checked sports coat who was shaking his head vigorously.
‘Professor Libby and his team discovered that carbon fourteen has a half-life of 5568 years, so if we start with 100 grams of carbon fourteen, 5568 years later we will only have 50 grams and in another 5568 years 25 grams, and so on. This standard rate of decay is the key to radiocarbon dating because the ratio of carbon fourteen to the stable carbon twelve can be measured very accurately.’
In the projection room at the back of the theatre Giorgio Felici put on a pair of fine leather gloves, opened his well-used tool box and extracted the Russian-made Vinovka Snaiperskaja Spetsialnaya sniper rifle with its integral silencer from the felt-lined interior. Unseen, he rested the barrel in one of the square wooden openings and focused the cross-hairs of the sights on Professor Rosselli sitting at the table on the stage. With a minimum of movement he swung the sights onto Dr Bassetti. Pert little breasts, he thought dispassionately, and casually wondered what she would be like in bed.
Allegra explained how plants obtained all their carbon atoms from the atmosphere and how animals and humans gained carbon from eating the plants.
‘Therefore, at any one time, the ratio of carbon fourteen to carbon twelve is the same in the plants, and therefore in humans and animals, as the ratio in the atmosphere.’
To complete her introduction Allegra explained the crux of the theory. ‘When a plant or an animal or human dies, the intake of carbon atoms stops, which starts up a time clock and the ratio of carbon fourteen to carbon twelve is fixed at that point. Carbon twelve is stable and the amount in the body remains unchanged. At the moment of death the amount of carbon fourteen starts to decrease, as does the ratio. By precisely measuring the ratio of carbon fourteen to carbon twelve we can get a very accurate measure of the age of a sample. It raises some interesting questions about the evolution of man over a relatively short period of hundreds of thousands of years compared to the age of the Earth, which is measured in billions.’
Allegra moved into high gear. In a dizzying array of overheads she went through the principal techniques of gas proportional counting, liquid scintillation and accelerator mass spectrometry and how the various techniques might be applied to date objects in archaeology and other fields. Forty minutes later Allegra ended her lecture to a round of spontaneous applause.
‘Well done. They liked it and so did I,’ Professor Rosselli whispered approvingly. ‘With the possible exception of the short fellow in the front row who likes bright colours,’ he added, his hand over the microphone. The man in the sports coat was again shaking his head as Professor Rosselli announced that Allegra would now take questions and his hand was first in the air.
Professor Rosselli nodded to him and he leapt to his feet, flushed and agitated.
‘My name is Walter C. Whittaker the Third,’ he said, introducing himself in a high-pitched southern drawl, ‘and I represent the Reverend Jerry Buffett from the Buffett Evangelical Centre for Christ in Atlanta, Georgia.’ The man was short with thinning red hair, a freckled complexion and a thin, wispy moustache.
‘As if we couldn’t guess,’ Professor Rosselli whispered to Allegra in a conspiratorial aside as she prepared to move back to the lecturn.
‘I think you and Professor Rosselli are seriously misguided, Dr Bassetti. I will have some questions for Professor Rosselli that will destroy his theory on the origin of DNA at the end of his lecture, but your theory that you can use carbon dating to date something like the Dead Sea Scrolls is nonsense. Carbon dating would have us believe that the world is billions of years old, but the Bible says carbon dating is just plain wrong. In the beginning God made them male and female, and I am quoting from Mark 10:6. If we were to take your science as true, the Bible would make no sense at all.’
‘Amen to that,’ someone in the front whispered loudly enough for it to be heard several rows back, prompting a titter in the audience. Unfazed, the man continued.
‘It would make no sense at all to have Man appear after billions of years because the Bible tells us quite clearly that Man was in the world from the very beginning of creation. And since Man only appeared a few thousand years ago, passages from Mark only make sense if the world is also just a few thousand years old, which we know to be the case, since the Bible is the Word of God.’
Allegra groaned inwardly and shot a glance at Professor Rosselli, who gave her his trademark wink. He was enjoying the proceedings immensely and was more than a match for the man in Joseph’s coat.
‘Do you have an actual question, Mr Whittaker?’ Professor Rosselli asked.
‘I’m coming to that, sir. Rest assured, I’m definitely coming to that. The Great Flood, Dr Bassetti. Genesis clearly points out that every mountain on the Earth was covered to a depth of 6 metres.’
Which in the case of Everest makes just on 8715 metres and we got there in just forty days and forty nights, a rainfall of 225 metres a day. Some downpour, some flood, Allegra thought sceptically, now prepared to question dogma as she never had before.
‘The Great Flood buried vast amounts of carbon twelve which I would point out raised, not lowered, the ratio of carbon fourteen that plants would have absorbed after the flood. Making them seem a lot older than they really are.’
‘Well, if you don’t mind, Mr Whittaker, you will appreciate that there are other people in the theatre and I’ll now ask Dr Bassetti to comment on your assertions.’ Professor Rosselli had had enough.
‘I can’t imagine any question that is more important than one that is concerned with a Biblical basis of truth, but I await the good doctor’s response with interest.’
At last the Bible-thumping man from the Deep South sat down. Allegra glanced around the room. Many of those present, especially the undergraduates, had huge grins on their faces, but the challenge had been thrown down and she was clearly expected to answer it.
‘Thank you, Mr Whittaker. You raise some interesting points. Let me repeat that carbon dating does not give a date down to an exact year.’
Walter C. Whittaker the Third smirked.
‘But we do claim accuracy within a few decades, and when we are dealing with tens of thousands of years that is quite a small margin of error. In the realm of fifty thousand years or so, as accurate as carbon dating might be, we still check it, and to do that, we compare our results using tree rings or dendrochronology.’ Allegra flashed up an overhead of a majestic bristle cone pine in the White Mountains of California that was more than four thousand years old.
‘Trees produce one tree ring each year, and if we compare the carbon fourteen concentrations in tree rings of a known age, we can accurately check our age range for any specimen.’
Mr Whittaker looked a lot less smug but he was not done yet.
‘Show me a tree that is more than six thousand years old.’
‘Indeed, Mr Whittaker, there are none,’ Allegra responded easily, ‘but we have overcome that problem. We can extend this theory by using non-living specimens from the wood of ancient buildings where the date of construction is known quite accurately.’
‘And I think there was a question up the back,’ Professor Rosselli interjected pointedly.
The audience applauded, delighted that Mr Whittaker had been dispatched, along with his theory of the world being only as old as last Tuesday.
Giorgio Felici calmly adjusted the range to the 77 metres he had measured earlier and refocused the cross- hairs on Allegra’s breasts as she answered more questions.
CHAPTER TWENTY-THREE
Jerusalem
G iovanni pushed open the now familiar rusty gate to the Sisters of Charity Convent in Jerusalem and climbed the steps. It had been over five years since he had first arrived in the Holy Land, although it seemed like only yesterday, and his little church in Mar’Oth had been completely rebuilt. Poor as they were, the villagers of his home town of Maratea had raised the money for two statues. One of Christ in thigh-length boots with a gnarled walking stick, and one of the Virgin Mary in blue. Very Italian and a little out of place in the Middle East but when Giovanni had unpacked the crates he had fought back tears. Patrick, who had educated him on Jerusalem and the Holy Land as no other guide ever could, had re-consecrated the church. He had seemed genuinely surprised, not only at the
