Last week in Liverpool, we hosted a series of symposia for participants in a dual PhD programme involving the University of Liverpool and National Tsing Hua University, in Taiwan, that has been operating for nearly a decade.  On the first day, we brought together about dozen staff from each university, who had not met before, and asked them to present overviews of their research and explore possible collaborations using as a theme: UN Sustainable Development Goal No.11: Sustainable Cities and Communities.  The expertise of the group included biology, computer science, chemistry, economics, engineering, materials science and physics; so, we had wide-ranging discussions.  On the second and third day, we connected a classroom on each campus using a video conferencing system and the two dozen PhD students in the dual programme presented updates on their research from whichever campus they are currently resident.  Each student has a supervisor in each university and divides their time between the two universities exploiting the expertise and facilities in the two institutions.

The range of topics covered in the student presentations was probably even wider than on the first day; extending from deep neural networks, through nuclear reactor technology, battery design and three-dimensional cell culturing to policy impacts on households.  One student spoke about the beauty of mathematical equations she is working on that describe the propagation of waves in lattice structures; while, another told us about his investigation of the causes of declining fertility rates across the world.  Data from the UN DESA Population Division show that live births per woman in the Americas & Europe have already fallen below the 2.1 required to sustain the population, while it is projected to fall below this level in south-east Asia within the next five years and in the world by 2060.  This made me think that perhaps the Gaia principle, proposed by James Lovelock, is operating and that human population is self-regulating as it interacts with constraints imposed by the Earth though perhaps not in a fashion originally envisaged.