Blurs

For most of Earth's history, there was no obvious reason to expect humans. There were forests. Oceans. Changing climates. Mass extinctions. Predators and prey. And millions of different evolutionary experiments taking place simultaneously. Our own lineage was just one of them. Today, humans are the only living primate capable of building cities, launching spacecraft and transforming the planet on a geological scale. But that raises an intriguing question. Was our evolutionary path unique — or could other primates once have been heading in a similar direction before environmental catastrophe changed everything? And an even more provocative possibility: Could a primate lineage have developed considerably greater intelligence, only to be pushed backwards — or wiped out — by environmental catastrophe? There is no evidence that an advanced non-human primate civilisation existed. But the underlying evolutionary question is entirely legitimate. Evolution isn't a straight line One of t...

Rain looks deceptively simple. Water falls from the sky. It lands. It runs away. But every raindrop has passed through an atmosphere containing an astonishing mixture of material — dust, sea salt, soot, mineral particles, biological fragments, pollutants and countless microscopic aerosols. Some of that material is incorporated into clouds. Some is captured by falling raindrops. And eventually, much of it reaches the Earth's surface. Scientists call this process wet deposition. It is happening every time it rains. And it raises a fascinating question: Could rainfall be quietly contributing to the sediment layers that record Earth's history? The atmosphere isn't empty The air around us may look perfectly clear, but it contains enormous numbers of microscopic particles. These atmospheric aerosols can originate from deserts, soil, oceans, volcanoes, vegetation, fires, industry, vehicles and biological activity. Some particles are so small that they can remain suspended in the a...

When we think about unexplored places, our minds tend to go upwards. Space. Distant planets. The far side of the Moon. Perhaps an undiscovered world orbiting another star. But there is an extraordinary fact hiding in plain sight: We live on the surface of a planet that we have barely explored beneath our feet. We have sent spacecraft millions of kilometres into space. We have photographed distant galaxies. We have mapped enormous areas of the ocean floor from orbit. Yet deep below the ground is another world — one of rock, pressure, heat, water and microscopic life — that remains extraordinarily difficult to access. So just how much of Earth is still unknown? We haven't physically explored most of the deep Earth. Earth has a radius of roughly 6,371 kilometres. The deepest hole humans have ever drilled — the Kola Superdeep Borehole in Russia — reached just over 12 kilometres. That sounds impressive. And it is. But compared with the size of the planet, it barely scratches the surface...

Could some of our ancestors have spent far more of the Ice Age beneath the surface than we realise? When we imagine humans during the Ice Age, we tend to picture hunters crossing frozen landscapes, wrapped in animal skins, tracking mammoths and reindeer across windswept plains. It's an image that has become almost synonymous with prehistoric humanity. But there is another possibility. When conditions became brutally cold, perhaps the smartest place to be wasn't out on the frozen landscape at all. Perhaps it was underground. Humans have been using caves and rock shelters for hundreds of thousands of years. We know that Neanderthals, Denisovans and Homo sapiens repeatedly occupied caves, sometimes during extraordinarily cold climatic periods. But this raises a more intriguing question: Did some human groups retreat into underground environments for much longer periods during the most severe phases of the Ice Age? The answer isn't as straightforward as it might first appear. W...