The Riemann hypothesis is an unproven statement referring to the zeros of the Riemann zeta function.

Mathematically, the motion of a fluid is described by the so-called Navier-Stokes equations. In the spirit of Newtonian mechanics, these equations should determine the future motion of the fluid out of its initial state.

The aim of this article is to highlight some previous challenges that were also a stimulus to finding proof for some interesting results. With this pretext, we present three moments in the history of mathematics that were important for the development of new lines of research.

The Russian mathematician Grigori Perelman did not accept the Fields Medal in 2006 and refused the million dollar prize for solving Poincaré's conjecture, one of the millennium problems, in 2010.

The Poincaré conjecture is a topological problem established in 1904 by the French mathematician Henri Poincaré. It characterises three-dimensional spheres in a very simple way. This problem was directly solved between 2002 and 2003 by Grigori Perelman, and as a consequence of his demonstration of the Thurston geometrisation conjecture.

The Clay Mathematics Institute made a list of seven problems in May 2000; they were called the «millennium problems». Finding their solution has an added incentive: each solver will receive a million dollars as a prize.

Interview with Daniel Pauly, professor at the Fisheries Centre of the University of British Columbia in Vancouver (Canada), and leader of the project «The sea around us».

«It is a mistake to popularize science trying to place it as a protagonist to be explained»
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Interview with Pere Estupinyà

Science communicator, writer and public speaker. That is how Pere Estupinyà (Tortosa, 1974) describes himself. He is also known as «the sex scientist».

Interview with Jack Szostak, Nobel Prize in Physiology or Medicine in 2009, along with the molecular biology experts Elizabeth Blackburn and Carol Greider.

Cancer, one of the greatest problems of modern medicine, is also one of the most profound biological mysteries. And there are more than just one type of cancer: cancer has many different origins, development processes, and anatomic and pathological consequences.

Women make up the majority of the university students at the beginning, but are progressively overtaken by their male colleagues, until they become an invisible minority in the highest levels of the system.

Recent gender analyses have been opening new paths for innovation and excellence. They are the basis for the *Gendered Innovations* project. However, this work did not come out of nowhere; it is supported by decades of gender and science studies.

With the title of this monograph, *SheScience*, we want to delve on these two aspects. We are committed to science done by women in the same numbers and hierarchy as men, and to science that reveals differential characteristics between women and men, and those other aspects that are specific to women. Both often ignored.

The existence of habitable extra solar planets, is nothing new in science fiction cinema. Perhaps more interesting is the existence of unusual planets, such as the planet Tatooine from *Star Wars* (1977), by George Lucas, that orbits a binary star system.