Dating the Earth

Independent clocks, their assumptions, their failures, and how often they agree on the same rocks. This page is the front door to the section and links to all of it; the summary and verdict are still to be written.

Summary

To be written.  Independent clocks, their assumptions, their failures, and how often they agree on the same rocks.  17 articles in this section are written;  the rest are planned.  This page will eventually state where they came out, which arguments survived, and which were retired.

The articles

Linked titles are written.  Bold titles are planned.

  • Radiometric Concordance: Do the Dating Methods Agree? — Modern independent clocks on volcanic ash agree within 0.02 to 0.24 percent. Older whole-rock dates often disagree where inheritance, lead loss, and closure temperatures predict.
    • RATE and Helium in Zircons — RATE's helium data are real, but its 6,000-year age rests on irreproducible retention, a false mica barrier, circular fit points, and unsolved heat.
  • Radiocarbon Dating — Radiocarbon is the best-tested dating method in science, and its tree-ring-anchored calibration runs 12,310 absolutely dated years. The young-earth carbon-14-in-coal argument survives in one narrow form and fails in every wide one.
  • Radiometric Anomalies — Known-age lava flows, excess argon, inherited minerals, and what anomalous dates do and do not show about the methods.
  • Earth's Decaying Magnetic Field — The field has weakened since 1840, but reversals rule out 6,000-year exponential decay. Dynamo models also struggle over 4.5 billion years; that open problem does not establish a young earth.
  • Non-Radiometric Clocks — Ice layers, lake laminae, tree rings, growth bands and orbital cycles date the past by counting, with no decay constant anywhere in the arithmetic. Where they can be checked against radiometric clocks they agree to between 0.07% and 7%, and the disagreements were all found by the people who built the counts.
    • Ice-Core Layer Counting — Greenland ice is counted layer by layer to 60,000 years and no further; Antarctic ice is not counted at all. Inside the counted range, up to five independent seasonal chemical signals agree with each other and with argon, uranium and tree-ring clocks to within a few per cent.
    • Lake Varves — More than one lamina per year is real, documented, and happens in exactly the lakes chronologists avoid. Where varve counts can be checked — Lake Suigetsu against uranium-thorium, and any lake against raw carbon-14 — the dominant error is undercounting, not overcounting.
    • Tree-Ring Dating — A burst of solar particles in 774 CE marked one ring in 44 tree-ring chronologies on five continents, and every one of them has it in the same ring. False and missing rings are real; the quantitative test of whether they shortened the chronologies was run by a creationist and came out negative.
    • Growth Bands and Tidal Rhythmites — Corals were supposed to count the days in the Devonian year, and the mainstream abandoned them. Tidal laminae in a 620-million-year-old Australian sandstone survived, give 400 days and 13.1 months in the year, and destroy the young-earth argument that the Moon would have been touching the Earth.
    • Orbital Cycles in Rock — Counting the 405,000-year Jupiter–Venus eccentricity cycle across the Late Triassic gives 8.50 million years; uranium-lead on the same two horizons gives 8.48 ± 0.3. The circularity charge against orbital tuning is largely correct for the Neogene and does not reach that test.
  • Geochemical Clocks — Clocks that work by accumulation in a reservoir rather than by counting layers — salt in the sea, argon and helium in the air, thorium in a coral — each dividing an inventory by a rate, and each standing or falling on whether the reservoir is closed.
    • The Sea's Missing Salt: Ocean Sodium and the Age of the Earth — Austin and Humphreys' 1990 sodium budget caps the ocean's age at 62 million years, and every step of its arithmetic reproduces exactly. It fails on its inputs: two of the four largest are unmeasured or disowned by their own authors, and fluid inclusions in halite show seawater sodium oscillating rather than rising.
    • Atmospheric Argon-40 and the Total Radiogenic Decay Budget — Essentially all the argon-40 in Earth's air is the decay product of potassium-40, and the Genesis mission's solar-wind measurements rule out a primordial source. Six thousand years of decay at the directly measured degassing rate supplies one part in 2.5 million of it. The young-earth claim of a hundredfold argon excess is a documented misreading of Melvin Cook, and has stood uncorrected for fifty-three years.
    • Helium in the Atmosphere and the Age of the Earth — The air's helium budget does not balance, and the standard rebuttal overstates its case by a factor of three to seven. But the argument never gave a young earth on its own author's arithmetic, and the young-earth literature retired it twice — R. H. Brown in 1998 and Larry Vardiman in 2005 — while popular creationist books kept printing it.
    • Uranium-Series Dating of Corals and Speleothems — Two decay chains, radiocarbon, tree rings and ice layers all agree with ²³⁰Th ages on the same carbonates. None of that refutes a uniform speed-up of decay, and critics who say it does have skipped the algebra. What it does refute is a non-uniform speed-up, and measured δ²³⁴U pins ²³⁸U to ²³⁴U at 0.015 per cent.
    • Amino Acid Racemization — A dating method that gave a 5,000-year-old skeleton an age of 70,000 years, and whose inventor published the post-mortem himself. The chemistry was never wrong, the calibration was. The same chemistry says a 70-million-year-old fossil should be fully racemized, which is why the method cannot be turned around to produce young ages.
    • Cosmogenic Nuclide Dating — Cosmogenic dating is two clocks. A surface-exposure age divides concentration by production rate, so a higher past cosmic-ray flux would shrink it in exact proportion — a real weakness the field admits, with 7-27% hold-out misfits. A buried-sediment age depends only on two decay constants, and no flux change touches it at all.
    • Luminescence Dating: OSL, TL and the Young-Earth Objections — Luminescence dating is a dosimeter, not a decay clock, so two of the three standard young-earth objections to radiometric dating do not apply to it. Sunlight zeroes the clock at deposition, which puts any accelerated decay out of reach. The method's real failures are all over-estimates, and the field found them itself.
  • How Old Does the Bible Say Earth Is? — No verse states the age of the earth; the number is a sum of five links whose surviving text-forms put creation between about 4,200 and 5,600 BC and humanity under 7,600 years. The earth's age can be loosened by one exegetical move, humanity's cannot. A falsification table finds the young-earth reading unanswered on tree rings, ice, radiocarbon-dated Neolithic sites and the human genome, and the old-humanity reading failing the text of Genesis 4 and 5.

Verdict

To be written.