Earth science curriculum tailored to fit wavering fundamentalists

kbertsche mentions sn1987a. There are several threads on this forum that discuss this supernova event, and it is a special case ideal for your questions: this star exploded twice -- the first time it threw off a layer of gas that expanded away from the star, the second was the nova event. What is measured is the light from the nova striking the shell of gas from the previous explosion by the time delay in seeing light from the nova star directly and then the light from the interaction with the shell. This star is also close enough so that the subtended angle can be measured, and this defines a triangle by simple geometry. Thus you can calculate the actual distance.So not only the Nova would need to be faked, but the previous explosion that formed the outer shell.A similar distance measurement is Eye of Sauron - the ring to "rule" them all ... distance 19 megaparsecsIf we assume that god/s don't lie or lay traps (no jokers) then we can assume that evidence represents reality, and that last assumption is all we need to do science.EnjoyEdited by RAZD, : .

Indeed, you can watch Cobalt decay just as it does on earth. As I recall there was discussion of this on at least one thread here. Message 72 shows how we know the distance, and Message 109 discusses why we know the speed of light AND the radioactive decay rates have been constant for 170,000 years.Another indication that decay rates have been constant for a goodly while are Uranium haloes Are Uranium Halos the best evidence of (a) an old earth AND (b) constant physics?Enjoy

You are now hopelessly hooked on EvC.I look forward to your 1,000th post ...There is no cure

These are two topics you can introduce without challenging theistic beliefs.From Atheists can't hold office in the USA?, Message 618

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That the "absence of evidence is evidence of absence" is a logical fallacy is clearly, imho, demonstrated by this image:

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All A is B does not mean that all B is A. (pursuant to Earth science curriculum tailored to fit wavering fundamentalists -- having a short course on logic would be a good starting place?)

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It should be noted that many theists do perceive evidence of god/s, many feel they have a "personal relationship" with their god, others see little things as evidence of divine interventions, miracles, etc.

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Good resources for logical fallacies are:
http://onegoodmove.org/fallacy/toc.htm
Formal fallacy - Wikipedia
Page not found - Nizkor
Logically Fallacious - WebpagesOther peeps may have other references.

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... Can the basic tenets of skepticism ...

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Skepticism

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In ordinary usage, skepticism (US) or scepticism (UK) (Greek: 'σκέπτομαι' skeptomai, to think, to look about, to consider; see also spelling differences) refers to:

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1. an attitude of doubt or a disposition to incredulity either in general or toward a particular object;
2. the doctrine that true knowledge or knowledge in a particular area is uncertain; or
3. the method of suspended judgment, systematic doubt, or criticism that is characteristic of skeptics (Merriam—Webster).

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In philosophy, skepticism refers more specifically to any one of several propositions. These include propositions about:

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1. an inquiry,
2. a method of obtaining knowledge through systematic doubt and continual testing,
3. the arbitrariness, relativity, or subjectivity of moral values,
4. the limitations of knowledge,
5. a method of intellectual caution and suspended judgment.

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... particularly "the method of suspended judgment, systematic doubt" or "a method of intellectual caution and suspended judgment." ... be applied widely, and is it a useful approach to learning new things?

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Logic and skepticism are natural and necessary parts of science, as is the intellectual caution due to the tentativity of knowledge.Enjoy

There have been a few threads discussing what this entails (I referred to one, Is My Hypothesis Valid???, that involves the starting process - developing an hypothesis).Heres a flow chart I put together for another thread: As you can see the process is never ending, whether the test result is positive or negative you go back and make either a new hypothesis or a new prediction to test, pausing only to report on results.This particular image is public access, free to be copied and used.Enjoy

Actually BP is defined as 1950 ce -- basically the time when atomic bomb testing started really messing up the 14C/12C ratios in the atmosphere.It is useful to use a single timeline with all dates measured directly from that point backwards as it avoids the slight error cause by not having a zero year ce/bce (the year before 1 ce is 1 bce).CE/BCE refer to "common Era" and is the secular version of AD/BC.Enjoy

