Earth science curriculum tailored to fit wavering fundamentalists

Oh yes, and I know exactly which ones. Very well put. From my experience, you can have the perfect answer to every question and evidence up and down and there is still a process of usually many years to get the mind to internalize and accept. I watched this process with one of my sisters who is now agnostic/atheist. The brain simply won't allow the deprogramming to occur overnight with most folk.Good advice. Thanks
JB

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

Good flowsheet on the scientific method.Now, to stretch your imagination, lets see one for Intelligent Design.That should be fun!

I've been working my way through this amazing resource. I'm not going to pretend that I follow it all to a T first pass, but I'm working on it. So freaking cool to have found y'all here to help educate me on this stuff.THANKSJB

I found this one over at Pharyngula: http://scienceblogs.com/...16/explanatory-filter-20-in-one-s

Ok, I'm normally pretty capable when it comes to research, but I simply can't seem to find out what calendar year the "0" year in the INTCAL13 calibration data ties to. 2013 seems doubtful for several reasons.I'm sure someone here knows for sure.Thanks in advanceJB

And while I'm on the topic of C14 dating ...(First, let me be clear that when I refer to "sources I've read, I don't get my info from ICR, etc)In my learning about C14 dating, I've read literally dozens of papers and many web sites (including suggestions from this group.)One thing I'm a bit confused about is the sources seem almost evenly split between describing the ratio between C14 and C12 as part of the measurement process and saying nothing about ratio and merely talking about measuring the C14.I'm trying to figure out if
A: the ratio is relevant
B: if relevant, how is the ratio used.Following is an example that is confusing me. It's from a link suggested to me by RAZD.How Carbon-14 Dating Works | HowStuffWorks

quote:

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Dating a Fossil

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As soon as a living organism dies, it stops taking in new carbon. The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced. The carbon-14 decays with its half-life of 5,700 years, while the amount of carbon-12 remains constant in the sample. By looking at the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of a formerly living thing fairly precisely.

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A formula to calculate how old a sample is by carbon-14 dating is:

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t = [ ln (Nf/No) / (-0.693) ] x t1/2
t = [ ln (Nf/No) / (-0.693) ] x t1/2

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where ln is the natural logarithm, Nf/No is the percent of carbon-14 in the sample compared to the amount in living tissue, and t1/2 is the half-life of carbon-14 (5,700 years).

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So, if you had a fossil that had 10 percent carbon-14 compared to a living sample, then that fossil would be:

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t = [ ln (0.10) / (-0.693) ] x 5,700 years
t = [ (-2.303) / (-0.693) ] x 5,700 years
t = [ 3.323 ] x 5,700 years
t = 18,940 years old

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So in the above example (green background portion) it clearly talks about comparing the *ratio of carbon-14 to carbon-12* in the sample to the *ratio* in the living organism and using that to date. But yet when I look at the formula provided, I don't see any utilized ratio, only the %C14 is input to the formula. What am I missing?One thing to please remember. The list of things that I am NOT is long (mathematician, chemist, physicist, etc) so while I'm not particularly slow on the uptake, there's a TON of things I've never learned about science and math. Just think of me as the kid of intentionally isolated fundamentalists who ran away and pulled himself up by his bootstraps by educating himself best he could by reading and you'll pretty much have me nailed.Thanks to EVERYONE who is helping me along with my education. I'm so appreciative of your knowledge and patience.JB

Perhaps "ratio" is not quite the right word, but the percentage of carbon-14 is a percentage of the carbon in the sample, not of the total sample. So you do need to know how much carbon-12 there is.

Well, if there are bits of it that give you trouble, this is in fact my fault. I would welcome any questions, criticisms, or indications of the rough patches.

I presume that you're looking at dates with the initials BP after them. BP stands for "before present". So year 0 is, in fact, now, and then larger number are years further into the past.

First, you don't date "fossils" with carbon-14 dating. Fossils are once-living things that have had their organic materials replaced by stone. Stone doesn't date well when you're looking for organics.But, some "fossils" are only partially fossilized, and retain some organics, so they can sometimes provide a date.The initial ratio between C14 and C12 is not a problem, as that figure can be supplied through calibration. It was initially assumed that the levels of C14 were constant, but that was shown not to be the case early on (see De Vries 1958).The need from that point on was to establish the initial correct ratios, and that has been done using the calibration curve--the most recent of which in IntCal13.In other words, the atmospheric levels of C14 vary a bit, maybe up to about 11 or 12%. To get a more accurate date, this factor needs to be accounted for. Calibration against tree-rings, varves, corals, and other annular data provided a means to do this. And, historical items of known ages such as Egyptian relics, are also used.The bottom line--C12 is pretty much a constant, while C14 is a variable: it varies both from the initial value and due to radioactive decay through time. But, by controlling for that initial value through calibration the remaining variable is time so the method becomes quite accurate.As for the math--I'll leave that as an exercise for the student.

The word 'compared' in the following sentence (Emphasis added by me) means to take a ratio:

quote:

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where ln is the natural logarithm, Nf/No is the percent of carbon-14 in the sample compared to the amount in living tissue, and t1/2 is the half-life of carbon-14 (5,700 years).

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So if the amount of c-14 in the original sample was .5% and in the final measurement was 0.05%, the Nf/No is 0.05%/0.5% or 0.10. So Nf/No is the ratio of two percentage numbers.

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

The data I downloaded was a comma delimited file with 5 fields (and no header).The first field is a steady countdown of numbers (starting at 50000) by set increments, the second fields is also a countdown of numbers with some scatter but always hovers near the value of the first field. The other fields appear to be things like error ranges and standard deviation stuff.Because of its steady incremental nature, I assumed that the first field is calender years (counting backwards from some fixed date) and the second fields was C14 dates but I concede that's a guess.Just trying to figure out for sure and anchor that 0(zero) row to some calendar date.Thanks
JB

Awesome -- that's what I needed to know.Do you know if the field that is incremented steadily is the calendar dates and the one with scatter is the C14, or is the lookup table the other way around where you look up your C14 date on the steadily incremented column and then it gives you the actual date in the column with the scatter?Thanks
JB