Ophiolite

Oh, Sorcerer. You have committed the unforgivable: you have me agreeing with Youdadonapogos! 40% of 100 approx (the number of deaths of children under ten in 1995) is approximately forty, which in a population of around forty million under tens (very approximately) is one in one million, which is to me 'few'.

Sorcerer, you suggest that Cook's visit to the Southern Ocean to view the transit of Venus was novel. Now, I'll grant you that observing the transit from there was novel. Journeying to the Southern Ocean was not, yet the investment was still made. For the reasons succinctly laid out by Sayonara, mankind needs to become a spacefaring species. (please note that 'needs to' is different from 'wants to' or 'has a right to') You are right to say that it will require a lot of resources to evolve the technology. Now, along comes a commercial organisation (who tend to be quite good at making effective use of resources in order to make a profit), and a bunch of rich people willing to pay for those resources. So all humanity benefits from some 'thrillseekers'. And to top it off, the 'commercial organisations' are in it as much because they believe passionately in space travel and will likely plow a lot of the profits, when they emerge, right back into development. I share some of your concerns. You say 'It's not what the wealthy are doing to me, it's what the wealthy are doing to the world'. I agree 100%. However you and I are wealthy. I know I am, and you have told us you are, for you own a bicycle. On a global scale owning a bicycle is wealth. (Why you probably even have two sets of clothes!)

Here is another link that provides a possible explanation for the Cambrian explosion. http://pr.caltech.edu/media/lead/072497JLK.html For me the real problem is the origin of life. When I say 'problem' I do not mean I feel a need to invoke a supernatural origin, rather that the current explanations are disturbingly incomplete. I'm confident we shall eventually understand the process, but we are not there yet.

May I commend to you all the following book. 'Rare Earth' by Peter Ward & Donald Brownlee published by Copernicus Books (ISBN 0-387-95289-6) The sub-title 'Why complex life is uncommon in the Universe' is a nice summary of their thesis. They lay out a suite of well presented evidence and carefully reasoned arguments as to why microbial life is probably common, but multi-cellular life very rare.

It very much depends upon what you mean by Atlantis. If you are thinking a continent sized land, located in the Atlantic Ocean, peopled by a culturally and technically advanced society, eventually destroyed by a cataclysm, then no: Not physically possible. Continents and oceans have quite distinct properties (notably crustal thickness and composition) and are not interchangeable over historical timescales. However, if by Atlantis you mean a civilisation, advanced for its time, but primitive compared with today's, located somewhere(!), destroyed by natural catastrophe, then there are a number of viable alternatives. 1.Current thinking favours the Minoan civilisation, centred in the Eastern Mediterranean and destroyed by the explosive eruption of Santorini around 1500BC. 2. The West Indies present several options including Cuba, Dominica and the Bahamas. Here destruction would have been in the form of rising sea levels. 3. A maritime culture based on the Azores. 'yourdadonapogos' suggests that Plato was just describing a utopian city. Clearly he, Plato, used the tale of destruction as a political warning to his contemporaries, but equally he was basing it upon fact. Atlantis is as mythical as today as Troy was before Schleimann discovered it.

I agree with Skye - currently insufficient evidence to tie it down. A, B and C are the valid scientific alternatives and there just is not enough conclusive data to eliminate one or confirm another. I'm very uncomfortable with the notion we went from simple chemistry to 'simple' life in only a couple of hundred million years. We may well identify the process in time, but at present we only have glimmerings of possibilities. At least some of the pre-biotic chemistry likely developed in interstellar clouds and on comets and provided Earth with raw materials that were a little less raw. So I lean towards panspermia - as psi20 says 'it's big out there'. At best we are going to find microbial life is plentiful - multicellular organisms uncommon, complex life forms rare and, perhaps, intelligent life unique.

I'll likely get accused of playing with words here, but surely we never accept a hypothesis on faith alone. Indeed, we never accept a hypothesis, full stop, period. We either reject it (having proven it invalid or found superior alternatives) or convert it (promote it) to a theory. The theory, if it is repeatedly substantiated across a spectrum of applicable circumstances, may eventually become a law. Some persons, regrettably even some with scientific training, still confuse laws (and theories and hypotheses) with facts. The laws (and theories and hypotheses) are there to explain the facts.

I don't see a practical point of computing the amount of CO2 that would be generated if ALL fossil fuel were combusted. Why? Two reasons, the first is trivial, the second seems fundamental: 1. The rate of absorption within the system has also to be considered and this would depend in part upon the time period over which the release occurs, changes in the efficiency of seqestration mechanisms (e.g. reversing deforestation), etc. 2. There is no conceivable, practical manner in which ALL could be burnt, because of the problems of recovery. Oil fields that have 'run dry' may have as much as half (indeed more) of their hydrocabons still in place. There is likely at least as much hydrocarbon again in rocks that are not considered resrvoirs or potential reservoirs. If you are meaning ALL RECOVERABLE hydrocarbons, then point 1. , above, is no longer trivial.