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Last Word

B1PP5G Spiral Galaxy M74 i. Image shot 2008. Exact date unknown.

What makes galaxies spin in a certain direction? Part two

One reader wonders if the outer-points of a galaxy’s spirals precede or trail the rotation

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GUILIN, CHINA - OCTOBER 16: Juri Hollmann of Germany and Movistar Team leads the peloton during the 4th Gree-Tour of Guangxi 2023, Stage 5 a 209.6km stage from Liuzhou to Guilin / #UCIWT / on October 16, 2023 in Guilin, China. (Photo by Tim de Waele/Getty Images)

This week’s new questions

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Brachycybe lecontii (F Andrognathidae) millipede

Is there a limit to how small an adult arthropod can be? If so, why?

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Beautiful sky and blue ocean; Shutterstock ID 122089855; purchase_order: -; job: -; client: -; other: -

Would whisking cold water up from the ocean depths help with warming?

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B095JB Swarm of gnats (Nematocera), Bavaria, Germany, Europe

Are gnats attracted to eyeballs, or do we just notice these ones most?

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champagne spoon

This week’s new questions

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Split view of a pod of sperm whales in a social group showing the sky and below the waterline, north western Mauritius.; Shutterstock ID 742662229; purchase_order: -; job: -; client: -; other: -

Why don’t marine mammals like whales get ‘the bends’?

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The Supermoon rises over houses in Olvera, in the southern Spanish province of Cadiz, July 12, 2014. Occurring when a full moon or new moon coincides with the closest approach the moon makes to the Earth, the Supermoon results in a larger-than-usual appearance of the lunar disk. REUTERS/Jon Nazca (SPAIN - Tags: SOCIETY CITYSCAPE TPX IMAGES OF THE DAY) - GM1EA7D0FC401

When was it realised that moonlight is reflected sunlight? Part 2

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How do dogs recognise that another animal is also a dog? Part 3

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2K6A82T Artist's concept of astronauts and human habitats on Mars.

This week’s new questions

What is the minimum number of working individuals that would be necessary for the survival of a settlement on Mars? And why aren't we equally capable with our left and right sides? Wouldn't this have given us a clear survival advantage?

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Why do fallen trees grow stems vertically from a horizontal trunk?

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What makes galaxies spin in a certain direction?

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Why can’t we conjure up smell and touch in our heads? Part 3

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This week’s new questions

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