This is the best few tens of billions years in the history of the universe to do cosmology. - Nima Arkani-Hamed

There are still many open questions that need answering: Why does gravity defy the notion of space-time in short distances? Why are there humongous quantum fluctuations in shorter distances? How is a larger Universe possible? These questions relate to the hierarchy problem and fine tuning and are divided into two stages. First, one should ask: “Why is there a macroscopic Universe that is not broken in the Planck scale,” and second: “Why are there large scale structures in the large Universe and they are not broken into Planck scale black holes?”

Two of the major questions left unanswered by the Standard Model of particle physics have to do with hierarchies of mass scales. The first is the flavor problem: what determines the masses of the quarks and leptons, and why do they span such a large range, e.g. why is the top quark 3 × 10⁵ times heavier than the electron? The second is the gauge hierarchy problem: why is the weak scale seventeen orders of magnitude smaller than the Planck scale?

... like most physicists, I really enjoy talking about physics.