Dare to take on the new challenge proposed by Chantal Ferrer for «Free fall», related to gravity and our perception of weight.

2020 will have an extra day, but what is the origin of this leap year? Amelia Ortiz-Gil, PhD in astrophysics and disseminator for the Astronomical Observatory of the University of Valencia, answers.

JORGE OLCINA answers: Clouds are formed by condensation of air vapour in the atmosphere. Despite their simple, smooth and generally graceful appearance and their varied shapes as suspended bodies in the air, the process of cloud formation is a very complex and largely unknown physical and

The sense we have of the world is build up with four dimensions, three of them are spatial and one is temporal. In effect, our brains perceive, through our sensorium, bodies of three dimensions that evolve over time. We can imagine worlds of less dimensions,