What happens here affects what happens over there: that is the essence of radiating. An influence travels from source to...

Physics Narrative 14-16

Radiations travel in beams: the power in a single beam, often related to the number of photons a second (emitted or absorbed)...

Physics Narrative 14-16

You have seen that two beams meeting can cause instructions from two sources to arrive at a single point–two lots of do like...

Physics Narrative 14-16

There is a lurking difficulty here, that cuts to the core of what physicists know about radiating.

Physics Narrative 14-16

Throw a pebble into a still small pond. What happens in one place pretty soon affects what happens in all. The up and down...

Physics Narrative 14-16

The explanation for diffraction already presented might seem a little vague: we suggested that passing through a slit allows...

Physics Narrative 14-16

So far there have been four parallel, but interwoven strands in the explanation of waves. Here we'll show how they are...

Physics Narrative 14-16

Radio waves can be both emitted and detected with long stick-like electrically conducting metal aerials. It is not too much of...

Physics Narrative 14-16

In these first three episodes of this topic, the idea of waves as an explanation for some phenomena has been taken apart and...

Physics Narrative 14-16