But in general relativity, the stage itself becomes the starring actor, the name emblazoned on the Playbill. To make a theory of gravity compatible with the relativity of space and time (now spacetime), Einstein realized that gravity is not a force at all, at least not of the kind envisioned by Newton. This is exactly the sort of maths I wish more people knew about: the surprising, the unexpected and, most importantly, the type that wins you free drinks. My goal in this book is to show people all the fun bits of mathematics. It's a shame that most people think maths is just what they were subjected to at secondary school: it is so much more than that.

This is the essence of mathematics. It is the pursuit of pattern and logic for their own sake; it is sating our playful curiosity. New mathematical discoveries may have countless practical applications – and we may owe our lives to them – but that's rarely why they were discovered in the first place. As the Nobel Prize-winning physicist Richard Feynman allegedly said of his own subject: ‘Physics is a lot like sex; sure it has a practical use, but that's not why we do it.'Mass and energy (which do not need to be strictly separated, as they are now regarded as equivalent thanks to Einstein’s special theory) change the shape of spacetime in their vicinity. You, reading this very text, are an entity in the universe, a thriving bundle of matter. You have mass and you have energy. The spacetime within you, throughout you, and near you is now distorted thanks to that mass and energy. Space and time are changed thanks to your existence.

A book from the stand-up mathematician that makes math fun again! Math is boring, says the mathematician and comedian Matt Parker. Part of the problem may be the way the subject is taught, but it’s also true that we all, to a greater or lesser extent, find math difficult and counterintuitive. This counterintuitiveness is actually part of the point, argues Parker: the extraordinary thing about math is that it allows us to access logic and ideas beyond what our brains can instinctively do—through its logical tools we are able to reach beyond our innate abilities and grasp more and more abstract concepts. In the absorbing and exhilarating Things to Make and Do in the Fourth Dimension, Parker sets out to convince his readers to revisit the very math that put them off the subject as fourteen-year-olds. Starting with the foundations of math familiar from school (numbers, geometry, and algebra), he reveals how it is possible to climb all the way up to the topology and to four-dimensional shapes, and from there to infinity—and slightly beyond. Both playful and sophisticated, Things to Make and Do in the Fourth Dimension is filled with captivating games and puzzles, a buffet of optional hands-on activities that entices us to take pleasure in math that is normally only available to those studying at a university level. Things to Make and Do in the Fourth Dimension invites us to re-learn much of what we missed in school and, this time, to be utterly enthralled by it. Things to Make and Do in the Fourth Dimension by Matt Parker – eBook Details Matt Parker is some sort of unholy fusion of a prankster, wizard and brilliant nerd--maths is rarely this clever, funny and ever so slightly naughty.” — Adam Rutherford, author of Creation That is what the maths kids knew. This is why people can make a career out of being a mathematician. If someone works in maths research, they're not simply doing harder and harder sums, or longer divisions, as people imagine. That would be like a professional footballer merely getting faster at dribbling up the field. A professional mathematician is using the skills they've learned and the techniques they've honed to explore the field of mathematics and discover new things. They might be hunting for shapes in higher dimensions, trying to find new types of numbers, or exploring a world beyond infinity. They are not just practising arithmetic.But in the language of Einstein there are no forces, no invisible strings. There is only spacetime and spacetime alone. In Einstein’s radical reevaluation of gravity, all objects travel in straight lines, always and forever. But the spacetime that those objects must traverse bends beneath them. A hiker making their way from one waypoint to another may travel in a straight line – according to a map and according to their feet, which are always placed directly in front of one another with every step – but must follow the bends and curves (not to mention the gnarled tree roots) along the trail, lest they get lost in the wilderness. And the rest of the universe responds. If we imagine an infinitely tiny particle traveling on a trajectory near you (in the parlance of physics we would call this a test mass to examine how gravity behaves absent other effects), we can ask how that particle responds to your presence. In the language of Newton we would say that your body exerts a gravitational field, an invisible influence, like the lingering smell of good cologne, and that the particle responds to that invisible influence by way of the sensation of a gravitational force, which changes its direction.