Consider that the amount of 12C is dependent on the size of the sample and the density of the carbon in the sample, so the same would apply to undecayed 14C (organic take-up of carbon is non-selective of isotopes), so to remove this variable from the testing the amount of 14C is compared to the amount of 12C. As this site was designed for kids to be able to understand (the whole "howstuffworks" site is great in that regard), it is a little simplified.That formula is the standard radioactive decay formula that can be used for any radioactive isotope. As noted we can use %14C/12C and the formula works. Think of it this way ... Nf = (14C/12C)_f
No =(14C/12C)_oSo Becomes Becomes There are a couple of squirrely aspects to 14C dating, this is one (and it could be an interesting exercise to run through how you do end up with Nf/No with the kids) -- another is that the modern measured decay half life is not used in dating, rather the original half-life estimated by Libby is used. This is so new dates of artifacts can be compared to old ones without confusion with which rate was used, and because they are then corrected with the calibration curve (that uses the old rate) and they want to avoid making a correction twice.The method (another good site)

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Libby, Anderson and Arnold (1949) were the first to measure the rate of this decay. They found that after 5568 years, half the C14 in the original sample will have decayed and after another 5568 years, half of that remaining material will have decayed, and so on (see figure 1 below). The half-life (t 1/2) is the name given to this value which Libby measured at 5568+/-30 years. This became known as the Libby half-life. After 10 half-lives, there is a very small amount of radioactive carbon present in a sample. At about 50 - 60 000 years, then, the limit of the technique is reached (beyond this time, other radiometric techniques must be used for dating). By measuring the C14 concentration or residual radioactivity of a sample whose age is not known, it is possible to obtain the countrate or number of decay events per gram of Carbon. By comparing this with modern levels of activity (1890 wood corrected for decay to 1950 AD) and using the measured half-life it becomes possible to calculate a date for the death of the sample.

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bold addedRadiocarbon Date calculation

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The Conventional Radiocarbon Age BP is calculated using the radiocarbon decay equation:

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t=-8033 ln(Asn/Aon)

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Where -8033 represents the mean lifetime of 14C (Stuiver and Polach, 1977). Aon is the activity in counts per minute of the modern standard, Asn is the equivalent cpm for the sample. 'ln' represents the natural logarithm.

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A CRA embraces the following recommended conventions:

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• a half-life of 5568 years;
  
• the use of Oxalic acid I or II, or appropriate secondary radiocarbon standards (e.g. ANU sucrose) as the modern radiocarbon standard;
• correction for sample isotopic fractionation (deltaC13) to a normalized or base value of -25.0 per mille relative to the ratio of C12/C13 in the carbonate standard VPDB (more on fractionation and deltaC13);
• the use of 1950 AD as 0 BP, ie all C14 ages head back in time from 1950;
  
• the assumption that all C14 reservoirs have remained constant through time.

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bold addedModern measurements put the half-life at 5730 years. This is not a problem as long as both calculated dates are calibration curves use the same half-life of 5568.Another way to think about it is that the calculated 14C date is actually a measurement of the percentage of 14C compared to 12C in the sample, which is then correlated with tree ring 14C/12C percentages to give an approximated age.EnjoyEdited by RAZD, : clrty

No, they still use the OLD half-life for the correlation curves. This is so any sample, old or new can be compared on the correlation curve to get a calibrated date. Like I said, squirely).What you actually have with a 14C date is a measure of 14C/12C plotted on a log scale and the "14C dates" can be converted back to 14C/12C numbers, at which point the half-life is irrelevant to the correlation and the calibrated date. Here is an example of this approach that I believe I posted this before: Christian Geologists on Noah's Flood: Biblical and Scientific Shortcomings of Flood Geology, part 4

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We will employ tree rings and carbon-14, but not in the way readers may be accustomed to seeing. We will not use carbon-14 to determine an age at all. We will simply measure how much carbon-14 is currently found in each tree ring. Carbon-14 decays with time, so if each tree ring represents one year of growth, we should see a steady decline in the carbon-14 content of each successive ring. Figure 5 shows tree-ring carbon-14 data from living trees extending back 4000 rings.[2] ...

