Monday, 16 April 2012

How Creationists Lie To Us - 4

Dr Paul D. Ackerman's creationist book,It's A Young World After All, is turning out to be a real little goldmine of examples of creationists' fallacies and how creationists, either through ignorance or deliberation, mislead and misinform their credulous customers.

I've dealt with the first two chapter in earlier blogs here and here. Today I'll look at Chapter 3. It's probably worth reminding ourselves again that Dr Paul D. Ackerman is not a research scientist and has never published peer-reviewed papers on biology, physics or cosmology. He is an assistant professor of psychology. His field of expertise is the human mind and how it can be manipulated.

Chapter 3 - The Solar Janitor.

Apparently feeling very please with himself for his 'brilliant' first two chapters where he inadvertently proved that earth is very old and showed us how creation 'scientists' misrepresent the science, Ackerman ploughs on with his clock theme. Here he uses the little-known Poynting-Robertson effect and, as we've come to expect now, misrepresents the science. Again, the reason for this - ignorance or deliberation - is left for the reader to judge.

Here he is in full flight:

In the past, when almost all scientists believed that evolution was true, they had no choice on the age issue. A dedicated evolutionist cannot be open-minded on this question, because evolution absolutely requires vast amounts of time. Thus, for evolutionist scientists the question has never really been "How old is the universe?" but rather "How is the universe old?" Since they "knew" it was old, clocks had to be found and interpreted according to this "known" antiquity.

Ackerman correctly states that It turns out that the slowing effect of Poynting-Robertson is directly related to the mass of the object being considered. He uses the analogy of a 'janitor' sweeping up dust and reasons that we could tell the time from the amount of dust remaining if we knew when the janitor started work. Yes indeed we could - if only the dust wasn't constantly being replaced.

Radiation from the Sun (S) and thermal radiation from a particle seen
(a) from an observer moving with the particle and
(b) from an observer at rest with respect to the Sun.
Briefly, the Poynting-Robertson (P-R) effect is the tendency of particles orbiting the sun to have a slowly decaying orbit and so spiral into the sun. It is due to the fact that photons radiate directly outwards from the sun but, because of their motion in orbit, particles strike them at a slight angle, so they exert a slight drag. In terms of quantum mechanics, a photon absorbed by a particle gives the particle a slight increase in mass so, to conserve angular momentum, the particle needs to move into a lower orbit.

Photons of course travel at the velocity of light - 186,000 miles per second - and have almost zero mass. A particle in orbit travels very much more slowly than this - in the order of thousands of miles an hour, so the P-R effect is most noticeable for very small particles and varies greatly depending on the particle's velocity. The P-R effect also diminishes the further away from the sun you get. Particles of a few microns in diameter (that is, having a radius of a few millionths of a meter) take a few thousand years to decay from as far away as earth is from the sun to evaporation point.

However, the P-R effect is not the only influence on the orbit of particles like meteors. Radiation pressure also impinges on the orbit of small particles and is much greater than the P-R effect. Particles of about half a micron are actually pushed away from the sun.

Image of comet Holmes from the 3.6-meter Canada-France-Hawaii telescope on Mauna Kea showing the large expanding dust coma. On the left, a 'raw' image is shown, in which the brightness reflects the distribution of dust in the coma of the comet (the nucleus is in the bright, point-like region to the upper left of center). On the right is shown the same image after application of the Laplacian spatial filter, to emphasize fine structures. The white/black circular objects are background stars enhanced by the Laplacian filter.
Ackerman is also assuming that all orbiting dust particles were present at the creation of the universe, so his 'clock' was started at that point in time. We know, of course, that this is simply not true. Particles can be 'placed' in orbit in at least two other ways. They can be knocked off the surface of bodies like the moon and Mars by impact of large meteors and, much more importantly, they can also be deposited by comets. In fact most people will be familiar with the periodic meteor showers when earth's orbit passes through the remains of a comet 'tail'. Each comet will deposit a new batch of dust particles of varying size and shape every time it comes in close enough to the sun to produce a 'tail'. That is precisely what the 'tail' is. For those few people who don't know what comets are, here is an article about them.

Ackerman either doesn't know this or hopes you won't. If you did know it - and now you do - you would know that Ackerman's P-R 'clock' is being continually re-set. It's as though someone is adding more sand to the top of the egg-timer.

It is hard to credit Ackerman with ignorance on the matter of cometary re-seeding however, because he gives the game away somewhat with:

When the earth passes through one of these meteor streams, it produces the popular spectacle of a meteor shower. Of relevance to the issue of time and Poynting-Robertson is that individual chunks of material in a meteor stream vary greatly in mass. Some chunks are small, some large, and some in between. Whipple calculated that over time the various pieces of material in a given stream would be sorted out according to size by the Poynting-Robertson effect. Initially all sizes of debris would be jumbled together in the stream. But, as time went by, the smaller objects would be pulled more quickly toward the sun, with the larger objects lagging behind. After a while the meteor stream would be nicely and neatly sorted. Furthermore, the degree of the sorting and the amount of separation between objects of different sizes would provide a clock for measuring the age of the meteor stream.

Using careful photographic techniques to examine meteors burning up in the earth's atmosphere during a number of meteor showers, Whipple and his research team found no dispersion whatsoever in any of the meteor streams studied. Whipple concluded that the meteor streams studied must be quite recent in their origin.

Absolutely correct. Meteor streams are quite recent in their origins. The P-R effect will have dealt with the dust from very much earlier ones. People can sometimes see them being formed with the naked eye and astronomers with telescopes frequently do. No one claims they are as old as the solar system. Unfortunately, Ackerman seems to have chosen yet another clock which doesn't work.

Even a blind watchmaker could probably do better than this.

Ignorance or a wilful attempt at deception? The choice is yours.





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