杏吧原创

Portrait of mother and baby sitting at the table, and feeding her with food and fruit. close up. The concept of feeding and weaning baby from the breast. Hispanic family; Shutterstock ID 2260034413; purchase_order: -; job: -; client: -; other: -

What was used to wean babies in prehistoric times?

Babies would have been fed altered versions of what everyone else was eating, say our readers, or perhaps a little tasty, nourishing bone marrow

Various disco, soul and funk, seven inch records at second hand store.

Why can鈥檛 we conjure up smell and touch in our heads?

Ben Lomond ski village and wild kangaroos on a quiet winter's day in Tasmania, Australia; Shutterstock ID 1815999107; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

Is it AI or just short for Alan? A reader rages against the machine

Tom Gauld: Is it a wiring problem?

Twisteddoodles on taking your time in the lab

The Global Winner The global winning image was taken by Laurent Formery (USA). Nervous system of a juvenile sea star (Patiria miniata) about 1 cm wide. Labeled with an antibody against acetylated tubulin after optical clearing, and captured using a color-coded Z-projection.

Life

Time for your close-up: vivid images of nature loom larger than life

Release Date September 12, 2019 10:00AM (EDT) Caption Anyone who has ever peered at Saturn through a small telescope is immediately enticed by its elegant rings, which make the far-flung planet one of the most exotic-looking, opulent worlds in the solar system. The latest view of Saturn from NASA's Hubble Space Telescope captures exquisite details of the ring system?which looks like a phonograph record with grooves that represent detailed structure within the rings?and atmospheric details that once could only be captured by spacecraft visiting the distant world. One such intriguing feature is the long-lasting hexagon-shaped structure circling the planet's north pole. It is a mysterious six-sided pattern caused by a high-speed jet stream. NASA's Voyager 1 spacecraft first discovered the "hexagon" during its flyby in 1981. The hexagon is so large that four Earths could fit inside its boundaries. (There is no similar structure at Saturn's south pole.) Other features, however, are not as long lasting. A large storm in the north polar region spotted by Hubble last year has disappeared. Smaller, convective storms?called super "thunderheads"?such as the one just above the center of the planet's image, also come and go.

Space

How to spot Saturn’s rings through a telescope

Ezra Bailey

Do shadows weigh anything?

Woman hand holding glass jar of honey

Why does honey stop dripping when there is still some on the spoon?

The honey stops dripping when the intermolecular forces overcome gravity, say our readers - also advising that a honey dipper is better than a spoon

Why do I need to be able to pronounce a word to recall it? (Part 2)

This week鈥檚 new questions

Would you trust a robot with eyes?

Tom Gauld on the company’s position that climate change isn’t real