For most of the Earth's history, life consisted of the simplest organisms; but then something happened that would give rise to staggering diversity, and, ultimately, life as complex as that which we see today. Scientists are still struggling to figure out just what that was.
2015 • Nature
Defying gravity and hurtling through space: the flying saucer is the ultimate science fiction vehicle. Using cutting-edge research and theoretical physics, Dr. Michio Kaku reveals how one day we could all be using the aliens' favorite mode of transport.
Hannah is going the other way by asking whether everything could, in fact, be smaller. But going smaller turns out not to be much safer... First, we shrink the Earth to half its size - it starts well with lower gravity enabling us to do incredible acrobatics, but things gradually turn nasty as everyone gets altitude sickness - even at sea level. Then we visit Professor Daniel Lathrop's incredible laboratory, where he has built a model Earth that allows us to investigate the other effects of shrinking the planet to half size. The results aren't good - with a weaker magnetic field we would lose our atmosphere and eventually become a barren, lifeless rock like Mars. In our next thought experiment, we shrink people to find out what life is like if you are just 5mm tall. We find out why small creatures have superpowers that seem to defy the laws of physics, meet Jyoti Amge, the world's smallest woman, and with the help of Dr Diana Van Heemst and thousands of baseball players reveal why short people have longer lives. Lastly, the Sun gets as small as a sun can be. We visit the fusion reactor at the Joint European Torus to find out why stars have to be a minimum size or fusion won't happen. And if our Sun were that small? Plants would turn from green to black, and Earth would probably resemble a giant, frozen eyeball. Which all goes to show that size really does matter.
A sword made of pure light that can cut through anything, the lightsaber is a truly awesome weapon. But it's not just a science fiction fantasy, Dr Michio Kaku reveals how we could one day build a real working lightsaber.
Where Am I? Is a new documentary about the skills we use to find our way around. Whether you are an Inuit hunter, a foraging insect, or just someone out for a stroll, your brain is performing one of its most fundamental services – it’s navigating. Why are some of us good at finding our way, while others are not? Good navigators are able to use both memory and imagination…remembering where they have been, and imagining where they’re going. Some researchers believe we build a cognitive or mental map when we navigate, a kind of bird’s eye view of our surroundings, a view that can be rotated and examined in our mind. There has been about sixty years of argument amongst scientists about whether humans and other mammals actually form these cognitive maps or not. The advent of GPS or Global Positioning Systems has changed the discussion about navigation. GPS triggers a simpler, more automatic navigational technique that does not involve building a mental map. With GPS, we simply respond to directions and may not truly understand where we are.
Hannah starts her journey by asking whether everything could be bigger, finding out what life would be like on a bigger planet. As the Earth grows to outlandish proportions, gravity is the biggest challenge, and lying down becomes the new standing up. Flying in a Typhoon fighter jet with RAF flight lieutenant Mark Long, the programme discovers how higher G-force affects the human body, and how people could adapt to a high G-force world. But by the time Earth gets to the size of Jupiter, it's all over, as the moon would impact the planet and end life as we know it. Next, Hannah tries to make living things bigger. The programme examines the gigantopithecus, the biggest ape to ever exist, creates a dog the size of a dinosaur and meets Sultan Kosen, the world's tallest man. Humans are then super-sized with the help of Professor Dean Falk to see what a human body would look like if we were 15m tall. The sun gets expanded, and Professor Volker Bromm looks back in time to find the largest stars that ever existed, before the sun explodes in perhaps the biggest explosion since the big bang.
What does quantum mechanics tell us about our world -- or are there many worlds due to probability waves? How does the general theory of relativity mesh with quantum mechanics? If you've wished you understood quantum mechanics (or at least grasped the basics) physicist Brian Greene can help!