Cosmologists recently celebrated the 10th anniversary of the dramatic discovery of the accelerating expansion of the universe. Instead of slowing down, the Hubble expansion of the universe was found to have been speeding up. The substance that is supposedly responsible for this accelerated expansion of the universe is generally referred to as "dark energy". There has been a spectrum of dark energy theories that attempt to explain this extraordinary phenomenon. In this colloquium we will give an overview of the dark energy puzzle: its history, current observational status, and the theoretical attempts. We then focus on a specific model that connects the dark energy with the well-known hierarchy problem between the standard model of particle physics and the Planck scale. Towards the end of this talk we will "predict" the state of dark energy 10 years from now.
Coffee and cookies before the presentation at 3:15 pm, and refreshments after the presentation will both be served in Room 128.