A World With One Season II
by Dwardu Cardona
Part II
Tree Rings
One of the main reasons why some paleo-climatologists have been
reluctant to accept a former universal spring-like environment to
account for the previous existence of Arctic and Antarctic sub-tropical
flora and fauna is that evidence exists which does seem to point
to past seasonal stability. This evidence comes from tree rings. As
every Boy Scout knows, tree trunks are marked out in transverse section
into concentric rings, one ring for each “season” of growth. In order to
tell the age of a felled tree, Boy Scouts are taught to count the number
of rings laid out in its trunk. Known as annular rings, these growth
marks owe their emergence to differences in the elements at the
beginning and end of each growing period.
Fossilized trees from various past ages show distinct annular rings.
Others do not. Wood retrieved from late Paleozoic deposits in the
southern hemisphere has been said to show pronounced ring growths. So,
also, fossils of deciduous trees from the Cretaceous. In fact,
fossilized wood samples ranging all the way from the Devonian to the
Eocene have been claimed to show well marked annular rings. More recent
work has tended to show that rings are either lacking or very weak in
all known specimens from the Devonian period which seems to indicate a
non-seasonal environment. Most fossil trees from the Carboniferous
period, which followed the Devonian, also lack rings. As Elso Barghoorn
noted:
“One impressive indicator of uniform climate over great areas of the
Carboniferous continents is the great absence of annual growth rings in
coal-swamp trees. The entire question of ring development in woody
plants is one fraught with botanical variables as well as climatic
variables. However, the consistent absence of any index of seasonal
growth seems difficult to explain except on the assumption that winter
cold and seasonality of rainfall were absent or at a minimum."
By the time we come to the late Permian period, still within the Paleozoic
era, we end up with a mixed bag. Fossil woods from Canada, Europe, and
Asia have weak or non-existent rings, while those from South America,
Africa, and Antarctica show prominent and wide growth rings. A mixed bag
from trees growing in different areas may be expected. But what about a
similar mixed bag from trees known to have grown in the same locality?
Thus, moving slightly closer to our time, we come to the Triassic period
of the Mesozoic era. Few fossil trees are known from this period and, up
till now, all of them come from Arizona’s petrified forest. One specimen
from this collection lacks annular markings, but others display very
wide prominent rings. In samples from the Jurassic and Cretaceous
periods of the same Mesozoic era, as well as from the Early Tertiary
period, tree rings range from prominent to non-existent.
When it comes to polar fossil plants, as Edward Berry noted:
“Detailed comparisons of these Arctic floras with contemporary floras
from lower latitudes…show unmistakable evidence for the existence of
climatic zones…” C. P. Brooks reached the same opinion, claiming that
climatic zones existed in the Eocene, as so did Ralph Chaney, who pushed
the margin up to the Pliocene. As Jane Francis noted, samples of wood
collected by her on Axel Heiberg Island showed clear annular rings over
a quarter of an inch wide. And, because the darker latewood added at the
end of the growing season featured very narrow bands, the conclusion has
been drawn that the trees grew rapidly during the twenty-four hour
sunshine period of the Arctic summer and then closed up shop during the
winter hours of darkness.
The problem with this, however, is that trees would not have survived
such prolonged periods of darkness. And then there is the fauna to
consider. What–did tapirs and crocodiles sleep through these darkened
months? Could land tortoises have migrated to warmer climes and back
again every year? Besides, where did the warmth that would have been
needed to thaw the Arctic ice cap come from? The present Sun is not
capable of accomplishing that feat. And if the Sun, as accepted by
orthodoxy, had been dimmer in those eras, it would have been able to
accomplish it even less. Or are we to believe that sub-tropical flora
and fauna existed in an ice-bound region, and for millions of years at that?
Needless to say, the evidence of the tree rings poses just as much of a
problem to the Saturnian scenario we have been considering. All of which
forces us to ask yet another question: Are annular rings really
indicative of seasonality?
