Gonzalez and Richards Chapter Five

A couple of postings ago, I got a bit tart with respect to an article in Astronomy magazine.  Some of the thought – which author Adam Frank judiciously distanced himself from! – was lampoonable.  And so, through world class humorist, Terry Pratchett, I wish further to lampoon:

It is now known to science that there are many more dimensions than the classical four. 

Scientists say that these don’t normally impinge on the world because the extra

dimensions are very small and curve in on themselves, and that since reality is fractal

most of it is tucked inside itself.  This means either that the universe is more full of

wonders than we can hope to understand or, more probably, that scientists make things up

as they go along.

But the multiverse is full of little dimensionettes, playstreets of creation where creatures

of the imagination can romp without being knocked down by serious actuality. 

Sometimes, as they drift through the holes in reality the impinge back on this universe,

when they give rise to myths, legends and charges of being Drunk and Disorderly.[1] 

Assumptions and implications are not the same thing.

Well, “Pale Blue Dot-ophiles,” chapter five of Guillermo Gonzalez’ and Jay W. Richards’ book The Privileged Planet is entitled “The Pale Blue Dot in Relief.”  What we have here is a comparison and contrast with Terrespheres in our own solar system and a cursory glance at those exo-planets that we have discovered lately. 

The chapter begins with a 1918 quote from Nobel laureate Svante Arrhenius, wherein we are told of the high probability of “no doubt” of life on the planet Venus (next in toward the sun from us).  The writer speculates about swamps and higher forms of life, even intelligent life.  Of course, now we know better; but, I wonder if we might have reasoned to the obvious conclusion that Venus could not be a haven for life of any kind.  Gonzalez and Richards seem to have a better spin on the terrestrial ball:

In a sense, these other bodies serve as a control group for comparing – or better,

contrasting – the remarkable features of our home planet.  Despite all we’ve been told

about the pale and insignificant blue dot, Earth is really quite an extraordinary

hostess for both life and scientific discovery (pp. 81-82). 

We are told first about Mars: if its ice cap melted, its sea would be only 10 to 20 feet deep.  There is not as much water as our Sci-Fi shows tell us.  Secondly, the perpetual dust storms not only erode anything we might like to look at, but make the planet virtually uninhabitable for anything but the most robust life.  Thirdly, Mars’ tilt and rotation are less than optimum.  Fifthly, its ice deposits, unlike our own, are not surrounded by oceans and thus there is no self-perpetuating ice formations.  Sixth, “Carbon dioxide, which changes directly from ice to gas at Mars’s surface, is the most abundant part of the Martian atmosphere, and is a poor substitute for water as a stable matrix for layered deposits” (pp. 84-5).  And hence, not only could you not do much by the way of scientific inquiry, you would have trouble processing the stuff to breathe. . . .  Seventh, Mars has no tectonic plate motion (although it might have previously – geologic timeframe again).  Eighth, because it does not have the kind of hot metallic core we have, Mars does not have as good of an electro-magnetic system for radiation deflection.  Compound that with its paper thin atmosphere and you have a dangerous place to live and too dusty a place from which to look either up or down. 

In any case, Mars’s atmosphere lacks enough oxygen to allow for fires on its surface, so Martians would probably enjoy neither Boy Scout cooking merit badges nor high technology (p. 86).

Venus is a bake oven at an average temperature of 900 degrees Fahrenheit.  It has no tectonic plate movement, nor electromagnetic defense field and so is a victim of the Solar wind. 

