In the centre of our galaxy sits a monster 4.3 million times the mass of the sun. But Sagittarius A* is tiny compared with other black holes in the universe, with some reaching up to 40 billion times the mass of the sun. They are the point where our laws of physics break, and how these giants get so big has puzzled scientists for decades.

Becky Smethurst is an astrophysicst at the University of Oxford and her work looks at how these behemoths affect the galaxy around them. 91av‘s digital features editor, Jacklin Kwan, sat down with her to discuss what black holes are, how the supermassive ones get so big and Smethurst’s amazing career.

What really happens in the quantum world? In this conversation, physicist Sean Carroll explores some of the deepest mysteries in quantum mechanics: the famous double-slit experiment, wave function collapse, the Many Worlds interpretation, entropy and the arrow of time. Speaking to 91av reporter Jacklin Kwan, Carroll discusses why electrons appear to behave like waves, how observation seems to affect reality and whether the universe constantly branches into countless parallel worlds. Carroll also explains the measurement problem, the challenges of interpreting quantum theory and why physicists still debate what quantum mechanics is actually telling us about the nature of reality. Carroll is a theoretical physicist, cosmologist and author whose work focuses on the foundations of physics, quantum mechanics, cosmology and the nature of time.

Read more: Why quantum physics says there’s a multiverse