Actually, annular rings are only formed in those plants whose growth is
interrupted by a regular winter or dry “season.” The increment of new
wood formed in these trees is marked by a distinct line which is
produced by the contrast between the late summer of one year and the
spring of the next. The lines of separation between successive rings
marks the limit of a microscopically thin layer of cells, known as the
cambium, which lies between the wood and the bark, at the end of each
successive growth period. The bark then cracks and/or expands to allow
for the new growth of wood, and the tree trunk is thus thickened. It
should be noted, however, that the cambium responds mainly to conditions
of temperature and rainfall rather than the incidence of light.
But what about trees growing in tropical and equatorial regions where
seasonal differences disappear? Do they still grow rings? As it happens,
many kinds of evergreen tropical trees do not grow rings. But
others do. As Barghoorn reported: “In existing woody plants,
annual ring development may occur under nearly uniform climatic
conditions, as in equatorial rainforests.” What, then, is it in this
seasonless environment that tells these trees that a year has passed and
that it is time to grow more wood and thus form a new ring?
That the growth of annular rings is not tied to seasonal change
is evidenced by the fact that some trees have been known to grow as much
as three or four rings in one year. Nor is this an uncommon situation,
as Nelson Glueck noted, especially in trees which grow on sloping ground
that turns wet and dry several times in one year because of rapid
outflow of water. According to an item in Nature magazine,
multiple rings in larch trees were normal in 1919; in fact, larches seem
to be prone to multiple ring growth.
Meanwhile, trees which miss growing a ring in certain years have also
been known. As Herbert Sorensen pointed out:
“In dry and climatically harsh years, no detectable growth may occur. In
this case no ring is formed and the ring is missing for that season of
the year.”
In some cases, as much as five percent of the rings may be missing. In
fact, growth rings are lacking in a majority of trees which thrive in
subtropical and tropical climates while others fail to grow rings
regardless of climate.
What all of this declares is that tree rings are poor indicators of
seasonal change. In fact, let us be honest about it, they are not
indicative of seasonal change at all. But if tree rings do not indicate
seasonal change, what, then, do they indicate?
We have already noted that the cambium responsible for the growth of trees
responds mainly to conditions of temperature and rainfall rather than
the incidence of light. And, in fact, when it comes to the growth rate
of trees, water is the limiting factor. In other words, water is the one
true constituent which limits the growth of cambium and thus the
formation of growth rings. This is what tree rings, when they grow at
all, truly indicate–a cycle dictated by the availability and cessation
of an adequate water supply.
That being the case, the lower incidence of light from the Saturnian
sun, as compared to the higher incidence from our present sun, would
have posed no obstacle to the growth of trees. Temperature would also
have posed no problem because, while the Saturnian sun would not have
been as hot as our present Sun, its proximity to Earth would have
compensated for its lower caloric output.
As we have seen, it is quite apparent that trees grow rings, or fail to
grow rings, regardless of seasonal change or stability. More
importantly, if trees can, as they do, grow rings in tropical and
equatorial regions in which there is no appreciable seasonal change,
what is so problematic with having trees growing rings in a sub-tropical
Arctic which enjoyed but one spring-like season?
The Axial Tilt Hypothesis
Some might ask: Why not leave Earth in the Solar System and simply
straighten Earth’s axis?
This, too, would have ensured a world with one season, an eternal
spring. And as difficult as it might be to later tilt Earth’s axis to
the angle it now holds, it seems more feasible than the hypothesis we
have been proposing. This, in fact, had been suggested by various
authorities at the end of the nineteenth century as, for instance, by
Julius Hann: “The simplest and most obvious explanation of great secular
changes in climate, and of former prevalence of higher temperatures in
northern circumpolar regions, would be found in the assumption that
earth’s axis of rotation has not always had the same position, but that
it may have changed its position as a result of geological processes,
such as extended rearrangement of land and water.”