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Does that help?Enjoy

Actually no, unless what you want is a slightly more accurate calculated 14C date. When you use the calibration curve it corrects for (a) the variation in atmospheric 14C at the time the ring (sample) formed due to cosmogenic variations, and (b) the difference from raw 14C date (with old half-life) to actual tree ring date.Correcting the raw date to 5730 from 5568 and then entering the calibration curve would mean you have corrected it twice. More to the point, when the corrections are made the artifact dates become older.Correct. An old YEC argument I remember was that 14C is unreliable because not enough time has passed for 14C to reach an equilibrium level (which has to do with chain decay in other radiometric isotopes). See
An Index to Creationist Claims PRATT list
(points refuted a thousand times)
CD011.1: Carbon-14 VariabilityEnjoy

Actually the incremental axis would be the raw calculated 14C age (the information you have available) and the scatter would be due to the year to year variation in original atmospheric levels of 14C and the number of possible matches for that level of 14C, the standard deviation comes from measurement error and they introduce some smoothing of the data that doesn't really affect the results significantly. You need to see it graphically for clarity:Again from my material for updating the age correlation thread: Radiocarbon-Based Chronology for Dynastic Egypt (OK = Old Kingdom):

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... Radiocarbon dating, which is a two-stage process involving isotope measurements and then calibration against similar measurements made on dendrochronologically dated wood, usually gives age ranges of 100 to 200 years for this period (95% probability range) and has previously been too imprecise to resolve these questions.

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Here, we combine several classes of data to overcome these limitations in precision: measurements on archaeological samples that accurately reflect past fluctuations in radiocarbon activity, specific information on radiocarbon activity in the region of the Nile Valley, direct linkages between the dated samples and the historical chronology, and relative dating information from the historical chronology. Together, these enable us to match the patterns present in the radiocarbon dates with the details of the radiocarbon calibration record and, thus, to synchronize the scientific and historical dating methods. ...

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... We have 128 dates from the NK, 43 from the MK, and 17 from the Old Kingdom (OK). The majority (~75%) of the measurements have calibrated age ranges that overlap with the conventional historical chronology, within the wide error limits that result from the calibration of individual dates.

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The modeling of the data provides a chronology that extends from ~2650 to ~1100 B.C.E. ...

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This figure shows the distribution of uncalibrated radiocarbon dates against the modeled age. For each measurement, we show the mean and 1σ of the radiocarbon and modeled calendar dates: ... The calibration curve is shown as two black lines (1σ ). ...

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The results for the OK, although lower in resolution, also agree with the consensus chronology of Shaw (18) but have the resolution to contradict some suggested interpretations of the evidence, such as the astronomical hypothesis of Spence (24), which is substantially later, or the reevaluation of this hypothesis (25), which leads to a date that is earlier. The absence of astronomical observations in the papyrological record for the OK means that this data set provides one of the few absolute references for the positioning of this important period of Egyptian history (Fig. 1A).

