In an infinite universe, it is “absolutely clear” that there are other civilisations out there, Professor Brian Cox told the Mail & Guardian.
Cox – a working physicist, TV presenter and, according to Irish comedian Dylan Moran, the reason “a lot of women became very interested in the universe lately” – is promoting his new series, the BBC’s Human Universe, which he describes as a “love letter to the human race”.
“It is a celebration of exploration, of civilisation, of science [and] scientific exploration of the universe,” Cox said in a phone interview this week.
A generation ago, we thought that the Earth was unique and that our solar system was an anomaly in a cold, infinite universe. But today, as a result of spacecraft such as Kepler and astronomy observatories, we know that there are thousands of exoplanets, possibly billions. (Only a planet within our solar system can technically be called a “planet”. Planets orbiting other stars are “exoplanets”.)
Fourteen of these exoplanets have been confirmed as potentially habitable, meeting the many requirements for carbon-based life. Our Earth has a cushioning atmosphere, a magnetic core protecting us from the Sun’s cosmic radiation, and is the right distance away from our star in an area called the “Goldilocks zone”. This is the perfect location to allow for liquid water: if the Earth was closer to the Sun, water would evaporate; if it was further away, water would freeze.
Different types of life
But Cox draws a distinction between the different types of life: “There’s a difference between simple life and complex, multicellular organisms, then intelligence, then civilisation. There’s a big difference.”
In an infinite universe, “it is absolutely clear that there are other civilisations”, Cox says.
But in our own Milky Way galaxy, “civilisations are probably very rare”. There are 200-billion stars in our galaxy but we are the only civilisation we know of, Cox says. “And it took 3.8-billion years for it to emerge.”
He quotes novelist John Updike: “Astronomy is what we have now instead of theology. The terrors are less, but the comforts are nil”, but says that Updike’s sentiments are far from the truth.
“There is a great comfort to be found in the fact that we exist at all. It is a tortuous path from [evolving] from a single cell to a civilisation”, but we overcame this.
An important question at the moment is whether this has happened before in our solar system. On Tuesday Nasa reported that its Curiosity Rover had “tasted” organic molecules, such as methane, and water on Mars.
“Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life,” Nasa said in a statement. “Curiosity’s findings from analysing samples of atmosphere and rock powder do not reveal whether Mars has ever harboured living microbes, but the findings do shed light on a chemically active modern Mars and on favourable conditions for life on ancient Mars.”
Cox was on the committee that evaluated the European Space Agency’s ExoMars (Exobiology on Mars) programme, which plans to put a rover on Mars in 2018 specifically to look for signs of life.
“Obviously, we think there is a good chance of success.
“We don’t know how likely it is for life to emerge [but] if we find it on Mars, it will have happened twice. And life can be transferred within a solar system.”
A big boost in the search for civilisations in the universe will be the Square Kilometre Array (SKA), Cox says. The seat of the SKA Organisation is at the University of Manchester, where he is an advanced research fellow.
The SKA, a giant telescope that will comprise thousands of antennae in Australia and Africa, with the core in South Africa, will be the largest scientific experiment on Earth and will attempt to answer some of humanity’s most enigmatic questions, such as: Is there other life in the universe? How do galaxies form? And what is dark matter?
“The SKA will be exquisitely sensitive, an incredible machine,” says Cox, whose academic research began with astrophysics. “When you have got things like the SKA, you could hear the broadcasts of civilisations.”
Cox, a member of the High Energy Physics group at the University of Manchester, also works on the Atlas experiment on the Large Hadron Collider, a huge particle accelerator that smashes particles together at high speeds to understand the smallest building blocks of the universe.
But the reason he got into physics was astronomy.
“In schools, one of the things you have to do is inspire children. I don’t separate the investment in education, universities, research [down to] primary schools.
“Alongside health and security, it is the most important investment a country can make, especially for the future.”
Asked how this applied to South Africa, a developing country with a pressing need for basic services, Cox says: “You need money and, to be a richer country, you need investment in knowledge, the young. Science is a key part of that.”
The Human Universe programme will be flighted in South Africa next year.