By an “extended rearrangement of land and water,” Hann had in mind a
redistribution of the weight brought upon the surface of Earth by the
elevation of land in one place and the sinking of others in a different
locale. But, as James Croll pointed out: “A continent ten times the size
of Europe elevated two miles would do little more than bring London to
the latitude of Edinburgh, or Edinburgh to the latitude of London.”
This debate involved some of the giants of science that lived at the
time, including William Thomson (better known as Lord Kelvin), George
Darwin, Simon Newcomb, and Giovanni Schiaparelli, the latter of whom wrote:
“The permanence of the geographical poles in the very same regions of
the earth cannot yet be considered as incontestably established by
astronomical or mechanical arguments. Such permanence may be a fact
today, but it remains a matter still to be proven for the preceding ages
of the history of the globe.”
To which he added:
“The possibility of great shifting of the pole is an important element
in the discussion of prehistoric climates and the distribution,
geographic and chronologic, of ancient organisms. If this possibility is
admitted, it will open new horizons for the study of great mechanical
revolutions that the crust of the earth underwent in the past.”
The axial tilt debate then spilled into the early years of the twentieth
century. Thus, in 1929, Harold Jeffreys could still ask: “Has the
inclination of the earth’s axis to the plane of its orbit varied during
its history?” As he himself confessed: “The answer to [this] question is
a definite ‘Yes!’” By 1937, W. B. Wright continued to maintain that “the
earth’s axis of rotation has not always had the same position” and that
the “many changes of the position of the climatic zones on the surface
of the earth” were “due to a displacement of the pole from its present
position.”
In this respect it is noteworthy to note that when, in the 1980s, remains
of sub-tropical flora and fauna were discovered by Soviet scientists in
Spitsbergen, the axial tilt hypothesis was revived and, as of now,
continues to be the standing Russian (previously Soviet) understanding
of what had to have transpired in ages past.
According to Bernard Delair, theoretically, Earth ought to rotate
on a vertical axis “and may actually have done so in the geologically
recent past.” As he stated: “There ought to be no reason why any
Earth-like planet undisturbed for untold ages should not have a
vertically-positioned axis.”
Unfortunately, there are various problems with the axial tilt
hypothesis. To begin with, Delair’s declaration did not go unchallenged.
As Michael Reade pointed out, “a spinning ball forced to traverse an
elliptical orbit around a primary would adopt a tilted attitude.” As he,
in turn, assured his readers, “it is never possible to get a
free-spinning ball to spin with its axis either vertical or horizontal:
the principal axis of the ball always settles to a well-defined and
seemingly invariable angle of tilt.” This, as Reade pointed out, “has
long been known to engineers: spinning bodies, such as turbines or speed
governors, impose asymmetric stresses on their shaft bearings.”
True, as Jane Francis noted, had Earth’s axis been perpendicular to the
plane of the ecliptic, the Sun would have bathed the polar
regions with twelve hours of light every day. The Sun’s rays,
however, would have been weak and low-angled, similar to those
experienced just before sunset. And this would have been
insufficient for the growth of plants such as the remains of which have
been discovered in polar regions.
At bottom lies this additional fact: While the axes of the Solar System
planets point in different directions, those of Saturn and Earth come
close to coinciding. Saturn is tilted at 26.7 degrees while Earth’s tilt
is at 23.45 degrees. Both axes point to about the same spot in space.
Saturn’s present north star is the same as Earth’s. This is a situation
that would be expected had Saturn and Earth once shared the same
axis of rotation as the thesis being expounded here demands.
