THE SECRET LIFE OF THE DOG

New scientific studies regarding dogs and how dog and humans relate to each other. Domestication, nature-nurture, learningskills, love, attachment, science and other interesting topics relating to dogs and humans are shown in these vids.

A surprising theory is put forward: Dogs are wolfes genetically but they differ from wolfes in an important way.

HOW LONG IS A PIECE OF STRING?

Alan Davies attempts to answer the proverbial question: how long is a piece of string? But what appears to be a simple task soon turns into a mind-bending voyage of discovery where nothing is as it seems.

An encounter with leading mathematician Marcus du Sautoy reveals that Alan's short length of string may in fact be infinitely long.

WHO'S AFRAID OF A BIG BLACK HOLE?

Black holes are one of the most destructive forces in the universe, capable of tearing a planet apart and swallowing an entire star. Yet scientists now believe they could hold the key to answering the ultimate question - what was there before the Big Bang?

The trouble is that researching them is next to impossible. Black holes are by definition invisible and there's no scientific theory able to explain them.

DO I DRINK TOO MUCH?

Alcohol is by far the most widely used drug - and a dangerous one at that. So why are so many of us drinking over the recommended limits?

Why does alcohol have such a powerful grip on us? How much of our relationship with this drug is written in our genes? What are the real dangers of our children drinking too young?

PANDEMIC: A HORIZON GUIDE

In the wake of the swine flu outbreak, virologist Dr Mike Leahy uses over 50 years of BBC archive to explore the history of pandemics - infectious diseases caused by bacteria, viruses and parasites.

Inspired by the Horizon back catalogue, he tells the extraordinary story of smallpox, one of the most violent killers in history, as well as the success of mass vaccination and the global politics of malaria.