The most significant breakthrough in cosmology in the next 50 years will be that we finally understand the big bang.
In recent years, the big bang model – the idea that our universe has expanded and cooled over billions of years from an initially hot, dense state – has been confirmed and elaborated in spectacular detail. But the big bang itself, the moment of purportedly infinite temperature and density at the very beginning, remains a mystery. On the basis of observational data, we can say with confidence what the universe was doing 1 second later, but our best theories all…
