NU001: Setting The Scene
David Noel
<davidn@aoi.com.au>
Ben Franklin Centre for Theoretical Research
PO Box 27, Subiaco, WA 6008, Australia.
The art of discovery is to see what everybody sees, and think what nobody thinks
This suite of articles is reformulated from an earlier book, with each article title containing the number of the original chapter in the book. Within this suite, and placed in boxes for emphasis, are a number of
Propositions.
These Propositions are just that -- propositions. They are succinct, unhedged, and
uncomplicated suggestions on various aspects of the world of the present, the past, and the
future. Some of them are mild and uncontroversial, virtually self-evident, others could be
regarded as outrageous from the viewpoint of a conservative soul. I am not claiming that all
these propositions are "true" (for more on what "true" means, see NU017), and in fact they
cannot all be true, as some of them (e.g. Propositions 12E and 12F on dinosaurs) are apparently
mutually exclusive.
But I hope, at least, that they will provoke thought and perhaps some critical evaluation of
their implications. Many of them have scope for setting up tests, for extrapolation, for
prediction, in fact for running them through the whole gamut of objective probing which
reveals the "truth" or otherwise of any scientific theory.
Where the Evidence Comes From
A word about sources and data. This suite of articles contains almost no new data, no astounding new
results of trials. Some of the conclusions reached may be quite novel. But these conclusions
are based on the most prosaic data, much of it available for many years in standard sources.
A lot of the hard data quoted is taken from either the current (1989) edition of the Encyclopaedia
Britannica, or from the Ninth Edition of this work, published in 1875. Some comes from the
Guinness Book of Records!
In fact probably half the evidence used in this suite of articles was already available a hundred years
ago, and three-quarters available fifty years ago. Even the remaining 25% which has come
to light more recently has been mostly in the nature of confirmatory detail, rather than some
revolution in our views.
Hence the quotation at the head of this chapter. One of the side effects of this work will
be to show that "old" data can be reworked with success, like some mineral tailings, to reveal
unsuspected new riches.
The Timescale of Events in this Suite Of Articles
It may be useful for the general reader if some background is given on the timescale of
events which figure in this suite of articles.
Almost all references will be to events which occurred many millions of years (my) before
the present. Currently, the age of our entire Universe is widely believed to be about 13,700 my; the Earth itself (and its satellite, the Moon) are believed to be about 5,000 my old.
Of course, life on Earth did not begin until a long time after the planet was formed (usually
assumed to have been by condensation of gaseous material). An event occurred at around 600 my
ago which was very obvious from the record of fossils found in the rocks. Before 600 my
the rocks are almost empty of signs of life; after this time, rocks which were formed in a way
suited to the preservation of fossils (say on the beds of shallow seas receiving a continuing load
of sediments) may be crammed with fossils.
Fossils are often excellent indicators of the conditions which applied at the time and place
where the creatures which left the fossil remains grew, and so they have been studied in great
detail. Most of our knowledge of the geological past has been gained from fossils. So we have
quite a good and detailed picture of events since around 600 my
, and a much poorer picture of
what happened before that.
The Ages of the Rocks
Table 1 shows how geological time is divided up; the different slabs of time can be regarded
as layers of rock, with the youngest at the top. The time since abundant life has existed is
conventionally divided up into three large sections, called Eras. These are, in order of
increasing age, the Cenozoic Era, the Mesozoic Era, and the Paleozoic Era (these terms mean,
roughly, the times of Young, Middle, and Old Life).
Table 1. Time Divisions in Earth's History
Each Era is itself divided up into smaller units called Periods or Epochs. The names of
these units are shown in the table. Rock and fossil dating methods are now accurate enough
so that the beginning and end of each of these Periods can be dated to the nearest my, in the
younger rocks at least. A change from one period to the next is usually marked by a significant
change in the fossil record, and in fact this change is fundamental, because it is usually the
reason
for splitting the record of the rocks up into different parts.
