2016-10-19

More things in heaven and earth

Horatio : 
O day and night, but this is wondrous strange!

Hamlet : 
And therefore as a stranger give it welcome.
There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.

Horatio would certainly be as bewildered as we are today by the evergrowing number and diversity of things modern science investigation keeps discovering at a steady pace. A recurrent motto in science papers and articles I stumbled upon lately is more than expected, as the following short review illustrates, traveling outwards from earth to heaven. 

New living species, both living and fossil ones, are discovered almost on a daily basis in every corner of our planet, from the soil of our backyards to the most unlikely and remote places, and more and more studies suggest there are way more to discover than we already have. But the number of living things might be dangerously challenged by the growing number of artificial ones, products of our frantic industry cluttering our homes, backyards, cities and eventually landfills.

Even if a very populated one, our small planet is just itself a tiny thing in the universe, among a growing number of siblings. The number and variety of bodies in the Solar System, as well as the distance we can expect to find them, have been growing beyond expectations. Closer to us, a survey of impacts on the Moon over seven years has yielded more events than expected based on previous models of the distribution of small bodies in the inner Solar System. Images of the solar atmosphere by the SOHO coronograph has yielded an impressive number of spectacular sungrazing comets. And missions to planets have unveiled a wealth of amazing landscapes, comforting hopes to discover life in some of them.

Beyond the exploration of our home stellar system, the discovery of thousands of exoplanets did not come as a real surprise (our star being an exception would have been a big one), but there again we begin to discover more than expected, from an earth-sized planet around the star next door to improbable configurations such as planets orbiting binary stars. Moreover, free-floating, or so-called rogue planets, not tied to any specific star, are certainly cruising throughout our galaxy, and although very few of them have so far been actually detected, due to the extreme difficulty of such observations, some studies suggest they may outnumber the "regular" planets, those orbiting a star. Regarding stars themselves, the most recent catalog contains over one billion of them, which is less than 1% of the estimated total star population of our Milky Way galaxy, while new studies tend to indicate that the number of galaxies in the observable universe is at least one order of magnitude higher than previously thought. Even exotic thingies such as merging black holes, of which detection is now possible based on the transient ripples they create on space-time (aka gravitational waves) appear to be more frequent than expected. And the universe has certainly more in store, including the infamous missing mass, dark matter of which nature remains unknown.

The sheer number of objects unfolding in the depths of space and time is well beyond the grasp of human imagination and cataloguing power, not to mention philosophy. But fortunately the modern Horatio gets a little help from his friends, the machines. The overwhelming tasks of data acquisition, gathering and consolidation, identification, classification, cataloguing, are now more and more delegated to machines. Artificial intelligence, and singularly machine learning technology is beginning to be applied to tasks such as classifying galaxies or transient events. Using such black box systems for scientific tasks is stumbling again on issues linked to inscrutability, which we addressed in the previous post. Scientific enquiry is a very singular endeavour where whatever works is not easily accepted and the use of inscrutable information systems can be arguably considered as a non-starter. 

There are more and more things indeed in heaven and earth that we know of, and we are more and more eager to accept the unknown ones we discover every day. But the ones our poor imagination might be forever unable to fathom are those new ghosts haunting our intelligent machines. Are we ready to welcome those strangers?

[Edited, following +carey g. butler's comments to strikethrough above intelligent. Let me be agnostic about the fact that machine learning systems (or whatever systems to come) are intelligent or not, because I don't know what intelligent means exactly, be it natural or artificial. The "ghostly" point here is inscrutability.]