Posted dd Mmmm 201?, Revised December, 2010


In Celebration of Psalm Nineteen:
God's handiwork in Creation

Chapter 5
Creation of the Solar System and the Earth*

Introduction. The universe is an exceedingly hostile place, and an implausible host for complex life. Scientists already noted this fact at the beginning of the 20th century, and the discoveries since then have sharpened this realization a thousand-fold, as the modern science of cosmology -- totally unknown and unimaginable at that time -- took shape01.

Earth's life-supporting environment must persist in the face of incredibly hostile forces. The full magnitude of these hostile forces will be topics of future chapters, as the Creation Narrative unfolds. At this point, limiting our observations to the physical universe, the implausibility is already apparent:

• The project of developing life on Earth consumed almost 4 billion years, or (including the time required to form the Earth and the Solar System) about a third of the entire life of the universe -- over half of the time that the Milky Way galaxy has existed.

As we will see in the following chapters, this 4 billion year extent is an unavoidable minimum amount of time, given that the preparation of the environment and the development of life used natural processes (as opposed to divine fiat) whenever such processes are adequate to achieve the needed result. This length of time is driven by the time needed to perform deliberative tasks, not allowing for the false starts and blind alleys of random chance. There was no dawdling, despite the superficial appearance of vast lengths of empty time.

• Only a small subset of newly-formed stars are Sun-like -- that is they have about the same size as the Sun and they are hydrogen-burning. I would add to this -- AND they have a habitable zone that would support the 4-billion year development of life. Virtually none of the stars visible to the naked eye are sun-like -- visible stars are generally too bright and too large, hence their lives are much shorter than 4 billion years. The star 18 Scorpii is a nearby sun-like star (about the same age as the Sun) that is 46 ly away in the Scorpion constellation. The star 51 Pegasi is a second example (50 ly) but it has a Jupiter-like planet that is in a very close orbit, which would appear to rule out the conditions necessary for the development of life. This was the first planet discovered outside of the Solar System.

• Without exception, the mechanisms that engine the creation of the elements, of galaxies, the Solar System, and the Earth were, and remain, incredibly violent, and hostile to the sustenance of anything so delicate as living cells. And to maintain the Earth's life-supporting cocoon for 4 billion years while this creative violence proceeds everywhere throughout the universe is incredibility-squared. Danger and potential destruction exist everywhere and loom repeatedly over the 4 billion year timespan.

- The essential elements of life were cooked in the seething interiors of stars.
- The stars die in violent cataclysms to spew out these elements and create the heavy elements that could not be formed in the stars. This death releases untold amounts of energetic and deadly radiation that radiates out at the speed of light to destroy any life in its way.
- New stars formed from the ashes, and repeated the cycle of creation and destruction, every part of which is violent and completely destructive to life.
- The Solar system includes billions of stars in all stages of creation and explosive destruction. The Sun and its planets travelled through this multitude of stars for the entire span of four billion years of life on Earth, without even once engaging with even a single one of the stars in a way that would destroy the delicate cocoon that held life on earth
- In all this time, the earth was subject to the random vagaries of radiation coming from nearby supernovas and other cosmic events, without suffering even a single catastrophic annhilation.
- At the same time, the Earth also avoided life-destroying interactions with material contained within the Solar system -- asteroids, comets and other lethal projectiles. The Earth's orbit proved to be stable over the entire time, despite the potentially destabilizing effects of nearby planets and other debris.
- Over this 4 billion years (See the box on Solar Heating), the balance between the Sun's slowly increasing radiation as it aged, combined with the Earth's own furnaces of slowly diminishing radioactive decay, balanced out to provide a continuous temperate environment.

The typical way that this implausibility is expressed within the scientific community is in the "Rare Earth Hypothesis" that "advanced life on earth is probably unique in the universe." This remark results from a realization that the probability of advanced life occurring (even once -- except that we are here!) is vanishingly small, a result that we will discuss further in Chapter 15 when we look in depth at the Anthropic Principle. How is  it possible that this incredible Creation Narrative actually occurred? The fact begs for the conclusion that it could not have happened by chance, apart from God's active intervention. For further remarks, see the box below, The Goldilocks Universe.

The First Stars. The first-generation stars are called Population III (metal-free) stars. Their fuel is the primordial hydrogen and helium, and they form heavier elements (called "metals" in astronomy) through the iron group by nuclear fusion. These stars are identifiable (in theory) by spectral analysis, showing the absence of elements heavier than the iron group.

In fact, at the present time, no category III stars have been found; in other words, all of the stars that are viewable from the vicinity of the Earth are Population I (metal-rich) stars (including the Sun) and Population II (metal-poor) stars. Each successive star generation's life-death cycle enriched the matter in space further, so that more recently formed stars have higher content of the heavier elements.

Most of the first stars were many times more massive than the Sun, typically over 100 solar masses (100+ Mo). These massive stars burn the primordial fuels at much hotter temperatures, and as a result burn much faster than the Sun, with typical lifetimes of a few million years.

Supernova Beginnings. The primordial stars ended their lives in supernova explosions, or collapsed into black holes. The ashes of the supernovas effectively distributed heavier elements throughout space. The supernovas that occurred at the death of these first stars sent compression shockwaves throughout nearby space.  These shockwaves intersected with other shockwaves and concentrations of matter to trigger the formation of second generation stars. As a result, the material universe developed a "cosmic web" of filaments that persists to today, with stars forming in intersecting filiaments and sheets (Figure 1). This web appearance contrasts with the continuous (nearly but not quite uniform, density) distribution that (probably) characterized the first generation of stars.

sponge appearance of universe
Figure 1
The Cosmic Web (Simulation)
Note that the hot spots tend to occur along filament intersections.
For another visualization, see the "Cosmic Web" at NASA, Structure of the Universe.

Supernovas and Star Nurseries. As far as is known, all of the stars in the heavens today formed from the remnants of supernovas. Black holes become sinks of lost matter that cannot form further stars (except for material that slowly "evaporates" from the black holes, called Hawking radiation). Thus the birth and death of stars in supernovas is an essential prerequisite to the creation of our habitable earth and its solar system. The Orion Constellation, about 1,500 ly distant, contains the closest large region where the birth and deaths of stars occur, and provides a marvelous window into the star-creation process -- a great example of the Silent Speech: see the box on the Orion Star Nursery.

Ashes of supernovas accumulate to repeat the birth and death of new stars. The debris surrounding a star may then consolidate to form a solar system with planets: the Sun is an example03.

The Crab Nebula is an example of the remnants of a supernova explosion (Figure 2). This explosion occurred in 1054 AD
in the Taurus Constellation, well within historic times. It was recorded as a "Guest Star" by Chinese and Arab astronomers, and also appears to be depicted in native American petroglyphs found in the Americas. The ashes of that supernova formed a nebula which has spread to a width of about 11 light-years. Near the center of the nebula is a pulsar, a rapidly spinning neutron star remnant of the original star, about 20 miles in diameter, that rotates 30 times per second04.

Crab Nebula
Figure 2
Crab Nebula

The Orion Star Nursery
Nebulas in the Orion constellation give us a valuable window into the process of star formation, and thus amount to a visual laboratory to test star formation theories.

These nebulas are nearby, relatively youthful (as astronomical objects go), and include a complete spectrum of star formation from gravitational collapse through the ignition process for new stars. It seems likely that the study of the Orion Nursery will lead in the next few decades to a greatly deepened visual understanding of the star formation process.

