From deep in the TED archive, Danny Hillis outlines an intriguing theory of how and why technological change seems to be accelerating, by linking it to the very evolution of life itself. The presentation techniques he uses may look dated, but the ideas are as relevant as ever.

What if you're in surgery and the power goes out? No lights, no oxygen -- and your anesthesia stops flowing. It happens constantly in hospitals throughout the world, turning routine procedures into tragedies. Erica Frenkel demos one solution: the universal anesthesia machine.

We believe that we should work to be happy, but could that be backwards? In this fast-moving and entertaining talk from TEDxBloomington, psychologist Shawn Achor argues that actually happiness inspires productivity.

Surgery, chemotherapy and radiation are the best-known methods for treating cancer. At TEDMED, Bill Doyle presents a new approach, called Tumor Treating Fields, which uses electric fields to interrupt cancer cell division. Still in its infancy -- and approved for only certain types of cancer -- the treatment comes with one big benefit: quality of life.

Peter van Uhm is the Netherlands’ chief of defense, but that does not mean he is pro-war. At TEDxAmsterdam he explains how his career is one shaped by a love of peace, not a desire for bloodshed -- and why we need armies if we want peace.

Women aren’t micro--so why do they only get micro-loans? At TEDxWomen reporter Gayle Tzemach Lemmon argues that women running all types of firms-- from home businesses to major factories-- are the overlooked key to economic development.

Imagine playing a video game controlled by your mind. Now imagine that game also teaches you about your own patterns of stress, relaxation and focus. At TEDxToronto Ariel Garten shows how looking at our own brain activity gives new meaning to the ancient dictum "know thyself."

Every doctor makes mistakes. But, says physician Brian Goldman, medicine's culture of denial (and shame) keeps doctors from ever talking about those mistakes, or using them to learn and improve. Telling stories from his own long practice, he calls on doctors to start talking about being wrong.

In the 1970s, Diana Nyad set long-distance swim records that are still unbroken. Thirty years later, at 60, she attempted her longest swim yet, from Cuba to Florida. In this funny, powerful talk at TEDMED, she talks about how to prepare mentally to achieve an extreme dream, and asks: What will YOU do with your wild, precious life?

2012 may be the year of 3D printing, when this three-decade-old technology finally becomes accessible and even commonplace. Lisa Harouni gives a useful introduction to this fascinating way of making things -- including intricate objects once impossible to create.