Patriot:
you know weve gone over this and you keep throwin around the "restraints of your religion" etc. etc. and ask where my evidence is? yet I have not
listed one Bible verse, and you ask where my evidence is? I have brought it forth, the stink bug
LCKob:
Stink Bug? THAT IS YOUR TRUTH ... THAT IS YOUR PROOF ONE EXAMPLE OF WHAT APPEARS TO BE AN IRRUDICIBLY COMPLEX PHENOMENA?
ARE YOU SERIOUS YOU REALLY CALL THIS PROOF?
SORRY, but I am only offering EVIDENCE on Flagellum ...
ID tells us that things with "irreducible complexity" couldn't have evolved by natural means. They therefore conclude that since Darwinian
evolution can't explain how complicated biological structures came to be, that scientifically proves that there is a "designer" to life.
They don't say that it is God. ID proponents are too careful for that. If they were to say God made things the way they are, their true intention
would become clear.
They want to provide an intellectual framework for religious people to reject evolution without feeling totally illogical.
This is flawed in two ways.
First, their examples of "irreducible complexity" are in fact reducible. The bacterial flagellum is the most frequent example cited by ID
proponents.
The 30 or so protein components do need each other to make a functioning flagellum. However, they didn't need to evolve together, as ID people claim,
to be selected by evolution.
The question is whether fewer than the 30 subunits of the flagellum could have had any other function. By comparing gene sequences for similarity with
computers, we can see that the answer is clearly "yes."
The pore-forming base of the flagellar structure is very similar to the base of the type III secretion system, which allows many bad bacteria, like
Salmonella, for example, to infect host cells.
Other parts of the flagellar structure are also similar to the sex-pilus (yes, bacteria can have "sex" too), that allows conjugation and gene
transfer.
In Actinobacillus, an operon of just seven genes, and only three with homology to flagella and secretion system genes, forms its own rudimentary
secretion system, dubbed the tad operon. This bacteria lives in your mouth and is mostly responsible for making the slime that forms on your teeth
when you don't brush. Without the secretion system, it can't make slime.
In fact, an even more rudimentary homologous secretion system, with just four genes, is found in many other bacteria (including the Mycobacteria we
study in my lab).
Irrefutably, the complexity of the flagellum is reducible. The ID people will probably go on to think of new "irreducible" examples of complexity,
and the real scientists with some free time and a blog will reduce those as well.
The second flaw in ID is more fundamental. That is, their basic argument has no logical basis; because something is very complex, it doesn't
necessarily have a "designer."
Patriot:
is one that you all ignored, oh and how about the laws of nature (again the Law of entropy for example) the scientific method, Ive even brought
forward the orbit of the moon, and you just gloss over it and rant and rave over "religion" I ask for evidence for evolution and instead of giving
it you just tell me its on the sites-yes Ive read countless different sites on evolution, science textbooks, even heard evolutionary scientists talk
on the matter. I didnt ask for what they believed or for their evidence, where is your evidence.
LCKob:
One of the nice things about the Scientific Methodology is the fact that due to such rigid standards ... it is not only possible, but effecient to
site sources ... so you are tired of reading ... thats too bad, because obviously you have not delved deep enough.
Patriot:
Im not debating religion, Im debating science, so wheres your evidence? how do you explain evolution working around the Law of entropy? how bout the
moons orbit? you say evolution keeps moving forward but theres no evidence? so go on, present it, if it is in such high demand then stop debating
religion and bring forth your evidence.
LCKob:
Entropy did you say:
It is often asserted by creationists that the evolution of life is impossible because this would require an increase in order, whereas the second law
of thermodynamics states that "in any natural process the amount of disorder increases", or some similar claim. "Entropy" is frequently used as a
synonym for "disorder".
Of course, this represents a serious misunderstanding of what thermodynamics actually states. It can be explained patiently (or less than patiently,
after the 1000th iteration or so) that entropy only strictly increases in an isolated system; that there are no completely isolated systems in nature,
save maybe the universe as a whole; and that the whole idea of isolated systems is really an abstraction for pedagogical purposes; but still the
creationist won't let go. There just has to be some reason why "order cannot come from disorder", and the reason must be in thermodynamics. That's
the science that talks about order and disorder, isn't it?
