BBC Four HD SkyTV

1/2. In this mind-bending film, Jim Al-Khalili explores the universe at its smallest, from tiny insects to living cells and viruses, before finally arriving at the atom. [S] [HD]

4/6. Professor Ben Garrod explores how skin has evolved remarkable ways to enable animals to communicate with each other, from vibrant displays of colour to skin pouches to amplify sound. [S] [HD]

1/2. Derek Brockway walks in Dylan Thomas's footsteps around Swansea before heading to the Llansteffan Peninsula and the Three Rivers estuary. [S] [HD]

3/3. Professor Robert Bartlett explores the impact of the Normans on southern Europe and the Middle East, as they spread south in the 11th century. [S,AD,SL]

1/2. In this mind-bending film, Jim Al-Khalili explores the universe at its smallest, from tiny insects to living cells and viruses, before finally arriving at the atom. [S,SL] [HD]

Programmes start at 7.00pm. [HD]

Programmes start at 7.00pm. [HD]

5/6. What is the most toxic animal on earth? Why is a rhino armour plated? Professor Ben Garrod discovers the complex ways in which skin helps defend animals against threats of all kinds. [S] [HD]

2/2. Derek Brockway learns how New Quay on Cardigan Bay inspired some of Thomas's greatest work, before touring Laugharne with Dylan Thomas's granddaughter. [S] [HD]

After years in the shadows, UFOs are being studied seriously. Follow scientists as they try to unravel the mystery of the strangest objects in our skies. [S,AD] [HD]

Architect Sir Norman Foster looks at the jumbo jet, a unique 'building' that flies. First broadcast in 1991. [S]

An attempt to restage the first official broadcast on British television 80 years later. [S,AD] [HD]

Dramatisation of the events of 1936, as the BBC prepares for the world's first high-definition TV service. However, behind the scenes at Alexandra Palace complications arise. [S] [HD]

A short film from 1936 that gives viewers an insight into how television came to Alexandra Palace. [S]