logo
episode-header-image
May 2023
27m 59s

The impossible number

Bbc World Service
About this episode

There is a bizarre number in maths referred to simply as ‘i’. It appears to break the rules of arithmetic - but turns out to be utterly essential for applications across engineering and physics. We are talking about the square root of -1, which makes no sense.

Professor Fry waxes lyrical about the beauty and power of this so-called ‘imaginary’ number to a sceptical Dr Rutherford.

Dr Michael Brooks, author of The Maths That Made Us, tells the surprising story of the duelling Italian mathematicians who gave birth to this strange idea, and shares how Silicon Valley turned it into cold hard cash. Professor Jeff O’Connell, Ohlone College California, demonstrates that it is all about oscillations, and Dr Eleanor Knox, philosopher of physics at KCL and a senior visiting fellow at the University of Pittsburgh reveals that imaginary numbers are indispensable for the most fundamental physics of all - quantum mechanics.

Up next
Oct 26
The Life Scientific: Gillian Forrester
What do the very first writhing movements of babies have in common with orangutans solving problems for food? Well, according to Gillian Forrester they may both offer clues about how we humans developed language. Working with her great ape colleagues, Gilly Forrester – Professor ... Show More
26m 29s
Oct 19
The Life Scientific: David Canter
Although books and movies might suggest otherwise, catching criminals is of course less about hunches and gut instinct, and more about gruelling analysis of hard data - including when it comes to the psychological side. David Canter is an Emeritus Professor of Psychology at the U ... Show More
26m 29s
Oct 12
The Life Scientific: Edith Heard
Imagine looking at a map of a city you thought you knew inside-out, only to discover a collection of tightly knit neighbourhoods that nobody had ever realised existed... Edith Heard has achieved something rather similar with DNA.Edith is a leading expert in epigenetics: put simpl ... Show More
26m 28s
Recommended Episodes
Feb 2023
The Impossible Number
There is a bizarre number in maths referred to simply as ‘i’. It appears to break the rules of arithmetic - but turns out to be utterly essential for applications across engineering and physics. We’re talking about the square root of -1. WHICH MAKES NO SENSE.Professor Fry waxes l ... Show More
41m 48s
Mar 2022
Is maths real?
<p>Faced with one cake and eight hungry people, it’s pretty obvious how maths underpins reality. But as mathematics gets further from common sense and into seemingly abstract territory, nature still seems to obey its rules - whether in the orbit of a planet, the number of petals ... Show More
32m 15s
Jan 2020
What is infinity?
<p>Is there something bigger than infinity? Does quantum mechanics affect how I think? And why can I suddenly do algebra? As ever, we’re not afraid to tackle the big questions on CrowdScience. After a previous episode about the relationship between mathematics and reality, we rec ... Show More
33m 45s
Oct 2023
A Mathematician Asks ‘Is Math Real?’
<p>When math is based on abstract concepts, how do we know it’s correct? Dr. Eugenia Cheng takes on that question in a new book.</p><p> </p><p>The concept of math has been around for a long time, developing independently in many different cultures. In 1650 BC, the Egyptians were ... Show More
33m 8s
May 2024
192 - What is Math?
tail spinning
1h 5m
Apr 2023
138 - Unsolvable Math Problems
tail spinning
1h 7m
Mar 2024
Echoes of Electromagnetism Found in Number Theory
<p><span>A new magnum opus posits the existence of a hidden mathematical link akin to the connection between electricity and magnetism. Read more at QuantaMagazine.org. Music is “Clover 3” by Vibe Mountain.</span></p> 
20m 40s