In fact, it isn't. Look through any thermodynamics text. You will find discussions about ideal gases, heat engines, changes of state, equilibrium,
chemical reactions, and the energy density and pressure of radiation. Entropy and the second law are powerful tools that allow one to calculate the
properties of systems at equilibrium. At the very most, there may be a paragraph or two somewhere in that thick book alluding to some kind of relation
between entropy and "disorder". Writers of pop science books like to make the same kind of relation, and will ask their readers to consider things
like the state of their rooms--tidy or messy--and compare the (supposed) decrease in orderliness of the room over time to the "tendency of entropy to
increase". But what of entropy and disorder? Where does that identification fit into the structure of thermodynamics?
The answer is, nowhere. It is not an axiom or first principle, it is not derived from any other basic principles, and nowhere is it required or even
used at all to do any of the science to which thermodynamics applies. It is simply irrelevant and out of place except as an interesting aside. The
only reason that that identification has been made stems from the different field of study called "statistical mechanics". Statistical mechanics
explains thermodynamics, which is a science based on observed phenomena of macroscopic entities, such as a cylinder full of gas, in terms of more
basic physics of microscopic entities, such as the collection of molecules that comprises the gas. This was a great achievement of nineteenth-century
physics, led by Ludwig Boltzmann, who wrote down the only equation that connects entropy with any concept that might be called "disorder". In fact,
what is commonly called "disorder" in Boltzmann's entropy equation has a meaning quite different from what creationists--and some writers of pop
science--mean by disorder.
The equation in question reads:
S = k ln W.
That admittedly won't tell the reader much without some background. Boltzmann's entropy equation talks about a specific kind of system--an isolated
system with a specified constant total energy E (although the constant E does not explicitly appear in the equation, it is implied and crucial) in a
state of equilibrium. It tells us how to calculate the entropy, S, of that system in terms of the microscopic particles (molecules) which make it up.
On the right hand side, k is a universal constant now known as Boltzmann's constant [1.38 × 10-23 joules/kelvin, for the curious --Ed]. The function
"ln" is the natural logarithm, and the argument of the logarithm function is the quantity W. W is a pure number that connects the microscopic with
the macroscopic.
Suppose the system we are looking at is a volume of gas inside an insulated container. The gas is specified to have total energy E, which is constant
because the container is insulated so that no heat can enter or leave and rigid so that no work can be done on the gas by compression. There are
roughly 1022 molecules of gas in a wine-bottle-sized container if the gas is at atmospheric pressure and room temperature. At any particular moment,
each molecule is at a particular position inside the container and has a particular velocity. The position and velocity of a particle constitute its
state, for Boltzmann's and our purposes. The collection of the states of all the molecules at any moment is called a microstate of the whole volume
of gas. A microstate of the gas system is constrained by two requirements: first, the positions of the molecules are constrained to lie within the
container (which has volume V); and second, each molecule's velocity determines its energy, and the sum of the energies of all the molecules must
equal E, the total energy of the gas. An interesting question is, how many different microstates are there that satisfy these requirements at energy E
and volume V? The answer to that question, provided we can calculate it, is the number W, which is the number sometimes referred to as the measure of
"disorder".
Right away it can be seen that there are some problems squaring this with the everyday concept of "disorder". For one thing, this number is not even
a property of any single completely specified state (microstate) of the system, but only a property of all possible microstates--in fact, it is the
number of possible microstates. And W is a very large number indeed. Consider the bottle of gas: moving any one of the 1022 different molecules in it
slightly from a given position counts as another microstate. Imagine then moving them two at a time in all possible combinations, then three, then
four...
(As an aside, it turns out that the number of microstates, though enormous, is not infinite, as it might seem from considering that space is [so far
as we know] continuous, so that one could consider moving a molecule [or adding to its velocity] by ever smaller amounts, racking up microstates with
no limit. The uncertainty principle of quantum mechanics puts a lower limit on the difference in position or velocity that can be distinguished as a
separate state.)
The point of thinking about the number of possible microstates consistent with the observable macroscopic state is that the system never stays in one
microstate for long. In a gas in equilibrium, the molecules collide with each other constantly; with each collision their velocities change and the
state changes. This happens something like 1014 times per second for every molecule in a gas at normal pressure and temperature. The states are so
randomized by all these collisions that that at any given moment, every single microstate is equally probable. This is a postulate of statistical
mechanics for an isolated system at equilibrium. The collection of microstates is called a statistical ensemble; it is the universe of possible states
from which the system draws its actual state from moment to moment.
So in what sense can a system with large W be said to be highly disordered? Just this: the larger W is (the more possible microstates there are), the
greater is the uncertainty in what specific microstate will be observed when we (conceptually) measure at a predetermined moment.
