Is anyone out there? The telescope will enable scientists to detect very weak radio signals from far away, perhaps indicating intelligent life
For someone whose job title could read Man Most Likely to Blow Your Mind, Bernie Fanaroff looks pretty conventional. Short, affable and 64, Fanaroff is wearing a V neck and gray slacks and offers coffee and sandwiches when we meet in his windowless office on a busy thoroughfare in central Johannesburg. Then he opens his mouth, and out tumbles all manner of cosmic craziness.
Consider the fact, says Fanaroff, that we have no idea what 96% of the universe is made of. Cosmologists have known for some time that only 4% of the universe is stuff like dust, gas and basic elements. Dark matter, says Fanaroff, accounts for 23% to 30%; dark energy makes up the rest. (Dark, Fanaroff explains, is the scientific term for "nobody knows what it is.") Dark matter is constantly working to hold the universe together. Dark energy is pulling it apart. Since the universe is expanding, dark energy is apparently winning.
Fanaroff is consumed by such fundamental mysteries, to say nothing of the larger riddles surrounding the Big Bang. It's to investigate all this — to answer questions about The Origin of Everything — that he is working on the Titanic Telescope, an astronomical instrument 50 to 100 times more sensitive than anything yet created. The telescope will see so far across space — scanning a billion galaxies, up from the currently known million, with an ability to pick up the energetic equivalent of an airport radar on a planet 50 light-years away — that it might even find evidence of aliens (if they happen to be in range and using radio-emitting devices). It will see so far back in history that it will transport astronomers closer to the Big Bang than any previous telescope. It will help answer questions such as whether Einstein's theory of general relativity holds, what cosmic magnets look like and whether black holes are hairy. (Honestly. It's in a brochure Fanaroff hands me.) It will also, it is hoped, massively accelerate global computing power, as the volume of data it will generate will be greater than the amount so far created in all human history and more than the entire Internet can handle. And if all that sounds a little spacey, get this: Fanaroff's hoping to build the thing in Africa. "It's a massive leap into the unknown," he announces, somewhat superfluously.
Fanaroff's real title is project director. The proper name for the Titanic Telescope is the Square Kilometer Array (SKA) radio telescope — so called because it will be made up of thousands of radio-frequency receivers, which have a collective area equal to 1 sq km. Some of the receivers are 12-m-diameter dish antennas, some are smaller, and some are flatter, fish-eye constructs. Each of them targets a different frequency range to deepen and expand astronomy's view of the sky. That kind of stargazing power requires a lot of real estate here on Earth. The SKA plan calls for 20% of the antennas to be clustered within a 1-km radius, 50% within 5 km and some as far as 3,000 km away — which would put them in eight other African countries, assuming the headquarters is in South Africa, as Fanaroff hopes.
Scattering so many dishes across such a wide area and collating their images into one composite will produce the same effect as building a single dish half the size of the earth. Why the obsession with size? Because with telescopes, bigger is always better — improving resolution and helping triangulate more precisely on cosmic targets — and the SKA is meant to be the best ever built.
Astronomers can already see back 13.5 billion years, about 400,000 years after the Big Bang, by looking at light very far away — and, therefore, very long ago. But they get no further. Why? Because the Big Bang was extremely hot, and only after around 400,000 years did it cool enough to allow protons and neutrons to form into atoms, most important, hydrogen — the first element. Before that 400,000-year point, what existed was a very hot, dense primordial fog. And we can't penetrate that with optical devices like the Hubble Space Telescope or the European installation in Chile's Atacama Desert called the Very Large Telescope. (Remember that obsession with size?) Radio telescopes can't penetrate the haze either. But what a radio telescope — particularly a very big, very sensitive one — can see into is a somewhat more recent foggy period known as the Dark Ages, and mysteries aplenty lurk there. Hence the supersize SKA.