Saturday, 1 April 2017

The moons of Saturn and echoes of a synthetic universe

As fans of Star Wars might be aware, George Lucas is nothing if not visually astute. His thumbnail sketches for the X-wing, TIE fighter and Death Star created the essence behind these innovative designs. So isn't it strange that there is a real moon in our solar system that bears an astonishing resemblance to one of Lucas's creations?

At the last count Saturn had 53 confirmed moons, with another 9 provisionally verified - and as such assigned numbers rather than names. One of the ringed planet's natural satellites is Mimas, discovered in 1789 and at 396 kilometres in diameter about as small as an object can be yet conform to an approximate sphere. The distinguishing characteristic of Mimas is a giant impact crater about 130 kilometres in diameter, which is named Herschel after the moon's discoverer, William Herschel. For anyone who has seen Star Wars (surely most of the planet by now), the crater gives Mimas an uncanny resemblance to the Death Star. Yet Lucas's original sketch for the battle station was drawn in 1975, five years before Voyager 1 took the first photograph with a high enough resolution to show the crater.

Okay, so one close resemblance between art and nature could be mere coincidence. But amongst Saturn's retinue of moons is another with an even more bizarre feature. At 1469 kilometres in diameter Iapetus is the eleventh largest moon in the solar system. Discovered by Giovanni Cassini in 1671, it quickly became apparent that there was something extremely odd about it, with one hemisphere much brighter than the other.

As such, it attracted the attention of Arthur C. Clarke, whose novel 2001: A Space Odyssey described Japetus (as he called it) as the home of the Star Gate, an artificial worm hole across intergalactic space. He explained the brightness differentiation as being due to an eye-shaped landscape created by the alien engineers of the Star Gate: an enormous pale oval with a black dot at its centre. Again, Voyager 1 was the first spacecraft to photograph Iapetus close up…revealing just such a feature! Bear in mind that this was 1980, whereas the novel was written between 1965 and 1968. Carl Sagan, who worked on the Voyager project, actually sent Clarke a photograph of Iapetus with a comment "Thinking of you..." Clearly, he had made the connection between reality and fiction.

As Sagan himself was apt to say, extraordinary claims require extraordinary evidence. Whilst a sample of two wouldn't make for a scientifically convincing result in most disciplines, there is definitely something strange about two Saturnian moons that are found to closely resemble elements in famous science fiction stories written prior to the diagnostic observations being made. Could there be something more fundamental going on here?

One hypothesis that has risen in popularity despite lacking any hard physical evidence is that of the simulated universe. Nick Bostrum, the director of the University of Oxford's Future of Humanity Institute has spent over a decade promoting the idea. Instead of experimental proof Bostrum uses probability theory to support his suppositions. At its simplest level, he notes that the astonishing increase in computing power over the past half century implies an ability in the near future to create detailed recreations of reality within a digital environment; basically, it's The Matrix for real (or should that be, for virtual?)

It might sound like the silliest science fiction, as no-one is likely to be fooled by current computer game graphics or VR environments, but with quantum computing on the horizon we may soon have processing capabilities far beyond those of the most powerful current mainframes. Since the ability to create just one simulated universe implies the ability to create limitless - even nested - versions of a base reality, each with potentially tweaked physical or biological laws for experimental reasons, the number of virtual realities must far outweigh the original model.

As for the probability of it being true in our universe, this key percentage varies widely from pundit to pundit. Astronomer and presenter Neil deGrasse Tyson has publicly admitted he considers it an even chance likelihood, whilst Space-X and Tesla entrepreneur Elon Musk is prepared to go much further, having stated that there is only a one in a billion chance that our universe is the genuine physical one!

Of course anyone can state a probability for a hypothesis as being fact without providing supporting evidence, but then what is to differentiate such an unsubstantiated claim from a religious belief? To this end, a team of researchers at the University of Bonn published a paper in 2012 called 'Constraints on the Universe as a Numerical Simulation', defining possible methods to verify whether our universe is real or virtual. Using technical terms such as 'unimproved Wilson fermion discretization' makes it somewhat difficult for anyone who isn't a subatomic physicist to get to grips with their argument (you can insert a smiley here) but the essence of their work involves cosmic rays. The paper states that in a virtual universe these are more likely to travel along the axes of a multi-dimensional, fundamental grid, rather than appear in equal numbers in all directions. In addition, they will exhibit energy restrictions at something called the Greisen-Zatsepin-Kuzmin cut-off (probably time for another smiley). Anyhow, the technology apparently exists for the relevant tests to be undertaken, assuming the funding could be obtained.

So could our entire lives simply be part of a Twenty-Second Century schoolchild's experiment or museum exhibit, where visitors can plug-in, Matrix-style, to observe the stupidities of their ancestors? Perhaps historians of the future will be able to run such simulations as an aide to their papers on why the hell, for example, the United Kingdom opted out of the European Union and the USA elected Donald Trump?

Now there's food for thought.