Atop Observation Hill -a steep 800-foot-high mound of volcanic rock and gravel overlooking the Ross Ice Shelf and the US McMurdo Station in Antarctica - is a large wooden cross. On the cross are etched the names of five explorers: Capt. R.F. Scott, Dr. E.A. Wilson, Capt. L.E.G. Oates, Lt. H.R. Bowers, and Petty Officer E. Evans, “who died on their return from the pole March 1912.”
Below it is the last line of Tennyson’s “Ulysses”: “To strive, to seek, to find, and not to yield.”
The cross is a stark reminder of the hazards of Antarctica. Robert Scott and his men reached the South Pole in January 1912, but died on the return journey, unable to cover the final 11 miles to a depot full of supplies.
When a search party reached Scott’s tent the following November, they found more than 30 pounds of geological samples. People were left wondering whether Scott and his men could have traversed those fateful 11 miles, if not for the rocks.
Nevertheless, the fossils found in those rocks gave scientists the first glimpse into Antarctica’s past, setting in motion the spirit of scientific inquiry that pervades the continent today.
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As Francis Spufford noted in an anthology of polar writing: “Carrying [the rocks] along was, perversely, among the most forward-looking things Scott ever did. It anticipated the coming time when scientists, not explorers, would be Antarctica’s defining inhabitants; when understanding, not surviving, would be the most pressing human business there.”
Scott would have appreciated the role Antarctica’s playing in our attempt to understand our universe. Unusual atmospheric conditions make the continent the perfect place from where to launch gigantic long-duration balloons, which carry aloft telescopes and experiments to the edge of Earth’s atmosphere, from where they study everything from cosmic rays to the radiation left over from the big bang.
Also, the thin, dry and high-altitude air above the South Pole makes it ideal for telescopes. Even the gigantic ice sheet that blankets East Antarctica is being used for detecting slippery particles called neutrinos: detectors embedded deep in the ice-sheet look for flashes of blue light that’s emitted when neutrinos from outer space strike the ice.
I travelled to Antarctica to witness first-hand the continent’s transformation from a frozen and forbidden frontier to one that is at the forefront of research in cosmology and astronomy. It was one of a series of trips I made for The Edge of Physics , a travelogue that highlights the hard work that goes into making sense of our universe.
The book begins with a pilgrimage to Mount Wilson Observatory near Pasadena, California. It was here, in the 1920s, that astronomer Edwin Hubble discovered that the universe had other galaxies besides our own, and these galaxies were all speeding away from us. His discovery of this expanding universe laid the foundation for the big bang theory.
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The next trip took me deep into an old abandoned mine in Soudan, Minnesota. There, shielded by half-a-mile of rock above, physicists are running sensitive experiments designed to look for dark matter, mysterious stuff that is thought to make about 23 per cent of the universe. Astronomers cannot see dark matter, but can detect its gravitational influence on stars and galaxies, and the hope is that the special underground detectors can find the particles that make up this unknown component of the universe.
The search for dark matter is ongoing at Lake Baikal in Siberia. I went there in winter to see physicists deploying detectors deep below the surface of the largest freshwater lake in the world. Without the funds to deploy ships and submersibles, the Russian scientists are forced to work in winter, when they can use the lake’s frozen surface as a working platform.
They are looking for neutrinos from the centre of our galaxy. Theory tells that dark matter particles that have accumulated there should be smashing together, and spewing out neutrinos. If the Lake Baikal Neutrino Telescope were to see such neutrinos, it would constitute indirect evidence for the existence of dark matter. But none have been seen yet.
In direct contrast to the icy environs of Lake Baikal is the high and dry Atacama Desert in the Chilean Andes. I went there to see the European Southern Observatory’s Very Large Telescope. Situated atop the 2635-metre-high Mount Paranal, this quartet of 8-metre-class telescopes is being used to study the expansion of the universe and shed light on something called dark energy. This is the energy inherent in the fabric of spacetime and is thought to be causing the expansion of the universe to accelerate. It makes up 73 per cent of the universe, and its exact nature is a mystery.
By studying how the expansion of the universe has changed over time, cosmologists hope to better understand dark energy. To see how other telescopes are helping in this quest, I went to the summit of Mauna Kea in Hawaii. This 14000-feet-high mountain is home to some of the world’s largest telescopes, including the 10-metre Keck I and II.
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These telescopes, as big as they are, will get dwarfed by something called the Square Kilometre Array – the world’s largest radio telescope. Slated to be built in either the Karoo in South Africa or the Australian Outback, it’ll consist of 3000 antennas spread over a vast and empty land. The telescope has to be built in regions without any radio interference (the kind spewing out from mobile phone, radio and television towers). To see just how remote and desolate such land has to be, I travelled to the heart of the Karoo in South Africa, just south of the Kalahari Desert.
My travels then took me to McMurdo Station in Antarctica and to the South Pole, where I witnessed hardy, hard-drinking men and women drilling 2.45-kilometres holes in the ice to install detectors for the IceCube neutrino telescope—an instrument that will monitor a cubic kilometre of ice for the telltale flashes of blue light that emanate from neutrinos smashing into the ice.
My travels ended in Ladakh, India, where Indian astronomers are building what could be the template for the next generation of high-altitude observatories. Such regions are so remote that astronomers will no longer be able to live and work there, so telescopes will have to be robotically controlled from gentler climes.
It’s very clear that that these remote and pristine regions of Earth have to be protected if we are to continue building terrestrial telescopes and instruments that can peer deeper into space and further back in time in order to answer the most profound questions faced by humanity: how did the universe begin and how will it end?
Anil Ananthaswamy is a consultant for New Scientist and the author of The Edge of Physics: Dispatches from the Frontiers of Cosmology