[connectthedots]

Radiometrics are accurate to +- 1% based on current half-lives, calibration against other knowns, and they correlate with a number of other measuring methods.

+- 1%? I doubt that you could find a majority of evolutionists who would agree that they could approximate the age of the earth within 1%. I think that is simply a number pulled out of thin air.

My comment was poking fun at the IDist idea of 'specified complexity'. The idea is that both nature and intelligence can 'design' complexity, however only intelligence can produce complexity that is 'specified'.

I don't think that accurately reflects the ID position.

[MineralMan]

"I don't think that accurately reflects the ID position."

From my reading of the ID literature, it appears that it has not been around long enough to have developed a solid position.

ID is a stopgap measure, only. It is not a serious field of study, IMO. Since it cannot be tested in any way, there's no room for research. It's really just a concept being used to wedge creationism into the science classroom.

Because of those things, it will fail to emerge as a serious field of study. How would you get a degree in "Intelligent Design Theory." One class and you'd be done.

[Ichneumon]

[Radiometrics are accurate to +- 1% based on current half-lives, calibration against other knowns, and they correlate with a number of other measuring methods.]

+- 1%? I doubt that you could find a majority of evolutionists who would agree that they could approximate the age of the earth within 1%. I think that is simply a number pulled out of thin air.

Tell you what, why don't you go actually learn the topic before spouting off more of what you "think" about it based on nothing more than your presumptions?

From The Age of the Earth, we find that yes, Virginia, many radiometric methods of dating the Earth have an accuracy in the range of 1%:

How Old Is The Earth, And How Do We Know?

he generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%). This value is derived from several different lines of evidence.

Unfortunately, the age cannot be computed directly from material that is solely from the Earth. There is evidence that energy from the Earth's accumulation caused the surface to be molten. Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface.

The oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods). Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenland, Australia, Africa, and Asia.

While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age.

The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites. This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204). A plot is constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.

If the solar system formed from a common pool of matter, which was uniformly distributed in terms of Pb isotope ratios, then the initial plots for all objects from that pool of matter would fall on a single point.

Over time, the amounts of Pb-206 and Pb-207 will change in some samples, as these isotopes are decay end-products of uranium decay (U-238 decays to Pb-206, and U-235 decays to Pb-207). This causes the data points to separate from each other. The higher the uranium-to-lead ratio of a rock, the more the Pb-206/Pb-204 and Pb-207/Pb-204 values will change with time.

If the source of the solar system was also uniformly distributed with respect to uranium isotope ratios, then the data points will always fall on a single line. And from the slope of the line we can compute the amount of time which has passed since the pool of matter became separated into individual objects. See the Isochron Dating FAQ or Faure (1986, chapter 18) for technical detail.

A young-Earther would object to all of the "assumptions" listed above. However, the test for these assumptions is the plot of the data itself. The actual underlying assumption is that, if those requirements have not been met, there is no reason for the data points to fall on a line.

The resulting plot has data points for each of five meteorites that contain varying levels of uranium, a single data point for all meteorites that do not, and one (solid circle) data point for modern terrestrial sediments. It looks like this:

Pb-Pb isochron of terrestrial and meteorite samples.
After Murthy and Patterson (1962) and York and Farquhar (1972) .
Scanned from Dalrymple (1986) with permission.

Most of the other measurements for the age of the Earth rest upon calculating an age for the solar system by dating objects which are expected to have formed with the planets but are not geologically active (and therefore cannot erase evidence of their formation), such as meteorites. Below is a table of radiometric ages derived from groups of meteorites:

