When our Renaissance heroes Galileo, Copernicus, and Tycho Brahe cogitated the celestial sphere and removed humanity from the centre of the physical universe, they must have developed cricks in their necks – regularly looking over their shoulders for the ever-watchful ecclesiastical authorities who brutally insisted on maintaining the status quo. Six hundred years later we still want to understand the unknown and persist in our curiosity, although the consequences of our enquiry are not usually as dire as those faced by Copernicus. We continue to ask questions and one of these, for which there are still few answers, is ‘how did life begin?’. Embedded in a question like this are metaphysical quandaries that consider consciousness and our humanity; one wonders whether such attributes will ever enter the realm of the empirical. However, science can attempt to deal with explicitly empirical parts of the question, such as ‘how might organic molecules, that are critical to functioning cells, have formed on the ancient earth?’.
Thefirst article on this thorny topic dealt with an iconic set of chemical experiments conducted in the early 1950s. This post takes these experiments incrementally further.
In 1953 Stanley Miller, then a young postgraduate student under the tutelage of Harold Urey, conducted experiments that produced several organic compounds, including amino acids. The chemical reactions were all abiotic. They demonstrated that some of the important chemical ingredients of living cells could be produced without the interaction of life-forms. This was a huge step forward in scientists’ understanding of how life arose on earth.
This is a vexing question; perhaps the ultimate puzzle! It invokes wonder and intrigue for many, but for others it’s a question that invites derision and disbelief. Of course, we may never know the complete answer, or answers to the question “How Did Life Come About?“, but there is also no reason why science shouldn’t persist in asking it, in looking for the geological evidence, either here or in some other solar system, or devising experiments and models to help explain it. For all we know, it could be as simple an answer as it was to Richard Adams’ ultimate question in Restaurant At The End Of The Universe. The next two posts look at some scientific experiments that help us imagine how it might all have begun.
The Ancient Earth 4. Where did all that water come from?
The oceans cover 71% of our planet, and account for 97% of its total surface water. The greatest ocean depth is 10,994m in the Mariana Trench (near the Island of Guam), and the shallowest …, well most of you have been to the beach. They harbour a massive biomass (micro and macro) that comprises beautiful and complex ecosystems; they help feed our burgeoning population. They provide opportunities for explorers and metaphors for poets. But where did all that water come from? Continue reading →
The really ancient earth: How our atmosphere evolved
Take a deep breath. Savour it. One of the few absolutes of our physical world (that we probably haven’t looked after as well as we might have). This post continues the theme “The Really Ancient Earth” by looking at what we know about the origin of our atmosphere; some of the evidence and some of the hypotheses. What was it like on day 1 (about 4600 million years ago) and how did it evolved into our breath-taking world today? Continue reading →
Make your own meteorite crater – comparing experiment with the real world
This post shows you how to make your own meteorite crater – it’s pretty easy. There are also many interesting questions we can ask of our experiments with craters, like “how do they compare with real craters?“