How about, then, a perpendicular axis with an Earth in phase-lock around
proto-Saturn, much in the manner in which the Moon is presently
phase-locked around Earth, even if the Saturnian system was
outside the Solar System? This, too, fails to fill the bill because,
while such a system would entail a world without variable
seasons, it does not occasion one universal spring-like climate. Only
that hemisphere facing proto-Saturn would have been able to bask in
perpetual warmth, while the other hemisphere would have experienced
perpetual cold. More than that, even that hemisphere facing proto-Saturn
would not have reveled in a uniform warm regime. True enough, the
climate would not have been variable, but tropical and equatorial
regions would still have been much warmer than the poles. The poles, in
fact, would have been the recipients of low slanting rays and if such
slanting rays from our own Sun would have been inadequate to allow the
thriving of sub-tropical flora and fauna at the poles, neither would the
slanting rays from a brown dwarf star.
This brings us to the question I asked at the end of the first part of
this paper: How could proto-Saturn, permanently stationed above Earth’s
north polar region, have also warmed Earth’s southern pole, to say
nothing of the latitudes in between?
A
Denser Atmosphere
In
1991, Frederic Jueneman proposed a hypothesis in which he indicated that
Earth might once have been cocooned in a more massive atmospheric
envelope. This hypothesis is not foreign to orthodox astronomy. In 1997,
Armand Delsemme had also proposed a terrestrial envelope “100 times
denser than the present atmosphere.”
Although those who have posited this hypothesis have done so for reasons
of their own, this proposal can be extended to encompass a greenhouse
environment. Under such conditions, the warmth radiated by the north
polar Saturnian sun would have penetrated Earth’s dense envelope, which
would have also helped to spread it around, while disallowing it to
re-penetrate back out and dissipating in space. This is the mechanism
which astronomers presently accept to account for the excessive heating
of the planet Venus.
One problem this poses for the Saturnian model is that such a dense
atmosphere might have hidden proto-Saturn from terrestrial view, and we
know from man’s own fossilized memory that this was not the case. True,
man was not yet on the scene during the Tertiary period so, perhaps,
this should not concern us too much. Besides, there is the possibility
that the Saturnian sun could still be seen in a diffused sort of way
through the heavy clouds. At present, the same is true on Venus since
the Venera photographs of its surface show shadows. It is thus thought
that “a hazy Sun” might be “shining over Venus’s surface,” and that such
a “hazy Sun” would be visible in the sky.
An
alternative way in which this theory could be brought in line with the
Saturnian model is if Earth’s dense atmospheric envelope exhibited a
north polar clearing–a hole if you wish. Again, such a polar opening in
a planet’s atmosphere is not all that foreign in the Solar System. Venus
has such a polar opening–a “huge hollow” 1,000 kilometers wide–in its
own dense atmosphere right over its north pole, through which the
Sun might possibly be shining. If such was the case, the Saturnian sun
would have been clearly seen through the opening. More than that, it
would have warmed Earth’s Arctic regions even more effectively.
Unfortunately, a lamentable objection has to be raised against this
hypothesis since the proximity of the proto-Saturnian sun would have
raised Earth’s atmosphere in a tide precisely above Earth’s north
polar region. Thus, if a denser atmosphere did prevail on Earth, it
would have to have lacked a polar opening.
The Plasma Sheath
An
alternative hypothesis is to have the Saturnian system encased within a
plasma sheath. The first person I know to come up with this hypothesis,
as early as 1976, was Ralph Juergens. “Presumably,” he wrote, “both
[Saturn and Earth] would be enveloped in a common magnetosphere which…I
would equate with a sheath between the solar-wind plasma and any
material body, or closely coupled systems of bodies, at non-plasma
potential.” In 1981, Roger Ashton extended this idea by supplying this
plasma bubble, which is what a magnetosphere really is, with an opaque
surface that would have reflected proto-Saturn’s radiation back toward
both Saturn and its terrestrial satellite. Similarly, Wallace Thornhill,
many years later suggested that the “heat and light of an electric star
[such as he believes the proto-Saturnian brown dwarf star to have been]
is radiated both outwards and inwards from the photosphere”; that
“Earth, situated inside the speherical envelope of such a star…would
find the energy flux almost equal over the entire planet”; and that “all
objects orbiting in that region would receive the same energy per unit
area of their surface.”