Type	Number Dated	Method	Age (billions of years)
Chondrites (CM, CV, H, L, LL, E)	13	Sm-Nd	4.21 +/- 0.76
Carbonaceous chondrites	4	Rb-Sr	4.37 +/- 0.34
Chondrites (undisturbed H, LL, E)	38	Rb-Sr	4.50 +/- 0.02
Chondrites (H, L, LL, E)	50	Rb-Sr	4.43 +/- 0.04
H Chondrites (undisturbed)	17	Rb-Sr	4.52 +/- 0.04
H Chondrites	15	Rb-Sr	4.59 +/- 0.06
L Chondrites (relatively undisturbed)	6	Rb-Sr	4.44 +/- 0.12
L Chondrites	5	Rb-Sr	4.38 +/- 0.12
LL Chondrites (undisturbed)	13	Rb-Sr	4.49 +/- 0.02
LL Chondrites	10	Rb-Sr	4.46 +/- 0.06
E Chondrites (undisturbed)	8	Rb-Sr	4.51 +/- 0.04
E Chondrites	8	Rb-Sr	4.44 +/- 0.13
Eucrites (polymict)	23	Rb-Sr	4.53 +/- 0.19
Eucrites	11	Rb-Sr	4.44 +/- 0.30
Eucrites	13	Lu-Hf	4.57 +/- 0.19
Diogenites	5	Rb-Sr	4.45 +/- 0.18
Iron (plus iron from St. Severin)	8	Re-Os	4.57 +/- 0.21
After Dalrymple (1991, p. 291); duplicate studies on identical meteorite types omitted.

As shown in the table, there is excellent agreement on about 4.5 billion years, between several meteorites and by several different dating methods. Note that young-Earthers cannot accuse us of selective use of data -- the above table includes a significant fraction of all meteorites on which isotope dating has been attempted. According to Dalrymple (1991, p. 286) , less than 100 meteorites have been subjected to isotope dating, and of those about 70 yield ages with low analytical error.

Further, the oldest age determinations of individual meteorites generally give concordant ages by multiple radiometric means, or multiple tests across different samples. For example:

Meteorite	Dated	Method	Age (billions of years)
Allende	whole rock	Ar-Ar	4.52 +/- 0.02
	whole rock	Ar-Ar	4.53 +/- 0.02
	whole rock	Ar-Ar	4.48 +/- 0.02
	whole rock	Ar-Ar	4.55 +/- 0.03
	whole rock	Ar-Ar	4.55 +/- 0.03
	whole rock	Ar-Ar	4.57 +/- 0.03
	whole rock	Ar-Ar	4.50 +/- 0.02
	whole rock	Ar-Ar	4.56 +/- 0.05
Guarena	whole rock	Ar-Ar	4.44 +/- 0.06
	13 samples	Rb-Sr	4.46 +/- 0.08
Shaw	whole rock	Ar-Ar	4.43 +/- 0.06
	whole rock	Ar-Ar	4.40 +/- 0.06
	whole rock	Ar-Ar	4.29 +/- 0.06
Olivenza	18 samples	Rb-Sr	4.53 +/- 0.16
	whole rock	Ar-Ar	4.49 +/- 0.06
Saint Severin	4 samples	Sm-Nd	4.55 +/- 0.33
	10 samples	Rb-Sr	4.51 +/- 0.15
	whole rock	Ar-Ar	4.43 +/- 0.04
	whole rock	Ar-Ar	4.38 +/- 0.04
	whole rock	Ar-Ar	4.42 +/- 0.04
Indarch	9 samples	Rb-Sr	4.46 +/- 0.08
	12 samples	Rb-Sr	4.39 +/- 0.04
Juvinas	5 samples	Sm-Nd	4.56 +/- 0.08
	5 samples	Rb-Sr	4.50 +/- 0.07
Moama	3 samples	Sm-Nd	4.46 +/- 0.03
	4 samples	Sm-Nd	4.52 +/- 0.05
Y-75011	9 samples	Rb-Sr	4.50 +/- 0.05
	7 samples	Sm-Nd	4.52 +/- 0.16
	5 samples	Rb-Sr	4.46 +/- 0.06
	4 samples	Sm-Nd	4.52 +/- 0.33
Angra dos Reis	7 samples	Sm-Nd	4.55 +/- 0.04
	3 samples	Sm-Nd	4.56 +/- 0.04
Mundrabrilla	silicates	Ar-Ar	4.50 +/- 0.06
	silicates	Ar-Ar	4.57 +/- 0.06
	olivine	Ar-Ar	4.54 +/- 0.04
	plagioclase	Ar-Ar	4.50 +/- 0.04
Weekeroo Station	4 samples	Rb-Sr	4.39 +/- 0.07
	silicates	Ar-Ar	4.54 +/- 0.03
After Dalrymple (1991, p. 286); meteorites dated by only a single means omitted.