It can be seen from this that a liquid has less entropy than an equal mass of gas, and a solid has less still. In a solid, the molecules are
constrained to stay very near their original positions by intermolecular forces (that is, they cannot move very far without acquiring a large amount
of potential energy and thus violating the requirement that the total energy be constant and equal to E), and have average velocities much smaller
than the velocities of gas molecules; but they do vibrate around their average positions and so contribute some uncertainty in the instantaneous
microstate. If the solid is heated up, the vibrations increase both in size and velocity and the entropy of the solid also increases, all in agreement
with thermodynamics. In fact, the statistical definition of entropy reproduces all the results of thermodynamics.
Does it make any sense to apply this to the arrangement of furniture and other items in a room in the classic pop science analogy? To do so, we would
have to be sure that the situation fits all the postulates of statistical mechanics that are applicable to the statistical definition of entropy. The
room could be assumed to be at least approximately isolated, if the building was very heavily insulated with no windows. We might think the room was
approximately at equilibrium, if it was left undisturbed for a long time. But something is wrong here. There are an abundance of possible
"microstates" of the system--as many as there are possible ways of arranging all the items in the room, and moving any item by less than a hair's
breadth counts as a rearrangement. In principle, a rearrangement could be made without altering the total energy E of the system, unlike in a solid
object.
But in fact, there is very little uncertainty in the actual arrangement from moment to moment. The system stays in a set of very few "microstates"
for as long as we can watch without becoming bored. What's wrong? The room is not truly in equilibrium in the statistical sense--the "microstates"
are not equally probable, because they are not being randomized between "measurements". The statistical definition of entropy fails, and it makes no
sense to talk about the thermodynamic "disorder" of the room.
Creationists sometimes point to the complicated molecules in living cells as examples of highly "thermodynamically ordered" systems that need some
special explanation, or that can only "degrade" from that highly "ordered" state because of the second law, etc. But the identification of a
specified molecule with a well-defined state of thermodynamic "order" fails for a similar reason that the example of the untidy room failed.
The argument goes something like this: "There is only one possible arrangement of amino acids that makes up a specified 'functional' protein (or
only one possible arrangement of nucleotides that makes up a specified gene in DNA), while there are an astronomical number of possible arrangements
that are 'nonsensical' with respect to the life functions of the cell." Therefore, the functional protein (or gene) is presumably in an extremely
low-entropy state, as calculated according to S = k ln W.
Is this true? This line of argument considers the overall macroscopic state of the system to be not a particular protein or a particular gene, but
just "a protein" or "a gene", and considers the statistical ensemble to be the whole group of possible configurations of the same set of smaller
constituent molecules. In other words, the actual "specified" macromolecule that is observed is not taken as the overall state, but only as one of
the microstates.
But this runs into the same problem as the untidy room did: the configurations of molecules in cells are not randomized moment to moment; the supposed
microstates are not equally probable, because once in one configuration, a molecule tends to stay in that same one. In this case, it's because there
is generally an energy "bump" that has to be gotten over in the process of converting from one configuration to another. At a fixed energy less than
the peak of the "bump", a pre-existing configuration will stay the way it is. If the molecule is in the same supposed microstate every time we look
at it, its state is not being randomized, and it makes no sense to apply to it a statistical calculation that assumes that the probability of
observing that particular "microstate" at any time is vanishingly small, when in fact, that probability is near one.
By the same token, if this line of reasoning were correct, one could look in one of the reference books where the thermodynamic properties of various
chemical compounds are tabulated, and find that nearly all of them would have zero or very small specific entropies, because "there is only one way"
to combine two hydrogens and an oxygen to form a water molecule, for instance. Of course, this is not the case. So how do we calculate the entropy of
a molecule statistically? We calculate the number of ways it can vary--these could involve vibrational states, changes in overall shape, bond angle
bending, and similar effects. These changes all leave the molecule recognizable as the same specific combination of atoms. By this calculation--the
only one that matters--all the possible configurations have very similar entropies. There is no thermodynamic reason why a molecule or gene cannot, by
slight changes, go from one configuration to a different one that turns out to work better."
... and lets not forget the Moon ....
Controversy on the age of the Earth and Moon....
(There were helpful diagrams ... but since you can't be bothered to check site references ... too bad)
one of the common arguments made in support of young-Earth creationism is that the dynamic age of the Earth-moon system (as determined by the physics
of the Earth-moon tidal interaction) is too young to support a multi-billion year age for the system. In this article I will (a) review the basic
physics of gravity and tides, (b) review the history of theoretical models for Earth-moon tides, (c) review the paleontological evidence relevant to
the history of the Earth-moon system, and (d) demonstrate that the combination of theory and observation refute the young-Earth creationist arguments,
with reference to specific young-Earth arguments and their specific failures. This is intended as a review for readers not versed in physics and math,
so the arguments are presented as non-technically as possible. There are references to more technical work, for those who are interested in following
up any of the arguments presented here as accepted assertions.
