It sounds like they calibrated the magnetic field data to written history (ie, the bible and other religious texts). Carbon dating doesn't work for these years

It sounds like they calibrated the magnetic field data to written history (ie, the bible and other religious texts). Carbon dating doesn't work for these years because there is a plateau in the reference curve. [1] The earth must have had a weaker magnetic field (correlates with a low in sunspot activity), or there were lots of solar flares, or a supernova, near the beginning to create more c14 in the atmosphere than usual. Alternatively, the ocean "released" a bunch of old carbon to dilute the atmospheric c14 near the end of the period, thus making those years look older.[2] [1] https://en.wikipedia.org/wiki/Hallstatt_plateau https://en.wikipedia.org/wiki/Hallstatt_plateau [2] https://en.wikipedia.org/wiki/Marine_reservoir_effect https://en.wikipedia.org/wiki/Marine_reservoir_effect