School of Physics & Astronomy

Waves and Light

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Speed of Light

The speed of light: the cosmic speed limit. Einstein told us that nothing can go faster. Why is this?

Duration: 00:05:01


Explaining frequency in terms of guitars (which Prof Moriarty never needs an excuse to reach for).

Presenters: Philip Moriarty
Duration: 00:07:02


Waves or particles? What is a photon and how does it behave? There use to be a joke that scientists thought of light as a particle on Mondays, Wednesdays and Fridays, and a wave on Tuesday, Thursdays and Saturday. Sunday was a day of rest so no one bothered with it then! Now we think of it as sort of both, or neither - you can see we've come a long way!

Duration: 00:08:33

Rainbows and Double Rainbows

Rainbows: how are they made?, Why do we see double rainbows? Where should you look to find one? All these questions can be answered with a little dose of optical physics. The answer is quite simple really!

Presenters: Michael Merrifield
Duration: 00:07:02


Polarisation and polaroid, limiting light to going in just one way. How does this work: both with light and with microwaves? What happens when you are half way between polarising directions?

Presenters: Roger Bowley
Duration: 00:08:44

Why is glass transparent?

Why can light get through some materials and not others? As Professor Moriarty says: there are a number of explanations of this on the internet from the vaguely close to the completely wrong. So here he sets about explaining why some materials are transparent to light. Then we are off to the lab to show this in practice.

Presenters: Philip Moriarty
Duration: 00:05:56

Why is light slower in glass?

We all know that prisms can bend light, and split it into a spectrum. This happens because light travels slower in glass than it does in air (or a vacuum). However, doesn't light always travel at a constant speed, and how exactly can it get slower in glass?

Presenters: Michael Merrifield
Duration: 00:16:31

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School of Physics and Astronomy

The University of Nottingham
University Park
Nottingham NG7 2RD

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