Nearly half of all pregnancies in the United States are unplanned, the result of millions of people being unable to get the birth control method that works best for them. Reproductive health advocate and 2023 Audacious Project grantee Mark Edwards discusses Upstream USA's nationwide effort to expand access to high-quality contraceptive care by integrating it into primary health-care settings -- a crucial shift towards increasing equal health opportunities and empowering people to decide when and if they want to start families. (This ambitious idea is a part of the Audacious Project, TED's initiative to inspire and fund global change.)

Neurotechnology, or devices that let you track your own brain activity, could help you deeply understand your health. But without privacy protections, your innermost thoughts, emotions and desires could be at risk of exploitation, says neurotech and AI ethicist Nita Farahany. She details some of the field's promising potential uses -- like tracking and treating diseases from depression to epilepsy -- and shares concerns about who collects our brain data and how they plan to use it, ultimately calling for the legal recognition of "cognitive liberty" as we connect our brains and minds to technology.

"Breathing clean air is every child's human right," says grassroots campaigner Rosamund Adoo-Kissi-Debrah, while sharing the heartbreaking story of her seven-year-old daughter, Ella Roberta, whose asthma was triggered to a fatal point by air pollution. Now, Adoo-Kissi-Debrah is on a mission to raise awareness about the harmful effects of unsafe air on our health and the planet. In this moving talk, she details why governments have an urgent responsibility to take action on air pollution -- and ensure that all children have a chance to live full and healthy lives. After the talk our host Shoshana speaks with health policy expert Dr. Cara James on the necessary steps towards protecting everyone's right to a healthy environment.

According to the fossil record, ancient humans usually had straight teeth, complete with wisdom teeth. In fact, the dental dilemmas that fuel the demand for braces and wisdom teeth extractions today appear to be recent developments. So, what happened? While it's nearly impossible to know for sure, scientists have a hypothesis. G. Richard Scott shares the prevailing theory on crooked teeth. This TED-Ed lesson was directed by Igor Coric, Artrake Studio, narrated by Addison Anderson, music by Salil Bhayani, cAMP Studio.

As a death doula, or someone who supports dying people and their loved ones, Alua Arthur spends a lot of time thinking about the end of life. In a profound talk that examines our brief, perfectly human time on this planet, she asks us to look at our lives through the lens of our deaths in seeking to answer the question: "What must I do to be at peace with myself so that I may live presently and die gracefully?"