Wonders of the Universe

THE ORIGINS OF LIFE

The first step in understanding how the lives of stars are precursors to our own lives is to discover exactly what we are made of. There is possibly no more beautiful, and perhaps no more instructive, place on Earth to begin this journey than in the shadow of the world’s tallest mountain range. With over 100 peaks exceeding 7,200 metres (23,620 feet), the Himalayan range is truly a land of giants; nine of the ten highest mountains on Earth are part of the Himalayas. The greater Himalaya is home to forty-five of the world’s top fifty highest peaks. Spectacularly beautiful, it is the sheer scale of these mountains that hides a fascinating and instructive first step on the road to understanding the building blocks of the Universe. Despite their majesty, just a few tens of millions of years ago these mountains were something very different.

As well as being the largest mountain range on the planet, the Himalayas is also one of the youngest. Just seventy million years ago (a very short time in geological terms) the Himalayas didn’t exist. The relentless movement of Earth’s tectonic plates shaped these mountains in a geological heartbeat. As the Indo-Australian plate collided with the Eurasian plate at the rate of about 15 centimetres (6 inches) a year, the ocean floor in between began to crumple and rise up to form the mountain range. This means that much of the rock out of which these towering peaks are made was formed at the bottom of an ocean, only to be lifted up thousands of metres into the air over a few short millions of years.

The evidence for this extraordinary journey is not difficult to find. If you look closely at any piece of Himalayan limestone you will see it has a chalky, granular structure. What you are looking at are the petrified remains of sea creatures – the bodies and shells of coral and polyps that died millions of years ago in a long-lost ocean. Given a relatively short timescale and a bit of pressure, these biological remains are quickly converted into solid rock. Limestone can also be formed by the direct precipitation of calcium carbonate from water, although the biological sedimentary form is more abundant. We know that the Himalayan limestone is predominantly biological because we have found fossils at the top of Mount Everest! There is perhaps no better example of the endless recycling of Earth’s resources that has been going on since its formation almost five billion years ago.

We humans are also very much part of that system. As unsettling as it may sound, every atom in your body was once part of something else. It may have made up an ancient tree or a dinosaur, and you’ll be pleased to know it was certainly part of a rock. The reason this can happen – that the rocks of Earth can become living things and that living things will eventually die and become rocks again – is simple: everything in the Universe is composed of the same basic ingredients

When you are presented with the sheer magnitude of the Himalayas and the towering peak of Mount Everest, it is hard to believe that these huge mountains started off life at the bottom of an ocean.

Natural recycling at its most impressive. The Himalayan limestone has been proved to be predominantly biological, due to the quantity of fossils of sea shells and creatures that have been found at the summit of Mount Everest.

DIRK WIERSMA / SCIENCE PHOTO LIBRARY

Periodictable.com © 2010 Theodore Gray

THE PERIODIC TABLE

For many people the Periodic Table will provide a strong echo of the school science laboratory. At its simplest, this chart is a list of the chemical elements, fundamental units of matter, which were considered to be the smallest building blocks of the world. However, this table is much more than just a list. Although elemental theories of matter were first postulated in Greece, it wasn’t until 6 March 1869 that the Russian chemist Dmitri Mendeleev finally tamed the ever-expanding list of the basic constituents of matter. Mendeleev’s genius was to arrange the list of the sixty-six then-known elements into a table according to their chemical properties. In the process, the table not only provided a neat way of grouping the elements according to their properties, but also predicted the existence of eight elements yet to be discovered. Over the next thirty years, all eight were discovered, including gallium and germanium, and were found to have the exact properties predicted by Mendeleev’s table. The number of elements continued to grow, and by 1955 the one-hundred-and-first element was discovered (named Mendelevium as a tribute to the father of the Periodic Table) by a group of scientists at the University of California, Berkeley. To date, 118 elements have been categorised, the latest of which, ununseptium, was successfully synthesized and detected by a Russian– US team in April 2010.

Starting with hydrogen and ending with plutonium, the first ninety-four elements of the Table have been found occurring naturally on Earth. These elements are nature’s building blocks; the remaining twenty-four elements, can only be created artificially and live for very short periods of time. Using these ninety-four elements you can explain all of biology and chemistry without knowing about the underlying structure of protons and neutrons, electrons and quarks. This is because you need very high energies and temperatures to break apart the elements – a condition that only exists naturally deep inside the stars.

The first step of our journey to explain where we come from is to understand the origin of these ninety-four elements. But first we must discover how we know that everything we see in the sky is made of the same stuff as us on the ground