While this article is intended as a refutation of yet another ill conceived young-Earth argument, the introductory reviews do not refer to creationism
at all. Therefore, the article should work just as well as an introduction to the physics of the evolution of the Earth-moon system, even for those
readers not interested in the issue of creation vs. evolution.
Introduction to Gravity
Although gravity has been known to exist since people knew they could fall, it was not until Isaac Newton came along that a mathematical description
of gravity was forthcoming. It was Newton who showed that the force of gravity obeyed a simple algebraic equation, shown here as equation 1.
Fg = Gm1m2 / R2 equation 1
In equation 1, Fg is the gravitational force between two objects of mass m1 and m2 and R is the distance that separates the two masses. This equation
is important because it is the fundamental equation for describing the force of gravity in Newtonian physics. It is, however, an idealization; it
assumes the masses m1 and m2 are point masses, in that they have no physical size. But, of course, all real masses are not point masses, and therefore
do not exactly obey Newton's equation. However, as an approximation the equation works very well for masses that are separated by distances that are
very large compared to their physical size. For instance, in analyzing Earth's orbit around the sun, one needs to include the gravitational effect of
the other planets, as expressed by equation 1, but one need not worry about the fact that they are not point masses, since the differential effect is
not measurable.
Introduction to Tides
A tide is what happens when the masses we see in equation 1 are not separated by distances that are large compared to their physical size. A tide is a
"differential gravity", the result of the fact that extended bodies do not pull equally on all parts of each other, as equation 1 would imply. In
figure 2, below, we see how the tidal force operates between Earth and the moon, where the red arrows show the relative pull of the moon's gravity on
Earth.
Figure 1. The action of the Earth-moon tidal force
(Acknowledgement) The Earth-moon tidal force
As figure 1 shows, the force is not constant over the distance between the moon and the various parts of the Earth. The moon, being rather closer to
the near-side of Earth, pulls harder on it (where the red arrows are longer), while it pulls more lightly on the side of Earth that is farther away
(where the red arrows are shorter). In physics, we call this kind of effect a "gradient", and it represents the differences in force applied at
different points. The strength of that gradient is represented in equation 2 below.
DF / DR = 2Gm1m2 / R3 equation 2
In equation 2, DF / DR represents a change in the force (DF) with respect to a change in distance (DR). That variation in force, or tidal gradient, is
what produces the distortion in the shape of both Earth and the moon, while the force seen in equation 1 is what keeps Earth and the moon in orbit
around each other. As the red arrows in figure 1 imply, there is a "inward" pull on the poles of the Earth, towards the equator, which would tend to
squeeze the planet. Squeeze a rubber ball that way, and you can see for yourself that the inward squeeze causes an outward squish at the "equator"
of the ball. Add to that the effect that the moon pulls harder on those parts of the Earth that are closer to it, and the result is that the Earth is
squished, bulging towards the moon, and away from the moon. The effect is illustrated below, in figure 2.
Figure 2. The results of the Earth-moon tidal force
(Acknowledgement) The Earth-moon tidal bulge
The illustration in figure 2 above shows the solid earth (green) and the oceans (blue) in schematic form. The "solid" Earth really isn't all that
solid, and it does bend under the moon's tidal stress, but the water oceans are clearly far less "solid" than the rest of the Earth, and so they
will be much more deformed by the moon's tidal squeeze. Hence, the bulge is mostly ocean, and only a little bit ground. The gaseous atmosphere is
tidally squished too, but it does not figure much in the total system, and I will ignore it here (a detailed study of tides should not ignore
atmospheric tides, I only do it here because it does not figure prominently in this particular discussion).
In a static system such as in figure 2, the mostly ocean bulge points right at the moon. But the real system is not static; the moon goes around the
Earth, but the Earth spins on its daily axis much faster than that. So the spin of the Earth pulls the bulge out in front of the moon. The result of
this is illustrated below in figure 3, and we are now ready to understand the greater mysteries of tides and the Earth-moon system.
