Category Archives: AS and A2 Physics

Interesting stuff to help AS, A2 students and general readers

Dating Methods

This is a fossil skull of Homo Erectus, found in Africa. How old do you think it might be? Dating geological specimens involves an interdisciplinary approach using more than one dating method and cross-validating the results. Absolute dating methods include … Continue reading

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IB Astrophysics: Planets

Astronomy is an ancient science and it was only about 5-600 years ago that we began to make sense of what the ancients saw. The bedrock for modern thinking lies with Copernicus, Tycho Brahe – the first real astronomer – … Continue reading

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Black Body Radiation

A black body is an object which absorbs all the radiation falling on it. The best way to imagine a black body is to imagine a hollow ball, coated matt black on the inside with a tiny hole in it. … Continue reading

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Nuclear Fission

This post is a description of how neutrons produced in a fission reaction may be used to initiate further fission reactions – a chain reaction.  Both power stations and weapons use a variety of nuclear ‘fuels’ – poorly named since a … Continue reading

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Accuracy and Precision

IB exam questions sometimes ask you to think about the difference between accuracy and precision of a set of measurements. Ideally a measurement device is both accurate and precise, with measurements all close to and tightly clustered around the known … Continue reading

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Uniform Electric Fields

If you can do gravity, you can do electrostatics. They are both inverse square laws for non-uniform fields and behave similarly for uniform fields too. Remember this diagram? This time, imagine two parallel metal plates – very large, separated by … Continue reading

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Gravitational Fields 2. Non-uniform (radial) Fields

This post follows on from this earlier one which introduced Newton’s Universal Law of Gravitation. An object with mass creates a gravitational field around it sucking mass towards it – like a whirlpool. Imagine a paper boat. It will always … Continue reading

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