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.

Time is fundamental, space is emergent – why physicists are rethinking reality

From Isaac Newton’s ‘absolute space’ and ‘absolute time’, which envisioned the two phenomena as fundamental and separate, to Albert Einstein’s ‘spacetime’, which condensed them into a single concept, the relationship between space and time has been the mystery driving fundamental physics for more than four centuries. And over the past several decades, some physicists, including Lee Smolin of the Perimeter Institute for Theoretical Physics in Canada, have come to believe that the fabric of reality is perhaps due to be torn into yet again. In this interview with Robert Lawrence Kuhn for the series Closer to Truth, Smolin discusses how developments in quantum mechanics have left physicists with questions that special relativity can’t seem to accommodate, and why the solution might be a conception of reality in which time is fundamental, and space emergent.

The controversial New Age guru who believed self-love healed all – even AIDS

For gay men living with HIV and AIDS in the 1980s, their diagnosis was often accompanied by both fear for their lives and shame for having contracted a highly stigmatised disease. In Another Hayride, the US filmmaker Matt Wolf explores how the US self-help guru Louise Hay (1926-2017) gained an ardent following among HIV-positive gay men in Los Angeles, and then among people experiencing trauma throughout the country, by teaching that they could heal themselves through self-love. The short documentary is built from archival footage – the US talk show hosts Oprah Winfrey and Phil Donahue make cameos – and narration from the US writer and minister David Ault, who attended Hay’s weekly ‘Hayride’ support groups. Through his portrait, Wolf offers a nuanced recollection of Hay and her gospel of New Age healing, in which extraordinary compassion and magical thinking both played central roles.

Ums, likes and y’knows get no respect – but they’re vital to conversation

If you’ve ever listened to a recording of yourself speaking, the frequency with which you used fillers such as ‘um’, ‘uh’, ‘like’ and ‘y’know’ might have grabbed your attention – and perhaps your scorn. Indeed, these verbal hesitations have been viewed as undesirable since the days of ancient Greece and, more recently, the American linguist Noam Chomsky characterised them as ‘errors’ irrelevant to language. But could there be more to these utterances than initially meets the ear? In this short animation from TED-Ed, Lorenzo García-Amaya, assistant professor of Spanish at the University of Michigan, reveals how ‘filled pauses’ can give conversation partners important context clues, communicate emphasis, help tether related thoughts together, and so much more.

The ‘dangerous nonsense’ of phrenology shows how pseudoscience takes hold

In the 19th century, the Viennese physiologist Franz Joseph Gall placed a formidable thumb on the scales of the ‘nature vs nurture’ debate when he proposed a simple – and, as we now know, false – solution to the age-old conundrum. Everything you need to know about someone’s character, he argued, could be predicted by the shape of different brain regions – and by extension, the contours of their head. That phrenology, as it became known, was built on conjecture rather than empiricism was clear to a great many scientists of the era. Still, it caught on in the public consciousness, and often with sinister consequences. This animation from BBC Reel provides a brief history of phrenology, shedding light on why facile solutions often gain traction over rigorous empiricism, and how pseudoscience can sometimes open gateways for the real thing.