Ever wonder how the heart symbol came to stand for the actual heart? And why do we speak of the heart as the seat of love, when love really happens in our brains? Is it true that animals only get a billion heartbeats? This week, we give you enough cool cardiac science to make your heart skip a beat.
Why do we sleep? We spend a third of our lives in slumber, but science has yet to determine exactly why we have do it. Here’s a look at how sleep works, why we’re not getting enough sleep, what happens if you DON’T sleep, and an idea about where sleep came from in the first place.
2015 • Health
In part two, Professor Al-Khalili looks at the 19th century chemists who struggled to impose an order on the apparently random world of the elements. From working out how many there were to discovering their unique relationships with each other, the early scientists' bid to decode the hidden order of the elements was driven by false starts and bitter disputes. But ultimately the quest would lead to one of chemistry's most beautiful intellectual creations - the periodic table.
Glass so strong you can jump on it, rubber so tough it protects a clay pot dropped from 50 feet, endless varieties of plastic. Scientists and engineers have created virtually indestructible versions of common materials by manipulating the chains of interlocking atoms that give them strength—but have they made them too tough? Host David Pogue explores the fantastic chemistry behind the everyday.
Some 30 million Americans have sent their DNA to be analyzed by companies like 23andMe and AncestryDNA. But what happens once the sample is in the hands of testing companies, and how accurate are their results? NOVA explores the power of genetic data to reveal family connections, ancestry, and health risks—and even solve criminal cold cases.