Too Hot for God
A regular on talk.origins, John Boatwright, has been very excited by a graph of all the planets' surface temperatures. Is it a real proof of God, or just a load of hot air?
Introduction
John Boatwright, a regular on the talk.origins usenet group, has been very excited by a graph of all the planets' surface temperatures. Here it is:
The bold red line is an interpretation of what John thinks the planets' temperatures "ought" to be.
John maintains that the Earth does not fit on the line (with an expected surface temperature of around 440K) due to the intervention of some sort of god.
Another Look at the Data
Taking the physical and orbital data available at the Nine Planets website (which can be found at http://www.ex.ac.uk/public_html/nineplanets/data2.html), I replotted the graph including error bars where I knew them. The plotted data points here are the average surface temperature, but are still not sufficiently in agreement with the graph above to make this significant.
Plotted temperatures for the gas giants are measured at cloud tops or the 1 bar level, not at the surface.
Notice also that I have put Mercury back in the picture, which was omitted originally on the grounds that it had no atmosphere (it does - it's a very thin atmosphere of hydrogen and helium). The suggested curve is a remarkably poor fit to the data, such as it is. In fact, it is fairly easy to imagine a smooth curve through all the planets (including Earth), with the exception of Venus. So, surely (by John's hypothesis), Venus is the planet singled out by a god for special treatment.
That aside, it is still true that with the data presented, it is very difficult to make a useful comparison of surface temperatures,The gas giants (as mentioned before) have no surface as such, so the surface temperature is actually the cloudtop temperature. Mercury and Pluto have virtually no atmosphere, Mars has the slight protection of 0.007 bars of carbon dioxide, Earth's surface bathes under 1 bar of an oxygen/nitrogen atmosphere, and Venus swelters under an opaque blanket of carbon dioxide 10,000 times thicker than that on Mars.
Non Sequitur Argument
Although the original curve is not in any way meaningful, the Earth's deviation from any such meaningful curve still does not show the intervention of a god. Other physical explanations exist, such as the effect of living organisms which maintain the atmosphere away from equilibrium, internally generated heat, differences in atmospheric composition, and so on.
Conclusion
The "fit" between the data on the original graph and the observed data is very poor, especially when Mercury is reintroduced. In any case, no meaningful data can be gleaned from this graph due to the compositional differences of the planets' atmospheres.
Therefore, John's hypothesis is invalid both on the accuracy of fit and on the supposed reason for exemption.