Episode 44 - The Injectives with Hope Duncan - On Infinity

This week on The Mathematician's Podcast, we take a break from the philosophical and theological debates of the past to chat with an intellectual heavyweight of our own age! In another special "Injectives" episode, Ben is joined by Hope Duncan, a maths communicator and researcher at the University of Leeds whose particular interest is infinity. Join us as Hope tackles some fundamental (and some silly!) questions from Ben's school students, concepts like dividing by zero and the mass of the universe. The conversation quickly escalates into a fascinating discussion on the history and modern understanding of infinity, covering: The historical struggle with infinitesimals and their surprising decline in modern calculus. The dichotomy of potential vs. actual infinity, from ancient philosophers to modern #SetTheory. How we can "increase" infinity without changing its #Cardinality, illustrated with clever #Bijections between natural numbers and integers. The work of #Cantor in proving that not all infinities are created equal, introducing the concept of different "sizes" of infinity, like the uncountably infinite Real Numbers. A look at the #ZFC axioms, exploring the foundations of modern set theory, from the obvious (axiom of extensionality) to the profoundly abstract (axiom of choice). The implications of #Gödel's incompleteness theorems, revealing the inherent limits of axiomatic systems and the existence of independent statements within ZFC. Hope's personal research into #LargeCardinals – even bigger infinities that offer new ways to tackle unsolved mathematical problems. This episode is a captivating journey through the evolution of one of maths' most mysterious concepts, revealing that even at the bedrock of mathematics, there's still so much to explore and discover. Hope shares what motivates her to sit with the uncomfortable "why" of mathematics, making set theory sound like the ultimate puzzle.   You can find out more from Hope on Bluesky @hopeiona.bsky.social, or Youtube @hopeduncanmaths     The music was- "Danse Macabre - Finale" Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/     Keywords: #Mathematics #MathsPodcast #Infinity #SetTheory #Calculus #Infinitesimals #Cantor #ZFC #Axioms #Gödel #IncompletenessTheorems #LargeCardinals #PhilosophyOfMaths #HopeDuncan #TheMathematiciansPodcast