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Note that there are several other sample dates with similar correlation of 14C measurement to dendrochronology correlations, here it is the earliest/oldest set that is of interest as a measure of accuracy and precision. The dendrochronology correlation is shown as two lines in Fig 2 (+1σ and -1σ )The earliest/oldest dates in Fig 2 are shown at ~2660 BCE, with 7 samples placed together (with two more placed nearby). There are several possible matches for each of these samples, running from 2580 BCE to 2860 BCE -- due to the wiggle of the 14C amounts in that portion of the graph -- I get 5 possible matches for the lowest point with an average age of 2693 BCE, 8 possible matches for the next point with an average of 2660 BCE, 6 possible matches for the third point for an average of 2702 BCE, 12 possible matches for the fourth point for an average of 2733 BCE, 9 possible matches for the fifth point for an average of 2754 BCE, 6 possible matches for the sixth point for an average of 2750 BCE, 8 possible matches for the seventh point for an average of 2771 BCE, 8 possible matches for the eight point for an average of 2787 BCE, and 6 possible matches for the highest point for an average of 2788 BCE. Assuming these points all represent the same age, the overall average age is ~2740 BCE with σ of +/-88 years (2827 BCE to 2651 BCE). Shaw's date for the tomb is 2660 BCE, so this is in close agreement with that dating. Note that +/-88 years in over 4,700 years of tree ring chronology is an error of +/-1.9%. The error is partly due to the two stage process of using 14C data to convert to dendrochronological calendar age, but mostly due to the wiggle of the 14C levels that match these points.Note that this conversion does not depend on the calculation of 14C 'age' -- that is a purely mathematical conversion of the measured amounts of 14C and 12C in the samples, and then comparing those 14C/12C values to ones found in the tree rings to find the best match to the tree rings, just as was done for the biblical history times above.This does, however,introduce an extra source of error due to the number of rings that match those levels inside the +/-1σ margins of error.EnjoyEdited by RAZD, : clrty

Sorry I was referring to the graphical presentation of the data by Riemer et al (IntCal13):http://www.radiocarbon.org/IntCal13%20files/intcal13.pdfNote that the various sources of tree rings are very consistent through page 7 when they run out. Page 8 has a lot of scatter and a fair bit of it is likely due to the assumptions made on reservoir effect on the marine samples (see Corrections to radiocarbon dates.)btw CAL BP refers to calendar BP and not calibrated BP (even though this should be the same).I don't know how that table works - I've not looked at it. Maybe Coyote knows?Enjoy

First off there are two versions of uniformitarianism:1. The scientific position is that the laws of how things behaved have remained virtually the same,2. The YEC (misrepresentation) is that it is in contrast to catastrophism, and thus assumes no catastrophes in the past.CD200: Uniformitarianism

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Claim CD200:
The evolution model is associated primarily with uniformitarianism, but evidence of catastrophism makes the uniformitarian assumption untenable.
Source:
Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master Books, pp. 91-100.
Response:

1. Modern uniformitarianism (actualism) differs from nineteenth century Lyell uniformitarianism. The prevailing view in the eighteenth and early nineteenth centuries was that the earth had been created by supernatural means and had been shaped by several catastrophes, such as worldwide floods. In 1785, James Hutton published the proposal that Earth's history could be explained in terms of processes observed in the present; that is, "the present is key to the past." This was the beginning of uniformitarianism. Charles Lyell, in his Principles of Geology, modified Hutton's ideas and applied this philosophy to explain geological features in terms of relatively gradual everyday processes.
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   Geologists today no longer subscribe to Lyell uniformitarianism. Starting in the late ninteenth century, fieldwork showed that natural catastrophes still have a role in creating the geologic record. For example, in the later twentieth century, J. Harlan Bretz showed that the Scablands in eastern Washington formed from a large flood when a glacial lake broke through an ice dam; and Luis Alvarez proposed that an asteroid impact was responsible for the extinction of dinosaurs 65 million years ago. Actualism (modern uniformitarianism) states that the geologic record is the product of both slow, gradual processes (such as glacial erosion) and natural catastrophes (such as volcanic eruptions and landslides). However, natural catastrophes are not consistent with creationist catastrophism, such as "Flood geology." First, they are much smaller than the world-shaping events proposed as part of the creationists' catastrophism. More to the point, they still represent processes observed in the present. Meteorites, glacial melting, and flash floods still occur regularly, and we can (and do, as in the examples above) extrapolate from the observed occurrences to larger events of the same sort. The scale of events may change, but the physical laws operating today are key to the past.

