Prof Suzanne Aigrain

Abstract:

We present a method for computing upper and lower limits to the expected duration of planetary transits given a range for the parameters of the host star, while explicitly accounting for non-zero impact parameter and eccentricity, and placing a basic constraint on the orbital stability through a minimum planet–star separation at periastron. We find that, especially at longer periods, the transit can be considerably shorter or longer than previous searches have assumed. No transits are known with such short or long transit durations, but it is unclear whether this is a real feature of the planet population or a combination of transit probability, observational bias, and detection bias.

Abstract:

In the past fifteen years, file sharing of digital cultural works between individuals has been at the center of a number of debates on the future of culture itself. To some, sharing constitutes piracy, to be fought against and eradicated. Others see it as unavoidable, and table proposals to compensate for its harmful effects. Meanwhile, little progress has been made towards addressing the real challenges facing culture in a digital world. Sharing starts from a radically different viewpoint, namely that the non-market sharing of digital works is both legitimate and useful. It supports this premise with empirical research, demonstrating that non-market sharing leads to more diversity in the attention given to various works. Taking stock of what we have learnt about the cultural economy in recent years, Sharing sets out the conditions necessary for valuable cultural functions to remain sustainable in this context.