Showing posts with label formula. Show all posts
Showing posts with label formula. Show all posts

Thursday, 26 December 2019

Beware of insects with moustaches


Water must flow for all
I have written about my obsession with showerheads before, the way I tease the rubberised nipples if it is restricted or no water flow from any of the teats, this usually due to calcification.
It is not enough to stand under the shower, I look up and if just one of the teats is restricted, it needs to be sorted out. Every teat must be supplying a spray of water at its optimal capacity. In our apartment, I was met with a little extra difficulty, the teasing of the nipples did not work on two of the outlets of the innermost circle of 5.
The overhead shower which is a Hans Grohe product, the company founded in 1901 and is probably a global leader in faucets, showers, and taps with the model ‘Raindance’ of which there are many variants.
A census of the teats
After a few trials, I attempted unpicking the teats with a toothpick to no avail. Eventually, I dismantled the showerhead and found calcified deposits in the feeder assembly that I was able to unpick with a toothpick. On reassembling the showerhead, all the teats began working as intended.
Another thing that had bothered me was finding a simple mathematical formula to calculate the number of teats on a showerhead. There are diverse types, square, circular, rectangular, oblong and so on. This determines how the teats are arranged in the showerhead.
I have mostly encountered the circular arrangement with concentric circles with a quintuple setting in the innermost circle radiating out to 6 or 7 concentric circles. On the basic count, there were 5 on the innermost circle, then 10 on the next and 15 on the following.
A formula is reused
This would suggest an arithmetic or mathematical series. So, if there were 3 concentric circles based on multiples of 5 teats in each concentric circle, the total number of teats would be 5 + 10 + 15 = 30.
What makes this interesting is the cumulative number of teats and the series developing. On the 1st circle it is 5 or 5 * 1, for the second it is 15 or 5 * 3 and on the third, it is 30 or 5 * 6. I well-known series of 1, 3, 6, 10, 15, 21, 28 … is forming in the process. This, I have learnt is the triangular number sequence.
The detail from the link about suggests a formula of n(n + 1)/2. This would deal the determining the number of teats for regular concentric circles where each consecutive circle is a multiple in the natural sequence of the innermost circle. The series in the paragraph above would suffice for where the innermost circle has one teat and the next concentric circle has 3 using the triangular number sequence.
Hansgrohe Raindance showerhead
All numbers matter
The showerhead in the picture has m = 5 teats on the innermost circle with n = 6 concentric circles. For which I now have the formula m * n(n + 1)/2 and whilst the formula can be decomposed further, it is neater to keep it this way. I would then have 5 * 6(6 +1)/2 = 5 * 6 * 7 / 2 = 105 teats.
On the referenced blog where the rainfall showerhead at the Royal York Hotel had 7 concentric circles with 5 being the multiple, the applied formula would result in 5 * 7 * 8 /2 = 140 teats.
With my showerhead conundrum solved, I will happily bother my head with something obscure and productively silly as finding out if there are really any insects with moustaches in Cape Town, this showerhead mystery already fits the bill.
 Courtesy of the William Kentridge exhibition at Zeitz MOCAA, Cape Town.



Tuesday, 24 February 2009

A mathematical reflection on Shrove Tuesday

A time for reflection

Today is Shrove Tuesday [1], the day before Ash Wednesday [2] when those of a traditional Christian religious inclination embark on 40 days of self-deprivation to end on Palm Sunday in what is the Lenten season.

There might be many who would give up something for Lent [3], having not prepared for it, I wonder what I would be giving up for Lent.

Maybe what I should be doing is adopting something for Lent, some reflection, some introspection, some reminiscing, some meditation, some resolve and some giving of thanks in solemnity.

A time of fattening

But today is Mardi Gras [4] (Fat Tuesday), we get to throw together all sorts of leftovers and gorge ourselves silly before straitened and frugal times of spiritual renewal and reawakening.

In traditional households, it is Pancake Day and what toppings can one desire for pancakes than the richest flavours that would have calorie counters choking on their cholesterol.

It would be easier for me to obtain ready-made pancakes, maple syrup and ice cream from my supermarket and make happy with a quick oven warming but that is about to be marred with inanity.

In pursuit of useless science

A lecturer of mathematics first starts making things including pancakes and has ended up making things up with some complex mathematical formula needed to create the perfect pancake [5].

The amazing formula is “100 - [10L - 7F + C(k - C) + T(m - T)]/(S - E) with the closer you get to a 100 - the better the pancake.

Someone must be pulling my Lenten cords as it seems I should first be shopping for a Non Stick Aluminium Frying Pan – thankfully, I already have the choices of English Shropshire Honey [6], English Salisbury Plain Honey [7] or Scottish Heather Honey [8] – all acquired from your favourite grocery – Fortnum & Masons [9] on the Piccadilly last weekend when I snuck into London.

So, frying pan at the right temperature (T) using a thermocouple thermometer, number of lumps in batter (L) with some consistency value (C) and a flipping score (F) – flipping heck, it is a pancake for crying out loud.

Better to use the pancake recipe [10] on AllRecipes.com than follow this mad scientist tripe, the credit crunch can so easily be attributed to mathematicians [11] making things up with their complex investment vehicles that gave birth to superfluous credit and debt systems without the attendant risk balancing equations that has now brought our economies down to the knees.

Make things, make pancakes

Never before have we needed people and brains that make things so much as mathematicians should begin to think of how to make it up to us for their formulaic concoctions of silly pancakes and debt instruments – this time of Lent must surely bring us the greater repentance to desist from making things up.

If I ever wanted to use this formula it would be just to get the pancake mix to throw over the heads of mathematicians held up to public ridicule in stocks at the market square – the more rotten eggs and curdled milk the better.

One last day to descend into the debauched excess of a goodly pancake before one repents of it all in Lent with one last prayer – Dear Lord, in these straitened times, deliver our pancakes from the machinations of atrocious mathematicians bent on creating inscrutable formulae that equate to rotten pancakes ready to be binned.

Keep off our pancakes – I protest!

Sources

[1] Shrove Tuesday - Wikipedia, the free encyclopedia

[2] Ash Wednesday - Wikipedia, the free encyclopedia

[3] Lent - Wikipedia, the free encyclopedia

[4] Mardi Gras - Wikipedia, the free encyclopedia

[5] Formula for perfect pancake unveiled by scientists - Telegraph

[6] English Shropshire Honey

[7] English Salisbury Plain Honey

[8] Scottish Heather Honey

[9] Fortnum & Mason UK - Experts in food hampers and gift hampers

[10] Pancakes I - Allrecipes

[11] BBC NEWS | Business | The maths of the credit crunch