Meet your single-celled neighbours – a microbial tour of a metropolis

From an anthropocentric point of view, big cities are one of humanity’s most majestic achievements: massive, self-contained ecosystems built by, catering to, and inhabited by huge numbers of people. But you could forgive microorganisms for claiming that cities are actually theirs. After all, they outnumber humans in urban environments by the trillions. They also affect cityscapes in a far more tangible way: city planners and epidemiologists shape urban environments with pathogenic threats in mind.

For his experimental short film The Big City, the Canadian filmmaker Evan Luchkow put the hidden lifeforms of downtown Vancouver’s main roads under the literal microscope, documenting the various microbes he found to reveal, in his words, ‘the blurry boundary between human society and the natural world’. The result is an extraordinary and enlightening glimpse of the vast biodiversity with which we share our cities.

How do you message an alien? Carl Sagan offers some simple suggestions

Is there a foolproof way to announce our existence to other intelligent life-forms? It’s a brainteaser with vast potential consequences, and one that scientists seem to love puzzling over – even if some, such as Stephen Hawking, have questioned the wisdom of alerting advanced beings to our humble corner of the Universe. In this short video excerpt from a 1977 lecture at the Royal Institution in London, Carl Sagan – more optimistic about the prospect of alien benevolence than Hawking – offers one possible method. First, he establishes his belief that a common language among dissimilar beings in a shared universe should, in theory, be possible. He then presents a document coded in ones and zeroes, containing a message that he hopes could be decoded by an intelligent being anywhere in the Universe. Finally, Sagan recounts an experiment in which he presented the document to what he considers a ‘reasonably clever’ life-form – some of his graduate students at Cornell University – to see if they could decipher it.

Making sauerkraut is a spiritual matter for the ‘fermentation fetishist’ Sandor Katz

The US writer and activist Sandor Katz is one of the world’s leading experts on fermentation – a process born of the collaboration between people, time and microbes that makes possible such beloved culinary staples as bread, beer, wine, kimchi and miso. A self-described ‘fermentation fetishist’, Katz views this process as a humbling means of reconnecting with nature and its foodways, and has written several books on the subject and leads fermentation workshops in the US and abroad. In Sandorkraut, the US filmmakers Emily Lobsenz and Ann Husaini explore how an HIV diagnosis in 1991 led Katz on an unexpected path from New York City to a queer community in Tennessee, where he developed a spiritual connection with all things fermented.

Step into synaesthesia’s visual soundscape, built with the music of John Coltrane

The Israeli animator and artist Michal Levy is among the roughly 3 per cent of people who experience synaesthesia – a neurological condition in which people have a recurring sensory overlap, such as ‘tasting’ words or envisioning letters and numbers each with their own inherent colour. Levy possesses one of the most common forms of the condition, chromaesthesia, in which sounds and music provoke visuals. For her short film Giant Steps, Levy set out to convey her audiovisual experience of the John Coltrane composition ‘Giant Steps’ (1959). The resulting short animation is at once an intriguing window into the sensory world of a person with synaesthesia and an audiovisual delight, as Coltrane’s rollicking notes elicit a kinetic, cascading cityscape built from colourful blocks of sound.

To read more about synaesthesia, visit visit Aeon’s sister site, Psyche, a new digital magazine that illuminates the human condition through three prisms: mental health; the perennial question of ‘how to live’; and the artistic and transcendent facets of life.

The self is not always selfish: Mary Midgley takes on Richard Dawkins

When, exactly, did ‘survival of the fittest’ become synonymous with Machiavellian selfishness? According to the late UK philosopher Mary Midgley (1919-2018), conflating evolution with a ‘dog-eat-dog’ understanding of human nature was hardly born of Charles Darwin himself, who, in his writings, expressed how traits such as morality and communality were vital to our species’ survival. In this 2010 lecture at the Royal Society for Arts, Manufactures and Commerce (RSA) in London, Midgley explores ideas from her book The Solitary Self: Darwin and the Selfish Gene (2010) to discuss how frameworks of individualism have developed over the past several centuries. Ultimately, she argues, contemporary understanding of the self needs to be rescued from the culturally dominant clutches of Richard Dawkins’s The Selfish Gene (1976), which offers a misleading and perhaps even fatalistic view of human nature.