Figure 3 shows a portion of the Orion Constellation that extends from the left-most (easterly) star "Alnitak" in Orion's belt to the top portion of the sword -- see inset. The Horsehead nebula is a dark cloud to the right of Alnitak. The horsehead is backlighted by the red glow of hydrogen gas emissions excited by ultraviolet radiation from Sigma Orionis, which is the star system above the horsehead.

Below Alnitak is the Flame Nebula. The Orion Nebula (M42) shown in the upper right is a brightly glowing nebula faintly visible as a glowing cloud at the top of Orion's sword. It is the breeding ground for a number of new and borning stars and potential solar systems (called proplyds).

Horsehead and Orion Nebula
Figure 3
Nebulas in the Orion Constellation:
Horsehead Nebula (lower left) and Orion Nebula (upper right)

Over 98% of a nebula's mass consists of hydrogen and helium gas. Hydrogen appears as red tendrils (H-alpha radiation) in the following deep field photograph of the same region (Figure 4). The three stars of Orion's belt are on the left.

Horsehead and Orion Nebula
Figure 4
Deep Field View of Nebulas in the Orion Constellation:
Showing hydrogen tendrils

Alnikak, is about 800 ly from the Sun. The Orion Nebula is about 1350 ly distant, part of the Orion Molecular Cloud Complex05 which forms a large region around Orion's Belt and Sword.

Formation of the Milky Way. The material universe separated into gravitationally-bound regions quite early. These formed galaxies and super-clusters of galaxies. Our own milky way galaxy contains stars that are almost as old as the universe itself -- the red giant star HE 1523-0901 is about 13.2 billion years old, which implies that the Milky Way galaxy (or an immediate ancestor galaxy) had formed by about 400 My after the Big Bang. It seems likely that the center of the Milky Way is a massive black hole that formed when large primordial (category III) star(s) collapsed after burning.

Ironically, the age of a galaxy cannot (at present) be determined by its shape. In particular, grand design spiral galaxies (Figure 5) such as our own Milky Way do not have their present shape because they are "wound up" (as one might naively think). The shape is more likely formed by relatively static bands of mass concentration that reflect the gravitational tug of galaxy collisions or near misses early in the formation of the galaxy

Horsehead and Orion Nebula
Figure 5
Grand Design Spiral Galaxy M81

The Milky Way Galaxy is of course not directly viewable from a distance, but its form can be reconstructed (Figure 6).

Annotated Solar System Showing Major Regions
The Solar System From Deep Space
Figure 6
The Milky Way Galaxy (Reconstructed)
Showing the location of the Solar System

The Milky Way Galaxy Habitable Zone
The Solar System is located in the relatively narrow habitable zone of the Milky Way Galaxy. This zone is roughly midway between the gravitational center and the outer regions of the galaxy (Figure 6b). The central portions of the galaxy are uninhabitable because of lethal radiation and a relatively high density of stars; and the outer regions tend to be gaseous and lack an adequate supply of rocky material07.

The requirement for the Earth to have moderate, life-supporting conditions for some 4 billion years places heavy limits on the location of the Sun in the Milky Way.

The Sun's position in the galaxy is very critical for the following reasons:
- Within the habitable zone, stars orbit the galaxy center in about 200-300 million years. Therefore over the necessary billions of years, over 10 complete orbits will occur. The orbits must remain in the habitable zone.
- The Sun must be in a region of relatively low star density. It must always be far enough away from its neighboring stars to avoid near collisions or other gravitational interference.
- The orbit of the Sun around the center of the Milky Way is indeed almost perfectly circular, with a period of 226 Ma (1 Ma = 1 million years), one closely matching the rotational period of the galaxy. Therefore the Sun avoids passing through the high density arms of the galaxy.

In the event, our Sun is located on the edge of one of the spiral arms of the galaxy (In the Orion branch). This position gives the future earth-observer an additional benefit in that he can get a relatively unobstructed view of deep space. Consequently, the sky is dark, and not so filled with nearby objects that deep space is obscured from our view. In fact, this is a necessary condition for the existence of life, because other locations would be subject to excessive radiation and unstable orbits. The only major portion of the universe that is blocked from our view is that portion that falls in the line of sight with the center of the Milky Way, which is obscured because of the dense radiation and compactness of the galaxy center itself.  Even the disk-like Milky Way galaxy itself does not severely block our view of deep space because we are located sufficiently far from the dense spiral arms of the galaxy that we have a good view of deep space in nearly every direction. The Solar System is somewhat off the Orion Spur about half way between the galaxy center and the outermost spiral arms (Figure 5a).  This spur is between the Sagittarius Arm and the Perseus Arm, both roughly 7,000 light-years away.
The Solar System. The solar system condensed out of a gravitationally-bound dust cloud that was the product of a supernova explosion. A portion of the supernova's ashes separated out as a cloud of dust that gradually contracted under gravity. As it contracted, the angular momentum caused it to spin more rapidly and flatten, a phenomenon that is familiar to anyone who has experimented with the conservation of angular momentum in physics, forming a protoplanatary disc (proplyd)08.

It is possible that the Sun ignited when a
supernova shockwave passed through the solar proplyd. Once the Sun ignited, the solar wind (mass violently ejected from the Sun as a result of solar plasma storms) swept away the light, volatile material from the inner parts of the solar system, leaving the rocky debris of the supernova to form interior planets (Mercury, Venus, Earth, Mars), while the outer planets (Jupiter, Saturn, Neptune, Uranus) formed from the volatile material. Over time, the larger debris swept out material in their paths, gradually forming the planets.

ProtoplanetaryDisk.jpg NASA/JPL-CalTech
Figure 7
Protoplanetary Disk (artistic rendition)
Credit: NASA/JPL-CalTech

Jupiter's large mass and tidal effects on large solid objects prevented the aggregation into a planet between Mars and itself. These fragments form the Asteroid belt between Mars and Jupiter, as well as the Trojan Asteroids which share the orbit with Jupiter itself.
Over the billions of years following the formation of Earth, Jupiter's great mass cleared out debris on erratic orbits from the inner regions. The same effect also tends to deflect large meteorites (such as the Shoemaker-Levi meteorite) from penetrating the inner regions, providing an effective shield against disastrous collisions with the Earth.

Solar system
Figure 8
Solar System Inner Planets
Age of the Solar System. The supernova event responsible for the dust cloud that formed the Solar System occurred 4.54±.01 billion years ago. This age equates to the age of the oldest meteorites which consist of debris formed at the time of the original supernova explosion. The age is determined by radioactive dating based on the radioactive decay of elements with very long half-lives: Rubidium-87 to Strontium-87  (half-life 49 By) and Samarium-146 to Neodymium-142 (half-life 106 By), and other radioactive decay pathways. Confidence in this age estimate comes from the fact that the same maximum age comes out of many independent tests using many independent measuring methods on many different meteorites. It should be noted that radioactive dating gives the most recent time that the meteorite was last disturbed - through impact, melting, etc. So the oldest measured dates for meteorites are for meteorites that were undisturbed since their first formation -- younger ages correspond to meteorites that have been disturbed in some way.

Solar System Habitable Zone. The Sun has its own habitable zone, which is defined as a band around the Sun within which a planet could support complex life. Here the terms "Sun" and "Earth" are used in the generic sense of "A suitable star" and "A suitable planet" in which complex life could develop and thrive10.

