“Most people are completely unaware of what is in the water,” says Julian Cremona, a naturalist and photographer who is out to change that with his new book.

Plankton is an umbrella term for all kinds of different organisms floating in our waters, from plants, known as phytoplankton, to animals, known as zooplankton. They can be as little as 0.02 micrometres, the size of some viruses, or as big as 2 metres, the size of a large jellyfish. What they have in common is that they aren’t powerful enough to overcome the movement of water, unlike organisms that can resist the current. As Cremona writes, plankton are “drifting organisms that are unable to determine their long-term direction and are at the whims of the current”.

Cremona’s book is a guide to the different types of plankton found along the British coast, such as the larva of a Magelona worm, just 2 millimetres in size, in the main image. To take this photograph, Cremona fitted objective lenses from an old microscope to his camera.

Below is a shot of a tiny zooplankter, Oikopleura. Its body is made up of a trunk on top of a long tail, ranging from a few millimetres to a centimetre long. It has a lifespan of five to six days, over which it grows, reproduces and finally dies.

Some larger plankton are shown below, including a handful of compass jellyfish (Chrysaora hysoscella), which are mostly found in northern Europe. The umbrella of this jellyfish can stretch to 30 centimetres in diameter, and it uses its 24 tentacles to catch its food: small fish, crabs and other jellyfish.

Pictured below is a swarm of moon jellyfish (Aurelia aurita), the most common jellyfish to be found in the UK’s waters.

Some phytoplankton exhibit symbiosis with jellyfish and sea anemones, such as the aptly named snakelocks anemone (Anemonia viridis), pictured below. Single-celled Symbiodinium plankton live within the tissue of its green tentacles, where they perform photosynthesis and provide their host with carbohydrates. In return, the plankton receive inorganic carbon, nitrogen, phosphate – and a protected refuge in which to live.

Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more

Scratch that

When news editor Alexandra Thompson sent Feedback some research about the social science of long fingernails, a paper that runs to 20 pages, we knew we had to read it. Never mind Alex’s remark – “I don’t think long fingernails is that deep” – Feedback was delving in.

The has the delightfully verbose title “From status symbol to polysemous sign: Interpreting the meaning of artificially extended fingernails”. Wondering why people sometimes wear “artificially elongated fingernails” and how this behaviour is interpreted by the rest of society, the authors examined 45 newspaper articles and identified “eight interpretive frames” through which we can understand the trend for super-long nails.

Some of what is happening can be traced back to Thorstein Veblen’s classic analysis The theory of the leisure class: An economic study of institutions (1899). Veblen posited that the ruling class are engaged in “conspicuous leisure” in order to differentiate themselves from those doing actual work. One way to do that is to grow your nails really long, or wear nail extensions, to signal that you don’t have to work with your hands. However, the authors of the study don’t think that is what’s going on today.

They say that “the clear legibility of long nails as a symbol of leisure has been lost in contemporary societies”, since nail extensions are now found “on the hands of service workers as well as managers”. Instead, what is happening is frantic innovation in the beauty industry, driven by “capitalist market mechanisms”. This is accelerated by social media, where nail artists show off their most extravagant creations, with the result that “the status of nail work shifts from a routinised service to an autonomous art form whose value lies in complexity, originality and photogenic quality”. And that barely scratches the surface (see what we did there?). Never mind seeing a world in a grain of sand, you can see all of human society in a fingernail.

If we hadn’t enjoyed this paper enough, the citations are a gold mine. We had no idea there was a book called , but we want to hand out some sort of prize to the person who came up with that subtitle.

We also want to point out that the authors of the nails paper missed a trick. The proper use of super-long fingernails is to make really good tapping sounds in ASMR videos. We had to rewrite part of this column at the last minute, so we put on to ease the resulting stress, only to wind up blissing out for half an hour and then writing the remainder in a panic.

A hill of beans

Feedback is pleased that our readers continue to bring us unhelpful units of measurement. Thanks go to Tony Levitt, who was at the Sedgwick Museum of Earth Sciences in Cambridge, UK, when he found a display explaining what goes into making a wind turbine. Apparently, it “can require over 1000kg of rare earth elements to build (the same weight as 2500 tins of baked beans!)”.

As Tony realised, this will look very different depending on whether the cans contain baked beans or not, and the display doesn’t specify. Tony decided to investigate. “Looking in our kitchen cupboard I found a solitary can, labelled as ‘400g net’, ” he writes. “According to my kitchen scales the combined can and contents actually weighs 468g.” If Feedback’s maths is right (and it frequently isn’t), a full can is about seven times heavier than an empty one. We therefore find ourselves knowing the amount of rare earth elements needed to build a wind turbine, but only to within a factor of seven.

“To be fair to the Sedgwick, it is a great little museum,” adds Tony.

Meanwhile, Elizabeth Osbos pointed us to a marine forecast warning of a “rapidly rising swell”, on 6 June by – Te Ratonga Tirorangi. Specifically, “Combined wave heights in eastern offshore waters could reach or exceed the height of the Ohakune Carrot”.

Feedback wasn’t previously aware of the Ohakune Carrot, but we have familiarised ourselves. The small town of Ohakune lies at the heart of a major carrot- and parsnip-growing region, and to commemorate this industry, it has a giant fibreglass carrot standing by the road. The carrot is 7.5 metres tall and may be .

New Zealand readers: is the height of the Ohakune Carrot so generally and universally understood that it can be safely used to convey the heights of dangerous ocean waves?

Gaslit

In our ongoing quest for the science-themed tourist attraction with the most limited possible audience, we mentioned Denmark’s Gas Museum as a place that not many people would want to go to (30 May). This included John Blakey, who alerted us to its existence, but hasn’t actually attended.

But it has competition. Rebecca Ferguson (the professor of learning futures at the Open University, not the actor) and Bill Dickinson both wrote in to tell us about another museum of gas: the in Norfolk, UK.

“I wouldn’t want to gaslight John, but he may have forgotten [it],” writes Rebecca. She adds that “TripAdvisor ranks it fourth of the top attractions of Fakenham – beating both the Chocolate Factory Shop and the ruined abbey”.

Bill says the staff are very friendly, cheerfully turning a blind eye when he inadvertently stayed half an hour after closing time.

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Climate and health activist has been immortalised in a sculpture, The Solomon Siren – recently installed on her now-flooded former home: Kale Island in the Solomon Islands.

Rising tides completely flooded the 50,000-square-metre Pacific island in 2016. The sculpture sits in the intertidal zone, where patches of rubble and sand rise above the ocean surface from time to time.

Sculptor Jason deCaires Taylor made the sculpture as part of his Sirens series of installations around the world highlighting warming seas, sewage pollution and the presence of microplastics.

When flooding made life untenable, Bartlett and her family had to evacuate to one of the main islands. “Back then, [the island] was land – green, vibrant, full of life,” says Bartlett in a film accompanying the sculpture’s installation. “Kale became one of the first documented islands in the Solomons lost to sea level rise.”

The sculpture consists of a marine-grade stainless steel tree on which a life-sized figure of Bartlett leans. The artwork also uses biochar and pH-neutral cement. Hauntingly, as the tide rises and falls, it is intermittently hidden as waves roll over.

Incorporated into the sculpture are inscriptions recording past milestones of Kale’s submergence along with predictions for a sea level rise of up to 20 centimetres by 2046. But as Taylor says, the sculpture isn’t intended to work as a scientific measuring instrument, but as a “symbolic representation” of a changing relationship between land and sea.

“What happened is a warning not only for us, but for the world,” says Bartlett.