A Cosmic Puzzle: A new version of Einstein's cosmological constant may point the way to transcending general relativity.

Holographic Universe: Some theoretical results regarding black holes suggest that the Universe might resemble a giant hologram.

The Illusion of Gravity: The force of gravity and one of the dimensions of space may arise from the peculiar interactions of particles and fields in a World with fewer dimensions.

Variable Constants: Do the inner workings of Nature change over time?

The Landscape of String Theory: String theory predicts that the Universe might occupy some random "valley" from an almost infinite collection of valleys in an immense "landscape" of possibilities.

The Atoms of Space and Time: We perceive space and time as continuous, but if the exciting theory of loop quantum gravity is true, then in reality space and time exist in the form of discrete chunks.

Parallel Universes: They are not only found in science fiction; they are a direct consequence of cosmological observations.

The Myth of the Beginning of Time: According to string theory, the Big Bang was not the beginning of the Universe but merely the natural consequence of a pre-existing state.