Tuesday, April 21, 2009

History of nature

On April 17, 2009 Herman van Barneveld included this question in a comment on Tony's article:

"Is it within the realm of science to speak authoritatively on historical matters? (especially when it contradicts the Word through which God "...makes Himself more clearly and fully known as far as neccessary ......to His glory (Belgic Confession Art. 2)) Science can try to speak on history, but it can't do so without saying 'maybe' or 'we think' and make numerous assumptions."

Thank you, Herman, for your question. You do not explain what you mean by history. I shall take you to ask whether science can speak authoritatively on the history of nature because that is what science deals with. I know that some natural scientists include religion and morality under their conception of nature. This would make the history of religion and morality part of the natural sciences - a very controversial move indeed. For now I shall answer the former question.

First, three areas of the natural sciences that deal with history are the history of the cosmos in astronomy, the history of the earth in geology, and the history of life in biology. All can speak on history. Since I am a biologist, I will give you a biological example. Perhaps someone else can contribute one from astronomy.

One of the implications of continental drift is that South America, the Antarctic and Australia were once connected. Fossil studies show that pouched mammals (Marsupials) lived in both Australia and S. America before these three continents broke up. The prediction was made that there should be fossils of pouched mammals in the Antarctic. They were found in 1982. For the original publication, see
http://www.sciencemag.org/cgi/content/abstract/218/4569/284 . For a recent confirmation, see http://www.springerlink.com/content/h5r16469kqr06560/ . For a popular rendition, see http://www.naturalworlds.org/thylacine/introducing/about_marsupials_5.htm . This shows that in biology theories about historical events (continental drift, biogeographical distribution) can be used to make predictions which can be tested and accepted or rejected. For an animation of continental drift showing the distribution of fossils see http://www.exploratorium.edu/origins/antarctica/ideas/gondwana2.html .

A second example concerns cladograms (binary phylogenetic trees). The procedure of making a cladogram works exclusively with extant animals or plants. Specific DNA sequences are compared say between living fish, amphibians, reptiles, birds and mammals, and the number of differences in nucleotides counted. The more differences the longer the organisms concerned have been separately accumulating mutations. That is, the longer ago it is that they had a common ancestor. This information is used to construct a cladogram which shows the theoretical sequence in which the various groups compared separated from the ancestral line. In other words, this cladogram is a hypothesis which is then used to predict the sequence in which fossil representatives should be found. Again this shows that a theory (the tree) leads to predictions which can be empirically tested and rejected or accepted. For more background see http://en.wikipedia.org/wiki/Cladistic .

Assumptions are made as you say. The assumptions of scientific knowledge do not set it apart because all human knowledge makes assumptions. This compels us to be humble about knowledge claims.

8 comments:

Arnold Sikkema said...

Jitse suggested someone could comment on what astronomy can say about history. As I have some background in general relativity and cosmology, and teach an astronomy course, let me do so, focusing on one element of stellar and galactic history. Since the speed of light is finite, about 300,000 km/s, any light we see left its source at a time in the past which depends on how far away it is. Apart from our own, our nearest galaxy is Andromeda, which is 2,000,000 light years away, meaning that the light we see when we look at Andromeda --- visible to the naked eye as a fuzzy patch near Cassiopeia on a dark clear night, and with a good telescope shows up wonderfully --- left Andromeda 2 million years ago.

Now, galaxies are not static light sources, but they reveal intricate processes. Routinely, stars can been seen exploding; these are called supernovae. And so when we watch a galaxy over time we see processes which happened 2 million years ago (or, up to 13 billion years ago in the case of more distance galaxies). God's grandeur and power are clearly seen (Ps. 8) in the night sky, particularly as we remember that He created the stars, and knows each one by name (Psalm 147:4).

Assumptions are made, as in all sciences, and the validity of these assumptions is continually tested in terms of internal theoretical consistency as well as confirmations of observations with predictions.

Tony Jelsma said...

I have often heard of a distinction being made between historical and experimental sciences and I think it's a false distinction. I am a molecular biologist. If I do a reaction where I sequence DNA, I don't know if it worked until I examine the data. Does this make molecular biology an historical science? Whenever we do an experiment we collect data after the fact. The data is then analyzed to determine the answer. Whether the time lag between experiment and data analysis is microseconds or millions of years is irrelevant, it's still afterwards.
It is true that there are different types of studies. Experimental studies allow the manipulation of conditions and are preferable when possible. However, retrospective studies, such as the effects of chronic alcohol consumption (which would be unethical to do as an experimental study) are also valid, although one needs to be careful about potential confounding variables. Forensic science and archeology belong to the category of retrospective studies.
All of these types of studies are legitimate science.

hjvb said...

Some assumptions are very reasonable and made in a short space of time, so we can count on those assumptions being true. Others are unreasonable and are made under the assumption of uniformitarianism. And I find it absolutely confounding that even Christians refer to these 'theories' as 'evidence' but refer to the natural explanation of Genesis 1 as 'an interpretation'. Take for instance the creation of the Scab Lands East of Seattle. For 80 years they resisted the idea that these Scablands were formed from water because of a certain notion about long geological processes. Smart people who weren't so smart after all. Why? Because the interpretation was made to fit certain pre-conceived notions. Sticking to the scientific aspect for now, the assumption is made that light travels in predictable patterns throughout the universe. We also make assumptions about how God made light and the stars. Who are we to say that God didn't stretch out the stars from our galaxy. There is no proof that the galaxy is that old because we were not there. Old ages for stars may appear reasonable to our limited understanding, but it is just speculation that happens to contradict the reading of scripture. I fail to see the proof.

