SI units or metrification as many of you will know it resulted in the overall adoption of seconds, grams, metres, litres and Pascals in place of the commonly used minutes, pounds/ounces, feet/inches, pints and pounds per square inch. Okay so some parts of the world have developed a certain reluctance in the uptake of these units despite their development way back in 1960 - the UK for one clinging to miles and pounds of fruit and veg. Aren't we backwards ;)
The reason for blogging has been the recent absolute frustration at the overlaps in the system. In this case it concerns the use of the letter k. k as everyone should know represents 1000. However this substitution takes place for one thousand metres (km), grams (kg) and bytes (kb) to mention just a few, but it also gets placed into the number (£3k) as well. Once the idea that something might be wrong gets into my head then I have great trouble proving to myself what the correct way actually is, despite probably using it without thinking for years. In the current situation I have been happily converting km2 to m2 (square kilometres to square metres - 1:1,000,000) for absolutely weeks.. until the idea got into my head (thanks guys...) that km2 could actually mean 1000m2 - i.e 1000 square metres rather than 1 million.
Believe me it messes with your head and the more you think the more you doubt!
The consequences, bar the inevitable overestimating in this case jellyfish abundances and biomass - x grams per m3 suddenly reduces to 1000x less grams per m3..., is that I have been doubting the validity of all the other sources of data I have been using. "Maybe they meant 1 thousand instead of 1 million, maybe they meant something else, how can I tell?". The answer to the later bit is simply that I can't. I have to trust that the published figures are as they were meant to be. Arrrghhh.
All I can say is that at some point in my thesis I am going to define and write in words Exactly what I mean by g 100m3 and km2 so that there can be no confusion with my interpretation of the presumably-correct published history.
What a week!
By the way.. 1 Tonne of jellyfish in a square kilometre is exactly the same density as 1 gram in a square metre. Now convert from T km-2 to g 100m-3 using the web to work out the depth of the water where the samples were taken from... or even better from grams of Carbon m-3 to grams of wet weight per m-3 when the authors haven't provided an equation between one and the other. Good luck!
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