Figure 3. How tides transfer momentum to the moon
(Acknowledgement) How tides transfer momentum to the moon
The ocean bulge is pulled in front of the moon by Earth's spin; since the ocean is gravitationally stuck to the Earth, it has to go where the Earth
goes. But it can't go too far, because it is pulled back by the moon. The result, illustrated in figure 3, is that the ocean bulge is in equilibrium,
remaining essentially fixed with respect to the Earth and moon, while the solid Earth spins under the ocean. The ocean is gravitationally bound to the
Earth, but it is still fluid, and not stuck to the Earth the way a rock or a mountain is. There is an interface, namely the ocean bottom, where the
water and the Earth are free to move with respect to each other. That interface, like any other real physical interface, is not totally frictionless,
and that too is illustrated in figure 3 by the small caption that reads "Friction force". But in this case, "friction" includes all of the ways
that the ocean and the Earth impede each other. The ocean runs into the continents and has to wash around them (so how they are distributed around the
Earth makes a difference).
Since the Earth is trying to spin forward, but the ocean is held back by the moon, the Earth winds up trying to move through the oceans. Just as you
can feel the resistance if you try to walk through water, so the Earth feels the resistance trying to move through the water of the oceans, and that
resistance transfers energy from the Earth (causing its spin rate to slow), and to the oceans (sloshing them around and heating them up). But the
Earth-ocean system also exerts a torque (a "twisting" force) on the moon, because the line along the arrow labeled "B" in figure 3 is at an angle
to the line that connects the center of the Earth to the center of the moon. As a result of that torque, the Earth also transfers energy (causing its
spin rate to slow) through the ocean bulge, and gravity, to the moon (causing it to speed forward in its orbit, and therefore move farther away from
the Earth).
At this point we are ready to understand two important observations. First, the high and low ocean tides we all know about, are caused by the Earth
moving through the high and low parts of the ocean, seen in either figure 2 or figure 3. Since we are on the Earth, it looks to us, from our frame of
reference, as if the ocean is doing the moving, but however you want to look at it, the result is the same. The Earth and its oceans move with respect
to each other, because of the pull of the moon, and we see that motion as what we call high & low tides. Second, the moon is slowly drifting away from
the Earth. That means that the moon is not where it has always been with respect to the Earth; the Earth-moon system clearly must have evolved over
time. Can we figure out how the Earth-moon system has evolved? I will review the answer to that question in the next section.
Tidal Evolution of the Earth-Moon System
The description I have given so far is necessarily general, and leaves out a lot of details. But there is a lot of physics and mathematics hidden
behind that layman's facade, and it has to be dealt with in order to understand the real nature of the tidal relationship between Earth and the moon.
I will not develop any of that mathematics here. I will concentrate instead on reviewing the history of the scientific efforts to understand the
Earth-moon tidal system. Along the way I will make reference to numerous original sources, books, journal papers and the like. Those sources will
provide the reader with all of the mathematical and/or physical details one could wish to see. Readers eager to know more are encouraged to consult
those sources.
It was not possible to study tides in any quantitative, physical or mathematical sense, until Isaac Newton essentially invented the science of
mechanics, with the publication of his Philosophiae Naturalis Principia Mathematica in 1687. Since then a number of eminent scientists have struggled
with the problem of tides, including Edmond Halley, Pierre Laplace, and William Thomson (Lord Kelvin). But it was the celebrated English mathematician
and geophysicst George Howard Darwin Who really attacked the problem of Earth's rotation and the Earth-moon system with analytical zeal (G.H.Darwin;
1877, 1879, 1880; with an ironic twist on the creation-evolution issue, he was the son of Charles Darwin, the founding father of biological
evolution). Darwin considered ocean tides, and made some significant advances there, but he concentrated mostly on solid body tides in a homogenous
Earth. Today we know that ocean tides are much more important than solid body tides. Thomson was the first to show that tides transferred angular
momentum from Earth to the moon, and that transfer of momentum is what causes the moon to recede from Earth. But Darwin was the first to cast the
problem into analytical detail, setting the stage for explorations in the early 20th century.
Through most of the first couple of decades of the 20th century, the chief investigator of this problem was Harold Jeffreys. Jefferies published a
number of papers during the early 1900's, and extensively summarized the then current state of affairs in the first edition of his landmark book The
Earth (Jefferys, 1924). In that book (chapter XIV, Tidal Friction, pp 205-237 of the 1st edition) Jeffreys uses an estimate of tidal friction to
derive a maximum age for the Earth-moon system of 4 billion years. That estimated age remained unchanged in later editions at least through 1952. The
main problem that vexed Jeffreys, and later researchers, was their inability to fully describe ocean tides analytically, or even to know the numerical
values of oceanic tidal friction. But it is quite clear that by then, about 44 years after Darwin's work, Jeffreys knew that oceanic tides were more
important than solid body tides. The search for oceanic tidal response functions was on.