Herman van Barneveld

hjvb said...

I want to use the examples of the fossils found on Antarctica for a moment to show that we are still dealing with a certain amount of speculation when a prediction we make comes true. I can do a study and come up with a theory that people eating icecream has an effect on the hardness of the pavement they are standing on. I can make a correct prediction so that next time people eat icecream, the pavement softens again. But this doesn't prove anything. Like-wise, marsupial fossils found in Antarctica can mean a number of things: the continents could have been attached a long time ago and slowly drifted apart (assuming uniformitarianism, which I will deal with in another post by the way), or perhaps the continents drifted apart very quickly and have since slowed down, or perhaps the marsupials migrated before they were buried by a massive flood. (as a side-note, where in the world do we see fossils being formed today apart from land-slides or massive upheavals?; definitely not in tranquil ocean bottoms as long-age people claim)

Herman van Barneveld

Arnold Sikkema said...

Herman: Thanks for your remarks. I'm not a geologist or a paleontologist, so can’t address the specifics of the examples you put forward, although I must say your icecream/pavement theory is not an example of what science considers a successful prediction. But let me address here the issue of proof and theory.

PROOF: It is a popular misconception that science functions according to proof. Instead, it operates by way of considering observations, finding patterns, proposing theories, judging theories in a community of practioners on the basis of corroborating evidence, of naturalness, fruitfulness, internal consistency.

Consider the following from John Polkinghorne, “What was happening?”, Ch. 21 (pp. 158-176) of Rochester Roundabout: The Story of High Energy Physics (New York, Freeman, 1989), pp. 173f:

“Science is an activity of judgment, involving tacit skills. In [Michael] Polanyi’s oft-repeated phrase, ‘we know more than we can tell’. Science is a convivial activity, pursued in a community to whose judgment the individual scientist offers his efforts as a corrective to merely individual idiosyncracy, but controlled and determined by the stubborn facticity of the physical world whose understanding is being sought… [O]ne can recognise rational characteristics which are to be demanded of a scientific theory if it is to be accorded the epithet ‘good’. Kuhn suggested five: (i) accuracy; (ii) consistency; (iii) wide scope; (iv) simplicity; and (v) fruitfulness. Clearly a criterion such as simplicity involves in its application an act of personal judgment.”

THEORY: Theories are not, as some assume, random wild guesses thrown together to address some minor point, but internally consistent networks of generally applicable ideas proposed after significant effort by (usually) many people to classify, explain, predict, control things and processes. If over several hundred years with thousands of researchers, many of them Christians, astronomers and physicists develop the cosmic distance ladder, one cannot glibly toss that aside by suggesting some alternative, especially if meant to salvage a culturally-embedded predetermined reading of Scripture.

In this context, one must remember, as Tony said earlier, that both Scripture and the world are being interpreted.

Anonymous said...

If over several hundred years with thousands of researchers, many of them Christians, astronomers and physicists develop the cosmic distance ladder, one cannot glibly toss that aside by suggesting some alternative, especially if meant to salvage a culturally-embedded predetermined reading of Scripture. Well said, Arnold. I am constantly amazed at how well-meaning individuals in my sphere will readily discard virtually all of modern biology in conversation with me - and not see the irony, even though they know that this is my area of expertise. I wonder how they would feel if I took them to task on plumbing, house construction, or whatever they happen to be experts on?

Dennis Venema

YFNWG said...

I read a blog posting today on a different topic (anthropogenic global warming) which begins with a quote that is relevant to this discussion:

""Albert Einstein once said, “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.” Einstein’s words express a foundational principle of science intoned by the logician, Karl Popper: Falsifiability. In order to verify a hypothesis there must be a test by which it can be proved false. A thousand observations may appear to verify a hypothesis, but one critical failure could result in its demise. The history of science is littered with such examples.""

Much of the current "scientific" theories of the age and origins of the universe and life are based on "observations". However, they do remain only theories because there as yet does not exist a test robust enough to prove whether the theory holds water or not.

I have observed from the Global Warming debate that "observations" at times need interpretation in order to support or rebutt AGW. Quite often the interpretations are marred by the predisposition of the study authors to lean to one side or another. I would suggest that in the debate on the origins of the universe/life there are such predispositions, and as such one has to take a critical (some would say skeptical) viewpoint and not take any conclusions at face value.

Fred Nieuwenhuis

Arnold Sikkema said...

Thanks for your comment, Fred. One quite interesting example of how presuppositions affect theories is Einstein’s inclusion of the “cosmological constant” in general relativity, his theory of gravity. Believing that the universe had always existed roughly as it currently appears since eternity past, and concerned that gravity would cause the universe to collapse, he added this feature to his theory to ensure it properly represented a static eternal universe. Later, when Hubble’s observation that progressively greater redshifts are exhibited by more distant galaxies found its most straight-forward explanation in a creation moment at a finite time in the past, atheists were horrified and Einstein had to admit what he called the greatest blunder of his life. (There are a few interesting footnotes to this story. Hubble’s observations weren’t nearly as clear-cut as he thought, and Einstein’s cosmological constant refuses to go away, instead being an example of fine tuning.)

But another presupposition affecting theories is the assumption that Genesis 1 must be read in a particular way, namely that promoted by young-earth creationism; the non-Reformed origins of, and Scriptural problems with, that interpretation are discussed in articles by Tony Jelsma and Freda Oosterhoff (see “collected papers” in the sidebar).