i presented a link from cornell that suggests it isn't.Do you have any reason to think it may not be sound?
i presented a link from cornell that suggests it isn't.Do you have any reason to think it may not be sound?
Promise?leopold99: . . . You'll get yourself banned.
He can't even spell!oh god, more grilling from der fewer.
We give all members, including ourselves, quite a bit of leeway regarding the rule about insults, so long as the target is either a religionist or an antiscientist. Leopold appears to be both, so feel free to bring out the big guns.Most of you moderators are bashing on one individual with direct insults perhaps you should be banned.
completely off topic, opinionated, flaming, and trolling post.Promise?He can't even spell!We give all members, including ourselves, quite a bit of leeway regarding the rule about insults, so long as the target is either a religionist or an antiscientist. Leopold appears to be both, so feel free to bring out the big guns.
Hmmm... can't tell much from the link. Probably don't have the background to understand the implications anyway.i presented a link from cornell that suggests it isn't.
i asked james what he thought about the link hoping to get his viewpoint.Hmmm... can't tell much from the link. Probably don't have the background to understand the implications anyway.
How significant is this variance? What would the effects be... ie. would things appear older than they actually are, younger, no way of telling?
Can we minimize the effect by using several samples and other dating methods?
And since you don't seem to trust anything you weren't there to review, how can you trust these guys?
i asked james what he thought about the link hoping to get his viewpoint.
all he said was "nice link. well done" or something along those lines.
Recently, Jenkins, et al. have reported the detection of correlations between fluctuations in nuclear decay rates and Earth-Sun distance, which suggest that nuclear decay rates can be affected by solar activity.
how would you set up a control group for this type of experiment?No control group.
If they were serious, they should have done a simultaneous run with a 'blank' sample that was in an otherwise identical setup.
That would give their results a greater degree of robustness, and nipped a whole bunch of questions in the bud.
i don't know.Has that article been published in any peer-reviewed journal?
The answer is no, there is nothing on the Arxiv website to indicate that the article has been accepted for publication in any journal.i don't know.
i was only aware of the article because it was posted here on the forums.
Yes, some scientists "assumes" that if we find a 3 million year old piece of native rock then the Earth is at least three million years old.the age of the earth cannot be directly measured like for example a tree and its rings.
with any indirect method comes assumptions.
assumptions are things we take for granted but actually we have no proof of, that's why they are called assumptions.
this isn't necessarily true.Dating a meteorite gives us a date for the accretion disc. Indirectly that dates the Earth, since the Earth is also a part of the same accretion disc.
thanks, but i'm not exactly a noob.PS: Be careful of using the word "proof" in a science discussion. Strictly speaking, science does not do "proof", since in principle every scientific theory can be replaced with a better theory and every measurement comes with error limits on it.
all of the radiometric dating methods except one rely on the following assumptions:
1. beginning conditions are known
2. beginning parent/ daughter ratio is known.
3. constant decay rate.
4. no leaching or additions to parent/ daughter isotopes.
5. all assumptions are valid over the course of billions of years.
6. not really an assumption but the ability to measure extremely minute amounts of isotope.
i'm learning as i go james.How is (1) different from (2)? What "conditions" are you talking about in (1)?
c14 is not used to date fossils and very old rocksAs for (2), the process of formation of many radioactive nuclides is well understood, and these processes have been directly confirmed in experiments. For example, take C14 dating. From memory, C14 is formed by cosmic ray bombardment in the atmosphere. The rate at which plants absorb atmospheric C14 is testable. And we know for sure that once a plant dies it no longer absorbs carbon from the atmosphere.
agreed, but the possibility exists.There is no good evidence that radioactive decay rates are not constant, so this is a perfectly reasonable assumption until such time as contrary evidence comes to light.
how leaching occurs isn't the question.Mechanisms of leaching and addition are similarly well-understood. These are taken into account when scientists determine dates, and in particular the scientists always say when a given date might be unreliable due to such factors.
from what i've read radiometric dating can be considered reliable upto 8 times the half life.Not all radioisotopes are useful over billions of years. For example, C14 has a half life of only about 5700 years. Radioactive dating is not really useful once you get beyond a few multiples of the half life, due to the small amounts of radioisotope remaining.
i would assume that this isn't really a problem due to advances in measuring methods.The difficulty in measuring extremely minute amounts is exactly why short half-life radioisotopes are never used to determine vast ages (as explained immediately above).
how would you set up a control group for this type of experiment?
what do you mean by "blank sample"?
i am trying to picture what you mean but it eludes me for some reason.
c14 is not used to date fossils and very old rocks
if the universe did indeed start off with a bang then it's reasonable to expect some "very strange physics", at least in the earlier stages.
how leaching occurs isn't the question.
the question is "did it happen?"
the only exception would be a sample that was immediately isolated when formed.
from what i've read radiometric dating can be considered reliable upto 8 times the half life.
whether that is true or not i do not know.