boycott: "wild ass guess."
raygunfan: "EXACTLY"
No, not "exactly" and far from "wild ass guess".
In fact there are multiple data sources confirming such estimates, including this partial list of radio-metric materials:
| Parent Isotope | Stable Daughter Product | Est. Half-Life |
| Uranium-238 | Lead-206 | 4.5 billion years |
| Uranium-235 | Lead-207 | 704 million years |
| Thorium-232 | Lead-208 | 14.0 billion years |
| Rubidium-87 | Strontium-87 | 48.8 billion years |
| Potassium-40 | Argon-40 | 1.25 billion years |
| Samarium-147 | Neodymium-143 | 106 billion years |
| Rhenium-187 | Osmium-187 | 41.6 billion years |
Dates from these methods are consistent with each other and with dating from other methods, such as comparing mass & luminosity of the Sun with other stars and measuring Calcium-aluminium-rich inclusions in meteorites.
"Statistics for several meteorites that have undergone isochron dating are as follows":[36]
| Item | Meteorite | Radiometric material | Age of Earth |
| 1. | St. Severin (ordinary chondrite) | 1. Pb-Pb isochron | 4.543 ± 0.019 billion years |
| 2. Sm-Nd isochron | 4.55 ± 0.33 billion years | ||
| 3. Rb-Sr isochron | 4.51 ± 0.15 billion years | ||
| 4. Re-Os isochron | 4.68 ± 0.15 billion years | ||
| 2. | Juvinas (basaltic achondrite) | 1. Pb-Pb isochron | 4.556 ± 0.012 billion years |
| 2. Pb-Pb isochron | 4.540 ± 0.001 billion years | ||
| 3. Sm-Nd isochron | 4.56 ± 0.08 billion years | ||
| 4. Rb-Sr isochron | 4.50 ± 0.07 billion years | ||
| 3. | Allende (carbonaceous chondrite) | 1. Pb-Pb isochron | 4.553 ± 0.004 billion years |
| 2. Ar-Ar age spectrum | 4.52 ± 0.02 billion years | ||
| 3. Ar-Ar age spectrum | 4.55 ± 0.03 billion years | ||
| 4. Ar-Ar age spectrum | 4.56 ± 0.05 billion years |
Of course, by its nature science is never 100% irrefutable, but when evidence piles up from many sources, all pointing to consistent conclusions... well, that's as good as science ever gets.
