What accelerator mass spectrometry could do, and what improvements in bone chemistry could achieve, were not fully clear in the 1960s — but researchers were beginning to understand that the science was not static.

AMS radiocarbon dating — accelerator mass spectrometry — was the key advance.

Conventional radiocarbon dating measures the radioactive decay of carbon-14 atoms by counting the particles emitted as they decay.

This requires a relatively large sample — typically several grams of carbon — and produces a measurement based on the statistical rate of decay over a counting period.

AMS dating, by contrast, measures the carbon-14 atoms directly: it uses a particle accelerator to separate and count the actual atoms, rather than waiting for them to decay.

This produces two major advantages.