Verse epitaphs are our main and very abundant source for responses to individual deaths. We can almost never know exactly whose attitudes or values they express, but we can assume that they embody attitudes and values that it was acceptable to express publicly. Many at all dates seek merely to commemorate the dead person or convey grief, but, from about 400 bce onwards, others adopt a position on the fate of the dead person, though often hedged with a cautious ‘if’. Very many possibilities emerge: they range from a plain denial that anything survives death, via claims that the dead person is now (e.g.) in the aither/in the home of the blessed/on Olympos/with the heroes, to, very rarely, declarations that s/he is now actually a god. Strangely enough, support for such claims is never sought in the fact of the dead person being an initiate in a cult that promised advantage in the afterlife. In all this we see not so much individual choices as the range of options available for individuals to believe in. But we must also suspect that belief in the more optimistic options can seldom have been as firm as in a society where such options were authoritatively endorsed and alternatives not publicly countenanced.

In situ migration experiments using different radiotracers have been performed in the HADES Underground Research Facility (URF), built at a depth of 225 m in the Boom Clay formation below the SCK–CEN nuclear site at Mol (Belgium). Small-scale experiments, mimicking laboratory experiments, were carried out with strongly retarded tracers (strontium, caesium, europium, americium and technetium). Contrary to europium, americium and technetium which are subjected to colloid mediated transport, the transport of strontium and caesium can be described by the classic diffusion retardation formalism. For these last two tracers, the transport parameters derived from the in situ experiments can be compared with the laboratory-derived values. For both tracers, the apparent diffusion coefficients measured in the in situ experiments agree well with the laboratory-derived values.

In the large-scale experiments (of the order of metres) performed in the URF, non-retarded or slightly retarded tracers (HTO, iodide and H14CO3–) were used. The migration behaviour of these tracers was predicted based on models applied in performance assessment calculations (classic diffusion retardation) using migration parameter values measured in laboratory experiments. These blind predictions of large-scale experiments agree well in general with the experimental measurements. Fitting the experimental in situ data leads to apparent diffusion coefficients close to those determined by the laboratory experiments. The iodide and H14CO3– data were fitted with a simple analytical expression, and the HTO data were additionally fitted numerically with COMSOL multiphysics, leading to about the same optimal values.

The goal of this essay is to reopen the unfortunately unrefined but still illuminating proposal of August Dell a century ago – a proposal to read the motif of ‘bind and unbind’ in Matt 16.19 against the backdrop of ancient magical conventions – and to corroborate this hypothesis with philological precision and contextualisation. The present study seeks to demonstrate how central the motif of ‘bind and unbind’ was to most binding spells and amulets, and how the verbs λύειν and δέειν and their cognates might have evoked the conventions of binding magic when heard in religious and ritual contexts. We see Matt 16.19 as a literary reappropriation of a typical binding spell, crafted to highlight Peter's authority to ‘bind’ and ‘break’ whatever entities he should choose. Jesus' guarantee that he/God will ‘unbind’ whatever target Peter ‘unties' is to be understood as a clear indication that Peter is endowed with an invincible potency over every other spiritual entity, symbolised by the power to break any ‘binding’ spell. The security of the church against malevolent and harmful spiritual entities is further guaranteed by Christ's promise, if read in ancient binding magical conventions: Christ will give Peter the key of the kingdom of heaven so that Peter as the key-bearer may become a figure who can channel the full potency of the keyed object.