Freethought & Rationalism Archive

tgamble · 03-06-2002, 12:31 PM

On another forum a creationist stated:

Quote:

As for Radiometric dating alot of the text books still used when I was in school ( Sigh now that is depressing) were based on radiometric dating that used Coelacanths as a marker to verify the dates. They have since refined the process and are way more accurate but they are still using the misinformation based on Coelacanths instead of redoing the work to straighten it out. The old circular reasoning effect of " This creature died out ?million years ago so we calibrate the dating to this ." IT happened and they have still not done anything about it they just talk around it by saying how modern techniques are better wich I agree with but they still haven't gone back to correct what is obviously errors based on a presumption of fact.

Does radiometric dating even use fossils to verify dates? I pointed out that the Coelacanth found was a different genus. The response was basically "Is not".

thanks for the help.

lpetrich · 03-06-2002, 01:41 PM

As to radioisotope dating and fossils, fossils are often used for correlating the strata found at different sites, and are thus useful for cross-checking radioisotope dates worked out at different sites. Fossils are also useful for extending radioisotope dating to sites that may not have some convenient lava flows or volcanic ash that one can use for such dating.

And one very nice result of radioisotope dating is that it confirms the relative order of the fossils that had been deduced decades before, with the help of their consistent patterns of superposition. Yes, superposition and not expected sequence of evolution.

The Coelacanth was discovered to be living in a very out-of-the-way place: deep in the oceans. This fish is thus not the disaster that many creationists seem to think that it is.

[ March 06, 2002: Message edited by: lpetrich ]

tgamble · 03-06-2002, 01:52 PM

Quote:

Originally posted by lpetrich:
As to radioisotope dating and fossils, fossils are often used for correlating the strata found at different sites, and are thus useful for cross-checking radioisotope dates worked out at different sites.

ok. first, have Coelacanths been used for this purpose? If so, does the discovery of a living one make such useage invalid and if not, why not. (Or is it simply that it's a different genus from the one being used)?

Again, thanks for the help.

Coragyps · 03-06-2002, 01:53 PM

As I understand radiometric dating, the only "assumption" is that the laws of physics that lead to radioactive decay don't randomly change through time. Several decay sequences have been used to date meteorites to 4.56 x 10^9 years old, and there durn sure weren't coelacanths around then to calibrate against.
There's a very good page at TalkOrigins, IIRC, and another from some "christian geologist" page that go into depth on this. Or wait for Patrick.

Your second post just showed up!
Again, I'll bet half the farm that early U-Pb dating or the like was used to assign an absolute date to some particular fossil coelacanth, not the other way around. No one had anything but relative dates until Ms Curie, et al., pointed the way with radioactivity. The continued existence of any organism won't change nuclear decay one little bit.

[ March 06, 2002: Message edited by: Coragyps ]

ps418 · 03-06-2002, 02:06 PM

Tgamble, your friend is completely full of [sh]it. Fossils are NOT used to calibrate radiometric decay rates. Indeed, the whole idea does not even make sense, since you'd have to know the absolute age of a fossil independently of radiometric dating to use it for calibration, yet you can only get the absolute age by radiometric dating (further back that the Quaternary, that is).

Whenever someone makes claims like this, it should be second nature to demand a source.

Patrick

lpetrich · 03-06-2002, 02:33 PM

Quote:

Originally posted by tgamble:

(cross-correlating rock strata at different sites...)

ok. first, have Coelacanths been used for this purpose? If so, does the discovery of a living one make such useage invalid and if not, why not. (Or is it simply that it's a different genus from the one being used)?

I doubt that Coelacanths have been much used, because there are plenty of very common sorts of fossils, such as fossil protists and shellfish, that can and have been used. But even if they have been used, they would still be useful, because their presence in the fossil record is not changed by the discovery of a live one.

rockmom · 03-06-2002, 02:41 PM

tgamble-

Here are some of my thoughts on what your creationist said.

He is confused by qualitative versus quantitative dating. Qualitative dating is this came before that. Quantitative is this is 120 million years old and that is 100 million years old.

the creationist said:

Quote:

The old circular reasoning effect of " This creature died out ?million years ago so we calibrate the dating to this ."