Also note that the meteorite ages (both when dated mainly by Rb-Sr dating in groups, and by multiple means individually) are in exact agreement with the solar system "model lead age" produced earlier.

[b_sharp]

"+- 1%? I doubt that you could find a majority of evolutionists who would agree that they could approximate the age of the earth within 1%. I think that is simply a number pulled out of thin air.

1% of 4,500,000,000 years is 45,000,000 years, giving a range of 90,000,000 years. Why is that so hard to believe?

Plaisted (p. 24) calls for double-blind radiometric tests on Phanerozoic outcrops using different methods and different laboratories. Of course, interlaboratory studies on radiometric dating and multiple analyses on outcrops with different methods are nothing new. Examples are cited in Harland et al. (1990) for Phanerozoic samples and Dalrymple (1991) for meteorites and Precambrian outcrops. One of the older and well-known interlaboratory studies is Lanphere and Dalrymple (1965). The results of this study are also described in some detail in Jaeger (1979, p. 23-25). In Lanphere and Dalrymple (1965), 55 laboratories were sent a muscovite standard for dating. The average K/Ar date for the muscovite was 83.0 million years and the average Rb/Sr date was reasonably close at 85.7 million years. Interlaboratory standard deviations were only 1.2% for the K/Ar dates and 2.8% for the Rb/Sr dates. These excellent results refute creationist claims that K/Ar and Rb/Sr methods are inconsistent or imprecise.

From here

Note that this is not absolute dating accuracy but relative dating accuracy between methods.

"I don't think that accurately reflects the ID position.

According to Dembski it does. It factors into his explanatory filter in a big way.

[stremba]

Then perhaps you could tell us what the ID position is. From everything I've seen the ID position boils down to three statements.

1. There exists complexity of type X in biological systems.
2. Complexity of type X could not have formed via evolution.
3. Statements 1 and 2 imply that there must have been some intelligence that designed those biological systems containing complexity of type X.

Using the example of this argument that I am most familiar with, namely Behe's irreducible complexity argument, it can be shown that this argument is weak and unscientific. If you are unfamiliar, Behe defines a system as IC if removal of one part of the system results in the system being unable to perform its function.

I won't argue statement 1, namely that there exists irreducible complexity in biological systems. Statement 2, however, is demonstrably false. It is most certainly possible for IC systems to form via evolution. One must simply understand that evolution is not a direct process leading from one state to another, but rather a process that proceeds in fits and starts, sometimes leading to the loss of structures and systems, and sometimes resulting in the coopting of a part of a given system for the performance of a completely unrelated function.

For instance, given a system containing parts C, D and E, the system is IC if removal of C, D, or E results in loss of system function. However, it's possible that C, D and E all evolved separately performing functions completely unrelated to the function of system CDE. If that's the case, then there's no reason to believe that if C, D, and E all separately give a survival advantage to an organism that these couldn't have evolved separately. Furthermore, it's possible that a system evolved sequentially starting with part A, and adding parts B, C, D, and E in subsequent generations, to form system ABCDE. Once this system is in place, parts A and B prove to be redundant and are eliminated by further evolution, yielding our IC system CDE. Therefore, the claim that IC systems could not possibly have evolved is demonstrably false.

As for statement 3, this is where ID leaves the realm of science. Statement 3 is not falsifiable and furthermore does not follow from statements 1 and 2. Eliminating the possibility of evolution does not lead to the conclusion of a designer. Perhaps some other natural process is involved.

