A second batch of carbon-14 tests recently completed on the Dead Sea Scrolls is unlikely to settle any of the many outstanding disagreements concerning the interpretation of the scrolls, or even their dates.

Although in general the new carbon-14 tests are, in the words of the report on the tests, “in reasonable agreement with palaeographic estimates” of the age of the scrolls, there are enough deviations and uncertainties to provide argument for all sides.

Carbon-14 tests give only a range of dates, sometimes quite wide. Even more important, the range itself must be qualified: Test conclusions state only that in 68 percent (one sigma) of the cases the date will be within a particular range; if the range is increased (from one sigma to two sigmas) the percentage can be increased from 68 percent to 95 percent. Expressed somewhat differently, the probability is 68 percent (or 95 percent) that the date falls within a particular range.

To explain this more concretely, let’s look at a particular example. Take the text known as 4Q521, the Messianic Apocalypse. This 14-line fragment speaks of a single messiah who will rule heaven and earth; it describes the resurrection of the dead in the time of the messiah and contains some verbal parallels with the Gospels of Matthew and Luke.c In the words of the authors of the report on the most recent carbon-14 tests,d “This text is the focus of much debate in research, in particular with regard to its possible connection with early Christianity.”

Those scholars who connect 4Q521 with early Christianity would like to date it as late as possible. Other scholars date it earlier. Emil Puech, who published the fragment in the Revue Biblique, dates it on the basis of his paleographic analysis (the shape, form and stance of the letters) to sometime between 100 and 80 B.C.E., long before Jesus’ time.

How does this compare with the result of the carbon-14 test of this fragment? According to the test, there is a 68 percent probability that this fragment dates between 35 B.C.E. and 59 C.E., and a 95 percent probability that it dates between 93 B.C.E. and 80 C.E. Obviously, this kind of result doesn’t much affect the debate over the date of the fragment or its relationship to early Christianity. Each side can make its case on the basis of the carbon-14 results.

This is not meant as any criticism of the people who performed the tests. Nor does it suggest that these tests were unnecessary. On the contrary, they add to the available dating evidence. We need all the evidence we can get. But, unfortunately, the results are too gross and too iffy to settle any arguments, although in general the results confirm the accuracy of paleographic dating.

The recent tests included 18 different scrolls and two pieces of linen that had allegedly wrapped the scrolls. Refined techniques (accelerator mass spectrometry [AMS]) for carbon-14 testing now require only a minute sample—from two to ten milligrams. (A gram is 0.035 of an ounce; a milligram is one-thousandth of this.) The team collected their samples from ragged parts of top or bottom edges, so no significant damage was caused to the scrolls themselves.

The scrolls tested included one that had previously been testede (the results were very close to one another) and three documents that contained internal dates (the results were, in the words of the report, “in good agreement”). But, as seems always to be the case, in one fragment the difference between the carbon-14 date and the paleographic date was more than a couple hundred years: According to the paleographic estimate, the fragment (4Q258) dates to about 100 B.C.E. According to the carbon-14 test, the range (at two sigmas) is 119–245 C.E. The report found this discrepancy “difficult to explain.” Tests of a second sample from this same fragment brought the results closer in line to the paleographic date, but this will not satisfy scholars who wish to denigrate the carbon-14 tests.

The test on one of the linen fragments confirmed the expected dating with a 95 percent probability that it dates from 193 B.C.E. to 11 C.E. But the other linen fragment dated to the 13th or 14th century B.C.E. It had been acquired from bedouin on the antiquities market; the bedouin said it came from Cave 2 at Qumran. The truth is that it probably came from another wadi (Wadi Murabba‘at), where similar textiles were found.

The new carbon-14-test results are scheduled to be published both in the journal Radiocarbon and in ‘Atiqot, a journal of the Israel Antiquities Authority.