Wednesday, 30 May 2012

It's life Jim, but not as we know it...

There is a quite famous formula in science called the Drake Equation. It was developed by Frank Drake, Emeritus Professor of Astronomy and Astrophysics at the University of California, Santa Cruz in 1961 as part of the SETI programme, and it sets a framework for trying to estimate the number of detectable extraterrestrial civilisations in our galaxy, the Milky Way. I'm going to bore you now with the basic details of this formula, because I find the concept of it quite interesting. So in all it's glory here it is:

N = R^{\ast} \cdot f_p \cdot n_e \cdot f_{\ell} \cdot f_i \cdot f_c \cdot L

That looks pretty meaningless, so let's break it down a bit:

N is the number of civilisations within our galaxy with whom we may be able to communicate, i.e. the target number we are interested in.
R* is the rate of new star formation in the galaxy.
fp is the fraction of these stars which have planets in orbit.
ne is the number of planets in each star system which may be capable of supporting life.
f is the fraction of these planets which actually go on to develop life
fi  is the fraction of these which evolve intelligence
fc is the fraction of intelligent civilisations which have detectable interstellar communication.
L is the length if time during which each civilisation emits detectable communication.

I won't go into the details of each of the factors, but if you want to read more follow the link above to the Wiki page. Current best estimates of the various factors leads us to a final N number of somewhere between 0 and 182,000,000. This varies mainly because the actual values of several of the factors are a matter of some conjecture, and we are forced to guess what these might be. In particular the values for f fi and fc are open to debate, because we have no data on which to base our estimates. So we may be alone, or our galaxy may be teeming with intelligent life we are yet to discover. However because of the vast distances involved (the Milky Way is a spiral galaxy roughly 110,000 light years across containing around 300 billion stars) if the number of detectable civilisations is moderate (say 10,000 or so) they may be sufficiently far away that we can't find them with our current level of technology, and any signals being emitted by them may not have reached here yet, and may not do so for hundreds or thousands of years.

As stated above there is a lot of conjecture about the values of some of the factors, leading to such a wide variety of possible answers that its use as a predictive tool is questionable. It does, however, provide an interesting starting point to stimulate thought about the likelihood of extraterrestrial life. Unfortunately it is unlikely to be a successful conversation starter at the vast majority of social functions :)

One of the more interesting possibilities raised by the Drake Equation, and one for which we are now beginning to be able to assign numbers, is the likelihood of life existing elsewhere, even in its simplest form. We already know the rate of stellar formation, and therefore the number of stars in our galaxy, and we are starting to be able to make good guesses at the number of these with planets, and what proportion of these planets lie within the goldilocks zone, the orbital distance at which liquid water might exist on the planet's surface, and therefore the zone in which life as we know it is most likely to arise. Our assumption is that life is pretty likely to arise where conditions exist which favour it. This is based on studies of the diversity of life on Earth, the one place where we know with certainty that life has evolved. Life inhabits pretty much every available habitat on our little ball of rock, and manages quite nicely in environments you and I would find quite unbearable. So it doesn't seem unreasonable given favourable conditions that at some stage elsewhere a complex organic molecule began to replicate itself. If we replace R* with the total number of stars in our galaxy (300 billion) to get a current snapshot and then use conservative estimates N becomes:

300,000,000,000 x 0.34 x 0.005 x 0.13 = 66,300,000

That is over 66 million planets or moons in the Milky Way which may contain even rudimentary life as we know it. In our own solar system there are a couple of reasonable candidates. Mars is a possibility. We know water ice exists on the planet, and at some stage in the past it had liquid water on its surface. Recent photographs suggest the existence of subterranean caves, and it is likely that ice exists in a sort of permafrost under the soil surface. Both of these habitats support basic life on Earth. A more exciting possibility is Europa, a moon of Jupiter. Like Earth it has a metallic core surrounded by rock. The entire surface is covered by a layer of water roughly 100km thick. The massive gravity of Jupiter exerts strong tidal forces on this layer, which creates sufficient heat through friction to allow a significant ocean of liquid water to exist underneath the icy exterior. And anywhere where we see permanent liquid water there is a strong likelihood that life may exist. Hopefully the question will be answered one way or another when the Jupiter Icy Moon Explorer investigates Europa around 2030. I can't wait :)

