Length of a Day on Uranus Revised, Pour Height Influences Coffee Quality, and Plastics Recycling Falls Short.

A Long Day on Uranus, a Better Method of Making Coffee and Disputed Dino Decline

By Rachel Feltman, Fonda Mwangi & Alex Sugiura

Rachel Feltman: Happy Monday, listeners! For Scientific American’s Science Quickly, I’m Rachel Feltman. Let’s catch up on some of the science news you might have missed last week.

We’ll ease into things with a new study on a subject that’s bound to perk you up: coffee. Up until now the best way to learn more than you ever wanted to know about pour-over coffee was to ask literally any guy at a party in Brooklyn. But a study published last week in the journal Physics of Fluids brings some actual science into debates over how to brew the perfect pot of joe.

Using transparent silica gel particles in place of coffee grounds, researchers captured high-speed footage showing exactly how water flows through a pour-over setup under different conditions. They determined that the best way to brew a strong cup of coffee was to maximize the contact time between water and coffee grounds while also allowing for plenty of mixing so as much coffee as possible was extracted. The team says the key is to pour slowly—to maximize contact—and from a greater height to increase the water velocity. A slim stream of water from a gooseneck kettle can help optimize this process. As those dudes from parties in Brooklyn have probably already told you. If you get it right, the researchers say, you can actually get a stronger cup of coffee using a smaller quantity of grounds. They recommend experimenting by subtracting a small amount from your usual bean count—maybe a couple of grams per serving—and then trying cups brewed at different pour heights until you find a strength you like.

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Now that we’re all bright-eyed and bushy-tailed, let’s move on to another troubling story of cuts in federal funding for research. Last Tuesday the U.S. Department of Commerce announced that the Trump administration will pull around $4 million in research grants for climate change-related projects from Princeton University. According to a press release from the Department of Commerce, the projects funded by these grants “are no longer aligned with the program objectives” of the National Oceanic and Atmospheric Administration and “are no longer in keeping with the Trump Administration’s priorities.”

One of the targeted projects focuses on how water supplies might fluctuate as global warming progresses. The Department of Commerce stated that “using federal funds to perpetuate these narratives does not align with the priorities of this Administration,” which is, frankly, chilling language to use when talking about climate change research. The press release also accused some of the slashed projects of increasing “climate anxiety,” which is a phrase that’s increasingly being used to cast folks’ concerns over very real evidence about the climate crisis in a hysterical light.

Speaking of environmental threats: a study published last Thursday in the journal Communications Earth & Environment found that less than 10 percent of the plastic made worldwide in 2022 contained recycled materials. The world produced more than 400 million tons of plastic that year. And some estimates say that amount will more than double by 2050. The new study also found that just around 28 percent of all plastic waste made it to the sorting stage and only half of that plastic was actually recycled. While China had the highest plastic consumption overall in 2022, the U.S. had the highest amount of usage per person, according to the researchers. On average, each individual in the U.S. consumed about 476 pounds [216 kilograms] of plastic that year.

Now, obviously plastic usage is a massive, complex, systemic problem that high income countries around the world need to address, so this isn’t me trying to make you feel guilty about your ever-growing pile of old takeout containers. But if you’ve been looking for something to motivate you to start making some slightly less convenient choices in the name of using less plastic—carrying reusable straws and silverware with you, finding a local bulk grocery store that lets you use your own containers—maybe these new findings can fire you up to make a change.

Now let’s check in with a cosmic neighbor. The Small Magellanic Cloud is a galaxy not far from our own, and a new study published in the Astrophysical Journal Supplement Series suggests that things might be getting a little hectic over there. Within the SMC, researchers tracked the motion of roughly 7,000 stars, each one more than eight times the mass of our own sun. The team found that the stars were moving in different directions on the galaxy’s respective sides. The scientists think that the gravitational pull of the nearby Large Magellanic Cloud—which, to state the obvious, is the bigger of the two galaxies—might be pulling the SMC apart. The researchers say that studying how the SMC and LMC interact with both each other and with the Milky Way will help us understand how galaxies form and behave.

In other space news, it turns out that a day on Uranus lasts slightly longer than we thought. A study published last Monday in Nature Astronomyused data from the Hubble Space Telescope to estimate the ice giant’s rotation rate with unprecedented accuracy. Our prior estimate of 17 hours, 14 minutes and 24 seconds came from Voyager 2’s 1986 flyby of Uranus. That figure relied on measurements of the planet’s magnetic field and radio signals emitted by its auroras. For a better estimate scientists used more than a decade’s worth of Hubble data to track the movement of Uranus’s auroras, which helped them zero in on the actual location of the planet’s magnetic poles. The researchers’ findings added a whopping 28 seconds to Uranus’s previously estimated rotational period. And hey, every second on Uranus is precious.

We’ll wrap up with some new findings on the demise of the dinosaurs. Some earlier research has suggested that dinosaurs were already on the outs before that infamous asteroid struck the killing blow. But a study published last Tuesday in Current Biologyargues that the dinosaurs were doing just fine before that pesky space rock came along, thank you very much.

Researchers analyzed the North American fossil record for the 18 million years preceding the mass extinction event in question—about 8,000 fossil specimens in total. That fossil record does indeed seem to show that dinosaur populations started declining millions of years before the asteroid hit. But the new study suggests it’s not the dinosaurs themselves that declined but simply their mark on the fossil record. The researchers argue that geological changes made dinosaur fossils less likely to be preserved in places where archaeologists could one day access them. It’s certainly not the end of this debate, but it’s now a little more plausible to imagine that, had things gone down a little differently, we might still have dinosaurs roaming the Earth today—other than birds, of course.

That’s all for this week’s news roundup. We’ll be back on Wednesday to talk about a trendy disinfectant that sounds almost too good to be true: hypochlorous acid. Tune in to get the full scoop on this so-called miracle molecule.

Science Quickly is produced by me, Rachel Feltman, along with Fonda Mwangi, Kelso Harper, Naeem Amarsy and Jeff DelViscio. This episode was edited by Alex Sugiura. Shayna Posses and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news.

For Scientific American, this is Rachel Feltman. Have a great week!