We feel it every moment of our lives but for physicists, gravity is the longest running unsolved mystery of the universe. Why do all objects that have mass pull on one another? Cutting-edge theories are proposing unexpected answers.
It's called the speed limit of the universe. Einstein blew all of our minds when he worked out the Theory of Relativity, and showed that space and time were malleable substances. He also theorized that we as humans can never travel faster than the speed of light, which leaves the stars and other galaxies almost impossibly out of our reach. But the dreams of Star Wars and Star Trek are not dead. In fact, there could be ways to travel faster than the speed of light - and some of them are already being tested in labs around the world.
Quantum theory, the best explanation of how atoms and anything smaller behave, is so weird even scientists who have mastered it find it baffling. But bit by bit scientists are finding maybe it's not so weird as comparable behavior is discovered in our every day world. It's just that no one noticed before.
Our minds store our entire lives, our memories and our deepest desires. Tell no one, and our thoughts remain our own. But our brains are biological computers. Computer hackers can tamper with our email. Could brain hackers someday be able to rewrite our thoughts?
Death is life's greatest certainty. But that may be about to change. Scientists have discovered an immortal animal that may hold the secret of endless regeneration. They're on the brink of editing our DNA so that we can cure death like a disease. Or is dying necessary for the survival of our species?
2017 • Science
Every 17 minutes in America, someone is killed with a gun. Politicians can't seem to stop the violence. But epidemiologists, psychologists and big data crunchers are discovering that gun crime spreads like a virus -and science may be able to stop its spread.
2017 • Science
Austrian physicist Erwin Schrödinger, one of the founders of quantum mechanics, posed this famous question: If you put a cat in a sealed box with a device that has a 50% chance of killing the cat in the next hour, what will be the state of the cat when that time is up?
Physicist Jim Al-Khalili routinely deals with the strangest subject in all of science - quantum physics, the astonishing and perplexing theory of sub-atomic particles. But now he's turning his attention to the world of nature. Can quantum mechanics explain the greatest mysteries in biology?
Jim Al-Khalili investigates the amazing science of gravity, recreating groundbreaking experiments, including the moment when Galileo first worked out how to measure it. He investigates gravity waves, finds out from astronauts what it's like to live without gravity, sets out to find where in Britain gravity is weakest and so where we weigh the least, and helps design a smartphone app that volunteers use to demonstrate how gravity affects time and makes us age at slightly different rates.
2017 • Physics
Extra dimensions of space — the idea that we are immersed in hyperspace — may be key to explaining the fundamental nature of the universe. Relativity introduced time as the fourth dimension, and Einstein’s subsequent work envisioned more dimensions still — but ultimately hit a dead end. Modern research has advanced the subject in ways he couldn’t have imagined. John Hockenberry joins Brian Greene, Lawrence Krauss, and other leading thinkers on a visual tour through wondrous spatial realms that may lie beyond the ones we experience.