Friday, 15 January 2010

An Astronomy lesson from Zimbabwe and the USA. 2010-01-15

Friday 15th January 2010 at 21:36 GMT
I must be in need of something better to do. When I was little, I used to do sums in my head for amusement and I decided to try some mental arithmetic last week to see if I could still do it!

I rememeber considering the US government's debt a few years ago, when it was 6 trillion dollars. I realised that this was in fact an astronomical sum, literally. You see, 6 trillion miles or 6 million million miles as the famous astronomer Patrick Moore put it, is equal to one light year, the distance the fastest thing in the universe, light, travels in a year. So the USA was already in a truly astronomical amount of debt. Forget the distance of Neptune, which is about 3 thousand million (now called 3 billion) miles; that is a mere snip. I mean that is nowhere near the extent of this year's bonuses for the bailed out investment banks, is it? Solar System scales are not sufficent to describe these sums of money; interstellar scales are needed.

The nearest star is Proxima Centauri, a red dwarf that orbits alpha Centauri, the latter of which is visible clearly in the southern sky. They are 4.2 light years away. That is abut 25 trillion miles. Sirius, the brightest star in the sky (partly because it is one of the nearest) is 8.6 light years away; that's about 50 trillion miles or 80 trillion kilometres. Now that is about equal to the unfunded liabilities of the USA in US dollars.

A mile or a kilometre is a nice unit, because it takes a little effort to walk it; 15 or 10 minutes respectively. And it takes a little effort to earn a pound, a euro or a dollar for an ordinary working person in the western world and a lot more effort for the average person in China or India. So it's a good thing to consider as a measure. Now think how much effort it would take to walk all the way to Sirius and you get an idea of whether the US debts are ever going to be paid off!

Right, let's get to Zimbabwe. Things get even more interesting because even the seemingly unimaginable distances of space are barely enough to describe the debasement of their currency.

What started me off on this bout of maths, apart from the sheer mind-numbing tedium of living in cultureless central England was this graph, shown below, charting the inflation of the Zimbabwe dollar since 1/1/2001, an interval of a mere 9 years, by plotting how many Zimbabwe dollars traded for 1 US dollar. It starts at 100 and then rises steadily, then wildly to somewhere between 10 to the power of 23 and 10 to the power of 31, depending on whether you believe official or unofficial data, internal goverment or external agency data.

In the worst case, the US dollar was worth 1,000,000,000,000,000,000,000,000,000,000 Zimbabwe dollars, i.e. 10 to the power of 30, or 1 E+30.

I wondered what this might represent. Well, in fact, after doing some mental arithmetic, I arrived at the shocking conclusion that this number is about equal to the distance across the entire observable universe, in millimetres.
I am sure therefore, that by the end, 1 Zimbabwe dollar (or perhaps even 1,000 Zimbabwe dollars) would not have bought you a single molecule or even a single atom of anything, given that there are about 1 E+23 atoms in a gram!
Chart courtesy of the fabulous
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