From a bee’s hexagonal honeycomb to the elliptical paths of planets, symmetry has long been recognized as a vital quality of nature. Einstein saw symmetry hidden in the fabric of space and time. The brilliant Emmy Noether proved that symmetry is the mathematical flower of deeply rooted physical law. And today’s theorists are pursuing an even more exotic symmetry that, mathematically speaking, could be nature’s final fundamental symmetry: supersymmetry.

Infinite Worlds A Journey through Parallel Universes

The multiverse hypothesis, suggesting that our universe is but one of perhaps infinitely many, speaks to the very nature of reality. Join physicist Brian Greene, cosmologists Alan Guth and Andrei Linde, and philosopher Nick Bostrom as they discuss and debate this controversial implication of forefront research and explore its potential for redefining the cosmic order. Moderated by Robert Krulwich and featuring an original musical interlude, inspired by parallel worlds, by DJ Spooky.

2015 • Astronomy

Quantum Reality: Space, Time, and Entanglement

Ninety years after the historic double-slit experiment, the quantum revolution shows no sign of slowing. Join a vibrant conversation with renowned leaders in theoretical physics, quantum computation, and philosophical foundations, focused on how quantum physics continues to impact understanding on issues profound and practical, from the edge of black holes and the fibers of spacetime to teleportation and the future of computers.

A Thin Sheet of Reality the Universe as a Hologram

What we touch. What we smell. What we feel. They’re all part of our reality. But what if life as we know it reflects only one side of the full story? Some of the world’s leading physicists think that this may be the case. They believe that our reality is a projection—sort of like a hologram—of laws and processes that exist on a thin surface surrounding us at the edge of the universe.

2014 • Physics

Beyond Beauty the Predictive Power of Symmetry

From a bee’s hexagonal honeycomb to the elliptical paths of planets, symmetry has long been recognized as a vital quality of nature. Einstein saw symmetry hidden in the fabric of space and time. The brilliant Emmy Noether proved that symmetry is the mathematical flower of deeply rooted physical law. And today’s theorists are pursuing an even more exotic symmetry that, mathematically speaking, could be nature’s final fundamental symmetry: supersymmetry.

2016 • Math

Engineering the Brain Deploying a New Neural Toolkit

A new generation of technology is revolutionizing neuroscience, allowing a closer study of the brain than had ever seemed possible. The techniques are hybrids of optics, genetics, and synthetic biology with the ability to manipulate brain activity, often in real time. Through direct stimulation of neural connections, some of these techniques hold the promise for the treatment of diseases like depression or schizophrenia.

2019 • Brain

Gravitational Waves: A New Era of Astronomy Begins

On September 14th, 2015, a ripple in the fabric of space, created by the violent collision of two distant black holes over a billion years ago, washed across the Earth. As it did, two laser-based detectors, 50 years in the making – one in Louisiana and the other in Washington State – momentarily twitched, confirming a century-old prediction by Albert Einstein and marking the opening of a new era in astronomy. Join some of the very scientists responsible for this most anticipated discovery of our age and see how gravitational waves will be used to explore the universe like never before.

2016 • Astronomy

Hidden Dimensions Exploring Hyperspace

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.

2015 • Physics

Neutrinos Matter and Antimatter the Yin Yang of the Big Bang

What happened to all of the universe's antimatter? Can a particle be its own anti-particle? And how do you build an experiment to find out? In this program, particle physicists reveal their hunt for a neutrino event so rare, it happens to a single atom at most once every 10,000,000,000,000,000,000,000,000 years: far longer than the current age of the universe. If they find it, it could explain no less than the existence of our matter-filled universe.

2019 • Physics

How Music Affects Your Brain Notes on the Folds

Scientists are now finally discovering what thinkers, musicians, or even any of us with a Spotify account and a set of headphones could have told you on instinct: music lights up multiple corners of the brain, strengthening our neural networks, firing up memory and emotion, and showing us what it means to be human. In fact, music is as essential to being human as language and may even predate it. Can music also repair broken networks, restore memory, and strengthen the brain?

