Cheap, quick and tasty, fast food became a culinary craze in the 1950s. But has our quest for convenience created an irreversible health crisis?

Fifteen international agencies spend $62 billion every year on space travel. What's fueling our costly — and dangerous — drive to explore the universe?

In the 21st century, China has become a global economic powerhouse. Why was the rest of the world so slow to notice its rise to the top?

Plastics have transformed how we live, but progress comes at a high price: 7.8 billion tons of waste. Are plastics a miracle or a catastrophe?

Oil has brought great wealth to the Middle East and ignited major wars. Is it a blessing or a curse for the region, as well as the rest of the world?

We share the planet with an estimated 9 million robots, from self-driving cars to surgical arms. Could they one day completely replace humans?

Feminism has ushered in sweeping changes to society, securing rights for women around the world. How much further do we have to go?

Over 10% of the world's electricity comes from nuclear power. But with radioactive waste and the threat of nuclear meltdown, are we playing with fire?

Nearly 40 million people are living with HIV. After decades of research and activism, how far have we come in finding a cure and battling the stigma?

DNA analysis has given us the tools to map disease, solve crimes and more. But in our rush to decode DNA, are we leaping before we look?

Once a secret military program, GPS now guides our daily lives, from providing directions to finding friends. But what do we trade for this convenience?

MP3s transformed how we listen to music — and spawned digital piracy. Streaming helped the industry recover, but how can artists get their fair share?

Credit cards changed the global economy and attitudes about personal spending, but record levels of consumer debt beg the question: Just who's in charge?

Growing evidence suggests that psychedelic drugs could treat brain injuries and psychological problems. But can we get past their controversial history?

Bottled water is a big business, selling itself as a tastier and healthier alternative to the tap variety. Is there truth behind the claims?

Thanks to dating apps, finding love is easier than ever. But are we now so focused on playing the game that we're missing out on real connection?

They're used for everything from entertainment to medicine — and now for weapons straight out of science fiction. Have lasers become too hot to handle?

The home fitness revolution has exploded into a multibillion-dollar industry. Are home workouts a healthy habit... or just hype?

A groundbreaking medical reproductive procedure has made parenthood possible for millions around the world... but at what cost?

Sweet deal or bitter pill? High fructose corn syrup rose up to dominate supermarket shelves, but what is it doing to our health?