大象传媒

Donald Canfield is the professor of ecology and director of the Nordic Center for Earth Evolution聽 in the Institute of Biology, University of Southern Denmark. Much of his research has focused on the study of oceans and lakes, examining the progressive oxygenation of the atmosphere through time and how this ultimately allowed for the development of large animals.

His theory about the relationship between sulphur, iron and oxygen during the development of the earth鈥檚 atmosphere lead to the coining of the phrase 鈥淐anfield Ocean鈥�.

His book, Oxygen: A Four Billion Year History, explores the vast history of oxygen on Earth and emphasises its relationship with the evolution of life and the evolving chemistry of the planet.聽

Don discusses the early evolution of oxygen on Earth and the rise of oxygen breathing animals.

Peter Calverley is Professor of Respiratory Medicine at the University of Liverpool and President of the British Thoracic Society. In this role he focused on building links with both patients and government, and worked to highlight the shortfall of Respiratory academics in the UK.

His primary research interest is the management of COPD (chronic obstructive pulmonary disease: an umbrella term for lung diseases including chronic bronchitis, emphysema and chronic obstructive airways disease, usually resulting from tobacco smoking). He has updated existing therapies, including oxygen therapy, and developed new ones.聽

Peter talks about the history of oxygen in medicine and our understanding of its application today.

Kathrin Altwegg is Professor of Space Research & Planetary Sciences at the University of Bern, and principal investigator on the Rosetta mission鈥檚 ROSINA instrument.

ROSINA stands for Rosetta Orbiter Spectrometer for Ion and Neutral Analysis. The instrument combines two mass spectrometers with a pressure sensor. The mass spectrometers are able to determine the composition of a comet's atmosphere and ionosphere, measure the temperature and bulk velocity of the gas and ions, and investigate reactions in which they take part. The pressure sensor can be used to determine gas density and rate of radial gas flow. Kathrin describes ROSINA as feeling like a 鈥渢hird child鈥�.

Kathrin鈥檚 work with ROSINA has overturned several prevailing theories about the evolution of the climate and geology of Earth. When the instrument landed on a comet last year it detected a high prevalence of heavy water, suggesting that, contrary to previous thinking, the majority of Earth鈥檚 water cannot have arrived here in the form of ice on comets. In addition, the detection of molecular oxygen on and around the comet contradicted a number of modelled predictions which held that any free molecular oxygen would react with hydrogen and form water.

Kathrin explains how they discovered the oxygen molecules in the tale of comet 67P and what it might mean.聽