It is not falsifiable because it's impossible to conclusively determine that a system wasn't designed. For example, suppose you see 10000 coins scattered about on the floor, seemingly at random. How would you falsify the statement that some person intentionally put the coins in that exact position? We would normally conclude that someone probably spilled the coins from a container and they landed in their current position under only the influence of gravity and friction, but we cannot falsify the notion that someone laid each individual coin in place intentionally.

Similarly, in biological systems there's no test that can determine that a particular system is not designed. If one is willing to put constraints on what a particular hypothesized designer could or would design, then maybe there would be a testable hypothesis. For example, if a claim were made that the designer would never have included lethal alleles in an organisms genome were made, then we would have a testable hypothesis. If lethal alleles are found (which they are), then this claim is falsified, and this version of ID is falsified as well. However, ID proponents are very careful to specify absolutely NOTHING about the characteristics of a designer, so there is no scientific hypothesis of ID.

This is my best understanding of the ID position. It is cerainly and unconvincing and weak argument, and one that is unscientific. If there's somewhere where I have misunderstood or mischaracterized the argument, I am sure you can correct me.

[stremba]

Then perhaps you could tell us what the ID position is. From everything I've seen the ID position boils down to three statements.

1. There exists complexity of type X in biological systems.
2. Complexity of type X could not have formed via evolution.
3. Statements 1 and 2 imply that there must have been some intelligence that designed those biological systems containing complexity of type X.

Using the example of this argument that I am most familiar with, namely Behe's irreducible complexity argument, it can be shown that this argument is weak and unscientific. If you are unfamiliar, Behe defines a system as IC if removal of one part of the system results in the system being unable to perform its function.

I won't argue statement 1, namely that there exists irreducible complexity in biological systems. Statement 2, however, is demonstrably false. It is most certainly possible for IC systems to form via evolution. One must simply understand that evolution is not a direct process leading from one state to another, but rather a process that proceeds in fits and starts, sometimes leading to the loss of structures and systems, and sometimes resulting in the coopting of a part of a given system for the performance of a completely unrelated function.

For instance, given a system containing parts C, D and E, the system is IC if removal of C, D, or E results in loss of system function. However, it's possible that C, D and E all evolved separately performing functions completely unrelated to the function of system CDE. If that's the case, then there's no reason to believe that if C, D, and E all separately give a survival advantage to an organism that these couldn't have evolved separately. Furthermore, it's possible that a system evolved sequentially starting with part A, and adding parts B, C, D, and E in subsequent generations, to form system ABCDE. Once this system is in place, parts A and B prove to be redundant and are eliminated by further evolution, yielding our IC system CDE. Therefore, the claim that IC systems could not possibly have evolved is demonstrably false.

As for statement 3, this is where ID leaves the realm of science. Statement 3 is not falsifiable and furthermore does not follow from statements 1 and 2. Eliminating the possibility of evolution does not lead to the conclusion of a designer. Perhaps some other natural process is involved.

It is not falsifiable because it's impossible to conclusively determine that a system wasn't designed. For example, suppose you see 10000 coins scattered about on the floor, seemingly at random. How would you falsify the statement that some person intentionally put the coins in that exact position? We would normally conclude that someone probably spilled the coins from a container and they landed in their current position under only the influence of gravity and friction, but we cannot falsify the notion that someone laid each individual coin in place intentionally.

Similarly, in biological systems there's no test that can determine that a particular system is not designed. If one is willing to put constraints on what a particular hypothesized designer could or would design, then maybe there would be a testable hypothesis. For example, if a claim were made that the designer would never have included lethal alleles in an organisms genome were made, then we would have a testable hypothesis. If lethal alleles are found (which they are), then this claim is falsified, and this version of ID is falsified as well. However, ID proponents are very careful to specify absolutely NOTHING about the characteristics of a designer, so there is no scientific hypothesis of ID.

This is my best understanding of the ID position. It is cerainly and unconvincing and weak argument, and one that is unscientific. If there's somewhere where I have misunderstood or mischaracterized the argument, I am sure you can correct me.