A number of considerations go into determining the habitable zone.

The Sun must be very similar to our Sun in size and type. This is necessary so that it will provide stable heat and illumination for the four billion years required to prepare the Earth for advanced life11.

The Earth must be a rocky planet. The inner planets (to the Asteroid Belt) tend to be rocky, and the outer planets (Jupiter and further out) tend to be formed from lighter, volatile elements.

The Earth's surface temperature must maintain water in the liquid state (0-100°C). The zone of liquid water is between Venus and Mars (which has solid carbon dioxide at the poles). In our own Solar System, only the Earth is within the temperature zone for liquid water. This requirement also implies that the Earth's orbit must be nearly circular.

All planetary orbits must be stable and nearly circular. Practically,  this means that the planets should not interfere with each other. In the case of our Solar System, all of the planets have nearly circular, concentric orbits, all of which are within a few degrees of the plane defined by  Earth's orbit.
The orbits of the large planets such as Jupiter and Saturn must also be nearly circular so that they do not disturb the orbits of a planet in the habitable zone.

The Earth must have an atmosphere that protects it from harmful Solar and Cosmic Radiation.

Formation of the Earth and Moon
12. About 4.52 billion years ago, late in the accretion stage and at a time when the Earth had formed a thin crust over a molten core, a Mars-sized object collided with the Earth. The collision was relatively gentle (as astronomical collisions go), and projected crustal material into a close orbit around the Earth (Figure 9). These fragments again accreted over time to form the Moon, which consists of material similar to what is found in the Earth's crust.

Moon Formation
Figure 9
Collision that formed the Moon

The Mars-sized object probably was another accreted planet in the same orbit with the earth. In any case, the impact melted the Earth again. The Moon formed from the orbiting fragments of the collision. At first it was in a close orbit which gradually increased to the present day
13. Tidal friction gradually slowed the Moon's rotation until it eventually became synchronized with the Earth, so that today the Moon presents the same face to the Earth at all times.

For the next 300 million years
, the Earth and Moon were bombarded by many objects from space -- perhaps the Solar System passed through a belt of debris, or collisions in the Asteroid belt propelled debris in the path of the Earth and Moon14 .  The oldest craters on the Lunar Highlands are from this period, ending about 3.8 Ba. Major bombardment continued until about 3.2 Ba, mostly, it is assumed, from the left-over fragments from the formation of the Solar System.

The current heavily cratered Moonscape (Figure 10) shows the results of this bombardment, which probably hit Earth as well. During this time the Moon had solidified, but the Earth remained molten -- partly due to the effect of impacts, and partly due to the extreme tidal effects of a nearby moon.

Moon Crater 302
Figure 10
Moon Crater 302

At about 3.9 Ba (billion years ago), the Earth cooled to below the boiling point of water. At this point the Earth's crust was relatively smooth and the entire Earth was covered by water to a depth of about 800 feet. There were frequent and violent volcanos which wracked the Earth, and spewed out water, nitrogen and other gaseous material. Volcanic cones occasionally pierced the ocean surface, but quickly eroded because of the high tides.

Normally one would expect from this scenario that the Earth would have relatively little water. It is not certain where the water on Earth came from -- whether from water buried deep in rocks (hydrates, for example), or whether the water arrived from bombardments from the asteroid belt or from outside the Solar system. In any case, when Earth grew by aggregation, its own gravity was able to hold vaporized water, but not the lightest gases such as hydrogen and helium which would leak out into space unless they combined with some heavier molecules.

The Earth was largely cloud-covered (much like Venus today) and the atmosphere consisted primarily of Nitrogen, with trace amounts of carbon dioxide. The ocean was quite salty because it had formed as the Earth cooled from a molten state, so it was filled with minerals to the saturation point.

At this point the Earth was heated by a combination of the Sun and radioactive elements, particularly Uranium, which was still aged far less than its half-life since the time of the Supernova. The radiation level of solid material in the crust was comparable to the radiation level of fuel rods used in modern Nuclear power plants -- about 3%. See the Box on Solar Heating.



The Silent Speech          Origin of the Solar System and Earth
The form and composition of the Solar System gives clear evidence of how it formed from the remnants of a supernova that occurred about 4.55 Ga ago. The evidence includes the following physical facts:

1. Shape. The solar system is a rotating, flattened disk, a shape that results when a loose, roughly spherical, rotating aggregation of widely dispersed matter contracts under gravitational attraction. The flattening occurs perpendicular to the axis of rotation.

2. Composition. The Sun is made up of the same elements that form its satellites. The primary source of energy is hydrogen fusion but the presence of the heavier elements indicate that the Sun formed from the remnants of earlier stars.

3. Gradient. The inner planets are smaller and consist primarily of heavier elements - rocky material - while the outer planets are larger and consist primarily of lighter elements. The solar wind propels the lighter gaseous elements of the warmer inner planets towards the region of the colder outer gaseous planets. The cold of the outer regions slows down the kinetic energy of the gases to form liquids or solids which the massive outer planets then capture.

4. Age.  The radiometric age of meteorites has an upper limit of about 4.55 Ga, which indicates that this is the time of a supernova explosion that produced the material of the solar system.

The Silent Speech          Speech from the Heavens

The Visibility of Deep Space.  The Solar System is located off of one of the arms of the Milky Way galaxy. As a result, the night sky is dark and deep space is accessible to our telescopes. If the Solar System had been located in a more "normal" position in the galaxy, then the deep space view would be much more obstructed by neighboring stars in our own galaxy.

The Moon and Earth Shadow During an Eclipse. During a solar eclipse, the Moon's disc almost exactly covers the Sun. Because of this, the Sun's corona and solar flares are clearly visible. The spectrum of the element Helium was first discovered by P.J.C. Janssen in 1868, a French scientist, P.J.C. Janssen, during a solar eclipse. In 1919 a solar eclipse provided the first confirmation of Einstein's prediction that light bends in a strong gravitational field. Anther element first discovered in the Sun's corona during a total eclipse: Coronium (1869). This was a mystery since the element did not appear to be in the periodic table. The mystery was solved in 1927 when I.S. Bown identified it as highly ionized iron (missing 13 electrons). See here for a chronology of discoveries about the Sun from analysis of solar eclipses.

In a total lunar eclipse the moon is not completely dark because it is illuminated with light that has refracted through the Earth's atmosphere. The refracted light is toward the red side of the light spectrum, which gives the moon a reddish hue. For this reason, ancient references to a lunar eclipse often referred to it as a "moon of blood" or a "bloody moon." An example is found in the Bible at Acts 2:20 where the Apostle Peter, one of Jesus' disciples implies that there was an eclipse at the time of Jesus' crucifixion.
1999 Solar Eclipse2001 Lunar Eclipse
Figure 11

Reference: See Gonzalez and Richards, The Priviledged Planet: How Our Place in the Cosmos is Designed for Discovery (2004) for many additional remarks on how the Earth enjoys remarkable and unexpected opportunities for humans to explore the Silent Speech of the Cosmos.