In
the end, it may even be found that both postulates–a denser
atmospheric envelope and a plasma sheath–are quite compatible with each
other, since a denser terrestrial atmospheric envelope might have
existed within the Saturnian plasma sheath. We would thus have a
situation in which the light and heat from the proto-Saturnian sun would
have been reflected back, or otherwise radiated outward and inward, from
the plasma sheath and dissipated evenly through the greenhouse property
of Earth’s denser atmosphere.
Clues from Astronomy
Is
evidence concerning any of this available from other planets of the
Solar system? Only to an extent because, after all, the case I have been
presenting is somewhat unique–which is not to say that similar systems
might not yet be discovered out in space. Meanwhile, the extent to which
other planets can provide some evidence, no matter how slim, is
exemplified by Uranus. Very much like the Saturnian system I have been
describing, the temperature of Uranus is not only globally warm, but,
again like proto-Saturn, its north pole was found to be warmer than the
rest of the planet. Of added interest here is that when Voyager 2 made
this discovery, the north pole had been in darkness for forty years. As
Thornhill indicated: “This offers a clue as to how the Earth might
have had a uniform global climate during the Saturnian era…”
Even more recently, it has been discovered that Jupiter’s satellite, Io,
also has its poles as warm as its equator. “Aside from hot spots at
volcanic sites, night temperatures on Io appear to be about the same
near the equator as near the poles even though, as on Earth, the equator
gets more direct sunshine to heat the surface.”
True, Uranus and Io do not have a north polar sun to heat their northern
regions, and I only include these data to show that such a state of
affairs–global uniform temperature with a slightly warmer north pole–is
not of itself a bizarre situation.
That being the case, what need have we of an axial alignment between
proto-Saturn and Earth? Why do we need to have the proto-Saturnian sun
stationed in Earth’s north celestial pole to account for the single
spring-like season in which the Earth basked in past geologic eras.
After all, this state of affairs could just as easily have come about
had Earth been in a normal orbit around its primary. In other
words, nothing I have presented so far demands an axial alignment of the
two bodies concerned.
But consider now the following:
The Boreal Cradle
Back in 1868, Heer’s study of fossil Arctic flora led him to postulate
that the Arctic had served as the centre of new generations of plants
which then radiated south to America, Europe, and Asia. To quote Ian
Johnson:
“These migrations of new plant species and groups, which originated in
the Arctic and then became closely related ‘vicarious’ species through
simultaneous differentiation, elegantly account for the mysterious
similarity of tree and shrub vegetation in such scattered locations as
eastern Asia and Atlantic North America. This theory also explained the
resemblance noted by Heer of the Tertiary flora of Europe and the Recent
flora of eastern Asia and Atlantic North America.”
As
Johnson noted, while Heer’s theory dates to the late 19th century, his
“notion of an Arctic evolutionary cradle is startlingly modern,
in line with the work of Dawson and Hickey” to which we shall come in a
while.
E.
C. Pielou, on the other hand, reminded her readers of photoperiodism
which presents an “apparent obstacle to long, northward and southward
migration of plants” since such migrations would have moved said plants
out of their physiological niche. Long-day plants, for instance, cannot
survive in the tropics, while short-day plants cannot thrive in more
northern latitudes. This is because the photoperiodic length varies from
latitude to latitude and from season to season. Because day and night
lengths in the tropics approximate twelve hours each all year round,
photoperiodic variations are small to non-existent. In the mid-temperate
regions, photoperiodic spans can vary from up to nine hours in December
to up to sixteen hours in June. In the present Arctic regions,
photoperiodicity drops to zero in December, rising as high as
twenty-four hours in June.
All this, however, would have been of very little, if any, importance
during the Tertiary if Earth had basked under a continuous and universal
sub-tropical climate and light regime as seems to be indicated by the
evidence presented above. In the case at hand, the climatic requirements
would have been close to identical the world over. Migrating plants
would not have had to vacate any physiological niches; they would merely
have radiated into new areas the climatic properties of which would have
been near identical to the ones of their origin.