The oldest Period of all, that at the bottom of the Paleozoic Era, is called the Cambrian
Period. It is in the oldest Cambrian rocks that the first signs of profuse, active life are found.
The change is quite sudden. Something happened at the start of the Cambrian which greatly
favoured the development and expansion of life on Earth.
Once it was thought that the Cambrian actually marked the first appearance of any form
of life on Earth, and that the older rocks were completely devoid of fossils. More recently it
has been shown that these older rocks, called Precambrian and extending back to the
beginnings of the Earth itself, do in fact have some traces of life. Some of this life could be
as old as 3500 my, but the evidence is not clearcut, and argument continues on the exact nature
and age of this early life.
The actual figures quoted are subject to revision and refinement, but the general picture is
clear. For seven eighths of its 5,000 my existence, the Earth was almost devoid of life. About 600 my ago, life burst forth in abundance.About 230 my ago, a major change occurred, and about 70 my ago, another big change. Later in this suite of articles I will suggest some of the underlying reasons for
these abrupt changes.
About Rock Types
This is not the place for a detailed explanation of the different types of rock, but there is
one aspect of rock types which does have considerable relevance, and that is the distinction
between "continental" and "oceanic" rock types.
Both these rock types may be "igneous", formed by the cooling down of molten material. But
the continental rocks, which form the bulk of the material of the Earth's present continents,
are lighter in weight (and often in colour) than the oceanic ones and have a somewhat different
chemical composition. They are also called acidic rocks, and granite is the most typical
example
Oceanic rocks, also called "basic" rocks, are heavier in weight and usually dark in colour.
Basalt is a typical example. Oceanic rocks not only form the bedrock of all the major and
deeper seas and oceans, they also underlie the continental rocks of the land masses. The
situation has been represented as a continuous, solidified oceanic-rock "sea" covering the
whole of the Earth, with separate "rafts" of continental material floating on this solid "sea".
In agreement with this picture, the continental "rafts", which are usually 5-40 km
thick, are
said to be actually "immersed" in the oceanic-rock sea, their bases extending below the level
of rock in adjacent seabeds. And, in a classic Archimedes' Principle situation, the depth of
immersion is usually greater under higher mountains such as in the Tibet region -- just as if
the continents were really floating.
Naming Animals and Plants
Living creatures are identified by their "scientific names", which consist of two parts, a
genus name and a species name. For example, the walnuts are in the genus
Juglans
(from latin,
"Jupiter's nut"). The common walnut is
Juglans regia
(where "regia" means royal). It is normal
to print these scientific names in italics or underlined, and to have a capital for the name of the
genus (plural "genera") and a small letter for the species (plural "species").
Basically, a species represents the whole of a population which can interbreed. The genus
is the next broader grouping, representing all those species which are believed to be closely
related. Within a genus, interbreeding between species is sometimes possible (giving
"hybrids"), but not assured or common. The position is explained in rather more detail in
Chapter 2.
Genera are themselves grouped into the next broadest division, the family. In plants, the
names of these families usually end in "-eae". The walnut family, the Juglandaceae, includes
not only the true walnut genus
Juglans
but also
Carya
, the genus of the pecan and hickories,
and others.
We have now painted a rapid picture of the Earth, its history, and its inhabitants, using a
very broad brush. To continue this saga, we start by shrinking our focus right down, to look
at a very minute part -- Rottnest Island.
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
NU002: How Plants Spread and Change
Version 1.0, in printed edition of "Nuteeriat: Nut Trees, the Expanding Earth, Rottnest Island, and All That...", 1989.
Version 2.0, 2004, PDFs etc on World Wide Web.
Version 3.0, 2014 Sep 10, Reworked from Chapter 1 of "Nuteeriat" as one article in a suite on the World Wide Web. V. 3.1, Adjusted, 2025 May 31.
V. 4.0, Adjusted for *, 2025 Sep 28.