The "Goldilocks" Universe
Many scientists and writers have noted that the universe is remarkably fine-tuned for life -- it is "just right" as Goldilocks remarked about Baby Bear's porridge. This is the essence of the Anthropic Principle -- but it is more than just that the universe is "just right" for human existence, it is also "just right" for discovery. One could easily imagine a creation in which its most basic features would be impossible to discover -- in fact, that has been the default assumption of humans throughout history. Discovery of new facts always seems to come with amazement and disbelief: after all, humans have been contemplating the world for many thousands of years without knowing this fact -- perhaps it wasn't even missed!

Perhaps the most remarkable example of this default assumption came from the 19th century philosopher Auguste Comte, who gloomily observed regarding the starry heavens that

“On the subject of stars, all investigations which are not ultimately reducible to simple visual observations are … necessarily denied to us. While we can conceive of the possibility of determining their shapes, their sizes, and their motions, we shall never be able by any means to determine their chemical composition or even their density.”
Auguste Comte, 1835

Comte really stated what seems to be intuitively obvious. How is it possible that a person could analyse the chemistry in a star that is completely beyond reach? But less than twenty years after he said this, the new science of spectral analysis showed quite specifically that we can indeed learn quite a lot about the physical and chemical properties of the stars. And more recent advances, propelled in particular by the astrophysicist Fred Hoyle in the 1950s, have demonstrated that we can even determine the details of the star interiors, and of how they are the forges of the elements.

Books that specifically address the fine-tuning of our "Goldilocks" universe include the following:

Alexander von Humboldt  Cosmos: A Sketch of A Physical description of the Universe

[p. 068] The word Cosmos, which primitively, in the Homeric ages, indicated an idea of order and harmony, was subsequently adopted in scientific language, where it was gradually applied to the order observed in the movements of the heavenly bodies, to the whole universe, and then finally to the world in which this harmony was reflected to us. The word signified ornament (as an adornment for a man, a woman, or a horse). According to the testimony of all ancients, it was Pythagoras who first used the word to designate the order in the universe, and the universe itself.

[073] We shall never succeed in exhausting the immeasurable riches of nature; and no generation of men will ever have cause to boast of having comprehended the total aggregation of phenomena. ... the fruitful doctrine of evolution shows us how, in organic development, all that is formed is sketched out beforehand, and how the tissues of vegetable and animal matter uniformly arise from the multiplication and transformation of cells.

1902 Alfred Russel Wallace
Man's Place in the Universe.

 [p. 10] "Of late years, it is true, some few writers have ventured to point out how many difficulties there are in the way of accepting the belief [in a plurality of inhabited planets - dcb], but even these have never examined the question from the various points of view which are essential to a proper consideration of it; while, so far as it is still upheld, it is thought sufficient to show, that in the case of some of the planets, there seem to be such conditions as to render life possible. In the millions of planetary systems supposed to exist it is held to be incredible that there are not great numbers as well fitted to be inhabited by animals of all grades, including some as high as man or even higher, and that we must, therefore, believe that they are so inhabited. As in the present work I propose to show, that the probabilities and the weight of direct evidence tend to an exactly opposite conclusion."

1913 Lawrence J. Henderson The Fitness of the Environment.

[p. 292] To sum up, it appears certain that at least in a few instances, and possibly quite generally, purposeful tendencies exist in the organism which seem to be inexplicable by natural selection or any other existing mechanistic hypothesis.

[p312] There is, however, one scientific conclusion which I wish to put forward as a positive and, I trust, fruitful outcome of the present investigation. The properties of matter and the course of comic evolution are now seen to be intimately related to the structure of the living being and to its activities; they become, therefore, far more important in biology than has been previously suspected. For the whole evolutionary process, both cosmic and organic, is one, and the biologist may now rightly regard the universe in its very essence as biocentric. [emphases added - dcb]

A.E. Needham
The Uniqueness of Biological Materials

[preface] There were two main reasons for attempting this book. The first was an interest in the philosophical qustion: Is the uniqueness of life inherent in the material of living organisms? ... [second] whether, and in what ways, biological materials are unique.

John D. Barrow & Frank J. Tipler
The Anthropic Cosmological Principle.

[p. 3] "For there to be enough time to construct the constituents of living beings, the Universe must be at least ten billion years old and therefore, as a consequence of its expansion, at least ten billion light years in extent. We should not be surprised to observe that the Universe is so large. No astronomer could exist in one that was significantly smaller. The Universe needs to be as big as it is in order to evolve just a single carbon-based life form."

Wallace S. Broecker
How To Build a Habitable Planet
Harold J. Morowitz
Beginnings of Cellular Life:Metabolism Recapitulates Biogenesis
Guillermo Gonzalez & Jay W. Richards The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery.
Paul Davies
Cosmic Jackpot: Why Our Universe is Just Right for Life.
George V. Coyne & Michael Heller
A Comprehensible Universe: The Interplay of Science and Theology

The Silent Speech           The Silent Speech of Radioactive Decay

The radioactive decay of the elements is a valuable tool that can are useful for dating of events throughout the history of the universe. Table 1 lists the half-lives of some of the elements used in dating the age of the Earth and events in geological history09. The half-life dates indicate the most recent time that an object solidified -- thus for the oldest meteorites, which formed before the formation of the Solar System, indicate the date of the supernova that led to the Solar System itself.

sponge appearance of universe
Source: Newman & Phillip, Genesis One and the Origin of the Earth, p. 29

Meteorite Ages and Age of the Solar System
    The following radiometric ages for meteorites is summarized from G. Brent Dalrymple, Ages of Meteorites in the on-line article, How Old is the Earth? These ages are among the oldest recorded for meteorites, and are thus indicate the date of the supernova that preceeded the formation of the Solar System. See also G. Brent Dalrymple, Ancient Earth, Ancient Skies (2004) and The Age of the Earth (1991) Table 6.3, p. 287.

Measured Age -- Billion years (Ba)
Juvinas (achrondrite) 4.60 ± 0.07
Allende (carbonaceous chrondrite) 4.5-4.7
Colomera (silicate inclusion, iron meteorite) 4.61 ± 0.04
Enstatite chondrites 4.54 ± 0.13
Carbonaceous chondrites 4.69 ± 0.14
Amphoterite chondrites 4.56 ± 0.15
Bronzite chondrites 4.69 ± 0.14
Hypersthene chondrites 4.48 ± 0.1
Krahenberg (amphoterite) 4.70 ± 0.01
Mineral isochron  Norton County (achondrite) 4.7 ± 0.1

The average indicates a date of 4.60 Ba. As noted in the article, these dates are about 3% high because they are based on a somewhat low value for the decay constant of Rubidium-87. Thus the date for the Supernova should be about 4.5 Ba.

