Physicists are used to the idea that subatomic particles behave according to the bizarre rules of quantum mechanics, completely different to human-scale objects. In a breakthrough experiment, Aaron O'Connell has blurred that distinction by creating an object that is visible to the unaided eye, but provably in two places at the same time. In this talk he suggests an intriguing way of thinking about the result.

Modern medicine is in danger of losing a powerful, old-fashioned tool: human touch. Physician and writer Abraham Verghese describes our strange new world where patients are merely data points, and calls for a return to the traditional one-on-one physical exam.

With the same humor and humanity he exuded in An Inconvenient Truth, Al Gore spells out 15 ways that individuals can address climate change immediately, from buying a hybrid to inventing a new, hotter "brand name" for global warming.

At TED2009, Al Gore presents updated slides from around the globe to make the case that worrying climate trends are even worse than scientists predicted, and to make clear his stance on "clean coal."

In this brand-new slideshow (premiering on TED.com), Al Gore presents evidence that the pace of climate change may be even worse than scientists recently predicted. He challenges us to act.

Alberto Cairo's clinics in Afghanistan used to close down during active fighting. Now, they stay open. At TEDxRC2 (the RC stands for Red Cross/Red Crescent), Cairo tells the powerful story of why -- and how he found humanity and dignity in the midst of war.

How can we begin to understand the way the brain works? The same way we begin to understand a city: by making a map. In this visually stunning talk, Allan Jones shows how his team is mapping which genes are turned on in each tiny region, and how it all connects up.

With new data from the Keck telescopes, Andrea Ghez shows how state-of-the-art adaptive optics are helping astronomers understand our universe's most mysterious objects: black holes. She shares evidence that a supermassive black hole may be lurking at the center of the Milky Way.

In a zippy demo at TED U, AnnMarie Thomas shows how two different kinds of homemade play dough can be used to demonstrate electrical properties -- by lighting up LEDs, spinning motors, and turning little kids into circuit designers.

Every morning we wake up and regain consciousness -- that is a marvelous fact -- but what exactly is it that we regain? Neuroscientist Antonio Damasio uses this simple question to give us a glimpse into how our brains create our sense of self.

Cambridge researcher Aubrey de Grey argues that aging is merely a disease -- and a curable one at that. Humans age in seven basic ways, he says, all of which can be averted.