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Author Topic:   Why is uniformitarianim still taught?
Sylas
Member (Idle past 4746 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 26 of 89 (87637)
02-19-2004 11:16 PM
Reply to: Message 25 by Percy
02-19-2004 9:35 PM


Re: You're right, uniformitarianism should not be taught!
Percy writes:
This reveals little understanding of the way geological processes work. Sediment dropped by the violence of a hurricane in no way resembles the sediment of a quiet lake or sea. A geologist doesn't approach a formation with a priori assumptions that it's a quiet lake, but rather with a priori assumptions that the same processes that deposit sediment today also deposited sediment millions of years ago. If he finds tiny grain sizes he concludes quiet lake or sea, because today we find tiny grain sizes are only deposited by quiet water. And if he finds large grain sizes then he concludes violent event, because that's what we see happening today.
What Percy said. This has been a rather weird thread. I don't think this thread has identified any problems with the teaching or application of geology. The evidence shows that the Earth is very old, and has been formed by processes acting over long periods of time; processes which leave traces we see in the present and which are in many cases still occuring in the present.
The word uniformitarianism is nearly always used in the context of the history of geology in the eighteenth and nineteenth century. Modern geology has progressed considerably since those early days, and no longer fits exactly with all the views of the early uniformitarians, but the basic idea that the Earth is shaped continuously by processes in the past as it is being shaped by processes in the present remains foundational; not as an assumption but as a plain conclusion of evidence which has been extensively tested and studied at length. This foundation is not in any rational dispute.
Modern geology allows for sudden geological upheavals; but nothing like the global cataclysms involved by the early catastrophists. The catastrophists lost the scientific debate nearly two hundred years ago, because the models they were using do not match the evidence.
Cheers -- Sylas

This message is a reply to:
 Message 25 by Percy, posted 02-19-2004 9:35 PM Percy has seen this message but not replied

Replies to this message:
 Message 32 by hitchy, posted 02-20-2004 11:15 AM Sylas has replied
 Message 38 by Brad McFall, posted 02-20-2004 12:41 PM Sylas has not replied

  
Sylas
Member (Idle past 4746 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 31 of 89 (87708)
02-20-2004 11:10 AM
Reply to: Message 29 by Tamara
02-20-2004 10:15 AM


Re: what is kind?
Tamara writes:
holmes writes:
How about using (if you agree with me anyway), gradualism for slow processes, catastrophism for fast processes, and uni for the idea that either speed process of yesteryear were the same kind of processes we see today.
Ok, holmes, getting back to you on this one.
Here is my puzzle. Were the processes of yesteryear the same kind and same speed or intensity as we see today? We agree that they were not necessarily the same speed or intensity, right? Were they the same kind? Now by kind, do you mean natural, as in opposition to supernatural? Because on the face of it, just talking natural, it seems to me that for example, assuming that since the process of continental drift is extant today, it was also extant way back when, is incorrect. So what is meant by "kind"? Or let me give a fringe example: some astrobiologists have postulated the possibility of life being seeded from space, perhaps by design (meaning alien design). Now that would be a possibly unique event or process, not extant today. Maybe there are better examples.
I'll answer this; there is a chance you may hear it better from me.
The processes of yesterday are (as holmes suggests) the same kind as those of today; but the speed and intensity varies in different times and places. Why bother to bring up "speed" and "intensity"?
Hutton tended to think of constant rates of change; but that extreme form of uniformitarianism is really only of historical interest.
By kind, I would mean (and I am sure holmes does as well) nothing about a natural verses supernatural distinction. It would be perfectly possible to bring up a different "kind" of natural process in past; except of course that there is no evidential basis for it. There are a few instances in which we say that we don't know how a certain geological feature arose; but we still look for causes in terms of processes we know. The natural world is sufficiently subtle and complex that known processes can give rise to wholly unexpected results.
We do not just "assume" that processes we see now operated in the same way in the past. That is a common distortion made by creationists, and is swiftly cured by any level of exposure to earth sciences. The processes which occur leave identifiable traces, which allow us to actually measure and study processes of the past, and tell the ways in which they may be similar or distinct.
Continental drift, for example, was not inferred by watching it in the present and assuming it works in the past. Just the reverse, in fact. It was inferred from traces in the past, and only much later actually measured in the present. The varying rates and directions of motions of land masses can be inferred from studies of the earth. To say they are just "assumed" to operate in the past is a gross misunderstanding of how geology works.
This was, arguably, a new kind of process, although still completely natural. Once it was discovered, we still find in this case also that it works now as it did in the past. If you read up on the Wilson cycle, you will find more on modern plate techtonics, involving long cycles operating over many thousands or millions of years. You could think of various stages in that cycle as being a different "kind" of process in the past; but in fact it is all part of a cycle which we see continuing now.
You bring up the example of panspermia. The difficulty is that the available evidence indicates very deep levels of relationship between all life, to such a point that panspermia would have to date back so far as to be worthless for helping to illuminate any evolutionary trends.
As a model for biogenesis, panspermia is a long shot, wholly lacking in evidence and for which no credible mechanisms exist that make any sense. It is possible that some very simple organic molecules from space might have a role to play in the origins of life; that is an interesting speculation which cannot be ruled out but which does not really solve any of the major theoretical problems for biogenesis.
I am not a geologist. But on the face of it, from the vantage point of an Earthling, I see an earth being affected by all sorts of processes, some possibly unique, others common, some predictable, some unpredictable, some slow, some fast, with intensities changing. Do you see it differently?
I think you would do well to try learning a bit of geology before speculating. There are plenty of readable descriptions available.
Cheers -- Sylas

