The expanding universe is a complicated place. During inflation the universe expanded faster than light, but that's something that actually happens all the time, it's happening right now. This doesn't violate Einstein's theory of relativity since nothing is moving through space faster than light, it's just that space itself is expanding such that far away objects are receding rapidly from each other. Common sense would dictate that objects moving away from us faster than light should be invisible, but they aren't. This is because light can travel from regions of space which are superluminal relative to us into regions that are subluminal. So our observable universe is bigger than our Hubble sphere - it's limited by the particle horizon, the distance light could travel to us since the beginning of time as we know it.
2014 • Astronomy
Mathematical formulas can be found in the arrangement of seeds on a sunflower, the structure of the spirals in the shells of certain marine animals, and the distribution of leaves around a plant stem. These formulas recur in nature from snowflakes to the stripes on a zebra.
Predictions underlie nearly every aspect of our lives, from sports, politics, and medical decisions to the morning commute. With the explosion of digital technology, the internet, and “big data,” the science of forecasting is flourishing. But why do some predictions succeed spectacularly while others fail abysmally? And how can we find meaningful patterns amidst chaos and uncertainty? From the glitz of casinos and TV game shows to the life-and-death stakes of storm forecasts and the flaws of opinion polls that can swing an election, “Prediction by the Numbers” explores stories of statistics in action. Yet advances in machine learning and big data models that increasingly rule our lives are also posing big, disturbing questions. How much should we trust predictions made by algorithms when we don’t understand how they arrive at them? And how far ahead can we really forecast?
Dr Hannah Fry reveals how data-gobbling algorithms have taken over our lives and now control almost everything we do, without us being aware of it. Pitching the UK speed-cubing champion against a machine in the opening seconds of the lecture, Hannah sets the pace for a rapid voyage through this superhuman world. Hannah teams up with famed YouTuber Tom Scott to create a viral video and decipher YouTube's secret algorithm, comes face to face with four-legged guests to put animal image recognition machines to the test, and reveals how the NHS is matching organ donors in chains across the country to save hundreds of lives. But the breakthroughs are not restricted to the real world. Bafta award-winning special guests reveal the secrets of CGI in films such as The Avengers and Lord of the Rings, and supersized laser illusions bring the Royal Institution to life. An unexpected feathery guest opens our eyes to a new type of coding, where computers can be trained like animals using tasty rewards, with maths comedian Matt Parker and computing expert Dr Anne-Marie Imafidon bringing the topic to life. Finally, Hannah reveals how we've all been training up Google's AI in this way for years without realising it, and discovers how Google Health is using big data to give doctors a helping hand. The power of algorithms is undeniable. Hannah ultimately discovers how we can bend the world to our will and make anything possible, with a bit of mathematical thinking.
Professor David Spiegelhalter tries to pin down what chance is and how it works in the real world. A blend of wit and wisdom, animation, graphics and gleeful nerdery is applied to the joys of chance and the mysteries of probability, the vital branch of mathematics that gives us a handle on what might happen in the future. How can you maximise your chances of living till you're 100? Why do many of us experience so many spooky coincidences? Should I take an umbrella? These are just some of the everyday questions the film tackles as it moves between Cambridge, Las Vegas, San Francisco and Reading. Spiegelhalter discovers One Million Random Digits, a book full of hidden patterns and shapes, introduces us to the unit called the micromort (a one-in-a-million chance of dying), and uses the latest infographics to demonstrate how life expectancy has increased in his lifetime and how it is affected by our lifestyle choices - drinking, obesity, smoking and exercise.
2012 • Math