Guest Post: Building a habitable planet

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NASA

‘How to build a habitable planet’ is the title of a popular American college textbook which tells the story of the Earth from ‘The big bang to humankind’. It’s a big book – because it is a long story. All the evidence we have suggests that in its infancy the Earth was a most inhospitable planet and not very different from its near neighbours. Back then it had a transient volcanic landscape, a carbon-dioxide-rich greenhouse atmosphere and was periodically bombarded with asteroids from space. In contrast today we see a planet with mobile tectonic plates, oceans, continents, an oxygenic atmosphere and teeming with life, fundamentally different from Mercury, Mars or Venus. So, why? What is it about the history of the Earth which makes it so different now from its near neighbours? Continue reading

Guest Post: Artistic Molecules

rainbow freeimages Pawel JagodzinskiThis week as I was demonstrating “Messy Church Does Science”, I extracted someone’s DNA using salt water, washing-up liquid and methylated spirits.  At the boundary between these substances, a white substance forms that can be drawn out into a thin glistening thread made up of millions of stands of DNA – the twisted double helix.  That form itself is a wonderful example of the artistry that arises from a chaotic mix of chemical elements.  Yet perhaps true artistry is seen in the emergence of life that DNA shapes in all its diversity and beauty across millions of years. Continue reading

Water and Life: The Unique Properties of H2O

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A New Voyage by Brooks Bailey – Flickr (CC BY-NC-ND 2.0)

Water is a strange thing. The unique structure of its molecules allow it take on three different forms: a liquid that is easily absorbed into porous substances (i.e. it’s wet!), ice that floats, and a gas. In the book Water and Life: The Unique Properties of H2O, the biophysicist Felix Franks has contributed a chapter explaining some of these properties, and how they may have played a part in the origin of life.

The chemistry of life has adapted to water and become very dependent on it, so that even ‘heavy water’[i] is toxic in Continue reading