In defense of Astronomy

In modern society we take the night sky for granted. Astronomy is thought of as a fool’s errand (or worse, a nerd's errand) with no commercial benefit. But since the dawn of human curiosity, the three thousand stars visible to the naked eye have inspired great literature, art and science. The phases of Venus and the moons of Jupiter helped show that we live in a universe not centred on the Earth. The pirouetting motion of the moon around the Earth and the Earth around the Sun led inexorably to the idea of gravity. The observation of light from distant galaxies tore down the eternal notion of the universe and gave it a start date. All this from sitting on the ground, observing the sky above.

The thick clouds of Venus (nasa data centre)

 
But imagine, if it is possible, a world enshrouded by impenetrable clouds; with nights remarkable only for their lack of daylight. These planets do exist. Far above Venus’s highest peaks exists a thick sulphuric acid cloud layer that scatters all light away. Titan, Saturn’s largest moon, is also covered by haze, this time created by hydrocarbon molecules such as ethane. Even the Earth has its own layer – if human eyes were adjusted to a wavelength around 1mm we would see a star-consuming haze above caused by atmospheric water.

So, how would humanity have developed if the night sky was devoid of the features we take for granted now? It seems certain that humanity’s perception of our place in the universe would change - lives will be played out in two dimensions, as if sandwiched between two sheets of paper. In this parallel reality, the world would probably be thought of as flat until the time of global exploration.

Even if the study of mathematics, thermodynamics, electricity and magnetism continued, without observations of the other planets, the system of an Earth-centred universe may well have persisted. The idea of gravity would also be a relative late-comer, developed only after the force theories of electricity and magnetism. Not only would the theories of physics be different, but so would any notion of how our world formed. Only through observing our own solar system (and others) have we theorised how our planet and the seven other planets around our sun were formed. Without the night sky to prove this, ancient creation myths will have endured.

However, suppose this hypothetical civilisation reached a technological age. Having lived under cloudy starless skies for an eternity, picture the moment when the first ever rocket to carry humans above the thick hazy atmosphere arrived. Until pictures could be taken and developed, the stories of those first few astronauts would almost certainly be met with disbelief. After this eureka moment, the perceptual shift would be incomprehensible. Where before there was nothing but grey haze above, there was suddenly a universe teeming with stars. Planets circle in eccentric orbits around a great shining ball of fire at the centre of the solar system. Galaxies spin millions of light-years away containing a hundred billion suns. And this is what we get to see. Every night. The most amazing thing is that no one seems to realise how lucky we are.

Another Earth?

A few years ago, during the course of a pre-university preparation week, I took part in an Arts vs Sciences debate. (I say 'took part', I was one of the 90% that, never having debated before, stood at the back trying to avoid participation of any sort). But during the course of this petty intellectual squabble one argument stands out in my mind:.
"Art simply poses questions. It is up to science to answer them."
     I think the reason this stuck in my memory like gum to a shoe was because I was so opposed to it. When, I thought, has art ever given science a helpful push in the right direction? Was it only with John Milton's Paradise Lost that Newton could invent his law of gravitation? Did Picasso's 'Blue period' inspire Einstein to create the special theory of relativity. Could Stanley Kubrick's 2001: A Space Odyssey have led to our knowledge of black holes. The answer, to me, seemed to be a resounding No. Art kept to its corner of society, science kept to ours.

But today a piece of art set my mind rolling along avenues usually reserved for scientific thinking. The inceptive art piece was a trailer for an independent movie released in October called 'Another Earth'. The plot is set around the fantastical premise that a second planet Earth has appeared in the solar system, and on it is contained a carbon copy of all human life, including ourselves. Ok, so at first the idea of a planet cloning itself seems a little wacky, and I would completely agree. But it led me to think -how impossible would it be for two habitable planets, orbiting each other to circle a star such as our sun? Could there be a planetary system, somewhere, with two Earths?

Many bodies in the universe orbit each other in binary partnerships. Most stars are thought to have stellar companions formed when gas collapsed under their own gravity. Some of these binary systems such as Mizar and Acrux can be seen on clear nights. A handful of asteroids have been found that orbit each other as they slowly move about the sun. The dwarf planet Pluto and its large moon Charon are also often called a double planet system. This is because Charon, weighing in at one ninth of the mass of Pluto, orbits a combined centre of mass that lies between it and Pluto. But how about Earth-sized bodies?

Just like in art, original ideas are hard to come by in science - often it seems like everything interesting has been done. However, despite many discovered binary systems, a quick journal search for binary planet formation shows almost no results! Exploring whether these equal-mass double-planet systems are possible would not only be incredibly interesting, but also could become testable as more and more exoplanets are discovered. In fact, the detection of a binary exoplanet might even put to rest one of the longest standing arguments in planetary science - whether large, Jupiter-like planets formed by gravitational instabilities (which, being similar to star formation, might create binary systems) or by accretion (which wouldn't). They might also help explain why planets have been found wandering freely through the galaxy, as it might be easier for binary planets to destabilise and be thrown from the solar systems.  'Three-body problems' are extremely complex, however, and the interaction of the sun and with other large planets may make such systems impossible.

Despite my previous opposition, bouncing scientific ideas off art can generate interesting and unproven results. So maybe, just maybe, art has a use after all...