This message is a reply to:
 Message 29 by Tamara, posted 02-20-2004 10:15 AM Tamara has replied

Replies to this message:
 Message 36 by Tamara, posted 02-20-2004 12:07 PM Sylas has not replied

  
Sylas
Member (Idle past 4746 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 35 of 89 (87718)
02-20-2004 11:57 AM
Reply to: Message 32 by hitchy
02-20-2004 11:15 AM


Steve, Steve, Steve, Steve, Steve, Steve, Steve, Steve, Steve, Steve, Steve
hitchy writes:
ps...if you haven't already, sign the petition on the ohio thread in this forum. Good science education needs to stay that way.
I'm going to let this one slide. To see my reason for not signing, check out Message 24.
Cheers -- Sylas

This message is a reply to:
 Message 32 by hitchy, posted 02-20-2004 11:15 AM hitchy has not replied

  
Sylas
Member (Idle past 4746 days)
Posts: 766
From: Newcastle, Australia
Joined: 11-17-2002


Message 53 of 89 (87801)
02-20-2004 6:43 PM
Reply to: Message 51 by Tamara
02-20-2004 5:23 PM


Re: summing up, & one more question
Tamara writes:
YECs claim that since the old-fashioned form of uniformitarianism held sway in the past, data regarding the age of the earth are unreliable, because they build on knowledge that was built on top of this false assumption. How would you counter it, using examples that are easy to understand, and that do not get into arguing arcane points of radiometry?
Actually, I consider that radiometry is a great example; and one of my preferred illustrations to help someone see the errors in what they have been taught by YECs with respect to assumptions about the past in science. Single sound bits don't work; someone who simply gives up immediately an example requires a bit of thought will remain YEC. So let me show how I would use the example of radiometry.
YEC routinely state that radiometric dating is based on the assumption of constant decay rates.
As CS Lewis notes, a lie becomes much stronger when combined with a bit of truth. This is an example of that principle.
The claim of assumed constancy is true, if taken in the sense that the constancy of decay rates is a factor which does not need to be addressed or tested in the analysis of things that could plausibly go wrong with a particular dating study. Reading a scientific paper which applies dating you often see a fairly careful discussion of many potential sources of error in the analysis, usually in terms that fly way over the heads of people who have no familiarity with dating techniques, but it is clear that constancy of decay rates is not something which is even raised as an issue.
On the other hand, the term "assumption of constant decay rates" is false in the sense that science in general does not merely make this assumption, but has tested it rigorously at great length. Constancy of decay rates is a conclusion, based on many independent lines of evidence.
Observations used to establish the constancy of decay rates, include (but are not limited to):
  • Observations of nuclear reactions in distant stars and distant galaxies (for which the reactions took place thousands or millions of years ago).
  • Inferences about nuclear processes in the very early universe before galaxy formation.
  • Cross checking of dates against other non-radiometric dating methods.
  • Cross checking of radically different radiometric methods.
  • Study of residues from the Oklo natural nuclear reactor, active nearly two billion years ago.
  • Theory of quantum mechanics, which is itself one of the most precisely studied and tested models in physics. Radioactive decay is a process that is well understood. We know a great deal about the relevant forces and the structure of atoms, and how and why they decay. In fact, I would say radioactive decay is substantially better understood than gravity. This illustrates the principal that confidence in scientific models is related also to how well the underlying principals are understood.
  • Testing of a range of conditions in which decay might vary. If decay rates have varied, then can we reproduce the conditions under which this occurs? In some cases, yes; and none of them make any difference to dating techniques.
However, the particular way our putative YEC creationist phrases their objection, referring to knowledge built on false foundations, seems to suggest an ever deeper malaise and an almost insurmountable ignorance of how science works. Modern science is not built on flawed foundations in the sense of being called into question by revelation of certain inadequacies in eighteenth century notions of uniformitarianism. When models are disproved, the inferences based on those models must be shown compatible with improved understanding, or else the inferences are gone as well.
Cheers -- Sylas

This message is a reply to:
 Message 51 by Tamara, posted 02-20-2004 5:23 PM Tamara has not replied

  
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