To celebrate its diversity
South Africa became the rainbow nation.
There are a few problems with this.
Black isn’t on the rainbow.
White isn’t on the rainbow.
Brown isn’t on the rainbow,
pink isn’t on the rainbow
no-one’s actual skin colour is on the rainbow.
How is this when rainbows show every type of light?
Our eyes have only three colour-sensors[1]
so can’t tell a mix of blue light and green
from the aquamarine that lies in between
but know red plus purple isn’t myrtle
so you invent a colour, magenta,[2]
discover the rainbow is not enough
you must have pink.
This prompts us to think that
things reflect the whole spectrum
to different extents.
But some colours don’t exist if they get too intense
To find brown, tone things down
cause the same light
can look orange or yellow[3]
like gray looks white
if the dimness around it makes it look bright.
The amount reflected matters too.
Look, what I’m trying to say to you is colour’s complex,
context dependent, curiously hard to see[4]
how we can judge by the colour of skin
whatever kind of content lies within
when we can’t even pick out from that shade
the actual light waves overlaid so
when we talk of a rainbow of people or preferences
understand that our language has limited references
because people don’t fall onto lines
any more than they fit into boxes,
a spectrum is too small an infinity to capture personality[5]
so if you’ve dared to have a dream
where real people can be seen
because they know what eyes and words don’t show
then you can find me
somewhere over the rainbow


[1] There are 4 types of light-sensing cells in eyes, but the three cone cells (2 in the colourblind) are the ones that mainly judge colour. The other cells, rods, specialise in low-light or peripheral vision, and don’t compare results to other cells in order to judge shade most of the time, although they may help in low light. There are, however, a small number of humans with 4 distinctly different cones – functional tetrachromats, who may have higher levels of colour vision.

[2] This is effectively wrapping together the ends of the spectrum to make a loop.

[3] Dark red can also appear brown.

[4] Large amounts of colour vision are ‘filled in’ by the brain, due to the concentration of red and green cones in the fovea – outside the middle of our vision, colour perception is very weak for non-blue colours.

[5] This refers to a slightly technical point about the mathematics of infinity. It can be shown that there are several different types of infinity of differing size. All of the following depend on what assumptions are made about how numbers work, but the most common version is: we can say that the ‘smallest infinity’ is the number of whole numbers (1,2,3…). This is the same as the number of even numbers, as doubling each whole number gets an even number: there is a one-to-one match, so there must be the same number of numbers (even though there are clearly whole numbers that aren’t even). However there are definitely more numbers of any kind between, say, 0 and 1, than there are whole numbers. This is proven by Cantor’s diagonalisation argument. This is usually identified as the ‘next highest infinity’, the continuum, which is the infinity of a (non-pixellated) rainbow. Eyes can only distinguish between a few million (brightness-limited) colours, so can’t even manage the lowest infinity. However an object’s reflection is a function of the light wavelength being reflected with a different possible value at every point in the spectrum. The list of all possible reflection functions is a ‘power set’ of the rainbow, and power sets of infinite lists are always a higher infinity than that of the list. There are a few mathematical caveats that mean this may or may not be true in practice.


Science paper

Our group’s paper is on the front page of Science!

Basically, a new variety of solar cells called perovskites can re-use light rather than letting it go to waste. Some light hitting solar cells moves electrons around but does not result in electricity, but in these perovskite cells we find that this electron movement can turn back into light rather than being wasted. These solar cells have already generated enormous interest from researchers and businesses due to achieving high levels of efficiency in a very short time and this research suggests an extra factor that might allow us to improve them further. Their best efficiency has recently overtaken conventionally designed silicon solar cell efficiencies and this trick we’ve learned about is what makes the best simple solar cells (made of gallium arsenide) work so well – they make light tens of times before current is generated. There are a number of problems with implementing the same tricks in current perovskite cells (and it’s nowhere near as efficient as in gallium arsenide), but this is another reason to think there is a bright future for solar energy!

Oceanic Nutrient Cycles


Imagine the ocean, filled with glistening globules, falling,
this slow-mo downpour of snow serenely flows underwater
so I guess we ought to call it marine snow
and I guess you want to know what it is

It’s snot and junk and fishy gunk
gluey poo, dead planton too.
In tiny specks these things can float
but gravity grows as they too bloat
when bits stick to each sticky overcoat.
This is the nutrient link feeds the deep seas
a carbon sink stronger than trees
but if nutrients sink what feeds the heights?
Algae need to drink in more than lights.

Well the rivers are givers but it isn’t enough
some sun-shunning organisms dissolve falling stuff
but one grand brand of creaturea dredges the deeps
and ensures things don’t stay down for keeps:
the whale can go both high and low
and as swimming pools show,
mammal poo often floats
so whales may vent pink fecal plumes
which plankton, algae then consumes
and a new place of life blooms upon the map
come fish – feast – here be whale crap
and their poo too falls and festers,
broken down by micro-digesters
and it snows again.
Christmas on the abyss below
too dark for any plant to grow.

Then sailors became whalers and with slow whale birth
such travesty, this majesty near wiped off earth
and the fauna that adorn an ocean
starve without this marvel’s motion
for so valuable it seems is the iron in their cack
that killing whales, which eat krill, sets krill numbers back
Sure, sharks and squid will eat what’s hid
nearby, but what’s slid
down will not come back.
When these species we attack,
it’s only a biodiversity disaster
if we kill them faster
than they feed and breed
So another occupation that’s alright in moderation is fishing
but some smaller fish are just as nutrish
as one larger fish that makes a whole dish
but will cause the demolition
of the fish’n chip shops
when the fishing just stops
cause the larger fish take longer to grow
and there ain’t that many more in the sea doncha know.
Yet with whale-oiled algae, the whole sea, whole world can feast
But the cycle only spins when the greatest serve the least.


Irritable bowel syndrome

I have irritable bowel syndrome
About this condition, not much is known
Is it caused by the germs in my gut,
or a brain too fed up to talk sense to my stomach?
Scientists flummoxed
how yoga and yogurt
both make it not so hurt
how antidepressents its cessance has shown
but fibre can also work fine alone
or nothing.

Sometime I wish my brain could float free of this mess of a body
but its roots run too deep
there’s a billion neurones nested in your gut
that interact with a hundred trillion bacteria
that’s more than all the other cells here
consider this fact and see
it’s incredible that we find anything edible
that only 10% of us feel this resent
when our stomach’s pouring acid on infested intestines
our passages unpackaging the gloop we’ve ingested
it’s hardly surprising digestive unrest
increases our chances of being depressed

but for me
it’s when this disease of my bowel won’t abate
late at night that excitement keeps me awake
to write poetry
see my inspirations
are bowel irritation and sleep deprivation
so any gurgling sounds you hear
are the oozings of ideas
that arise from the writhe of my duodenum’s side
for between my gut and mind we find the source
of this bile, logical style
so why live in denial?
It’s far sweeter revealing how your gut is feeling
in speech and in poem than in growl and gut groan
so for the rest of you
may I suggest that you share your own syndrome?