Abstract: The last few years led to a revolution in our physical understanding of the Universe we live in. This revolution is driven by exciting new observations from space and from big telescopes on earth in many different wavelengths. We now have answers to some of the major questions of cosmology, and with these answers come new puzzles.

Will the expanding Universe eventually stop and recollapse or will it expand forever? In what rate? Is the Universe finite or infinite in extent? Is it curved or Euclidean? What is the composition of the matter and energy in the Universe? How much of it is luminous and how much is dark? What is the nature of the dark matter and the mysterious dark energy?

On our way to unfolding the properties of the universe, we meet challenges to the common wisdom, such as the question of whether the gravitational force is indeed always attractive.