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Author Topic:   Assumptions involved in scientific dating
edge
Member (Idle past 1817 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 67 of 222 (827276)
01-21-2018 10:25 PM
Reply to: Message 66 by DOCJ
01-21-2018 8:36 PM


Re: Questions
What assumptions are geologists making when dating rocks, etc?
It's really pretty simple. The assumptions are the the system is closed, the original isotopic composition can be estimated, the decay rates have been very nearly constant, that we can accurately measure the isotopes and that we can do the math correctly.
I assume here that you are talking about radiometric dating.
I'm wanting to find out the issues.
I'm sure you are. This is the typical YEC procedure: find some feature that is not satisfactory to their absolutist approach and attack that point. In other words, they want absolute proof of constant decay rates or absolute certainty of original daughter elements even though most geochronologists are pretty much comfortable with the assumptions. Any doubt, no matter how unrelated, insignificant or mitigated, is precious to them. There are a number of tests for the reasonableness of the assumptions, but the typical forum YEC will simply ignore that fact.
It's just a matter of if one of you are going to provide them. I'm looking at the information and a few of the assumptions I'm seeing are how much daughter product was in the sample, how much parent was in the sample, that their model of gravitational physics is true, and I'm sure there are some inside the formula such as constant variables..
Well for one, I'm not sure what a 'constant variable' is.
A really great thing would be for you, in good faith, to tell us the issues with your own method of dating geological events and then we could have a real discussion about the relative merits.
Edited by edge, : No reason given.

This message is a reply to:
 Message 66 by DOCJ, posted 01-21-2018 8:36 PM DOCJ has replied

Replies to this message:
 Message 68 by LamarkNewAge, posted 01-21-2018 10:56 PM edge has not replied
 Message 70 by JonF, posted 01-22-2018 3:57 PM edge has replied
 Message 75 by DOCJ, posted 01-22-2018 10:29 PM edge has not replied

  
edge
Member (Idle past 1817 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 74 of 222 (827329)
01-22-2018 7:45 PM
Reply to: Message 70 by JonF
01-22-2018 3:57 PM


Re: Questions
I prefer "premises" to "assumptions" since the latter connotes lack of solid foundation.
The system is rarely assumed closed. Isochron methods indicate if the system has been open and fails to produce a date. Ar-Ar and U-Pb (the two by far the most widely used) also indicate if the system has been opened and often produce a valid date anyway.
Isochron methods produce the original isotopic composition and a date as part of the method. In Ar-Ar the original isotopic composition seldom affects the date. In U-Pb (almost always on zircons) the crystallization process readily incorporates Uranium and strongly rejects lead so the original ratio of lead to Uranium is always zero or infinitesimal.
Complete agreement. I never know how far to simplify things and use common terminology. Although, I have to say that radiometric dating has changed a lot since I had any of that kind of work done.
One thing that most people do not understand is that if there a problem with a date it's kind of obvious from the viewpoint of an experienced researcher. In fact, right now I'm dealing with data that just looks bad for various reasons. It's going to take some more work. Same thing with the KBS Tuff. It didn't quite fit the known geology. And there is always an explanation.

This message is a reply to:
 Message 70 by JonF, posted 01-22-2018 3:57 PM JonF has not replied

  
edge
Member (Idle past 1817 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 182 of 222 (827595)
01-28-2018 10:42 AM
Reply to: Message 159 by DOCJ
01-27-2018 11:11 PM


Re: his really stupid "Questions"
How do geologists calculate the amount of the parent/and daughter chemicals in the Rock at creation?
They don't presume anything about the rock 'at creation'.
They just presume the daughter was the p and suggest it decayed ?
Are you asking or telling?
If you are asking, the answer is no.
I would think that is overly simplified.
It would be.
If that's what happens.
I wouldn't be able to presume a rock over billions of years had no contamination or no changes over all that time... Or that no daughter was present at creation.
It would appear that only YECs make the assumption that this is how radiometric dates are conducted.
We don't even have a good understanding of the universe..
But we do have AN understanding.
And, you have to admit, no understanding will ever satisfy the YEC movement.
Where it actually came from.. How it is actually functioning.. We don't actually know space has an ability to be curved.. atmospheric refraction can explain light traveling around a planet, or intrinsic properties can explain star light..
Mmm, ... I think you may want to speak for yourself on this.
But sure, we don't know everything, especially if you go far enough back in time. But we do know some things and we can only move forward by building on what we know.

This message is a reply to:
 Message 159 by DOCJ, posted 01-27-2018 11:11 PM DOCJ has not replied

  
edge
Member (Idle past 1817 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 184 of 222 (827601)
01-28-2018 11:30 AM
Reply to: Message 183 by Coyote
01-28-2018 11:04 AM


Re: Questions
Poor job! Your reply shows you know absolutely nothing about radiocarbon dating!
This is just another version of the old YEC position that if you don't know exactly what happened at the origin of the universe; then your current knowledge is unreliable and religious myth is preferable. That tiny doubt is precious, no matter how far back in time you have to go to find it.

This message is a reply to:
 Message 183 by Coyote, posted 01-28-2018 11:04 AM Coyote has not replied

Replies to this message:
 Message 188 by DOCJ, posted 01-29-2018 6:40 AM edge has not replied

  
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