Friday, 10 May 2013
You, in Perspective using numbers.
There are an estimated 1,000,000,000,000,000,000,000 stars in the universe, grouped in around 500 billion galaxies. Only some of those stars are in the ‘galactic habitable zone’, not too close to the centre nor too far away. It’s thought there are at least a hundred billion planets in the universe, probably far more, with wildly varying estimates of between 17,000,000,000 to 50,000,000,000,000,000,000,000 potentially habitable ones. In the Milky Way alone, estimates are between 500 million to over 150 billion Earth-like planets in the ‘Goldilocks’ circumstellar habitable zone.
In our system, large gas giants patrol the outer reaches removing many of the asteroids and comets that drift into dangerous proximity with the Earth. Earth orbits ‘the right type of star’ at the right distance in a stable ellipse, and it formed long enough ago for complex life to evolve, yet not so long ago that the required molecules were yet to form within the earliest stars. Earth has plate tectonics and a large moon that’s not so close it causes devastating disruption; both factors contributing to successful development of life on Earth, without which nothing would live here but bacteria.
It’s likely hundreds of millions of distinct species have evolved on Earth in the last four billion years, and 99.9% of those became extinct. There are currently between 10 to 30 million species of insects and around one and a half million non-insect animals, something like five and a half thousand of which are mammals.
On average a man produces 80 to 300 million sperm per ejaculation, which is approx. 363,680,000,000 to 1,363,800,000,000 in a lifetime. The ovaries of a female foetus contain six to seven million oocytes, around 400 of which will produce fertile eggs in her lifetime. The average number of children, i.e. successful pairings of sperm and egg producing offspring, per family in the UK in 2012 was 1.7.
Approximately 107 billion people have lived since our species evolved. In 1950 the global population was two and a half billion, in 1995 over five and a half billion and currently at about seven billion.
The genus Homo have lived on Earth for about 2,400,000; our species Homo Sapiens for about 200,000 years. ‘Behavioural modernity’ has been going on 50,000 years or so. The Industrial Revolution began much more recently, around 250 years ago.
Arguably the England we know today began 669 years ago when Edward III founded the Order of the Garter on April 23rd 1344, later adopting the flag of St George as their banner. A dramatic development in European politics, this simple thing led to changes in the shape of the political map and allowed the English to step out from the shadow of France for the first time since 1066.
Soon after this time about 25 million people died in Europe of the Black Death, around 75 million world-wide. 30-40% of the population of England died within two years. At that time infant mortality rates were already perhaps 30% and average life expectancy even for the wealthy was no more than early forties. A lot of people were dying without having children and at one point the national birth rate was lower than the death rate, with many towns being left to ruin as the dwindling population moved elsewhere to find work.
World War I, while the estimated 17 million deaths is fewer than the Black Death, still had a big impact long-term as the majority of the deaths were young men. In World War II over 60 million died, more than 2.5% of the global population. The Spanish Flu pandemic of 1918-1920 killed an estimated 50 to 100 million people worldwide, 99% of them under 65. In the space of three and a half decades the world lost a very large number of young people.
In the last hundred years life expectancy and quality of life in Europe and most of the nations that began as European colonies have continued to dramatically improve, infant mortality rates continue to drop and disease rates have been considerably lowered by good sanitation and improved medical knowledge.
This doesn’t mean life is now easy. It isn’t and perhaps never can or should be. Life is unimaginably precious. Each one of us is here as the result of circumstances that occurred against astronomical odds on every level: the specific laws of physics at the universal scale, the rare circumstances that led to the Earth we know, the long line of survivors that preceded you, the fortunate survival of your human ancestors who lived through war, famine and pestilence long enough to bring successive generations into the world, that your parents met and spent enough time together to conceive you, that you yourself were the result of that particular combination of sperm and egg, one of approximately four billion ways your parents’ DNA could be uniquely combined, that made up the single cell that gave rise to your body, not to mention all the experiences and sensations occurring throughout your life that helped continue to shape you into the person reading this.
You are unique, but you are also part of something much, much bigger than yourself, in both Time and Space. There is no pressure to change the world single-handed and no need. Working together is more effective. We are part of a global family that blurs the arbitrary lines between species and has existed on Earth for aeons. We can’t all ‘win’ and shouldn’t see life in such a simple and ugly way. We’ve already won because we’re here.
Let’s not mess it all up for the generations of unique individuals that come along after us.