[Dr. I. C. Spots]

“All of metrology uses certain assumptions”. This is a false statement. I have been in electrical calibration for over 20 years and I have never calibrated a piece of equipment based on an assumption. Calibration or metrology is simple; measuring an unknown against a known. If for example I'm going to measure resistance then I must have a STANDARD OHM to use, a unit of resistance agreed upon by national and international agencies. If you do not have a known standard than you can not calibrate that unit. If I had a customer that brought a meter to me to cal and I told him that I did not have a suitable standard but I took a good stab at it, he would demand his money back and take it to a reputable lab. Unless I have a rock that I know is 1 million years old then how can I accurately date anything to a million years? Without a known standard, anything else is guess work. The more guesses and assumptions you make the more inaccurate the result. Everyone knows what happens when you ASSUME.

[GourmetDan]

“All of metrology uses certain assumptions”.

"This is a false statement."

"Unless I have a rock that I know is 1 million years old then how can I accurately date anything to a million years? Without a known standard, anything else is guess work."

I think you just proved his point rather than falsifying it.

[metmom]

Unless I have a rock that I know is 1 million years old then how can I accurately date anything to a million years? Without a known standard, anything else is guess work. The more guesses and assumptions you make the more inaccurate the result. Everyone knows what happens when you ASSUME.

And where does one get a rock that one KNOWS is a million years old? How is that determined?