If you could watch a single atom of a radioactive isotope, U-238, for example, you wouldn’t be able to predict when that particular atom might decay.It might take a millisecond, or it might take a century. But if you have a large enough sample, a pattern begins to emerge.A useful application of half-lives is radioactive dating.
But the controversy was reignited yesterday, with scholars saying that in all probability it dates from the 13th century, amid suspicions that the museum disregarded the original carbon dating tests in order to preserve the potency and romance of Rome's most abiding symbol."It's a medieval work but that takes nothing away from its importance," said Adriano La Regina, an expert on Etruscan culture from Rome's La Sapienza University."From the 1700s onwards, it has been considered Etruscan.
But with new studies and the carbon tests, the dating has changed."Experts said the wolf was made from a single cast, using a technique which was not known to the Etruscans or Romans, who would have had to forge separate pieces and then solder them together.
Regional government officials said five adults remained in a serious condition at a hospital in Santander where the British youngsters, many of whom are thought to have been admitted as a precaution because they suffer asthma, spent most of the day.
Jose Manuel Igual, mayor of Arnuero which the village of Isla forms part of, said earlier this afternoon when the British schoolchildren were still in hospital and it was not clear whether they would be forced to stay on in Spain: 'I was very worried when I got the call this morning about what had happened but I have been to the hotel and been reassured by the emergency response and the fact that everyone who needed medical attention is receiving it.'We can talk about the causes and consequences later but the most important thing now are the people affected.'I have been told none of the British children who are in hospital are serious.'The youngsters were on the last day of their trip and I'm not sure if any will have to stay on or not.'But other hotels in Isla have been available to the group should they decide that's the best course of action as well as meals in other establishments.'There's been a great level of solidarity shown by people locally.'What we've tried to do is make life as easy as possible for those affected.'I think they're from the same school but I don't have too much information on that.'I haven't spoken to any of the children, just a monitor who said the coordination had been very good.' A hotel worker confirmed several British children had gone to hospital but said it was a precaution because of conditions including asthma that they suffered from. They only found about something was wrong when ambulances started arriving.'The problem has been on the second floor where Spanish pensioners were staying and was confined largely to four rooms.'One of the Spanish people taken to hospital is in a serious condition and our latest information is that seven people from that group are in hyperbaric oxygen chambers.'She added: 'The British children were taken to hospital simply to rule out the possibility they had suffered any harm.'The children in the rest of the group are at the hotel and will go by the hospital later for a check-up before the two groups take the ferry home from Santander as they were planning to do today.' A local Civil Guard spokesman confirmed British youngsters were among those taken to hospital.
For example, you can’t find the remaining amount of an isotope as 7.5 half-lives by finding the midpoint between 7 and 8 half-lives.
This decay is an example of an exponential decay, shown in the figure below.He said that during the Middle Ages the symbol of Rome was a lion, making it unlikely that there would have been much call for a she-wolf statue.Historians say it may have been based on an original which was cast in bronze in Constantinople in 1204, during the Fourth Crusade, but which was then lost or melted down.The museum reluctantly announced that it would amend an information plaque to reflect the renewed doubts over the wolf's age and provenance."Besides the current dating, which claims that the statue was created in the fifth century BC, we'll include the theory that it may have been made during the medieval era," said a statement from Rome's archaeology and heritage department.Umberto Broccoli, a senior heritage official, said some scholars still believed the wolf was of Etruscan origin.They found many areas have seen a dramatic increase in the amount of leaf cover (illustrated above)Dr Zaichun Zhu, a researcher at Peking University who also took part in the study, said: 'The greening over the past 33 years reported in this study is equivalent to adding a green continent about two-times the size of mainland USA and has the ability to fundamentally change the cycling of water and carbon in the climate system.' The researchers said there had been an increase in the growing season in various parts of the world, with up to 50 per cent of the vegetated area of the Earth's surface benefiting from increased carbon dioxide (illustrated)Dr Philippe Ciais, another co-author of the study and associate director of the Laboratory of Climate and Environmantl Sciences at Gif-suv-Yvette in France, said: 'The fallacy of the contrarian argument is two-fold.