HMDOWDCTHL?

Because

How Many Days Of Water Does Cape Town Have Left?

was too long for a blog post title. In my humble opinion, anyway.

If you want to know the answer to that question, then you might find a visit to local website howmanydaysofwaterdoescapetownhaveleft.co.za informative.

I went there just that this morning and I saw this:

Really?
Yes, whatever method they’re using, described as:

using our recent consumption as a model for future usage

provides us with the frankly terrifying prospect of October 7th being the day at which Cape Town’s dams hit the apocalyptic 10% mark.

But I think that they’ve got it wrong.

I thought I’d give the rudimentary calculation a go myself.
I went for the mathematically simple:

method.

Long story short, according to the latest city figures, we have 250581 megalitres stored, which is 27.9% of total storage capacity. As has been mentioned ad nauseum, the last 10% of our capacity is “unusable”, so clearly we can only use the first 17.9% bit of that (which is 64.2% of 27.9%).

That’s 160767 megalitres.

And we’re using 642 megalitres a day. So I make that

250 days – April 7th 2018

 

Far more reasonable, and more than a bit of a difference. I even did it in purple for you, and look, it does fit with Clem Sunter’s prediction/calculation.

Look, if you are going to have a website that only has one purpose, at least make it accurate. Does HasZumaQuitYet need checking too (he said, hopefully)?

Not great. Anyway, all in all, it’s still an excellent reminder that one way or another, pretty soon the only thing we’re going to be waist deep in is Shit Creek.

Sans paddle.

 

(I think I can see what they’ve done, by the way: they’ve divided the 250581Ml by 100 instead of 27.9 before multiplying by 17.9. I just don’t know who to tell about it. No contact details on there, see?)

Hand Sanitiser

I like this:

Turns out that a very small percentage of a very, very large number is still significant. Your hand sanitizer is only as good as the number of decimal points the nines stretch to.

by Jamie Condliffe in Gizmodo, on this:

xkcd16

via xkcd.

(It’s 20,000 for those of you struggling with your decimals.)

Satan’s Arithmetic

From Frederick Schoeman of Cape Town on Friday’s Cape Times letters page:

Satan’s Arithmetic

I believe that a couple of centuries ago, two mathematicians were demonstrating their numerical skills to the French monarchy when one of them stunned his opponent and the audience by reciting an algebraic formula and claiming it to be proof that “God lives”.
Could I borrow a leaf out of that man’s book and claim that, since the graph of world population growth over the past 1700 years looks like a serpent trying to slither up a wall, Satan is alive and thriving on human lust?

I’ve been doing some extensive research into Fred’s story, but the best that I could come up with was the the story of Leonhard Euler, who was a mathematician, but was Swiss, not French, and his presentation of an algebraic formula, claiming to be the proof that God lives. This presentation was made to another individual, Denis Diderot who was French, but was better known for his philosophical musing, rather than his mathematical prowess. In addition, this presentation was made in St Petersburg in 1774, in front of the Russian Empress Catherine II, rather than any French monarch.
Wikipedia tells us:

There is a famous anecdote inspired by Euler’s arguments with secular philosophers over religion, which is set during Euler’s second stint at the St. Petersburg academy.
The French philosopher Denis Diderot was visiting Russia on Catherine the Great’s invitation. However, the Empress was alarmed that the philosopher’s arguments for atheism were influencing members of her court, and so Euler was asked to confront the Frenchman.
Diderot was later informed that a learned mathematician had produced a proof of the existence of God: he agreed to view the proof as it was presented in court. Euler appeared, advanced toward Diderot, and in a tone of perfect conviction announced, “Monsieur! (a+b)^n/n = x, donc Dieu existe, répondez!”.

This roughly translates as:

Listen mate, a plus b to the power n, over n, equals x. That means God exists.
What do you say to that then, huh? HUH?!?

Allegedly, Denis failed to provide an immediate answer. Or indeed any answer:

Diderot, to whom (says the story) all mathematics was gibberish, stood dumbstruck as peals of laughter erupted from the court. Embarrassed, he asked to leave Russia, a request that was graciously granted by the Empress.

