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HYMJ79 The famous prehistoric stone circle at Stonehenge on a bright spring day.

How did ancient Britons manage to mark the solstices with Stonehenge?

They would have observed the rising of the sun over a long period, say our readers, marking where the furthest north or south sunrise happened to determine the solstices

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Mandatory Credit: Photo by R Dirscherl/imageBROKER/Shutterstock (14053960e) Snorkeler and Humpback Whales (Megaptera novaeangliae), Silverbanks, Dominican Republic Various 23aibebcaa

Could we use machine learning to converse with whales and dolphins?

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Man opening door of retro refrigerator freezer.; Shutterstock ID 2275541755; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

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2F4D4YW Two American crows sitting on a bare branch communicating with each other.

How do crows develop such distinct and individual 鈥榲oices鈥�?

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Close-up of delighted senior man twirling moustache and smoothing his grey beard. Man taking care of his bushy beard and mustache ; Shutterstock ID 559674487; purchase_order: -; job: -; client: -; other: -

Why does our hair go white while eyebrows stay their original colour?

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Blue and dark space landscape with planets and starry sky and mountains. Huge planet on the horizon volumetric lighting 3d rendered baackground.; Shutterstock ID 2208373835; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

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grass lawn with yellow daffodils in dutch garden 'Keukenhof', Holland; Shutterstock ID 172603808; purchase_order: -; job: -; client: -; other: -

Why are so many spring flowers yellow?

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The two interacting galaxies making up the pair known as Arp-Madore 608-333 seem to float side by side in this image from the NASA/ESA Hubble Space Telescope. Though they appear serene and unperturbed, the two are subtly warping one another through a mutual gravitational interaction that is disrupting and distorting both galaxies. This drawn-out galactic interaction was captured by Hubble???s Advanced Camera for Surveys. The interacting galaxies in Arp-Madore 608-333 were captured as part of an effort to build up an archive of interesting targets for more detailed future study with Hubble, ground-based telescopes, and the NASA/ESA/CSA James Webb Space Telescope. To build up this archive, astronomers scoured existing astronomical catalogues for a list of targets spread throughout the night sky. By so doing, they hoped to include objects that had already been identified as interesting and that would be easy for Hubble to observe no matter which direction it was pointing. Deciding how to award Hubble observing time is a drawn-out, competitive and difficult process, and the observations are allocated so as to use every last second of Hubble time available. However, there is a small but persistent fraction of time ??? around 2???3% ??? that goes unused as Hubble turns to point at new targets. Snapshot programmes, such as the one which captured Arp-Madore 608-333, exist to fill this gap and take advantage of the moments between longer observations. As well as creating beautiful images such as this, these snapshot programs enable astronomers to gather as much data as possible with Hubble. Links Video of A Snapshot of Interacting Galaxies

What would happen to Earth if the Milky Way hit another galaxy?

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Reindeers migrate for a best grazing in the tundra nearby of polar circle in a cold winter day.; Shutterstock ID 605430995; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

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Golden lion tamarin; Shutterstock ID 121264012; purchase_order: -; job: -; client: -; other: -

Why aren鈥檛 humans covered in hair like other primates are?

Our readers propose several possibilities for our naked bodies, from the need to cool down quickly while chasing animals on the savannah, to the aquatic ape hypothesis

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How can popped knuckles be so exceptionally loud? Part 2

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Why do older people seem to find that time passes more quickly? Part 2

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This week鈥檚 new questions

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Why do the climbing plants in my garden all twine anticlockwise?

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