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This may seem a bit geeky, but while you’re at the beach why not check out some of the things that like to live at beaches, or in the sea, the air, beneath the sand or on rocks. There are other things like waves that are pretty cool, especially if you like surfing, boogie-boarding or sailing, or even just looking at them to see how they work. Scientists ask questions like;
“what is it?”
“how does it work or how does it live?”
“how does it react to other things going on at the beach (including what people do)?”
In this post, I’m going to talk about TIME and take you on an adventure. I’m a GEOLOGIST so I talk about TIME a fair bit. The TIME I talk about is usually in thousands or millions or billions of years. These are really big numbers so how do I know what they mean; what is a million years really like?
“In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.” (Douglas Adams The Restaurant at the end of the Universe)
The question “How old is the Earth?” has provided us with some pretty interesting, often rancorous and even divisive debates over the last few hundred years. For some the debate remains unresolved. The science of dating things has progressed hugely over the last century and we can now provide, with significant confidence both relative age (A is older than B) and quantitative ages (radiometric dating) for all manner of physical objects. Age dating of earth materials is not just an interesting academic exercise; it has provided us with the tools to help evaluate energy and mineral resources, to assess the risks from natural hazards, and to study past geological events as they may relate to our future well-being.
So where do we begin? Perhaps at the beginning. Present estimates for the Big Bang and the formation of the Universe are about 13.8 billion years ago. We now know that our own Solar System began to form about 4.6 billion years ago which means there is an hiatus of 9 billion years. What happened during that great ‘interregnum’ is another story (how many other Solar Systems?). Our tale begins 4.6 billion years ago because that is closest to home. In this post we will be focusing on the bottom end of the time-line shown below. Continue reading →
A time-line for the first 4 billion years of Earth history
The Cambrian, that relatively brief period in geological history (40 odd million years) was witness to one of the most amazing series of biological events in the entire history of the Earth; the rapid, almost explosive appearance of marine critters with preservable shells and skeletons – a real first. Trilobites are probably the best known fossils from that period, but there are also some pretty weird and wonderful looking soft-bodied creatures (one famous fossil locality is the Burgess Shale near the town of Field, British Columbia). Most animal life today can track its origin to those early life forms. These events began about 540 million years ago (how easy these numbers roll off the tongue, or pen). But we also know that our Earth is pretty close to 4600 million years old (4.6 billion – How old is Earth); in other words there is almost 4 billion years, a humongous period of time in which, seemingly, not much happened. 4000 million years worth of boredom! This period is know as the “Pre” Cambrian, or Precambrian. Most Precambrian events did take place pretty slowly, but these events also determined the kind of world we now live in: the air we breath, the oceans and rivers, the biosphere and indeed life itself, all originated and evolved over this, the deepest of geological time. Continue reading →
I have created this Science in Context chart, partly because I am interested in the links, or the possibility of links among Science and other human endeavours like art, politics and so on. Science has never taken place in a vacuum; people who have conducted scientific investigations have had affiliations with or have needed to react to political or religious forces that helped shape our world – in some cases reacting simply to survive the vagaries of current ideologies. Science during the Renaissance and Enlightenment was often in conflict with prevailing religious dogmas. Thomas Kuhn, scientist and philosopher (of paradigm fame), would argue that this “tension” between science and the Church was crucial to the advancement of science in the Western, predominantly European world. In contrast to this often brutal conflict, eastern religions tended to coexist more harmoniously with their scientific cousins.