The BBC has an application on its news site which claims to be able to tell you 'what number' human you are, i.e. when you were born, how many others were already alive, and how many had lived? It claims to do this to the nearest person. This is adapted from the 7 billion and me site. Whilst I understand the serious point they're trying to get across, the stupidity of this claimed precision is mindboggling - it assumes both a known and agreed definition of 'first human' (and that ain't Adam), and accurate census data going back into pre-history. We don't have accurate census data going back five minutes.
To claim something that precise is misleading and distracting from the underlying message about population growth (which ultimately drives climate change, food shortage, resource shortages etc).
I can only enter data accurate to the nearest day, and yet it feels able to tell me that
When you were born, you were the: 3,881,935,677th person alive on Earth 78,133,984,133rd person to have lived since history began
If I make the smallest possible increase to my birth data, I am told:
When you were born, you were the: 3,882,143,819th person alive on Earth 78,134,317,296th person to have lived since history began
So, it appears that there is no way to be 79,133,984,134 or 79,133,984,135 or any of the other 333,163 options.
Thus, would it not have been better to say 'you are roughly the 78,134,000,000th person ever to have lived' and roughly the 3,882,000,000th person alive on earth?
I sent the following to the BBC (admittedly before I'd actually looked at the appropriate level of precision to claim, but the point remains.
This is a slick presentation of statistical woolly thinking. Whilst I understand the broader points about population growth, it is very bad for the public understanding of science to give such a precise figure for what 'number am I' based on a birthday (upon which there will have been many births).
Much better to round it off to an appropriate degree of precision and add (to the nearest X), e.g. 3,589,120,000 (to the nearest 10000)
There is also a 'fuzzy' start for the 'number of humans ever lived' - at what point do you start counting in a continuous chain of evolution? This is a systematic error, and I would guess an error of relatively small size given the current population, but still.
For the sake of the better engagement between science and the public, reduce the claimed precision, and explain why this has been done.
Indeed, to anyone with a science background, such a claimed precision undermines the veracity of the data (when, I suspect, it's the product of an over-zealous app programmer).
I wonder if they'll take it on board.