It's Ada Lovelace day, celebrating the work of women in mathematics, science, technology and engineering. To celebrate we bring you a selection of articles by female authors that were published on Plus this year (including those written by the entirely female Plus editorial staff). To find our more about the pioneering work of Ada Lovelace herself read our article Ada Lovelace - visions of today. You can also check out our Ada Lovelace day blogs from 2012 and 2011 for more by and about women mathematicians.

Do infinites exist in nature? — Marianne Freiberger and Rachel Thomas talk to physicists, philosophers and cosmologists in search of the unbounded.

The lost mathematicians: Numbers in the (not so) dark ages — Charlotte Mulcare asks what medieval mathematicians got up to and whether they left a useful legacy.

Let me take you down, cos we're going too ... quantum fields — In this four-part series the Plus editors Marianne Freiberger and Rachel Thomas explore the dramatic history of quantum electrodynamics.

Cognition, brains and Riemann — Joselle DiNunzio Kehoe explores our perception of space, Riemann's geometry and parallels between the two.

Folding the future: From origami to engineering — Kim Krieger finds an unlikely connection between combinatorics, origami and engineering.

What is space? — Francesca Vidotto tells us how the existence of tiny black holes make it impossible to measure lengths shorter than a shortest scale.

Are there parallel universes? — Plus editor Marianne Freiberger finds parallel worlds in the puzzling mathematics of quantum mechanics.

Is the Universe simple or complex? — Faye Kilburn asks biologists, physicists, mathematicians and philosophers for their idea of how the Universe is structured.