All the other planets (from fire-hot Mercury [well, on one side] to the gas giants, Jupiter, Saturn Uranus Neptune) are only worse.  However, some of the water moons around Jupiter and Saturn may be worth investigating.  Europa is the second Galilean Moon around Jupiter.  If it is oceanic, however, it may be “about a hundred kilometers deep, twenty times deeper than the typical basin depth of Earth’s oceans” (p. 88).  The pressure would be about 2.5 times that of Earth’s Ocean basins.  “Simple life can’t tolerate an arbitrarily large pressure.  Some microorganisms can grow at pressures up to one thousand times the pressure at sea level on Earth, but Europa’s ocean bottom may exceed this limit by about 30 percent” (p. 89).  The second problem is compound: it would be difficult for any light to penetrate the ice to get to the ocean.  Because it is so far from the Sun, and because ice is a reflective surface, there wouldn’t be a lot of energy to penetrate in the first place.  Because energy is necessary for biological reactions, there’s not much hope for life there.  Because life tends to live at the interfaces of land, air and water, and because Europa doesn’t have many of these, there’s not much likelihood of large quantities of life there.  Finally, because of how its orbit works with Jupiter and the other moons in Jupiter’s system, it is most likely that Europa’s ocean freezes over frequently. 

By contrast, we have all the advantages: water and ice balance, partly cloudy atmosphere, continents and plate tectonics, and electromagnetic shield for excess radiation and the right distance from the sun.

The authors then delve into Chaos Theory with respect to the various planets, moon systems and planetoids in the form of asteroids and comets.  It is difficult to predict where stuff is going to be over the long haul; but one thing that we do know is that our Earth has a remarkably stable orbit.  That is good both for measurability (we can be pretty certain of our distances) and habitability (we don’t have to worry about burning up or freezing to death in the near future). 

The next section deals with exo-planets discovered by observing the wobble of the parent stars.  I am not certain that we have actually seen any of them yet, but using the wobble method (detecting the Doppler shift of a star’s optical spectrum) we can determine that a star is responding to gravitational pull from a neighboring body.  (Incidentally, this has become a great hobby for amateurs.  They use this method and also the method of calculating the magnitude of stars if planets cross the plane of the star [eclipse, sort of].  The star will seemingly emit a smaller amount of light if its planets cross in front of it.) 

Cutting to the chase, we find that most of what we can “see” at this point in regard to exo-planets, is huge gas giants with orbits that are intrusive to the “Circumstellar Habitable Zone.”

Since you cannot live on a methane gas giant anyway, you really do not want one around messing up your world with its gravitational abominations either.  Another problem, that we have in the few cases where we have found gas giants that line up more like our own Jupiter and Saturn, is that their orbits are much more eccentric than our own Jupiter’s.  If you have to have gas giants around – and they are helpful for getting rid of solar systemic garbage – you really don’t want one wandering all over the solar system collecting space junk and messing up the orbits of perfectly good, non-eccentric Terre-planets.  How about on the moons of these huge exo-planet gas giants?  Well, the eccentricities just get compounded and the hot/cold thing would make the place most inhospitable for anything but the most robust of life – and that, only if all the other things are available for life (water, land, air, carbon, etc).  Another problem with moons on gas giants has surfaced by examinations of Ganymede and Callisto: because Jupiter collects space junk, all of its children get blasted as well.  Some of the impacts on these Galilean moons would be Planet Killers if they hit us. . . .  We are indeed “at the head of the pack.”

This brief tour of our planetary neighbors and their extrasolar cousins allows us to put the Earth-Moon system into proper perspective.  Earth’s long-lasting hydrological cycle,

plate tectonics, oscillating magnetic field, continents, stable orbit, and transparent atmosphere together provide the best overall “laboratory bench” in the Solar System. 

Earth’s surface strikes a balance between the permanence required to preserve patterns written on it and the dynamic yet gentle circulation that subtly sways these “recorder

pens” without tearing up its paper-thin crust.  The crust records and stores information while maintaining the most habitable environment for complex life in the Solar System. 

Continents amid oceans of water, enabled by plate tectonics – as Earth enjoys exclusively seem to be the best overall habitat for observers.  No other locations yet discovered

hold a candle to this one blue dot, however, pale it may appear to some.  Of course, it doesn’t follow that our Solar System has no role to play for life and discovery.  On the

contrary.  But that’s another story (p. 101).

Guillermo Gonzalez and Jay W. Richards, The Privileged Planet: How our Place in the Cosmos is Designed for Discovery (Washington, DC: Regnery, 2004).  

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