We can say that this fossil disappeared from the stratigraphic column at some point before or after other fossils disappear in the stratigraphic column.

Radiometric dates are not based on when a fossil appears or disappears. The are based on decay rates of radioactive isotopes.

He misunderstand physics, sedimentology, taphonomy, and geochronology.

lpetrich · 03-06-2002, 02:49 PM

One does NOT use fossils to calibrate radioisotope dating.

Instead, one can test hypotheses of radioactive-decay rate changes by comparing different radioisotopes. Unless they all change in perfect sync, relative changes will result.

Alpha decays happen by He4 nuclei doing quantum tunneling through the region near the nucleus, where the electric potential is too high to allow them to pass, if one uses classical mechanics. Beta decay happens as a result of a virtual W particle (about 100 times the mass of a nucleon) being produced as a neutron becomes a proton; the W then decays into an electron and an antineutrino. There are variants, like a proton becoming a neutron and a positron and a (true) neutrino -- and an electron and a proton becoming a neutron and a neutrino.

So if fundamental-constant values have changed over time, then one expects the various alpha and beta decay rates to change by different amounts. But they have not.

tgamble · 03-07-2002, 04:41 AM

The person I was reffering to posted the following response to your information.

Quote:

What I posted was preety plain Homer I am sorry you are having trouble digesting it. My statement wasn't That they calibrated the machines by it but that they used them as markers to correlate with their dating methods and if that is how it came accross I better check my typing. We were even taught in High school that Coelacanths were used in conjunction with Radiometric dating as they were known to be extinct for umpteen million years so no coelacanth would be in anything newer so anything they found including rock strata was dated according to the supposed age of the Coelacanth extinction. despite what you asked all your buddies on infidels confirmed the part you didn't post on their that they were used as correlative when used against Radiometric dating wich they have improved on as some of the old techniques were admittedly not always giving correct dates. As well thanks for going to another forum and pasting me as another "Creationist" as I am sure it didn't taint their opinion at al. Why not just post my whole referenc uncut instead of leaving out the bulk of what I said to mislead them? I guess trying to have an intelligent conversation about what I see as flaws and what you see as evidence doesn't make sense to you so you paste me as something else to get negative feedback. I actually take in everything you give me because I respect your opinion and you have proven me wrong in the past I like that because I love learning new things and learning the truth. I don't mind being wrong But I like clear evidence not a bunch of doubletalk and taking me out of context and painting me with a brush you know they will automatically ridicule. Maybe I respect you more that you do me

On that note I'm posting the entire post plus link to the post. I don't think it changes much but It's best to be sure.

<a href="http://forums.sympatico.ca/WebX?14@31.nB9faZHKhqp^16694@.f038210/81" target="_blank">http://forums.sympatico.ca/WebX?14@31.nB9faZHKhqp^16694@.f038210/81</a>

Quote:

none of your links show that they have actually found Precambrian below Cambrian fossils its all conjecture. They have not shown one instance where they have actually found them in the layers they say they should be in. As for Radiometric dating alot of the text books still used when I was in school ( Sigh now that is depressing) were based on radiometric dating that used Coelacanths as a marker to verify the dates. They have since refined the process and are way more accurate but they are still using the misinformation based on Coelacanths instead of redoing the work to straighten it out. The old circular reasoning effect of " This creature died out ?million years ago so we calibrate the dating to this ." IT happened and they have still not done anything about it they just talk around it by saying how modern techniques are better wich I agree with but they still haven't gone back to correct what is obviously errors based on a presumption of fact.

The Coelacanth is not a different Genus it is the exact same type. As for the horse genus thye have found in some areas of the world that certain genus types were eradicated by breeding crossovers within the past few thousand years with some thought to be extinct hose types still having genetic cousins yoday but altered through breeding processes by man.

You can put up all the lionks you want Homer and there is some good science in there but they have still never ever found one instance where the fossil record was as they portray it. not once have they found them in the order stated so it is still conjecture untill the facts line up with their Hypothesis. wether you believe it or not I think alot of the Creationist stuff is based on junk science but when the real scientists can't even agree unless its based on presumed facts I have to wonder what is going on.