2019 • Music

Measure for Measure Quantum Physics and Reality

When no one is looking, a particle has near limitless potential: it can be nearly anywhere. But measure it, and the particle snaps to one position. How do subatomic objects shed their quantum weirdness? Experts in the field of physics, including David Z. Albert, Sean Carroll, Sheldon Goldstein, Ruediger Schack, and moderator Brian Greene, discuss the history of quantum mechanics, current theories in the field, and possibilities for the future.

2014 • Physics

The Illusion of Certainty: Risk, Probability, and Chance

Stuff happens. The weather forecast says it’s sunny, but you just got drenched. You got a flu shot—but you’re sick in bed with the flu. Your best friend from Boston met your other best friend from San Francisco. Coincidentally. What are the odds? Risk, probability, chance, coincidence—they play a significant role in the way we make decisions about health, education, relationships, and money. But where does this data come from and what does it really mean?

2015 • Math

The Matter of Antimatter Answering the Cosmic Riddle of Existence

You exist. You shouldn’t. Stars and galaxies and planets exist. They shouldn’t. The nascent universe contained equal parts matter and antimatter that should have instantly obliterated each other, turning the Big Bang into the Big Fizzle. And yet, here we are: flesh, blood, stars, moons, sky. Why? Come join us as we dive deep down the rabbit hole of solving the mystery of the missing antimatter.

2018 • Physics

To Infinity and Beyond

By our third year, most of us will have learned to count. Once we know how, it seems as if there would be nothing to stop us counting forever. But, while infinity might seem like an perfectly innocent idea, keep counting and you enter a paradoxical world where nothing is as it seems.

Part 1

Wherever we find patterns and symmetry in nature, we also find that nature conforms to certain rules. Rules that combine elegance with efficiency. Rules that shape trees and river estuaries alike, and that continue to baffle scientists by their often unfathomable ubiquity.

**1/2** •
Nature's Mathematics •
2017 •
Math

Prediction by the Numbers

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?

What's an algorithm?

An algorithm is a method of solving problems both big and small. Though computers run algorithms constantly, humans can also solve problems with algorithms. David J. Malan explains how algorithms can be used in seemingly simple situations and also complex ones.

Weirder and Weirder

Hannah explores a paradox at the heart of modern maths, discovered by Bertrand Russell, which undermines the very foundations of logic that all of maths is built on. These flaws suggest that maths isn't a true part of the universe but might just be a human language - fallible and imprecise. However, Hannah argues that Einstein's theoretical equations, such as E=mc2 and his theory of general relativity, are so good at predicting the universe that they must be reflecting some basic structure in it. This idea is supported by Kurt Godel, who proved that there are parts of maths that we have to take on faith. Hannah then explores what maths can reveal about the fundamental building blocks of the universe - the subatomic, quantum world. The maths tells us that particles can exist in two states at once, and yet quantum physics is at the core of photosynthesis and therefore fundamental to most of life on earth - more evidence of discovering mathematical rules in nature. But if we accept that maths is part of the structure of the universe, there are two main problems: firstly, the two main theories that predict and describe the universe - quantum physics and general relativity - are actually incompatible; and secondly, most of the maths behind them suggests the likelihood of something even stranger - multiple universes. We may just have to accept that the world really is weirder than we thought, and Hannah concludes that while we have invented the language of maths, the structure behind it all is something we discover. And beyond that, it is the debate about the origins of maths that has had the most profound consequences: it has truly transformed the human experience, giving us powerful new number systems and an understanding that now underpins the modern world.

**3/3** •
Magic Numbers: Hannah Fry's Mysterious World of Maths •
2018 •
Math

The Illusion of Certainty: Risk, Probability, and Chance

Stuff happens. The weather forecast says it’s sunny, but you just got drenched. You got a flu shot—but you’re sick in bed with the flu. Your best friend from Boston met your other best friend from San Francisco. Coincidentally. What are the odds? Risk, probability, chance, coincidence—they play a significant role in the way we make decisions about health, education, relationships, and money. But where does this data come from and what does it really mean?

World Science Festival • 2015 • Math