Accuracy of Positional Measurements recorded in Star Catalogs
Star Catalog
Time Period
Ptolemy's Almagest (naked eye)
c. 200 AD
3-8 arc-minute
some systematic errors due in part to adjustments from Hipparches' sky catalogs. Ptolemy considered the (relative) accuracy of his tables at 10 arc-minutes.
Copernicus'  De Revolutionibus  (naked eye)
1543 AD
3-8 arc-minute
Used Ptolemy's tables, corrected and updated in the intervening years by many (mostly moslem) scientists.
Tycho Brahe
1590 AD
0.5 to 1 arc-minute (relative)
naked-eye measurements.
Circular approximation to Mercury's orbit had maximum systematic errors of up to 3 minutes.
Johannes Kepler
1609 AD
0.5 to 1 arc-minute Discovery of the Elliptical orbits of the planets removed all systematic errors. Fitting the Mars data with the Brahe/Copernican models showed errors up to 8 arc-minute.
Galileo Galilei
1610 AD
3 arc-seconds
Galileo's early telescope was able to resolve satellites of Jupiter that were separated by about 10 arc-seconds. Inherent error due to scintillation of the atmosphere is about ?? arc-seconds.
Planet diameters are: Jupiter - 20 to 40 arc-sec; Venus - 10 to 60 arc-sec; see
Friedrich Bessel (First parallax msmt of 61 Cygni)

First star parallax measured -- 0.3 arc-seconds for star 61 Cygni (distance 11.43 ly). Required precision timepiece(?)
Harrison's regulator clock 1790?
Atmospheric smearing

Atmospheric smearing of starlight is about 0.5 arc-second.
Twinkling (scintillation) can be 0.4 arc-second at clear, high altitude. Overall, a 1 arc-second smearing is considered good.  This affects spectral analysis of starlight as well as pointing.
Hubble Space Telescope
Hipparchus satellite

Present day accuracy 0.001 arc-second
Very Long Baseline Interferometer (VLBI) antenna arrays 2010?
10-6 arc-second Direct geometric distance measurements for certain classes of galaxies, out to 25 million light-years
(2009 Measurement of Galaxy NGC 4258 at 23.5x106 light-years ± 7%)


1, The width of the Moon is about 29.5 to 33.5 arc-minutes. The width of the Sun is about 31.6 to 32.7 arc-minutes. During a full solar eclipse the Sun's corona is visible over the entire perimeter. It remains complete for only a few seconds.
Earth's rotation will cause a star on the Ecliptic to move about 1 arc-minute in 4 seconds, so precise measurements of absolute position were exceedingly difficult and required accurate and reliable clocks, which did not exist until after Harrison's invention of the regulator clock. Tycho Brahe achieved accuracies of 0.5 arc-minutes in relative (star to star) position measurements averaged over a number of observations.
3. Parallax measurements using large baselines require very precise clocks. Cesium atomic clocks (accuracy ??) are used for ???

Direct measurement of Astronomical Distances by Parallax.  Parallax is the direct geometric measurement of changes in the direction of a stellar object when viewed at the extremes of a very long baseline. The first parallax measurements were done in the 1800s to measure the distance to the nearest stars. The accuracy and practical maximum distance that can be measured in this way depends on the length of the baseline and the precision of the angular measurement. The most accurate positioning at present is done in radio frequency astronomy using the Very Long Baseline Interferometer (VLBI) antenna arrays which receive signals from widely separated locations on the Earth. Of course the measurements depend on stellar objects that have suitable coherent radiations in these frequencies. The potential accuracy of current and planned VLBA precision is 10-6 arcseconds which equates to direct distance measurements out to 25 million lightyears. Recently, the galaxy NGC 4258 was measured at  23.5x 106 lightyears ± 7%, based on direct geometric triangulation. According to NASA, VLBI Radio Interferometry is hundreds of times more detailed than the Hubble Space Telescope and the dedicated Hipparcos parallax-measuring satellite.

The Goddard Space Flight Center  VLBI Summary says "VLBI is a geometric technique: it measures the time difference between the arrival at two Earth-based antennas of a radio wavefront emitted by a distant quasar. Using large numbers of time difference measurements from many quasars observed with a global network of antennas, VLBI determines the inertial reference frame defined by the quasars and simultaneously the precise positions of the antennas. Because the time difference measurements are precise to a few picoseconds, VLBI determines the relative positions of the antennas to a few millimeters and the quasar positions to fractions of a milliarcsecond. Since the antennas are fixed to the Earth, their locations track the instantaneous orientation of the Earth in the inertial reference frame."

Reference on various cosmological models and computer simulations.

Nearby Stars
The nearest star to the Solar System is at a distance of 4.24 light-years (Proxima Centauri, one of three stars in the Alpha Centauri group), and there are only 65 stars and 4 brown dwarfs within 16.3 light-years - 5 parsecs (See Figure 12).

Figure 12a
Stars within 14 Light-years
(From Wikipedia)

Figure 12b
The Local Group
Galaxies within 3 million Light-years
Principle galaxies are Andromeda and Triangulum

Solar Heating:
How Did the Earth's Temperature Stay Steady?
The Earth cooled from a molten mass around 4 billion years (
Ba) ago. By about 3.9 Ba, it was cool enough that an ocean of water covered the globe to a depth of about 800 feet. From this point to the present -- about 4 billion years, the Earth has maintained a habitable temperature in which life could thrive. During this time heat from the Sun increased about 25%.

Projecting backwards from today, with the Earth's temperature about 300°K, accounting for Solar luminosity alone, the Earth's temperature would have dropped below the freezing point of water about 1.5 By ago (Figure 13).

Figure 13
Solar Luminosity Relative to the Present
Solid line is solar luminosity relative to present (S/S0).  Thick bars are periods of glaciation.


Clearly the Earth's temperature is not dependent on the Sun's luminosity alone. So why was it relatively steady over the full 4 billion years?

There are three effects that appear to be involved.

•  Radioactive Heating. Radioactive heating of the Earth's interior has been a main contributor to maintaining a habitable temperature. The temperature of the earth today increases by about 25°C per km of depth (about 1°F per 100 ft.). This interior heat gradient is constantly replenished by the heat of radiactive decay in the Earth's interior, mostly from Uranium-235, Uranium-238, Thorium-235 and Potassium-40.

In the late 1800s, before the discovery of radioactive decay, the source for heat from the Earth's core was a great puzzle, since physical calculations at the time by
Lord Kelvin indicated that core heat would dissipate in a time on the order of 20-400 million years, which was far less than appeared to be the minimum time that life existed on Earth.

Radioactive decay contributed more to the Earth's surface heat in the past, because of the larger amounts of these radioactive elements. This heating effect decreased logarythmically over the entire period of the Earth's existence. It is estimated that 3 billion years ago, the heat production from the interior was double the present day amount, and this additional heat in the past -- added to the heat radiated by the Earth's interior cooling from a molten condition -- nicely compensated for the lower luminosity of the Sun.
Radioactive Heating
Figure 14
Radioactive Heating of Earth

Heat Absorption by the Oceans. The oceans are an effective heat sink for solar radiation. When the earth was completely covered with a global ocean, the efficiency of solar heating was at a maximum, and as the continents gradually formed through tectonic plate activitty, this efficiency dropped because landmasses do not absorb and maintain the heat as efficiently. This is the main point of the Kasting and Catling article cited in the figure above.

Tidal Friction. An additional contributor to early heating of the Earth was the tidal friction that resulted from the presence of a nearby moon. As the moon receeded and its rotation slowed to gravitational lock, this effect decreased over the life of the Earth. This
exaggerated tidal friction from a nearby moon added a minor contribution to heating of the early Earth environment. [QUANTIFY THIS].

Of these contributors, the "primary energy source of Earth is radioactive decay.  The sun, gravity, and meteorite impacts all contribute some energy, as well, but not nearly as much as that provided by radioactive decay (estimated for the bulk Earth at around 6.18x10-12 watts/kilogram)" Scott J. Badham, U. Wyoming.

Does Science Prove that God is superfluous?

