A newsletter for unflinching, ever-curious science-lovers. ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
November 7, 2025—Today, a confession from our columnist, astronomer Phil Plait. Plus, graphs show how diabetes rates are soaring globally, and what the FAA's flight reductions mean for your travel plans and safety. —Andrea Gawrylewski, Chief Newsletter Editor | | Below is an excerpt from the latest edition of The Universe, a weekly column by astronomer Phil Plait. I think you'll love Phil's unique and insightful (and sometimes cheeky!) coverage of the cosmos. Sign up for an alert and read it first. | | This image derived from Gaia data shows an edge-on view of our galaxy. ESA/Gaia/DPAC, S. Payne-Wardenaar, E. Poggio et al (2025) | | So it's confession time: I've been lying to you.
I've said on many occasions that our Milky Way galaxy has a flat disk (like in this column or this one). But it's not really flat—not even for a reasonable definition of the term.
Now, in my defense, I wasn't lying per se; I was simplifying. That's a perfectly acceptable and even advantageous thing to do in science. When you have some complex thing that you're trying to understand or explain, it helps to make it as simple as possible so that the math and physics are easier to crack. It's like assuming, at first, that Earth is a perfect sphere or that the sun contains all the mass in the solar system. Once you work out the basic equations that describe your simplified model, you can gradually add complexity back in—but in a way that makes the problem tractable.
And to be fair, when you look at the glow of the Milky Way from a dark site, it does look flat—flat-ish. And lots of similar galaxies and their disks also appear flat.
But a lot of them, maybe even most of them, aren't. They're wiggly and wavy and bendy. Our galaxy is among this warped group.
First, a quick overview: the Milky Way is classified as a disk galaxy, with a broad circular collection of stars, gas and dust about 120,000 light-years across. It's a few thousand light-years thick, so "flat" is at least a decent adjective to use for it. In the center is a central bulge of stars, and the whole thing is surrounded by a vast halo of stars and dark matter about a million light-years wide.
That last bit is important. Hang on a minute, and I'll explain why ... Read the rest of Phil's column here, and sign up in the blue box at the top of the article for an email alert and read it first every week.
| | More than 9.5 million people around the world have Type 1 diabetes—and the number is soaring. But scientists aren't completely sure why. Improvements in diagnostic tools and awareness may be driving some of this growth. Still, cases are rising relative to population size, regardless of the country's income status, and in young and old people alike. This reflects a general rise in cases and earlier diagnosis. | | Why it matters: The burden of this autoimmune disease is not equally distributed. The condition is more lethal in low-income countries, where hospitals and clinics are less equipped to detect and manage the disease. A 10-year-old with T1D in the United Arab Emirates can expect to live more than 50 years longer, on average, than a 10-year-old with T1D in Niger. What the experts say: "Type 1 [diabetes] is being diagnosed more than it ever has been before, but you need more in-depth studies to understand why these numbers continue to rise," says Stephanie Pearson, senior director of global responsibility at the nonprofit Breakthrough T1D. Today, scientists are exploring a few possible explanations, including biological triggers, infections, diet, lifestyle choices and even factors related to pregnancy. —Andrea Tamayo, Newsletter Writer | | | | |
SPONSORED CONTENT BY CRICKET MEDIA | | Raising Lifelong Readers with Cricket Media | | Kids benefit significantly from reading for pleasure, yet the percentage of kids who say they love to read has declined to historic lows. How can we inspire kids to become lifelong readers? Award-winning children's publisher Cricket Media shares these expert tips. | | | | |
- Test how well you read Scientific American this week by taking today's science quiz. Plus, here's today's Spellements puzzle and an extra challenging version of Sudoku (we call it Killer Sudoku).
| | MOST POPULAR STORIES OF THE WEEK | | - COVID Is Beginning to Surge Globally. Here's What We Know | 4 min read
- Catch the Taurid Meteor Shower—And Learn Why Scientists Are Watching It Closely | 4 min read
- Why We Struggle to Say No—And How to Get Better at It | 17 min listen
| | In his most popular column so far this year, Scientific American contributor and astronomer Phil Plait considers whether any life on Earth can survive the death of the sun. He gives a lively play-by-play of how the sun's natural aging process will affect Earth in about 3 billion years. Long story short, it's not pretty and if humans are still around, we'll have to relocate to another solar system. "Packing up and moving is never fun," he writes, "but if your house is on fire, there's not much choice." I highly recommend you sign up for Phil's column alerts, he brings a levity to complex cosmological concepts that is a true delight. | | Have a great weekend and see you Monday. You can email me anytime with your thoughts or ideas for how to improve this newsletter: newsletters@sciam.com. —Andrea Gawrylewski, Chief Newsletter Editor
| | | | |
Subscribe to this and all of our newsletters here. | | | | |
Comments
Post a Comment