The renowned physicist Juan Maldacena, of the Institute of Advanced Study in Princeton, has developed a great analogy to explain the beautiful symmetries that underpin the fundamental forces and particles, including the Higgs boson: he thinks of space as a grid of countries and of particles as travellers keen on making money by speculating with currencies.

In this interview cosmologist Marina Cortês explains how time emerges in a block universe, exploring the arguments for and against this theory, and alternative explanations where time is fundamental.

Most of us know what we mean when we say that something has happened. For theoretical physicists, however, this isn't an easy question. Sean Carroll of the California Institute of Technology explains why it's hard to define events and what to do about it.

Most of us know what we mean when we say that something has happened. Theoretical physicists, however, struggle with the concept of an event. Why?

Has the future already already been written? Is time just an illusion? Take a step outside of spacetime with cosmologist Marina Cortês to discover the block universe.

Fundamental physics says time is symmetric - so why does time move forwards for us in a block universe?

Is time real? Are we just puppets living out a future already written? Marina Cortês explains why she thinks time is fundamental and that we don't live in a block universe.

Marina Cortês is one of a growing number of physicists who believe time is fundamental. We ask her about the alternatives theories to the block universe, where time comes first.

Physics tells us that we live in a block universe, containing all of the past and all of the future. What does this perspective mean for our understanding of time, events, and free will?

A model of backward causation in which the future affects the past could help unite quantum mechanics and general relativity – and satisfy a challenge thrown down almost a century ago by Arthur Eddington.

Mapping the ancestral history of spacetime in an effort to unite quantum mechanics and general relativity.

A new model argues the forces between particles in the early universe loosed time’s arrow, creating temporal order from chaos.