October 6, 2023: Why we forget our dreams, outsized black holes in the ancient universe and hidden structures in the Amazon rainforest. —Andrea Gawrylewski, Chief Newsletter Editor | | | Why do we forget our dreams? Dreaming happens mostly (though not always) during rapid eye movement (REM) sleep. During REM sleep, the areas of the brain that transfer memories into long-term storage—as well as the long-term storage areas themselves—are relatively deactivated. Younger people and women also remember more dreams on average. And some studies have linked personality traits (introvertedness and creativity, for example) to frequency of memorable dreams.
Want more dreams? REM cycles lengthen the longer you sleep. The first REM cycle of the night is typically just a few minutes long, but by the end of an eight-hour night of sleep, a person has typically been in the REM stage for a good 20 minutes. So if you sleep only six hours, you're getting less than half of the dream time of an eight-hour night.
What the experts say: It is possible to train your brain to remember more of your dreams, says Leslie Ellis, a clinical counselor in British Columbia. The moment you wake up, even before you move your body, think about what you were just dreaming. This transfers the dream from short-term memory to long-term memory. | | | Supermassive black holes reside at the hearts of galaxies. In the nearby universe, an elegant ratio reigns: the mass of each central black hole is around 0.1 percent, or one thousandth, of the starry mass of the galaxy surrounding it. New observations by the James Webb Space Telescope of the distant universe—which, given light's finite speed, is also much deeper back in time—show that black holes and galaxies are proportionally much larger out there than they are in the younger, nearby universe: ancient black holes are 10 to 100 times more massive than the ones found in similar galaxies in today's universe.
How it works: JWST's data suggest that black holes are initially similar in mass to their host galaxies. Then, over billions of years, they reach the 0.1 ratio we see in local galaxies.
What the experts say: "We are witnessing a population of infant black holes overgrowing their nurseries and flourishing faster than expected in the distant, early universe," writes Fabio Pacucci, an astrophysicist at the Center for Astrophysics | Harvard & Smithsonian. Astronomers have even spotted another far-distant, early-universe black hole that may be as massive as its galactic host. | | | • Eight pages hidden in an archive led to the discovery of the story of Christine Essenberg, one of the first female oceanographers. | 30 min listen | | | • Draft CDC guidelines recommend a preventative dose of the antibiotic doxycycline to curb rising rates of STIs in some populations. | 6 min read | | | • Using a laser scanning system, scientists estimate that 10,000 structures could be hidden beneath the Amazon rainforest. | 4 min read | Earthwork on Amazonian landscape. Credit: Mauricio de Paiva | | | • In May, the EPA proposed critical standards to cut carbon pollution from power plants. Industry is responding with their common refrain--that the standards would require too many changes too quickly for them to adapt. But 50 years of environmental regulation shows that every time new rules appear, industry clamors against change and then finally innovates and rises to the challenge, writes David Hawkins, a senior attorney with the Natural Resources Defense Council. "It's time for industry to throw away its old playbook and put its engineers to work," he says. | 5 min read | | | ICYMI (Our most-read stories of the week) | | | • Cats Are Perfect. An Evolutionary Biologist Explains Why | 6 min read | | | • It's Time to Hear from Social Scientists about UFOs | 6 min read | | | • Scientists behind mRNA COVID Vaccines Win 2023 Nobel Prize in Physiology or Medicine | 7 min read | | | At the start of the COVID pandemic in 2020, dream researchers saw an explosion of the sheer number of dreams reported by people. Because they didn't have to wake up as early to commute, people had more time to sleep and enter that long REM state. On the one hand, more sleep seems like an advantage of stay-at-home orders, but on the other, anxiety-ridden dreams (which many were) likely added to the stress of that time. | I hope you get some extra time to snooze and dream this weekend! Reach out any time with feedback or suggestions: newsletters@sciam.com. Today in Science will return on Tuesday! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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