"I have no need for that hypothesis."
Marquis de Laplace07

LaPlace was wrong in his criticism of Newton -- in his claim, contrary to Newton's assertion, that the Earth's orbit is stable, the claim that led to the above quote (see the footnote). The real miracle, although Newton could not know it, is that the Earth has remained in a stable orbit for four billion years, the length of time required for the program of developing a place for human habitation to be carried out (as will be argued in the following chapters). The best efforts of modern scientists cannot project the stability of Earth's orbit beyond about 100 million years, simply because the orbit is inherently unstable, a consequence of the essential chaos that accompanies any multibody problem.

Cite WIKI article on chaos or earth's orbit or SLT.

"the solar system is a poor example of a deterministic universe" -- Stability of the Solar System
positions (orbital phases) of planets are not predictable on timescales longer than 100 Myr
WORKING. (2010) "Newton claimed God needed to interfere from time to time in order to maintain the stability of the solar system, but Laplace asserted that he had been able to give a mathematical proof of this stability. Later, however, this proof was shown to be flawed 37 by the work of Henri Poincarè (1892)."

. Certainly if he had invoked God in his proofs and demonstrations, it would have been a logical gap. His work does not comment on the harmony and exquisite fitness of nature, which is where the God question arises. THe best he could argue is a sterile perfection in mathematics.

Cite David Berlinski, The Devil's Delusion: Atheism and its Scientific Pretensions (2009).

but if so clear, how account for hoyle;s rmx?

He that cometh to God must believe that he is and that he is a rewarder of those who diligently seek him. Heb. 11:6

The fear of the Lord is the beginning of wisdom. Prov. 9:10; Ps. 111:10 

If Fred Hoyle's objections were not valid, then perhaps... but....

Fundamental to materialism, and Marxism.  Implies everything is determinate except for random contingency.

Cf.Dawkins' book. The God Delusion.

Newton quotes, Principia Book III, final section "General Scholium", p504 (regarding planets and other "solar systems") "though these bodies may, indeed, persevere in their orbits by the mere laws of gravity, yet they could by no means have at first derived the regular position of the orbits themselves from those laws. ... This most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being. And if the fixed stars are the centres of other like systems, these, being formed by the like wise counsel, must be all subject to the dominion of One...." [He doesn't explicitly invoke the issue of stability, but does remark that just the laws of gravity would not lead to such an orderly system].

p. 506 "Blind metaphysical necessity, which is certainly the same always and every where, could produce no variety of things. All that diversity of natural things which we find suited to different times and places could arise from nothing but the ideas and will of a Being necessarily existing."


Isaac Newton on the Stability of the Solar System

"I have no need for that hypothesis."
Marquis de Laplace07

The following are remarks by/about Isaac Newton about the Stability of the Solar System.

Principia, The only references to the Solar System configuration and stability are in Part III, General Scholium.
p. 504 (regarding planets and other "solar systems") "though these bodies may, indeed, persevere in their orbits by the mere laws of gravity, yet they could by no means have at first derived the regular position of the orbits themselves from those laws."

ibid "... This most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being. And if the fixed stars are the centres of other like systems, these, being formed by the like wise counsel, must be all subject to the dominion of One."

In these remarks, Newton doesn't explicitly invoke the issue of stability, but does remark that just the laws of gravity would not lead to such an orderly system. He marvels at the orderliness of the Solar system -- reflected in Bode's law (1772) about the planet orbits, and appears to believe that this could not be obtained by the "mere laws of gravity." If by "dominion" he means (which is likely) some level of "hands on" attention, then this leads directly to LaPlace's implied criticism.

Optics, p 378  "it's unphilosophical to seek for any other Origin of the World, or to pretend that it might arise out of a Chaos by the mere Laws of Nature ; though being once form'd, it may continue by those Laws for many Ages." ... "For while comets move in very eccentric orbs in all manner of positions, blind fate could never make all the planets move one and the same way in orbs concentric, some inconsiderable irregularities excepted, which may have risen from the mutual actions of comets and planets upon one another, and which will be apt to increase, till this System wants a reformation. Such a wonderful uniformity in the planetary system must be allowed the effect of choice."
-- Newton's Optics, 3rd Ed. 1721
also Newton Optics (Fordham)

Michael Nauenberg, U. California, Santa Cruz, The Reception of Newton's Principia. (2011?) "Newton claimed God needed to interfere from time to time in order to maintain the stability of the solar system, but Laplace asserted that he had been able to give a mathematical proof of this stability. Later, however, this proof was shown to be flawed by the work of Henri Poincarè (1892).", Stability of the Solar System "the concept of marginal stability for the Solar system: the Solar system is unstable, but catastrophic phenomena leading to the destruction of the System in its current form can take place only in a time comparable with its age, that is to say approximately 5 billion years. The observation of this present state then makes it possible to suppose that it always was thus for the Solar system, since the end of its formation." However this is the end result of some 4 billion years of initial preparation. The conclusion doesn't apply to the earth at the time that life was first created, about 4.9 Ba.

Scott Tremaine, Institute for Advanced Studies at Princeton, in the article "Is the Solar System Stable" (2011): "Newton’s comment on this problem is worth quoting: 'the Planets move one and the same way in Orbs concentrick, some inconsiderable Irregularities excepted, which may have arisen from the mutual Actions of Comets and Planets upon one another, and which will be apt to increase, till this System wants a Reformation.' [See Optics, above - dcb] Evidently Newton believed that the solar system was unstable, and that occasional divine intervention was required to restore the well-spaced, nearly circular planetary orbits that we observe today. According to the historian Michael Hoskin, in Newton’s world view 'God demonstrated his continuing concern for his clockwork universe by entering into what we might describe as a permanent "servicing contract” for the solar system.' "for practical purposes the positions of the planets are unpredictable further than about a hundred million years in the future because of their extreme sensitivity to initial conditions. As an example, shifting your pencil from one side of your desk to the other today could change the gravitational forces on Jupiter enough to shift its position from one side of the Sun to the other a billion years from now. The unpredictability of the solar system over very long times is of course ironic since this was the prototypical system that inspired Laplacian determinism."

LaPlace was wrong in his criticism of Newton -- in his claim, contrary to Newton's assertion, that the Earth's orbit is stable, the claim that led to the above quote (see the footnote). The real miracle, although Newton could not know it, is that the Earth has remained in a stable orbit for four billion years, the length of time required for the program of developing a place for human habitation to be carried out (as will be argued in the following chapters). The best efforts of modern scientists cannot project the stability of Earth's orbit beyond about 100 million years, simply because the orbit is inherently unstable, a consequence of the essential chaos that accompanies any multibody problem.

"the solar system is a poor example of a deterministic universe" -- Wikipedia Stability of the Solar System

Certainly if Newton had invoked God in his proofs and demonstrations, it would have been a logical gap. His work does not comment on the harmony and exquisite fitness of nature, which is where the God question arises. The best he can argue is a sterile perfection in mathematical deductions.

Cite David Berlinski, The Devil's Delusion: Atheism and its Scientific Pretensions (2009).

He that cometh to God must believe that he is and that he is a rewarder of those who diligently seek him. Heb. 11:6

The fear of the Lord is the beginning of wisdom. Prov. 9:10; Ps. 111:10 

Fundamental to materialism, and Marxism:  Everything is determinate except for random contingency.

Cf.Dawkins' book. The God Delusion.

