Wonders of the Universe - Brian Cox [85]
This is an immense amount of time; difficult to comprehend when we speak of the entire history of our species as the blink of a galactic eye. We live our lives in minutes, days, months and years, and to extend our feel for history across a galactic year is almost impossible. Yet here on Earth there are creatures that have existed for lengths of time that span these grandest of rhythms
THE GALACTIC CLOCK
Nothing stays still in the Universe, our galactic clock is forever ticking, moving everything on to a new chapter in the story of the Universe, marking out the days, weeks, months and years in each and every planet in our galaxy. Everywhere in the heavens, time moves on using its own rhythms; as you journey to the farthest reaches of the Solar System the length of a year gets progressively greater and the cycles become grander. Every solar system among the 200 billion that exist in our galaxy makes its own unique journey around the galactic centre, as we all orbit the supermassive black hole that lies at the heart of the Milky Way Galaxy.
Nathalie Lees © HarperCollins
ANCIENT LIFE
Pregnant sea turtles return to the sands on the Pacific coast year after year in one of the oldest life cycles on Earth.
The Ostional wildlife refuge on the Pacific coast of Costa Rica is home to one of nature’s most spectacular sights. On many nights of the year, a small number of tropical beaches along this thin land bridge between North and South America are visited by prehistoric creatures. They emerge from the ocean to lay their eggs in the sand. We filmed on Playa Ostional, a tiny strip of sand which is adjacent to a friendly village clustered around a makeshift football pitch. It is one of the few beaches in the world where large numbers of sea turtles make their nests, and the events that occur here form part of one of the oldest life cycles on Earth.
We are here to film the turtles hauling themselves from the ocean as they have done year on year without interruption for over 120 million years – half a galactic year. As we wait for them with our night-vision camera equipment, it is hard not to reflect on the sheer size of the mismatch in the histories of these ancient creatures and the species that built the football pitch by the sea. We humans know our planet well. We know there is a landmass called Europe, separated from Africa by a thin strip of ocean. We know that if you journey east from northern Europe you cross the vast expanses of Siberia and arrive eventually in Japan. Carry on, and you’ll cross the Pacific Ocean and meet the Californian coast in the United States. The shape of our countries and continents is familiar and seemingly eternal, but the ancestors of the turtles I can see bobbing offshore were waiting for the right moment to crawl out onto the land when the shape of our continents was very different; they were waiting one hundred million years ago in the same ocean, but in those days the beaches marked out shorelines of continents that would be totally unrecognisable to our eyes. As the turtles patiently waited for their moment to give birth in the sand, the continents of Earth were slowly on the move. North America was close to Europe, South America was connected to Africa and Australia was joined with the Antarctic. It is moving to see the care with which these ancient creatures dig deep into the sand to protect their precious eggs, but equally powerful to reflect on the temporal mismatch