Blurs

Beneath the waters of the Mediterranean lie the remains of thousands of ancient shipwrecks. Some are little more than scattered pottery. Others preserve evidence of ships that once carried enormous quantities of wine, olive oil, grain, metals and luxury goods across the Roman world. Together, these wrecks reveal something remarkable: the Roman Mediterranean was not simply a collection of isolated coastal communities. It was an enormous interconnected trading system. But the shipwrecks also raise a more difficult question. How large was this maritime economy really — and how much of it has disappeared from the archaeological record? A sea full of trade At its height, the Roman Empire controlled territory stretching across much of Europe, North Africa and the Middle East. The Mediterranean sat at the centre of this world. It provided the fastest practical route for moving large quantities of goods between distant regions. A cargo that might have required weeks or months to transport over...

For most of Earth's history, humans weren't here. For billions of years, life evolved without cities, writing, computers or anything resembling human civilisation. Yet intelligence itself is much older than humanity. Crows can solve problems. Octopuses can manipulate objects and escape enclosures. Dolphins cooperate and communicate. Elephants appear to recognise individuals and respond to death. Chimpanzees use tools. Even some insects display surprisingly sophisticated forms of learning and navigation. If intelligence has evolved repeatedly in living animals, an obvious question follows: How intelligent were the animals that are now extinct? We have fossils of enormous numbers of creatures that disappeared millions of years ago. We can reconstruct their skeletons. We can examine their teeth. We can sometimes identify their diet. We can estimate how they moved. We can even reconstruct aspects of their brains using the internal spaces preserved inside fossil skulls. But intellig...

In 1847, railway workers in northern England began hearing the sound of a pickaxe coming from underground — apparently from the very place where a navvy had recently been killed. Then one man was lowered into the tunnel to find out what was making the noise. There are railway ghost stories that seem to have been invented decades after the event. And then there are stories that appeared in print while the railway age was still young. One particularly strange example appeared in an 1847 newspaper under the wonderfully understated heading “A Railway Ghost.” It concerned a railway construction site near Stockham, where a worker had recently been killed when part of a tunnel collapsed. Not long afterwards, the men working nearby began hearing something that should not have been there. It sounded like someone working underground. A pickaxe striking rock. Again. And again. And again. The disturbing part was where the sound appeared to be coming from. It seemed to originate from the precise lo...

Thousands of years before modern astronomy revealed that rocks regularly arrive from space, ancient people were already collecting material that had fallen from the sky. Among the strangest examples are ancient metal objects made not from ordinary terrestrial iron, but from meteoritic iron — metal originating in space. Some of the most intriguing discoveries are ancient rings and other jewellery fashioned from this extraordinary material. Their existence raises a fascinating question: What did prehistoric people think when they encountered metal that had literally fallen from the heavens? Metal From the Sky Iron is common on Earth, but naturally occurring metallic iron is comparatively unusual at the planet's surface. Meteorites are different. Some meteorites, particularly iron meteorites, contain substantial quantities of iron and nickel. When pieces of these extraterrestrial objects survive their journey through the atmosphere and land on Earth, they can provide prehistoric commu...