Stability of Earth's Orbit

"I have no need for that hypothesis."
Marquis de Laplace15

LaPlace made this statement as an implied criticism of Isaac Newton's remark (in Principia) that


* The background is the horsehead nebula in the Orion Constellation (Figure 15). See the box on the Orion Star Nursery.

Horsehead Nebula
Figure 15
Horsehead Nebula
Alnitak, the left-most star in Orion's belt is to the left of the Horsehead.

^n01 For authors of this era who remarked on the uniqueness of Earth as a host for complex life, see the sidebox on Alfred Russel Wallace. He wrote Man's Place in the Universe in 1903. Also see Lawrence J. Henderson, The Fitness of the Environment (1913). These authors worked before the details of modern cosmology came to light.

^n02 "[It is estimated that] on average, a supernova explosion occurs within 10 parsecs (32 lightyears) of the Earth every 240 million years." Wikipedia article on Near-Earth Supernovas. This is roughly once for each time that the Sun completes an orbit around the massive center of the galaxy -- about 20 times over the span of life on Earth.

^n03 For convenience all stars after the first generation (including all stars observed to date) are called "second generation stars", although in truth they may be multiple generations away from their first generation ancestors. First generation stars contain only primordial elements (principally hydrogen and helium) plus the elements (up to the Iron Group) formed by fusion from them. Later generation stars contain a mixture of elements including heavy elements such as gold and uranium that cannot form by fusion from primordial elements.

The formation of stars may be triggered by supernova shock compression waves (see Figure 1). Some astronomers believe that a nearby supernova caused the ignition of the Sun. The shockwave from the recent supernova explosion SN-1987A appears to be spawning potential proto-stars in its shockwave -- See the time-lapse video between 1994 and 2006 of the SN-1987A shockwave, and the commentary at the webpage Death of Stars. It appears from this video that multiple future possible stars are forming in this shockwave in a total of under 20 years. This illustrates the kind of shock wave dynamics that leads to star formation.

^n04 This pulsar was first discovered on November 28, 1967 by Jocelyn Bell on an early radio telescope, the first observation of a pulsar. The Crab Nebula is located in our own Milky Way Galaxy. The last supernova observed in our Milky Way Galaxy is the supernova of 1572 in the Cassiopeia constellation, reported by Tycho Brahe. The most recently observed supernova is 1987a, located in the Magellenic clouds, a small galaxy that orbits the Milky Way but not in the Milky Way itself.

The rapid rotation is
because the neutron star remnant retains most of the original star's angular momentum, reduced to a 15-30 mile star diameter.  The pulsing is due to the magnetic axis, which is offset from the spin axis and sweeps through like a lighthouse beacon. The pulsing gradually slows over time, and eventually turns off after 10-100 million years.

Neutron stars form if the collapsing star's mass is less than about 4x the Sun's mass. Stars with
greater mass than this collapse to a black hole.

^n05 The distance to Alnitak was determined by parallax measurement on the Hipparcos satellite. Previously the star was thought to be about twice that distance (1,500 ly). Alnitak is a triple star system. The primary star is a blue supergiant about 28 Mo and will have a much shorter life than the Sun.

The stars of Orion's belt are all young -- 4 to 10 My old; 800-1500 ly distance; and massive blue giants -- 28 to 40 Mo. The largest (Alnilam, the middle star in the belt) may explode in a supernova within a million years. The rightmost star (Mintaka) is a double star, each about 20 Mo, which orbit each other in 5.73 days.

Within the Orion Nebula is the Trapezium. "The intense radiation of Theta1 Orionis C ionizes the whole Orion nebula. Its strong wind also shapes the famous Orion proplyds, young stars that are still surrounded by their protoplanetary dust disks."  Source: Orion Nebula Proplyd Atlas.

^n06 See for example the remarks by Megan Galbraith of RPI which concludes that the Milky Way formed about 10 billion years ago as a result of galaxy collisions.

By straightforward orbital dynamics, one can calculate that stars in the outer regions of galaxy M81 (Figure 5) will orbit the galaxy center with periods on the order of a few hundred million years, which means they would have had at least a dozen orbits over their lifetimes. If the stars moved in sync with other stars in their spiral arm, the arm would have coiled tightly around the galaxy center over the galaxy's multiple-billion year lifetime. In fact, the spirals appear to be relatively static regions of high density and individual stars appear to move from spiral to spiral during their orbital transit. Similarly, in its 240 My orbit around the Milky Way center, the Solar System appears to move between the Milky Way arms, rather than remaining in the present Orion branch. This may be a reason for the periodic behavior of the geological record which seems to have intervals of about 60 million years between major events.

^n07  [ADD INFO FROM Ward & Brownlee Rare Earth,  and Gonzalez & Richards The Privileged Planet].[FOOTNOTE: This is one of the observations of Gonzalez and Richards, The Privileged Planet. See also Brian Greene, The Elegant Universe.].

^n08  The flatness of the Solar System has already been noted in the discussion of Astronomy in Chapter 1. All of the planets orbit the Sun on orbits that are within 8° of the Earth-Sun plane.  See the slide presentation The Formation of the Sun and Planets

^n09 The (now) classic text on dating methods for geological events is Dalrymple, The Age of the Earth (see references).

^n10 We assume that life must involve solid matter. The specific requirements for the major life-supporting materials -- water, carbon, nitrogen, etc. -- will be considered in the following chapter (Chapter 6). Other authors have also considered (and rejected) the possibility of gaseous or liquid life forms -- see, for example Horowitz, Beginnings of Cellular Life (1992).

To be a bit more specific, life must involve both solid and liquid matter, with the liquid matter enclosed within solid walls (the essence of cellular life). As one author notes: "[T]he liquid state is the rarest in the Universe. In the depths of space, matter exists as either solid (dust, meteors, asteroids) or as gas (nebulae). Liquids are always 'leaking'. In the vacuum of space there is nothing to hold a liquid together. A drop of liquid would quickly evaporate. In the rest of the Universe, the most common unit is the star. All stars are made of gas. The temperature and pressure of even the coolest star ensures that all substances within the star are gaseous. Liquids can only exist as the 'filling' of a sandwich. What do I mean by this? Liquids require a solid surface to hold them and a gaseous or solid topping to keep them from evaporating away. A body like the moon which has no atmosphere cannot have any liquid on its surface. Without atmospheric pressure to keep it there, a Lunar liquid would quickly (in the geological sense) leak away and be lost. The only places in the Universe where liquids can exist are solid planets with atmospheres or planets where the liquid is covered by its frozen form."

^n11 See Chapter 4 for remarks about star types. The time requirement (4 billion years) is needed to prepare the Earth for advanced life (See Chapters 5-12, especially Chapter 7).

^n12 See the description of the formation of the earth and moon in David C. Bossard, A Fit Place to Live (2003).

^n13  Fossils that show daily, monthly and annual growth lines can be used to track the monthly and annual variations in tides and in seasonal changes. These provide direct measurements of the gradual increase in the Moon's distance from the Earth, and the related decrease in the length of the month and year (due to tidal slowdown and the lunar orbital period) with time. On average, the length of the day changes by about 20 seconds every million years (See Perry G. Phillips, Tidal Slowdown, Coral Growth, and the Age of the Earth). For example, in the Devonian Era (ca. 400 Ma) the year was about 400 days in length, due to the Earth spinning more rapidly, and the length of the month was about ??? days.

