#### All numbers are not equal

An introduction to the various types of numbers which are recognised as important.

More details | Watch now#### C60+ in space – a 28-year detective story about the Diffuse Interstellar Bands – Part 3

John Maier's team at the University of Basel solved the riddle of C60+ in 2015. In this brief view Colin Byfleet looks at the unique apparatus used in John's work.

More details | Watch now#### C60+ in space – a 28-year detective story about the Diffuse Interstellar Bands – Part 4

The early (mid 1990s) work on the electronic spectroscopy was carried out by John Maier's group, trapping C60+ in a neon matrix in this apparatus.

More details | Watch now#### Centripetal force – how do we measure it?

A short video showing a simple classroom method of checking the way in which this force is related to mass, speed and radius.

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An introduction into the writing down of fully balanced chemical equations. The process is explained starting with word equations, finding all the relevant formulas and then working with some useful rules for finding the correct coefficients in the b....

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The main problems associated with communicating with distant space probes like Voyager 1 are investigated. The role played by diffraction in limiting the amount of power receivable on Earth is discussed. The further problems of reaching a nearby st....

More details | Watch now#### Constructing Chemical Formulas

An introduction to constructing and recognising chemical formulas. Using 20 well-known elements, the valency-rules which govern the atomic ratios are explained and used with several examples.

More details | Watch now#### Estimation – Educated Guesswork?

How can we make sensible estimates of very large numbers? It is often very important to know the size of an unknown number, at least to within a factor of ten.

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How can we represent fractions in the simplest way? Equivalence of decimal and common fractions.

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An approach to adding and subtracting fractions, using an understanding of the processes involved.

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A presentation showing both the ideas about centripetal force and a simple classroom method of checking the way in which this force is related to mass, speed and radius.

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A look at what was known when Newton started to develop his theory of gravitation and how he used these ideas and data to make his great forward step

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