Dark matter is a more attractive thing to work on as it is a predictive paradigm.
Modified gravity has not been predictive.
Modified gravity has never made a prediction that has turned out to be accurate.
Simulators do not find modified gravity to be an attractive thing to work on.
We need to choose what to work on as we have finite resources and time.
Dark matter seems like a better line of inquiry because it is more promising.
It's somewhat amazing that cosmology, the study of the universe as a whole, can make any progress at all. But it has, especially so in recent decades. Partly that's because nature has been kind to us in some ways: the universe is quite a simple place on large scales and at early times. Another reason is a leap forward in the data we have collected, and in the growing use of a powerful tool: computer simulations. I talk with cosmologist Andrew Pontzen on what we know about the universe, and how simulations have helped us figure it out. We also touch on hot topics in cosmology (early galaxies discovered by JWST) as well as philosophical issues (are simulations data or theory?).
Andrew Pontzen received his Ph.D. in astronomy from the University of Cambridge. He is currently Professor of Cosmology at University College London. In addition to his research in cosmology, he frequently writes popular articles and appears in science documentaries. His new book is The Universe in a Box: Simulations and the Quest to Code the Cosmos.