In
the end, it is the available evidence that counts. Does the evidence
support the theory of a Tertiary plant migration from the Arctic into
more southerly latitudes?
In
the Canadian Arctic, Mary Dawson discovered tapirs and flying lemurs
which were closely associated in geologic context. But, further south,
the tapir was found in a Middle Eocene context, while the flying lemur
appeared in an Early Eocene stratum. Meanwhile, Leo Hickey, who had
already spent twenty years studying Eocene flora, came to the conclusion
that plants, together with marine invertebrates, had risen earlier in
the Arctic than in the mid-latitudes. Ancestors of the horse, camel,
rhinoceros, land tortoises, together with the flying lemur, and such
trees as the Mexican elm, walnut, and the redwood, originated millions
of years earlier in the polar regions.
“Dawson and Hickey in the early 1980s co-authored a paper in Science
where they argued that certain plants show up in the fossil record 18
million years earlier in the Arctic than elsewhere while some animals
evolved 2 to 4 million years ahead of their time north of the Arctic
Circle.”
Yet if the entire Earth basked in a sub-tropical climate during the
Tertiary period, to which the Eocene epoch belongs, how could this have
been so?
This is precisely where the north celestial placement of the proto-Saturnian
sun comes into its own. Thus, in addition to a universal climatic regime
which would have warmed Earth throughout all its latitudes,
proto-Saturn’s northern positioning would have ensured that Earth’s
Arctic regions would have been slightly warmer earlier than the
rest of the globe. In other words, Earth’s sub-tropical climate would
have itself advanced slowly from the polar regions to the more southerly
latitudes, with flora and fauna advancing along with the climate–just as
the geological and palaeontological evidence seems to call for.
It
thus seems that the Saturnian sun was already stationed above Earth’s
north pole from at least as far back as the Eocene Epoch of the
Tertiary Period of the Cenozoic Era which is dated by geologist to c. 58
million years ago. And even if this time span would have to be
drastically shortened, as it probably will have to be, sometime in the
future, it remains evident that the situation we have described would
have to have prevailed from long before the advent of man.
The Caretaker of the World
What must, however, also be stressed is that, when man finally arrived
on the terrestrial scene, the situation remained much the same, as
mythic themes unambiguously maintain.
Thus, much later in time, the Papago Indians of North America who,
together with the rest of humanity, were not yet on Earth during the
ages I have been discussing, continued to believe in a time when the
“sun” was closer to Earth. As recorded in one of their tales, told in
1883: “The sun was much nearer the earth then, so that it was always
pleasantly warm.” Of seasons there were none. “There was no winter and
no freezing cold.” It was only later, say these Indians, that the “sun”
was pushed “farther away from the earth” and then winter, snow, ice, and
hail appeared.
In a “sun” that was “nearer the earth” we again recognize the Saturnian
brown dwarf star which shed its light and warmth from Earth’s north celestial pole.
So, likewise, with the Zuni who maintain that winter came much later
when the “sun” escaped, rose into the sky, and drifted away. Had this
been our present Sun, where could it have been before that? Can
we not see that the Zuni have retained a memory of that time when Earth
had basked beneath the light and warmth delivered by a different
sun than our present one? Does this not tally with our conviction that
winter came upon the world when our previous Saturnian sun “drifted
away” as the present Sun pulled Earth away from its former primary?
It was no different among the Sioux who, as recently as 1981, were still
preaching that the four seasons had not pre-existed but were bestowed as
a boon at a later time.
What is also instructive is that man continued to hold the north
responsible for the eventual arrival of the seasons. The “sun” of
Creation, so claim the Sioux, appointed the north to be “the
caretaker of this earth.” More than that, at a time when “the sun did
not move yet, did not rise and did not go down,” when it “just stood in
one place,” the Creator “made the four seasons for the north to take
care of…” |