Sunday, 24 February 2013

Goldilocks - the Deceitful Harlot of Science.

I love Science, and I hope you, dear reader, agree with me that, as well as a proper basic education in the facts and processes of Science, it is important to be able to keep up to date with news and developments in Science.

Most people have neither the time nor inclination to be regular readers of the main Science journals,  so we rely on good Science journalism, in the news and documentaries.

Tabloid media are notorious in their narrow focus on the disastrous side of Science; before the LHC was switched on, tabloids fovused on the possibility that it would create planet-eating black holes. Now the Higgs is all but identified, the same journalists raise it as proof that our Universe will be destroyed by the imminent emergence of another Universe within our own.

One particularly annoying, and wide-spread feature of Science reporting (and, I fear, of certain branches of true Science, and thus the focus of this rant) is an ongoing obsession with Goldilocks.

Two of the great motivations in Science are the search for the origins of Life on Earth, and the hunt for Life elsewhere in the Universe. Every time tge discovety of an extra-solar planet is reported, somebody mentions alien Life, and finds some reason for it to be impossible - too hot, too cold, spinning too fast, too much radiation, too little light, all of these get cited as reasons for Life to be unique to our home planet.

Scientists happily reel off lists of factors required for Life to be possible - a temperature just and so, an atmosphere made up of this and that, a particular chemical make-up of the crust.  These Scientists present themselves as experts, as "astrobiologists".

Even tonight,  Brian Cox, a man for whom I have a great deal of respect as both a Scientist and as a populariser of Science, has fallen for the allure of the Harlot of Science; Goldilocks.

There is a persistent meme within astrobiology that there exists a "Goldilocks Zone", a set of conditions, only within which can Life meaningfully exist. Brian Cox's slip was to claim that an atmosphere of free oxygen is essential for complex Life.

I'm sorry, Brian, and all the others with a claim to expertise in astrobiology, but that's bollocks. The Goldilocks Zone doesn't even exist here on Earth. Life thrives in temperatures
from tens of degrees below freezing to hundreds of degrees above,  from pressures of tonnes per square centimetre to almost vacuum, in conditions from corrosive alkali to acid strong enough to strip the flesh from your bones. Inside solid ice, on the surface if Sun-seared rocks. Wettest swamp to driest desert. In months-long daylight to eternal darkness.

You get the idea.

We have yet to find a set of conditions that is naturally devoid of Life.

True, if you transplant a soft coral from the North Sea to the Atacama Desert or the mineral pools of Yellowstone, it won't last long, it won't last long, but that's not the point. It not that there is something that can live everywhere, but that,  everywhere,  there is something that can live.

The Goldilocks Zone is an illusion. It's an attractive illusion, one that panders to humanity's sense of pride, but an illusion all the same.

So, what's the truth?

Simply, to lift a quote from Jurrasic Park; "Life will find a way".

It will be Life, Jim, but not as we know it (sorry, I couldn't resist that one).

Astrobiologists, and the popularisers of Science, have a very narrow definition of Life; mainly water-soluble biochemistry, based on complex carbon-spined molecules, running on glucose metabolised with oxygen.

I prefer, though, a different, simpler definition; it has a reproductive process which involves a mechanism for heritability of traits, and there is, within that mechanism, the possibility of mutation and, thus, evolution.

Life (as we know it) makes exclusive use of DNA, but past forms, we believe, used the simpler RNA. Why could it not employ chemistry based on other molecules? Or a stream of digital information? Who says the mechanism of heritability is even required to reside within the actual organism?

I put it to you, dear reader, there is but one limitation on the existence of Life across the Universe; simply,  whether, should we encounter it, we would recogise it as Life at all?

One thing I do know; it won't have curly blonde hair.


  1. >We have yet to find a set of conditions that is naturally devoid of Life.

    Ummmm. Pretty sure life can't survive in the core of the sun...

    There's no need to deny that some parts of the universe are more habitable than others. As Dawkins points out, the anthropic principle is more than sufficient to explain it without appealing to a deity (or a human-centric universe).

    1. Actually, I've read articles hypothesising life formed of interlinked magnetic plasma tori, which could *only* exist within a star...

    2. I preface this with the disclaimer that my intent is nothing but friendly...though I do disagree with this particular point.

      Okay - life as we currently *know* and define it, dependent on water. Of course new and strange life forms can be hypothesized to exist under any set of conditions, but that isn't really helpful at all to the argument (in fact, it smacks of moving goalposts). And it is strange indeed to speak of "life" and mean "something I haven't found, but can imagine" when speaking in a scientific sense.

    3. Quite the opposite.

      Assumptions based purely on what we observe here and now actually restrict the search for Life.

      We "know" that Life requires six basic elements, carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur, and yet bacteria have been found that utilise arsenic instead of phosphorus.

      The teams looking for Life, and this is an error that goes all the way back to the first Mars landings, look for free oxygen as a marker of Life, or even chlorophyll, yet, for billions of years, this planet harboured Life without either, and even now there are pelagic organisms that utilise iron and sulphur in their energy cycles instead of carbon and oxygen.

      Water is just another of those assumptions. We can easily say that the chemistry of Life "requires" water, yet some of Life's chemistry is disrupted by the presence of water, and must be isolated within fats.

      You must be familiar with the concept of "AI", in which a software/hardware matrix is recognised as "alive"? There are valid models where naturally-deposited metalloid crystals, energised by solar flux, support natural digital life.

      If you do not like that idea, then what about von Neumann machines? Artificially created by other Life, they are, nevertheless, a form of Life that thrives and spreads without water.