This sudden stage fright could have been due to Euler’s sheer mathematical brilliance.
Or, conversely, it may have been caused by Diderot’s incredulity that some Swiss bloke had successfully baffled him with bullshit by spouting some maths at him and pretending that it meant something that it actually didn’t.
Why not try something similar at your local supermarket this weekend? At the Deli counter, ask for some ham. When the lady asks how much you’d like, exclaim loudly (remembering to use a tone of perfect conviction):
“Madam! a x squared, multiplied by b x, plus c, equals zero, therefore I’m off to the jams and spreads aisle. What say you to that?”.
See if she can find an immediate answer.

When she can’t, she must ask her boss’s permission to leave the country and go back to France.

Either way, there’s a whole lot more detail, including eye witness accounts, right here.

Of course, the formula didn’t prove that God exists at all, although it later proved invaluable in predicting how long one would have to wait for the next bus to the St Petersburg city centre.
Nice work, Leonhard.

So, the first of Fred’s paragraphs proven wholly misguided, yet almost slightly true, we move on to his second.
The bit about the snake.

But before that, at this point that I’d like us all to stop and consider some stuff for just a second. Firstly, put yourself in Fred’s shoes. At some moment in time, Fred actually felt that there was a connection between his 18th century algebraic French monarchy court presentation story and a graph of world population growth over the last 1700 years. Personally, I can’t see it. It’s like me taking an excerpt from a book on the dinosaurs and somehow linking it to the recent downturn in Malaysian rubber production.
But I digress. The important point here is that Fred saw this relationship.
Secondly (and still in Fred’s shoes), Fred sat down and wrote to the Cape Times about it. That is, not only did he feel that the connection was a valid one, he felt it was worth sharing – not just with his friends (although I have no idea if he put it on his Facebook wall) – but with the general population of Cape Town and surrounds.  While he was typing (or writing – who knows?) away, he still thought it was a good idea to sent it through to the letters page. When he addressed the envelope or entered the email address (ctletters@inl.co.za), he remained under the impression that the not only did his observation make complete sense, but that it was so important that 268,000 readers should be informed of it.
And then, once his thoughts arrived at the Cape Times office, at a time when sharks, rugby, racial issues, politics and cellphone masts (What? – Ed.) are at the forefront of all of our minds, Fred’s letter was one of the seven best that was received by the local rag that day.

Yes. Really.

But onto the serpent thing. I had a good luck around on the internet and the best graph I could come up with to illustrate  Fred’s serpent against a wall thing was this one:

Obviously, you can ignore the bit before 311 AD, as Fred didn’t consider that when making his serpentine comparison.
Personally, I felt that it was a bit of a stretch, but then I’m no expert on what exactly a serpent trying to slither up a wall looks like. That’s why I searched for “a serpent trying to slither up a wall” on google images.

This was the best that I could find:

Which seems to suggest that human population exploded upwards, remained almost static while traveling back and then forward again in time, before increasing almost exponentially, peaking and then dropping off to the current number. That aside, we shouldn’t overlook that fact that

…it’s gripping onto that brickwork because Satan is thriving on human lust.

A few points, if I may be so bold:

Firstly, algebra cannot prove the existence of God. Theologians might have their own reasons for why this may be, but mine is probably more simple: that he doesn’t exist and that it’s awfully difficult to prove the existence of something that doesn’t exist – algebraically or otherwise.
Secondly, unless I’m missing some big chunk of causality here, an alleged incident in a “Parisian” court chamber 200+ years ago doesn’t have any bearing on the fact that “Satan is alive and thriving on human lust”.
Thirdly, I do still quite like the idea of an algebraic duel:

Sir, you have insulted me and I demand satisfaction. Meet me at 6 o’clock tomorrow morning and bring a blackboard.
No calculators.

Fourthly, what does Fred want us to do? Not breed? Adam and Eve bred. Mary and Joseph bred (sort of). Hey, Mr and Mrs Schoeman (Snr) bred. Are these also examples of human lust upon which Satan is thriving?
Fifthly, any line graph looks a bit like a snake on a wall.
Any block graph resembles the Manhattan Skyline.
Any pie chart has the appearance of… well… a pie. Deal with it.
Sixthly, get your historical facts right if you wish to make a good impression on those reading, but remember that…
Seventhly, just because you think something, doesn’t mean it’s a good idea to write it down and send it to the Cape Times.
Lastly, just because you think something, doesn’t mean it’s a good idea to write 1300 words on it on your blog.

Liked this

My Mum won’t like this one.

If I had a posterous blog, things like this would go on it.

but I don’t, so they end up on here.

Taken (by request, nogal) from the often amusing Saturday Morning Breakfast Cereal cartoon site.