Dr.GH · 03-07-2002, 11:27 AM

T.G

Where do you find these guys? Radiometric dating methods do NOT use, and Never Have used vertebrate fossils for calibration. Carbon dating is calibrated by dendrochronology (tree ring counts) back to around 10,000 years, uranium decay to the limit of the 14C method at around 60,000 years. Thermoremnant Magnetic dating was partially calibrated by 14C and other methods.

Either your pal is lieing, phychotic, or just doesn't remeber what he was taught. Take your pick.

I just read the thread, and I think I lost 15 IQ points. The.... room.... is..... spinning....

[ March 07, 2002: Message edited by: Dr.GH ]

03-06-2002, 01:41 PM	#2
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	As to radioisotope dating and fossils, fossils are often used for correlating the strata found at different sites, and are thus useful for cross-checking radioisotope dates worked out at different sites. Fossils are also useful for extending radioisotope dating to sites that may not have some convenient lava flows or volcanic ash that one can use for such dating. And one very nice result of radioisotope dating is that it confirms the relative order of the fossils that had been deduced decades before, with the help of their consistent patterns of superposition. Yes, superposition and not expected sequence of evolution. The Coelacanth was discovered to be living in a very out-of-the-way place: deep in the oceans. This fish is thus not the disaster that many creationists seem to think that it is. [ March 06, 2002: Message edited by: lpetrich ]</p>

03-06-2002, 01:53 PM	#4
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	As I understand radiometric dating, the only "assumption" is that the laws of physics that lead to radioactive decay don't randomly change through time. Several decay sequences have been used to date meteorites to 4.56 x 10^9 years old, and there durn sure weren't coelacanths around then to calibrate against. There's a very good page at TalkOrigins, IIRC, and another from some "christian geologist" page that go into depth on this. Or wait for Patrick. Your second post just showed up! Again, I'll bet half the farm that early U-Pb dating or the like was used to assign an absolute date to some particular fossil coelacanth, not the other way around. No one had anything but relative dates until Ms Curie, et al., pointed the way with radioactivity. The continued existence of any organism won't change nuclear decay one little bit. [ March 06, 2002: Message edited by: Coragyps ]</p>

03-07-2002, 11:27 AM	#10
Dr.GH Veteran Member Join Date: Jul 2001 Location: Dana Point, Ca, USA Posts: 2,115	T.G Where do you find these guys? Radiometric dating methods do NOT use, and Never Have used vertebrate fossils for calibration. Carbon dating is calibrated by dendrochronology (tree ring counts) back to around 10,000 years, uranium decay to the limit of the 14C method at around 60,000 years. Thermoremnant Magnetic dating was partially calibrated by 14C and other methods. Either your pal is lieing, phychotic, or just doesn't remeber what he was taught. Take your pick. I just read the thread, and I think I lost 15 IQ points. The.... room.... is..... spinning.... [ March 07, 2002: Message edited by: Dr.GH ]</p>

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03-06-2002, 02:06 PM	#5
ps418 Veteran Member Join Date: Mar 2001 Location: Louisville, KY, USA Posts: 1,840	Tgamble, your friend is completely full of [sh]it. Fossils are NOT used to calibrate radiometric decay rates. Indeed, the whole idea does not even make sense, since you'd have to know the absolute age of a fossil independently of radiometric dating to use it for calibration, yet you can only get the absolute age by radiometric dating (further back that the Quaternary, that is). Whenever someone makes claims like this, it should be second nature to demand a source. Patrick

03-06-2002, 02:49 PM	#8
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	One does NOT use fossils to calibrate radioisotope dating. Instead, one can test hypotheses of radioactive-decay rate changes by comparing different radioisotopes. Unless they all change in perfect sync, relative changes will result. Alpha decays happen by He4 nuclei doing quantum tunneling through the region near the nucleus, where the electric potential is too high to allow them to pass, if one uses classical mechanics. Beta decay happens as a result of a virtual W particle (about 100 times the mass of a nucleon) being produced as a neutron becomes a proton; the W then decays into an electron and an antineutrino. There are variants, like a proton becoming a neutron and a positron and a (true) neutrino -- and an electron and a proton becoming a neutron and a neutrino. So if fundamental-constant values have changed over time, then one expects the various alpha and beta decay rates to change by different amounts. But they have not.

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