How to make an apple pie from scratch – Dr Harry Cliff

April 15, 2021 @ 19:00 (check your local time)

Watch the replay here:

In the 1980 smash-hit science documentary series Cosmos, Carl Sagan quipped that “if you wish to make an apple pie from scratch, you must first invent the universe”. Particle physicist Harry Cliff is mad that Sagan never followed up on the idea and so has spent the last two years attempting to write the ultimate apple pie recipe. Tracing the ingredients of an apple pie from today right back to the B of the Big Bang, Harry takes us on a tour of our current understanding of the basic building blocks of our universe and their cosmic origins. As we approach the birth of the universe, we discover that our most successful theories of particle physics tell us that the matter in our apple pie should never have existed in the first place. All attempts by physicists at CERN’s Large Hadron Collider to resolve this conundrum have so far come up empty handed, but could we finally be on the cusp of a deeper understanding of the origin of matter? And how far back can we ultimately go in understanding the very first moments of our universe? Harry will (attempt to) explain.

About Harry…

Harry is a particle physicist at the University of Cambridge working on the LHCb experiment, a huge particle detector buried 100 metres underground at CERN near Geneva. He is a member of an international team of around 1400 physicists, engineers and computer scientists who are using LHCb to study the basic building blocks of our universe, in search of answers to some of the biggest questions in modern physics.

​He also spends a big chunk of his time trying to share his love of physics with the public. He’s just finished his first popular science book, How To Make An Apple Pie From Scratch, which will be published in August 2021. From 2012 to 2018 he held a joint post between Cambridge and the Science Museum in London, where he curated two major exhibitions: Collider (2013) and The Sun (2018). He particularly enjoys talking about science in person and has given a large number of public talks, including at TED and the Royal Institution, alongside appearances on television, radio and podcasts.

Harry’s website is at
Harry is on Twitter at
Harry’s first book “How To Make An Apple Pie From Scratch” is out in August and is available for pre-order at