Later researchers came to the conclusion that Jeffreys had rather severely underestimated the true numerical value for oceanic tidal dissipation, and
had therefore overestimated the age of the Earth-moon system. Although they do not offer an age, Munk & McDonald (1960) said that Jeffreys had the
oceanic dissipation wrong by a factor of 100. It soon became apparent that the pendulum had swung the other way, and that there was a fundamental
problem. Slichter (1963) reanalyzed the Earth-moon torque by devising a new way to use the entire ellipsoid of Earth rather than treating it as a
series of approximations. He decided that, depending on the specifics of the model, the moon would have started out very close to Earth anywhere from
1.4 billion to 2.3 billion years ago, rather than 4.5 billion years ago. Slichter remarked that if "for some unknown reason" the tidal torque was
much less in the past than in the present (where "present" means roughly the last 100 million years), this would solve the problem. But he could not
supply the reason, and concluded his paper by saying that the time scale of the Earth-moon system "still presents a major problem"; I call this
"Slichter's dilemma".
Despite the effort expended on the problem over the years, a truly complete mathematical method for handling the tidal dissipation had not yet been
forthcoming. That problem was redefined by Peter Goldreich. Goldreich (1966) extended the realm of the problem well beyond the limits that Slichter
had set, as Goldreich had included solar tides and precessional torques. However, the age of the system being dependent on observed quantities, and
arbitrary factors in the model, Goldreich did not approach the question of age.
The years that followed saw the rise of plate tectonics and a major shift in geophysical thinking because of it. The mobility of the drifting
continents is a matter of major import, for by this time it was well realized that tidal dissipation in shallow seas dominated the interaction between
Earth and the moon. Kurt Lambeck was a major player in the tidal game at that time, authoring several papers. His study of the variable rotation of
Earth (Lambeck, 1980) remains the most extensive such study ever done. Lambeck noted that after the struggles of Slichter, Goldreich, and others, the
observed and modeled values for tidal dissipation were finally in agreement (Lambeck, 1980, page 286). However, this still left a time scale problem.
According to Lambeck, " ... unless the present estimates for the accelerations are vastly in error, only a variable energy sink can solve the
time-scale problem and the only energy sink that can vary significantly with time is the ocean." (Lambeck, 1980, page 288). In section 11.4,
"Paleorotation and the lunar orbit", Lambeck explicitly points out that paleontological evidence shows a much slower lunar acceleration in the past,
and that this is compatible with the models for continental spreading from Pangea (Lambeck, 1980, pages 388-394). It is important to remember that by
1980, Lambeck had pointed out the essential solution to Slichter's dilemma - moving continents have a strong effect on tidal dissipation in shallow
seas, which in turn dominate the tidal relationship between Earth and the moon.
While Lambeck pointed the way, Kirk Hansen (1982) got on the right road. Hansen's models assumed an Earth with one single continent, placed at the
pole for one set of models, and at the equator for another (the location is chosen to simplify the computations, but the basic idea of a one-continent
Earth may not be all that bad; Piper, 1982 suggests that our current multi-continent Earth is actually abnormal, and that one continent is the norm).
His continent doesn't move around as a model of plate tectonics would do it, but Hansen was the first to make a fully integrated model for oceanic
tidal dissipation directly linked to the evolution of the lunar orbit. As Hansen says, his results are in "sharp contrast" with earlier models,
putting the moon at quite a comfortable distance from Earth 4.5 billion years ago.
Hansen had already all but eliminated Slichter's dilemma with his integrated model of continents and tides. Kagan & Maslova (1994) treat the oceanic
tidal dissipation with fully mobile and arbitrary continents. Like Hansen, their models show time scales that are not a problem for matching the
radiometric age of Earth with the dynamic age of the Earth-moon system. Kagan & Maslova (1994), Kagan (1997), and Ray, Bills & Chao (1999) have
continued the study in even more detail, with plate tectonics fully integrated into their models of Earth-moon tidal evolution. Touma & Wisdom (1994)
do the calculation in a fully integrated multi-planet chaotically evolving solar system.
Although it may seem to the casual reader that the Earth-moon system is fairly simple (after all, it's just Earth and the moon), this is only an
illusion. In fact, it is frightfully complicated, and it has taken over 100 years for physicists to generate the mathematical tools, and physical
models, necessary to understand the problem. Slichter's dilemma, as I called it, was a theoretical one. He lacked the mathematical tools, and the
observational knowledge, to solve his problem. But those who came after got the job done. Slichter's dilemma is today, essentially a solved problem.