Sunday, 27 May 2012

The Wright man for the job

At the beginning of this month John Wright announced that he was not going to be seeking an extension to his contract as coach of the New Zealand cricket team. He will be standing down from this role following the end of the Black Cap's tour to the West Indies in July/August. No doubt a number of factors influenced this decision, and it looks as if it was Wright's to make. It seems that New Zealand Cricket (NZC) don't want him to go, with Chief Executive David White quoted as saying "we were keen to see him continue his head coach role, however understand and respect his decision to look for another challenge." I can only speculate as to the reasons, although rifts between him and Director of Cricket, and former Australian coach, John Buchanan have been suggested. Wright himself has said that he and Buchanan have different philosophies and approaches to the game, so it looks likely that this contributed at least in part to his decision not to continue in the role.

When Wright was first appointed as coach I had a great deal of optimism about the future of the Black Caps. He was a gritty and determined opening batsman for New Zealand for many years, and was half of what was arguably our most successful opening combination at test level. He and Bruce Edgar opened the batting together from 1978 to 1986, and scored a total of 1655 runs at an average of 31.82. This is only the 27th best opening pair in the history of cricket, and it is some measure of the relative weakness of New Zealand's record in test cricket that we remember them so fondly. Wright was also a very successful first class cricketer, scoring over 25,000 runs at an average of 42.35. 

After retiring from the game he took a brief hiatus for a couple of years and then moved in to coaching. It was as head coach of India that he really made his mark. He oversaw a remarkable rise in Indian cricket from 2000-2005, during which time they had series wins against Australia and Pakistan and made the final of the 2003 Cricket World Cup. That the Black Caps had their first test win in Australia for 25 years under his watch suggests he was making real strides with the team, and keen observers could see an almost palpable difference in the way the team approached the game.

Wright comes across as a no-nonsense kind of fellow, one who wouldn't suffer fools gladly, and I suspect that he tackles coaching with a fairly old-school approach, focussing on basic skills and fitness. Rumours abound that he was feeling disenfranchised by the management style at NZC and that he felt he was spending too much time writing reports and attending meetings. This type of new age management style doesn't go down terribly well with a lot of kiwis, and it is likely that Wright is one of them. I am deeply disappointed that he felt it necessary to stand down, and the Black Caps will suffer from his loss. Personally I think NZC made a huge mistake appointing Buchanan and putting in place systems that alienated Wright, and I'm sure they will rue this decision in seasons to come. I hope they will be able to find someone for the coaching role who will build on the good work Wright has begun, but I won't be holding my breath.

Thanks for the memories John, you'll be missed by true cricket fans.

Thursday, 24 May 2012

A dam shame

Yesterday the news broke that Meridian Energy has decided not to proceed with its bid to build a new hydroelectric dam on the Mokihinui River, north of Westport. The reasons cited by Meridian include the "high costs and risks surrounding a scheme that encroached on environmentally sensitive land." This makes it sound as if Meridian are concerned about the environment, but in the end the process of approval was simply made too hard and too costly for them to proceed through the Environment Court. Conservation groups are of course claiming this as a victory.

Let me say, first of all, that I care about environmental issues as much as any comfortable middle-class left of centre pakeha family man. By this I mean I happily put out my recycling bin each fortnight safe in the knowledge that I am saving the world, I have a number of those odd curly light bulbs at home, and I tut-tut to myself under my breath when I see a big dirty corporate being painted as doing something nasty to the environment on Campbell Live. I was not happy with the idea of opening up National Parks for mining, because there is a place for preservation of our native species and natural beauty for future generations. Very little ruins the aesthetic appeal of an area like digging it open to mine it, and there are plenty of tracts of land in private ownership which could be exploited for their mineral wealth first. 

