Dan Gilbert, author of "Stumbling on Happiness," challenges the idea that we'll be miserable if we don't get what we want. Our "psychological immune system" lets us feel truly happy even when things don't go as planned.

For the past 70 years, scientists in Britain have been studying thousands of children through their lives to find out why some end up happy and healthy while others struggle. It's the longest-running study of human development in the world, and it's produced some of the best-studied people on the planet while changing the way we live, learn and parent. Reviewing this remarkable research, science journalist Helen Pearson shares some important findings and simple truths about life and good parenting. Duration: 12:17.

Alzheimer's doesn't have to be your brain's destiny, says neuroscientist and author of "Still Alice," Lisa Genova. She shares the latest science investigating the disease — and some promising research on what each of us can do to build an Alzheimer's-resistant brain. Duration: 13:47.

The ability to recognize sounds and identify their location is possible thanks to the auditory system. That’s comprised of two main parts: the ear, and the brain. The ear’s task is to convert sound energy into neural signals; the brain’s is to receive and process the information those signals contain. To understand how that works, Douglas L. Oliver follows a sound on its journey into the ear.
Duration: 5:16.

When Henry Molaison (now widely known as H.M.) cracked his skull in an accident, he began blacking out and having seizures. In an attempt to cure him, daredevil surgeon Dr. William Skoville removed H.M.'s hippocampus. Luckily, the seizures did go away — but so did his long-term memory! Sam Kean walks us through this astonishing medical case, detailing everything H.M. taught us about the brain and memory. Duration: 5:25.

Focuses on the geotechnical aspects of hazardous waste management, with specific emphasis on the design of land-based waste containment structures and hazardous waste remediation. Introduction to hazardous waste; definition of hazardous waste, regulatory requirements, waste characteristics, geo-chemistry, and contaminant transport. The design and operation of waste containment structures, landfills, impoundments, and mine-waste disposal. The characterization and remediation of contaminated sites, the superfund law, preliminary site assessment, site investigation techniques, and remediation technologies. Monitoring requirements.

Watch a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator. Adjust the damping and tension. The end can be fixed, loose, or open.