives? Electric cars probably spring to mind but what about other options that might actually be better choices? This is relevant for the GCSE course and, … Continue reading Auto-electric?
Mr Tarrant's physbang 'blog 