Once all of the details are included in the physical models of the Earth-moon system, we can see that there is no fundamental conflict between the
basic physics and an evolutionary time scale for the Earth-moon system.
The Paleontological Evidence
I have thus far illuminated the theory, the construction of the mathematical methods used to understand the details of the Earth-moon tidal
interaction. But theory and observation, theory and evidence go hand in hand in the empirical sciences, and this is no exception. Tides, and the
Earth's rotation leave behind tell-tale clues about Earth's past. So, when Lambeck (1980) or Stacey (1977) say that tidal dissipation must have been
lower in the past, that's neither an idle guess, nor a knee-jerk reaction. It is an attitude consistent the evidence.
The first critical observation is How fast is the moon moving away from Earth now? This linear motion away from Earth had to be estimated from the
observed angular acceleration, or it had to be calculated from theory, the former being preferred, since it is an observed quantity. Stacey uses an
astronomical estimate of 5.6 cm/year (Stacey, 1977, page 99). Lambeck gives 4.5 cm/year (Lambeck, 1980, page 298). It's an important number, because
it reveals the true strength of tidal dissipation. But today the number can be observed directly, as a result of three-corner mirrors left behind by
Apollo astronauts. Lunar laser ranging establishes the current rate of retreat of the moon from Earth at 3.82±0.07 cm/year (Dickey et al., 1994).
But what about the past rate of retreat? Paleontological data directly reveals the periodicity of the tides, from which one can derive what the rate
of retreat would be to match the frequency. It is also a non-trivial point that it proves the moon was physically there. After all, if your theory
implies that the moon was not there at some time in the past, but your observed tidal evidence says that it was there in the past, then it's pretty
clear that the theory, and not the observation, needs to be adjusted.
This paleontological evidence comes in the form of tidal rhythmites, also known as tidally laminated sediments. Rhythmites have been subjected to
intense scrutiny over the last decade or so, and have returned strong results. Williams (1990) reports that 650 million years ago, the lunar rate of
retreat was 1.95±0.29 cm/year, and that over the period from 2.5 billion to 650 million years ago, the mean recession rate was 1.27 cm/year. Williams
reanalyzed the same data set later (Williams, 1997), showing a mean recession rate of 2.16 cm/year in the period between now and 650 million years
ago. That these kinds of data are reliable is demonstrated by Archer (1996). There is also a very good review of the earlier paleontological evidence
by Lambeck (1980, chapter 11, paleorotation)
As you can see, the paleontological evidence indicates that moon today is retreating from Earth anomalously rapidly. This is exactly as expected from
the theoretical models that I have already referenced. The combination of consistent results from both theoretical models and paleontological evidence
presents a pretty strong picture of the tidal evolution of the Earth-moon system. Bills & Ray (1999) give a good review of the current status of this
harmony. Without realizing it, they have also explained well why the creationist arguments are unacceptable.
The Creationist Arguments
I don't know who first brought up the age of the Earth-moon system as a pro-creationist argument. But the first example I am aware of is Barnes
(1982, 1984). Barnes says, "It has been known for 25 years that the earth-moon system cannot be that old", and assuring us that "Celestial
mechanics proves that the moon cannot be as old as 4.5 billion years", goes on to quote the last sentence from Slichter's (1963) paper, "The time
scale of the earth-moon system still presents a major problem" (in fact, Barnes should not have capitalized the "T" since this is a sentence
fragment, not a full sentence, but in this case the oversight is inconsequential). It is noteworthy that Barnes is happy to quote a paper already 19
years old in 1982, and 21 years old in 1984, yet despite a research physics background, declines to bother researching anything post-Slichter. If he
had, he would have found Lambeck (1980), a major work which clearly indicated the real nature of Slichter's dilemma (or even Stacey, 1977, which
already showed the conflict between Slichter's theoretical dilemma and the paleontological evidence available at the time). And, of course, Kirk
Hansen's 1982 paper predates Barnes' 1984 reiteration by two years, yet is ignored despite being recognized even then as a major step forward.
Barnes shows the same kind of sloppy and lazy approach to "research" that permeates young-Earth creationism, although his is a particularly
egregious case (as it also was for his arguments concerning Earth's magnetic field).
