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An 'indicator'? You mean that you must assume how much daughter element was present initially? You mean it's not measured? If not measured, then it must be an assumption based on an inference based on an extrapolation of a current measure.

Excess helium in zircons has been measured. Google 'RATE project'

'Experimental facts' are *only* valid for the time period covered by the experiments.

And your assertion that higher radioactive rates in the past would have overheated the earth is obviously based on an unmeasured assumption that the energy emitted is a function of the event rather than a function of time.

It is also disingenious to pretend that anomalous results do not occur in radiometric dating. They happen all the time and are thrown out if they do not meet 'a priori' assumptions.

Now, what was it you were saying about 'no assumptions'?

"The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions about the initial amount of the daughter nuclide in the radioactive decay sequence are needed. Indeed the initial amount of the daughter product can be determined using isochron dating."

An 'indicator'? You mean that you must assume how much daughter element was present initially? You mean it's not measured? If not measured, then it must be an assumption based on an inference based on an extrapolation of a current measure.

No. Any lead-204 in a zircon was there when the zircon was formed. Period. Similarly, if you do a rubidium strontium date, any ⁸⁴Sr, ⁸⁶Sr and ⁸⁸Sr was there at formation, since only ⁸⁷Sr is a decay product. So using the non-radiogenic isotopes, you can calculate how much ⁸⁷Sr was there at the beginning.

Excess helium in zircons has been measured. Google 'RATE project

I've seen it. In fact, I've analyzed the paper in detail. Now those are assumptions! They didn't find excess helium. They found more helium than they thought they should, based on some very dubious assumptions of helium closure temperatures, and some downright dishonest data analysis.

And your assertion that higher radioactive rates in the past would have overheated the earth is obviously based on an unmeasured assumption that the energy emitted is a function of the event rather than a function of time.

The Law of Conservation of Energy is not an assumption.

It is also disingenious to pretend that anomalous results do not occur in radiometric dating. They happen all the time and are thrown out if they do not meet 'a priori' assumptions.

All scientific work turns up anomalies. Good practice is to discard them only if there are independent reasons for doing so.

Now, what was it you were saying about 'no assumptions'?

I wasn't. I asked you to identify the assumptions. So far you're 0 for 3. Want to try again?

"'Experimental facts' are *only* valid for the time period covered by the experiments. "

Not when it comes to Evos they are not.

They take an inference and call it evidence.