A free, daily newsletter for anyone who loves science, inspiration and awe ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
June 27, 2025—Mollusks gesticulate, too. Plus, experts debate whether using ChatGPT is making us lazy; and here's how to bond with your kids now that school's out. —Andrea Gawrylewski, Chief Newsletter Editor | | Illustration showing an example of a slingshot maneuver used by spacecraft to travel through the solar system. In this example, the spacecraft flies close by Mars, then by Jupiter, each time receiving a boost that allows it to ultimately reach Saturn. Walter Myers/Stocktrek Images | | Researchers observed the common cuttlefish (Sepia officinalis) routinely wave its arms in four flashy gestures. Damocean/Getty Images | | Cuttlefish undulate their tentacles in four distinctive flashy moves, possibly to communicate with one another. Researchers recorded videos of the mollusks wielding their arms, and used a hydrophone to record the underwater sounds and vibrations caused by their movements. Then, they played either the visual or audio recording to different cuttlefish. The cuttlefish responded to both with specific, repeated and relatively complex arm gestures the researchers dubbed "up," "side," "roll," and "crown." Why this is interesting: Researchers have seen cuttlefish use their tentacles to flirt or frighten predators, but these more intricate moves suggest their communication is more complex than previously thought. Additionally, this might be the first time researchers have witnessed cuttlefish use vibrational signals to converse—a testament to the creatures' cleverness.What the experts say: "It's interesting that they communicate visually and maybe acoustically," says Sam Reiter, a neuroethologist at the Okinawa Institute of Science and Technology in Japan. He believes that before this behavior can technically be called a "sign language," researchers must show that the moves mean something.—Andrea Tamayo, newsletter intern | | Amanda Montañez; Source: "Cuttlefish Interact with Multimodal 'Arm Wave Sign' Displays," by Sophie Cohen-Bodénès and Peter Neri in BioRxiv. Published online May 5, 2025 (reference) | | | | |
- Test your scienc savviness with this week's science quiz. Also check out today's Spellements, and remember, if you spot any words missing from the puzzle, email them to games@sciam.com. Readers sent in some great words this week! You people are impressive. Here are a few:
- nutation: The swaying or rocking motion of the axis of rotation of an object, like a planet or gyroscope.
- phthalate: A chemical added to plastics to make them flexible.
- widefield: A term from microscopy (using a microscope to see things too small for the naked eye) for a field of view that takes in the entire viewing area.
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| | Every Friday in summer we'll recommend a great, freshly-published science read. Tell us what you're reading or if you try any of the books we suggest! | | Is a River Alive? By Robert Macfarlane. Norton, May 2025.
 In 2008, Ecuador startled the world. Articles 71 to 74 of its newly-ratified constitution stated that nature has rights—rights to be respected for its existence and the crucial, life-giving services it provides; rights to be restored when damaged; and that states are obligated to intervene when human activities might disrupt these inherent rights. In his latest book, Is a River Alive? nature writer Robert Macfarlane travels to three very different rivers (in Ecuador, in India, and Eastern Canada) to examine the question of a river's sovereignty. He discovers that rivers create interconnected, and often fragile, worlds of plant and animal species—confirming they are life-giving wherever they run, as many indigenous populations throughout the world have recognized for thousands of years. Now, rivers are fighting for their lives as corporations, governments, pollution and climate change violate their vitalizing flow. "Muscular, willful, worshipped and mistreated, rivers have long existed in the threshold space between geology and theology," Macfarlane writes. "Rivers are—I have found—potent presences with which to imagine water differently. We will never think like a river, but perhaps we can think with them." | | If you recall for a few minutes, you likely have many memories of rivers. Rivers you encountered as you traveled to a new place. Rivers in your hometown. Rivers you boated down or sat by on a leisurely afternoon or tossed stones into. As Macfarlane observes, networks of rivers form a kind of planetary circulatory system that supports nearly all life, much like veins in the body circulate oxygen, nutrients and waste. Join me today in saying a little thank you to rivers. | | It's been a pleasure to be on this journey of discovery with you this week. Send any thoughts to: newsletters@sciam.com. See you Monday. —Andrea Gawrylewski, Chief Newsletter Editor
With contributions by Andrea Tamayo | | | | |
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