However, Meridian's decision saddens me. I think most people would acknowledge that we need to invest in more electricity generation capacity. The problems several years ago with low levels in hydro lakes in central Otago highlights how fragile our supply can be, and how dependent we are on benevolent weather patterns. So it seems a no-brainer to build a dam on the West Coast, an area which receives the highest and most consistent rainfall in the country. That's the reason my dad moved us away from the Coast when I was a young lad, to get away from the rain. Meridian's plan involved building a dam on an isolated river that nobody really knew existed and would have generated power to supply 50,000 homes. The resulting lake created would have been 14km long, and the area would have been opened up for recreational purposes to Coasters.

Yes, there were environmental issues involved here, the area plays host to kiwi, bats, blue ducks, eels, fish, etc. But it isn't as if the lake would have sprung up overnight drowning all and sundry instantaneously. These things take time. I'm pretty sure the kiwi and bats* would have walked up the hill to keep their feet/wings dry and I doubt the ducks, eels and fish would be complaining about a lake to swim around on/in. I understand the arguments about reducing the area of natural habitats available for these species to breed and live in, and I am generally sympathetic to these concerns. But this is one of those occasions when I think we ought to have considered the economic and infrastructural benefits over and above these concerns. And if the government is, as looks inevitable, planning on selling off a part share in Meridian, showing that the nation is sympathetic to development wouldn't be a terrible signal to send to potential investors.

*Note that our native bats aren't especially strong fliers, they tend to spend a great deal of their time crawling around on the forest floor.

Tuesday, 22 May 2012

And so it begins...

Subtitle: The one where the scene is set.


Welcome to my blog. It took me a long while to make up my mind about starting a blog. At first I thought that it would be a waste of my time, and that nobody would really care what I have to say about stuff. But then I got to thinking, well, why shouldn't I? After all, I'm moderately intelligent and have 44 years of life experience on our little ball of rock swinging gracefully around our star, so I might, on occasion, make an observation which enlightens or entertains.

Who am I? Well, I live in New Zealand, home to hobbits, sheep, adventure tourists, and the occasional nerd like me. I'm a big fan of my home country, but there are things going on here which variously amaze, annoy and dumbfound me. At the time of writing my wife and I are about to become parents for the first time, with our baby daughter due around the end of June. This is an adventure soaked in anticipation and trepidation, and is undoubtedly something I will be discussing at some length here. That'll be fun, I hear you say :)

No doubt a reasonably common theme here will be my disenfranchisement with politicians at both central and local government levels. Occasionally I will rail for or against issues about which I am passionate, and I make no apologies for embracing my leftist leanings. I am also, as my brief bio suggests, a science and IT geek, and the content here will reflect that. Expect posts about cool sciency stuff, especially the life sciences and astronomy, interspersed with comments about things IT with a bit of gaming thrown in for good measure.

By far and away my favourite sport is the noble game of cricket. I love the swings in fortune during test matches, and the little defining moments which can change a game. I don't mind the shorter versions, but for me test cricket will always be the purest form of the game. Like many kiwis I am interested in rugby, but not with the fervour demonstrated by a number of my fellow countrymen, so it won't be high on my list of topics.

Settle in folks, sit down, put your feet up and make yourselves at home. This blog will likely be a bit of a mixed bag; I intend to touch on a number of topics which interest me, as stated above. With a bit of luck I will find the time to post with reasonable frequency, but as the aphorism goes, the road to hell is paved with good intentions. I make no excuses if when our baby comes I drop out of the loop a bit, I expect this to be a pretty busy time.

Note also that this blog is a bit of a work in progress, so expect  things to evolve over time as I tweak things a bit. Cheers!