John W. Wells, Coral Growth and Geochronometry (1963) cites measured fossil coral gowth lines from the Middle-Devonian that show year lengths of 385 to 410 days, average 400. A later article in the same year, Colin T. Scrutton, Periodicity in Devonian Coral Growth, backs up his assertions, see Figure 16. A later article by Stephen Jay Gould,  The Inexorable Tick of Time, New Scientist, 3 May 1979, p.367)
extended this work to growth lines in Nautilus shells to show that the Moon's period was much less (i.e. distance from the Earth was much less) in the older fossil records.

Devonian Coral periodicity
Figure 16 (Plate 86)
Coral Daily Growth Lines
Devonian Era, 370 Ma

^n14  Recent work seems to point to the conclusion that the oldest Moon Craters are from objects that originated in the Asteroid Belt. The distribution of crater sizes correlates well with the size distribution of asteroids in the Asteroid Belt. See

^n15  Isaac Newton and others tried to explain the remarkable stability of the solar system. Newton suggested at one point that God must occasionally intervene to keep things from going astray. He argued, "This most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful being." [Newton, Principia, 1687]. John Erik Fornaess, in Newton and Divine Intervention (2004), argues, "When two entities interact in known ways, the resulting behaviour can be calculated. When three or more entities interact in known ways, the resulting behaviour can not be calculated. One says usually that the system might be chaotic." A century later (1787), Pierre-Simon Marquis de LaPlace developed new mathematical methods which he applied to planetary motion, and claimed to prove that the planetary orbits  are indeed stable. Hence, when he presented his book Celestial Mechanics to Napoleon, who asked him "where God fit in" he replied, based on his  mathematical work, "I have no need for that hypothesis." In fact, Fornaess argues, Laplace -- not Newton -- was in error. Despite the error that led to the remark, it has become a kind of rallying cry for atheists. See, for example, The Positive Atheist.

The Scholarpedia article on the Stability of the Solar System states: "An integration over 200 million years showed that the solar system, and more particularly the system of inner planets (Mercury, Venus, Earth, and Mars), is chaotic, with a Lyapunov time of 5 million years (Laskar, 1989). An error of 15 m in the Earth's initial position gives rise to an error of about 150 m after 10 Ma; but this same error grows to 150 million km after 100 Ma. It is thus possible to construct ephemerides over a 10 million year period, but it becomes essentially impossible to predict the motion of the planets with precision beyond 100 million years."

Scott Tremaine, Institute for Advanced Studies at Princeton, in the article "Is the Solar System Stable" (2011) says, "for practical purposes the positions of the planets are unpredictable further than about a hundred million years in the future because of their extreme sensitivity to initial conditions. As an example, shifting your pencil from one side of your desk to the other today could change the gravitational forces on Jupiter enough to shift its position from one side of the Sun to the other a billion years from now. The unpredictability of the solar system over very long times is of course ironic since this was the prototypical system that inspired Laplacian determinism."

16   ^n16  n

17   ^n17  n

18   ^n18  n

19   ^n19  n

20   ^n20  n


Broecker, How to Build a Habitable Planet, also Rare Earth and the Privileged Planet
ALFRED R. WALLACE Man's Place in the Universe 1903. See also the Wallace Collection for further materials., One of the earliest to suggest an "Anthropic Principle"

C. Brent Dalrymple, The Age of the Earth (1991). and Ancient Earth, Ancient Skies (2004).

[Gonzalez] Guillermo Gonzalez and Jay W. Richards, The Privileged Planet: How Our Place in the Cosmos is Designed for Discovery (2004).

Newton's Principia Mathematica, English translation by Daniel Adee (1846)

Nick Strobel Astronomy Notes.  See in particular the discussion of the spiral arm structure of the Milky Way.
Donat G. Wentzel, Astrophysics for University Physics Courses. This course includes many worked-out examples that are thoroughly explained in terms of basic physics.

Science Encyclopedia

Talk Origins is a useful site for scientific information about origins.

The website Universe Review at gives a pictorial account of the formation of the Earth.

Biographies of prominent physicists of the Twentieth Century: Meintner, Einstein, Hoyle, Heisenberg, etc.
Ruth Lewin Sime, Lise Meitner: A Life in Physics (1996)
Simon Mitton, Conflict in the Cosmos: Fred Hoyle's Life in Sciences (2005)
Abraham Pais, Subtle is the Lord: The science and the life of Albert Einstein (1982)
Abraham Pais, Niels Bohr's Times (1991).
Of particular value are the books written by the physicist Abraham Pais because he  describes in detail the reasoning and insight that occurred at each stage in the development of modern physics, going far beyond the normal materials of a biography. His book Inward Bound: Of matter and forces in the physical world (1988) gives a marvelous synopsis of this development.

Alfred Russel Wallace
Alfred Russel Wallace was a contemporary with Charles Darwin, and made large contributions to Evolutionary theory, although his role has been largely overshadowed by Darwin's.

His main and lasting contribution in later life was to give, in 1903, one of the earliest developments of the Anthropic Principle, the view that the universe is finely tuned in contemplation of its role in the creation of advanced life. This is presented in a lecture and a book, both with the title, Man's Place in the Universe. The following are some quotations from the lecture.

The Anthropic Principle
  "[T]he tendency of all recent astronomical research has been to give us wider views of the vastness, the variety and the marvelous complexity of the stellar universe, and proportionally to reduce the importance of our little speck of earth almost to the vanishing point, and this has been made use of by the more aggressive among modern skeptics to hold up religious creeds and dogmas to scorn and contempt. They point out the irrationality and absurdity of supposing that the Creator of all this unimaginable vastness of suns and systems, filling for all we know endless space, should have any special interest in so pitiful a creature as man, the degraded or imperfectly developed inhabitant of one of the smaller planets attached to a second or third rate sun; while that He should have selected this little world for the scene of the tremendous and necessarily unique sacrifice of his Son in order to save a portion of these “miserable sinners” from the natural consequences of their sins, was, in their view, a crowning absurdity too incredible to be believed by any rational being.

But during the last quarter of the past century the rapidly increasing body of facts and observations leading to a more detailed and accurate knowledge of stars and stellar systems have thrown a new and somewhat unexpected light on this very interesting problem of our relation to the universe of which we form a part; and altho these discoveries have, of course, no bearing upon the special theological dogmas of the Christian, or of any other religion, they do tend to show that our position in the material universe is special and probably unique, and that it is such as to lend support to the view, held by many great thinkers and writers to-day, that the supreme end and purpose of this vast universe was the production and development of the living soul in the perishable body of man.

The Agnostics and Materialists will no doubt object that the want of all proportion between the means and the end condemns this theory from its very foundation. But is there any such want of proportion? Given infinite space and infinite time, and there can be no such thing as want of proportion if the end to be reached were a great and worthy one, and if the particular mode of attaining that end were the best, or perhaps even the only possible one; and we may fairly presume that it was so by the fact that it has been used and has succeeded."[emphases added]
Lecture, p. 473-4

The Uniqueness of the Earth
  "All the evidence at our command goes to assure us that our earth alone in the Solar System has been from its very origin adapted to be the theater for the development of organized and intelligent life. Our position within that system is therefore as central and unique as that of our sun in the whole stellar universe."
Lecture, p. 482

Prof. Charles H. Smith of Western Kentucky University, has prepared a Bibliography of Wallace's writings, many available online.

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