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Author Topic:   Earth science curriculum tailored to fit wavering fundamentalists
RAZD
Member (Idle past 1426 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


(1)
Message 948 of 1053 (770333)
10-03-2015 5:31 PM
Reply to: Message 947 by ThinAirDesigns
10-03-2015 10:33 AM


Re: Self-replicating molecules in the wild
An excellent question, and as far as I know the answer is no, not really.
The closest would be RNA viral strands or prions, but those hijack cells to make reproductions of themselves.
So the next question is what is different about the environment today than a pre-life environment ... aside from the atmospheric composition issue ... and the obvious answer is that the environment today is filled with bacteria that would avidly consume the building block amino acids.
Cool example of bacteria being everywhere was a show I saw for kids to encourage them to wash their hands:
Teacher opens a fresh loaf of (white) bread and
  1. uses sterile tongs to place one piece in a ziplock bag (this is the control)
  2. washes her hands and put a second peice in a second ziplock bag
  3. passes a third piece of bread around for everyone to handle before putting it in a third ziplock bag
compare after a week or two.
Found this by search:
hand washing bread experiment
Not a demonstration of self-replication, but of what they would be up against today.
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


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This message is a reply to:
 Message 947 by ThinAirDesigns, posted 10-03-2015 10:33 AM ThinAirDesigns has replied

Replies to this message:
 Message 950 by ThinAirDesigns, posted 10-03-2015 7:29 PM RAZD has seen this message but not replied

  
RAZD
Member (Idle past 1426 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 953 of 1053 (772108)
11-06-2015 7:44 AM
Reply to: Message 951 by ThinAirDesigns
11-05-2015 9:01 PM


Re: Missing rings in dendrochronology
I understand that 2 rings per year is rather easy to detect (cellular difference as I follow it), but does anyone have any idea how one could detect missing rings? I'm not talking about a situation where one tree among many might for some reason be one ring short in a common sequence (solved by crossdating), but rather where a large climate event might cause widespread loss of a year in all the trees in a say an entire region.
Some species are more prone than others to either multiple rings or missing rings. The Bristlecone Pines are apparently more susceptible to missing rings and the evidence comes from three sources:
1 -- a second study done 19 years after the Methuselah chronology ended, where a number of the trees had missing rings and none had multiple rings,
2 -- a second Bristlecone Pine chronology from a different mountain area than the Methuselah chronology; it (only) extends 5,000+ years into the past (compared to 8,000+ for the Methuselah one), but it matches ring width to ring width for those 5,000 except for two places where the new chronology has missing rings and the old one has very narrow rings,
3 -- comparison to the two european oak chronologies (one Irish and one German, which agree ring for ring for 12,000 years iirc, except for 3 years difference) using measured 14C levels (which should be the same regardless of any change in 14C decay rate) and this shows that the Bristlecone Pine chronologies are short some 37 years total (an 0.5% error rate).
Could the oak chronologies also be missing rings? Possible, but I would still argue that they are as accurate as one could wish for -- even an 0.5% accuracy is pretty phenomenal in science, and the oaks are closer to 0.02% accuracy.
Knowing there are sources of error and being able to estimate how much they can affect the data is one of the critical elements of scientific evaluation of data.
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 951 by ThinAirDesigns, posted 11-05-2015 9:01 PM ThinAirDesigns has not replied

  
RAZD
Member (Idle past 1426 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 960 of 1053 (772130)
11-06-2015 5:56 PM
Reply to: Message 958 by ThinAirDesigns
11-06-2015 4:09 PM


Re: C14 dating question
I recall one claim about a tree that 14c dated older than the tree rings. Apparently it grew in a volcano caldron and the CO2 from the volcano vents had old carbon from deep in the earth. Can't find the reference now.
Yes missing rings are a small conundrum to find. The practical approach is to calibrate the chronologies to known dates -- such as the year without a summer or known volcanic eruptions that cause other climate dips (Year without a summer was the summer following Krakatowa iirc). That gives you a statistical error and you can use that to create bracket dates with standard deviations. To my mind these turn out to be amazingly small errors over thousands of years.
There is also a newly known oldest tree -- another Bristlecone Pine that by ring count dates to 5,065 years old (in 2015), and I don't know if this is missing innermost (pith) rings as the others are, so this would be a minimum age, and from the comparison of the two Bristlecone Pine chronologies with (at least) 2 missing rings in one chronology we'd have to say the likely age is (at least) 5,066 +/-1 years.
I note that this is older than most YEC dates for the Noachin Flood ...
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 958 by ThinAirDesigns, posted 11-06-2015 4:09 PM ThinAirDesigns has not replied

  
RAZD
Member (Idle past 1426 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 966 of 1053 (772521)
11-15-2015 12:18 PM
Reply to: Message 965 by ThinAirDesigns
11-15-2015 9:56 AM


Re: Hugh Miller Debate
The "Arena" is a separate area where everyone can see an exchange, but only those invited to the exchange can participate - this keeps exchanges on very specific topics cleaner with less side commenting to derail things.
So it would be like our "The Great Debate" forum. If you provide a link we can run a "peanut gallery" thread to discuss and advise.
And you can invite people to join our peanut gallery, and get some good cross-current trading of information.
Sounds fun.
Enjoy

we are limited in our ability to understand
by our ability to understand
RebelAmerican☆Zen☯Deist
... to learn ... to think ... to live ... to laugh ...
to share.


Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)

This message is a reply to:
 Message 965 by ThinAirDesigns, posted 11-15-2015 9:56 AM ThinAirDesigns has not replied

  
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