Quantum Radio

 This is a brilliant little programme on BBC Sounds. The presenter goes to Helgoland to ask quantum physicists "what is quantum?". 

Light detection in the eye

 

This explained clearly how we see colour. I read an interesting report in Physics World recently about seeing brand new colours. Each type of cone cell detects over a range of wavelengths. There is overlap of these ranges which means that certain wavelengths trigger two different cone cell responses. This masks them so we don't see those colours independently. Researchers have used very narrow laser light to hit single cone cells so that the response comes from only one type of cone cell, avoiding the overlap problem.

Dog Vision

 

The exhibition at Tullie House on Colour was a lovely mix of basic science and art. I was left playing spot the difference with these pictures but I did figure out which end of the spectrum is missing for dogs.

Colour Blindness

 

Doing the colour blindness test is one of my earliest memories from Primary School. Interesting to see them again all these years later.

Curved space-time

This trellis at The Newt near Glastonbury reminded me of the diagrams of space-time when it is curved by gravity in General Relativity!

Sun dial for the dead

Spotted in the cathedral at St Davids. It must work on light through a window. I don't think I've ever seen an indoor sundial before and certainly not one on a tomb!

Levelling the Land

Every bridge on the Lancaster Canal seemed to have a benchmark. Then the penny dropped. Benchmarks were used for linear surveys - ideal for a canal. The canal needed to be level to retain the water so surveying must have gone from bridge to bridge. But does that imply that the bridges were built as each section was dug? I suppose I'd assumed they dug the whole canal and then added the bridges but actually that wouldn't make sense in terms of access for local residents ...