DeYoung (1992) offers his own model. Actually, he offers an equation. DeYoung asserts that the rate of change of the lunar distance as a function of
time must be proportional to the inverse 6th power of the lunar distance (presumably because the lunar tidal amplitude is proportional to the inverse
cube of the distance, and the tidal acceleration is proportional to the square of the amplitude, though DeYoung does not say this). He then runs some
numbers in the equation, and concludes with remarkable poise that he has demonstrated a maximum possible tidal age for the Earth-moon system of 1.4
billion years. The same calculation can be found in Stacey (1977), with reference to more precise versions. They all get about the same answer as
DeYoung, and there is no doubt but that what DeYoung did he did right. However, if you do the "wrong" problem, you may not get the "right" answer!
As Stacey pointed out (Stacey, 1977, pages 102-103) it makes more sense to assume that the oceanic tidal dissipation was smaller in the past, which
would have the effect of making the calculation that of a minimum age, as opposed to the maximum age proposed by DeYoung. But, of course, we are
comparing DeYoung (1992) with Stacey (1977), a gap of 15 years (it's nice to see that DeYoung, like Barnes, is keeping up with the tempo of current
research). That gap includes Lambeck (1980) and Hansen (1982) (wherein it was demonstrated that a 4.5 billion years age was compatible). Granted that
DeYoung (1992) wrote before the 1994 papers of Kagan & Maslova or Touma & Wisdom, which are directly contradictory to his results. However, Hansen's
(1980) results also directly contradict DeYoung, but come 12 years before. This observation does not inspire confidence in the value of DeYoung's
one-equation model for the evolution of the lunar orbit. But, as made clear by Bills & Ray (1999), the constant of proportionality, which Stacey
suggests is not constant, is in fact a ratio of factors that represent dissipation, and deformation. It is clear that neither of these can be
constant, and once that is understood, we can see clearly that DeYoung simply did the wrong thing right, and curiously wound up with a correct form of
the wrong answer.
Walter Brown (Brown, 1995) presents essentially the same model as DeYoung. I have seen only the online technical note, but not the printed book.
Unfortunate, for the equations do not appear on the webpage, despite being referenced as if they were there. However, Brown does offer the quick-Basic
source code for his program that calculates the minimum age of the Earth-moon system. His equations are there, and he seems to be using the inverse
5.5 power of the radius rather than the inverse 6th power used by DeYoung (Brown's usage here is consistent with the equation given by Bills & Ray,
1999; whether one chooses to use the inverse 6 or inverse 5.5 power seems an issue of model dependence). Otherwise, Brown's approach appears to be
quite the same as DeYoung's, and subject to exactly the same criticism. He ignores the time variability of dissipation and deformation. It is perhaps
humorously ironic that both DeYoung and Brown fail, because they are implicitly making an improper uniformitarian assumption (the constancy of
dissipation and deformation), which evolutionists have learned to avoid.
Conclusions
I don't know if there are other, "authoritative" creationist sources for the "speedy moon" argument. But if there are, it is unlikely that their
arguments presented differ much from those seen here. I spent quite a bit more time reviewing the actual science of the Earth-moon tidal interaction
because once it is well developed, the flaw in the creationist arguments becomes so obvious that it hardly seems necessary to refute them. The most
remarkable aspect of this, I think, is the somebody like DeYoung, who certainly has legitimate qualifications (a PhD in physics from Iowa State
University), would offer up such a one-equation model as if it was actually definitive. That kind of thing works as a "back-of-the-envelope"
calculation, to get the order of magnitude, or a first approximation for the right answer, but it should have been clear to an unbiased observer that
it could never be a legitimate realistic model. It is also of considerable interest that both DeYoung and Brown published their refutations of
evolution only after evolution had already refuted their refutations! Barnes didn't do all that much better, having overlooked Hansen (1982) for two
years. My own conclusion is that my intuitive expectations have been fulfilled, and creation "science" has lived up to its reputation of being
either pre-falsified, or easy to falsify once the argument is evident.
As for the real science, remember that science is not a static pursuit, and the Earth-moon tidal evolution is not an entirely solved system. There is
a lot that we know, and we do know a lot more than we did even 20 years ago. But even if we don't know everything, there are still some arguments
which we can definitely rule out. A 10,000 year age (or anything like it) definitely falls in that category, and can be ruled out both by theory and
practice.
Actually I am just surprised and disappointed .... you did say PROOF after all .. not incidental elements of explainable ID doctrine. .... not
evidence ... but proof positive ...
Okay, now I am ready for your REAL PROOF ... as in ...
Main Entry: 1proof
Pronunciation: 'prüf
Function: noun
Etymology: Middle English, alteration of preove, from Old French preuve, from Late Latin proba, from Latin probare to prove -- more at PROVE
"3 : something that induces certainty or establishes validity"
[edit on 16-11-2005 by LCKob]