I apologise in advance for the whimsical nature of this post. If you don’t want ‘philosophy’, you might prefer to read this, this or this; all of which are rich in sciency goodness and have interesting questions and comments for you to ponder.
I was listening to Flanders and Swann (audio link at the end) and was minded to research the words of C.P. Snow, who kicked up a stink by suggesting that there is a gulf between the arts and the sciences. The most often quoted section of his essay is the following…
A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists. Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. Yet I was asking something which is the scientific equivalent of: Have you read a work of Shakespeare’s?
I now believe that if I had asked an even simpler question — such as, “What do you mean by mass, or acceleration?” which is the scientific equivalent of saying, “Can you read?”, not more than one in ten of the highly educated would have felt that I was speaking the same language. So the great edifice of modern physics goes up, and the majority of the cleverest people in the western world have about as much insight into it as their Neolithic ancestors would have had.
The Second Law of Thermodynamics is a fairly intricate affair but it can be simply stated as, “cold things tend to warm up and warm things tend to cool down“. This means that, given no external heat source, a system will tend towards a state where everything is the same temperature. At this point no work can be done because work involves a change in energy state, which can’t be achieved where there are no differences to begin with.
Entropy is a measure of the randomness of a system. The more evenly distributed the energy is, the higher the degree of randomness. That might sound wrong but imagine a room with a warm end and a cold end. This is an organised state. A properly random room would have the heat equally distributed throughout. Entropy reaches its maximum in a system where the energy is completely evenly distributed and therefore no energy changes (and hence no work) occur.
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Mass (measured in kg) is different from weight (measured in Newton). Mass is the amount of stuff that something is actually made from whereas weight depends upon the local gravity. Your mass would be the same whether measured on Earth or in deep space. Your weight is different because on Earth gravity pulls down on each kg with a force of 10 N but in space there is no direction to the force of gravity so no weight is registered. The more mass an object has, the more energy it requires to accelerate it.
Acceleration is the change in an object’s speed (velocity) over time. An object’s speed will change if it has unbalanced forces acting on it. This car will accelerate because the force from the engine is greater than the force of friction holding it back (you can tell that from the length of the arrows). The difference in the two forces is called the resultant force. The car’s acceleration will be proportional to the resultant force divided by the mass of the car. The more massive the car, the lower the acceleration. That is why Formula One cars are built from such light materials.
Dr Snow (he had a PhD in physics) was a novelist. He was well placed to comment on ideas that spanned the arts and sciences. He made the quoted comments in 1959 and I wonder whether it still applies today. Perhaps in modern society it is not simply a matter of ‘science v art‘ but of ‘scepticism versus a willingness to believe things without evidence‘.
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We all rely on instinct to an extent but, when trying to assess a scientific claim, it must be evidence that counts. And not merely the evidence but also how that evidence was generated – in other words the scientific method. What sort of claims are not scientific claims? Questions about health, diet, the environment and politics must have answers that correspond to the most amount of evidence or the most amount of good. I would include claims about religion here too. They are statements about how the Universe works and should be supported by evidence, or dismissed until sufficient evidence is presented. Of course, what constitutes evidence is the great next question!
Questions…
- What formula lets you calculate density from mass and volume?
- If my mass is 78 kg, what is my weight on Earth in Newton? (working)
- What force opposes motion?
- What are the basic steps of the scientific method?
- What can you say about the forces acting on a parachutist…
(a) When he first leaps from the aeroplane?
(b) When he initially opens his parachute?
(c) As he drifts contentedly toward the ground?
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When I was at University, between extended periods of listening to AC/DC, Megadeth and Iron Maiden, I enjoyed a reggae band called Culture. This is them playing “Two Sevens Clash” with Kenyatta Hill standing in for his late father Joseph Hill.
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