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Links:
University of Oregon. n.d. Uniformitarianism. http://zebu.uoregon.edu/2003/glossary/uniformitarianism.html

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Further Reading:
Lyell, Charles, 1830. Principles of Geology. London: John Murray. http://www.esp.org/...lyell/principles/facsimile/title3.html

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So confusing the issue with a different definition.Scientific law uniformitarianism can be tested:

1. sn1987a demonstrates uniformitarianism with decay rates the same 170,000 years ago, and that the speed of light has not changed,
2. uranium halos demonstrate uniformitarianism with constant decay rates during their formation over hundreds of thousands of years,
3. the oklo natural fission reactor demonstrates uniformitarianism with decay chains through isotopes the same as we see today,
4. coral heads show that the length of the day was shorter and there were more days per year in the past (see Message 10 -- the corals have daily growth rings within the annual formations) just as predicted by astronomical observations and demonstrating that the orbital mechanics involving the earth moon system have not varied significantly for over 400,000,000 years.

There are many such examples. Well I would classify it more as a scientific "law" than an assumption (or a conclusion): somethings seen so pervasively (like gravity) that it hardly needs testing -- except to show YEC folks that it has been observed.As mentioned, wiki can be edited by anyone, and articles that some people find contentious (like evolution) periodically get "hit" with changes.IIRC Dr A discussed uniformitarianism in his book as it affect geology.There is also a discussion of how Lyell influenced Darwin at Page not foundEnjoy

This is a slightly different take on their old argument that 14C is not in equilibrium in the atmosphere (so the earth is young), and -- like quote mining -- is it taking one piece of data out of context.The answer is correct, as far as it goes, but not as complete as it could be. Note that the date of Cook's claim is right at the peak of the bomb testing 14C generation (1966) -- and that creationists like to repeat old (falsified) arguments. That means that Cook is using the bomb generated 14C as "natural" formation (which he then extrapolates into the past ignoring the data from pre testing times). The Cook claim is not talking about today levels, which remain high from the testing. Note there are still bomb tests, and we also have Chernobyl and Fukushima that have caused measurable radioactivity in the atmosphere, so I would expect it to still be above normal sun cosmic ray generated 14C, but when you look at that graph you can see what looks like a pretty good exponential decay curve for it to continue dropping today towards the natural generation level on the chart -- ie it is currently decaying faster than it is being generated, and has been since 1966.Enjoy

Ah.Well, it is always a good idea to look at where creationist information comes from that is behind their claims as a starting point. I can provide several examples where science provides information that is then misused\misidentified by creationists to "prove" the science wrong. This is a new one in the list for me.Certainly the timing of the Cook claim is important to see where he gets the "data" to extrapolate back in time -- data provided by science to show the effect of nuclear testing on 14C levels in the atmosphere. By simply ignoring the nuclear testing effect Cook claims that 14C production is increasing and increasing faster than it is decaying.Once this "meme" is introduced in Creationist circles it will get repeated ... even in 1982. This is where Chris Weber's response is incomplete, or less complete than it could be. He should have - imho - addressed the time of the Cook claim and the conflation of nuclear (bomb) 14C and cosmic ray (natural) 14C, and then sorted out cosmic ray (natural) 14C production from total production. Instead his response is only related to the cosmic ray (natural) 14C fluctuations.Now look carefully at the chart again: Compare the graph at 1981 and 1982: it is higher in 1982 than in 1981 because of the natural fluctuation in cosmic rays and hence in the production of 14C in the atmosphere by cosmic rays. That "noise" in the data is the result of the natural variation of cosmic rays and the related production of atmospheric 14C -- it changes year to year.Weber's answer ... ... is in relation to this natural variation from year to year ... and ignores the nuclear (bomb) 14C residual decay. His answer was written in 1982.AND part of the problem is that "natural level" 14C is portrayed on the chart as a flat line instead of showing the annual variations, so it should read "average natural level" or "1950 standard level" or something similar.EnjoyEdited by RAZD, : ...

It would appear that he didn't even think of looking at data for the chart, but just went with the standard response to the "equilibrium" type creationist argument ...Enjoy