You can't calculate how much 87Sr was present at the beginning without first *assuming* that it is relatively proportional w/ 84Sr, 86Sr & 88Sr. Because of this assumption, you are *assuming* the amount of 87Sr that was present when the isochron was formed. Maybe that doesn't qualify as an assumption in your mind, but it does in mine.
And yes, they did find excess helium. You do the same thing when you assume how much helium should be present. Why criticize your opponent for the same thing that you do?
And the Law of Conservation of Energy is not violated with a faster rate with lower energies per event. See Setterfield.
http://www.setterfield.org/zpe.htm#zpeandatom
When 3 of 8 isochron samples by Dalrymple return dates of 34 billion years, there are no good 'independent' reasons for discarding these anomalies.
(Dalrymple, G. B., 1984 How Old is the Earth?: A Reply to ‘Scientific’ Creationism In “Proceedings of the 63rd Annual Meeting of the Pacific Division, American Association for the Advancement of Science” vol. 1, pt. 3, Frank Awbrey and William Thwaites (Eds).)
You are the one who is backpedalling furiously. You went from 'no asumptions on radiometric dating' to a focus only on isochrons. That's a huge step backward as non-isochronic methods were once presented as reliable just as isochron methods are today.
The only difference is that science hasn't figured out all of the problems w/ isochron dating yet. But they are starting to come out and that's not good for you.
In your reply about the formation of the geological column, you said- "In other words, the geological column has been formed over a 3000 year period since Creation. A similar statement can be made for radiometric ages of astronomical bodies, like the Moon, or meteorites." The Bible says the Flood lasted for about one year. So how could it have been formed "over 3,000 years"?
Setterfield: ...it is established from the physics of the situation that some atomic processes, including radiometric decay are light-speed dependent. More correctly, both light-speed and radioactive decay are mutually affected by the increasing energy density of the ZPE. Thus, as light-speed is smoothly dropping with time, so is the rate of radioactive decay upon which radiometric dates are dependent. The redshift data reveal that the bulk of this decay has occurred over a 3000 year period during which predicted radiometric ages dropped from 14 billion years down to a few thousand years on the atomic clock. More particularly, the Cryptozoic strata formed over a period of 2250 years, while the Phanerozoic strata formed over a period of 750 years...
The asteroid impacts that ended the Mesozoic would have been expected to wipe out the dinosaurs. Yet a few dinosaurs were still there up to 2 million atomic years after the impact. They cannot account for this. However, the redshift data explains why. The speed of light at that point in time was about 500,000 times its current speed, so that 2 million years were just 4 years of actual time - soon enough after the catastrophe and the changing conditions it brought...
Are there any pre-Flood rocks that we can find today?
Setterfield: On the data I am using from the redshift, the Flood occurred about 700 million atomic years ago. The oldest earth rocks about 4.4 billion date from near the birth of Noah or a little earlier on the redshift correction. If the redshift correction is used, the Sturtian diamictites are the beginning of the Flood. Any rocks which are prior to the Sturtian diamictities would be pre-Flood.
No. You know that it does not exceed 7%, because that's the current abundance, and it's increasing with time. We understand isotope fractionation processes pretty well, and we know they're very weak for a divalent ion like Sr2+. We also can extrapolate back the abundance of 87Sr to the time the rock was formed, based on the known concentration of 87Rb in the lithosphere. There will be some error associated with that, but not much, becuase the abundance of 87Sr is quite low in the first place, and it is formed very slowly. So you certainly know it's in a very narrow range somewhat below 7% of all strontium. So if you know the abundance of the other isotopes, you can calculate the initial abundance of 87Sr at any time in the earth's history, probably to better than 1% accuracy.
And yes, they did find excess helium. You do the same thing when you assume how much helium should be present. Why criticize your opponent for the same thing that you do?
No, they did not. They found less helium than must have been produced by radioactive decay. We know how much helium was produced, because we know the amount of uranium that decayed to lead.
See Setterfield. Setterfield is a fruit-loop whose ideas have ben rejected by the scientific community and even by the more respectable YECcers.
When 3 of 8 isochron samples by Dalrymple return dates of 34 billion years, there are no good 'independent' reasons for discarding these anomalies.
The only difference is that science hasn't figured out all of the problems w/ isochron dating yet. But they are starting to come out and that's not good for you.
The two references you've given citing 'problems' are 17 and 22 years old. Hardly 'starting to come out'!
What do you mean specifically? Are you suggesting that the several isotopes of Sr behave differently chemically? If not, then how will you arrange to vary the ratio of their concentrations in the minute parts of a lava flow that form a single zircon?
What can happen, according to what I've read, is that a zircon can be pulled into a later flow and act as the nucleus for additional crystal formation. Then the isochron won't give any age, or rather it would give two if we had enough data points.