Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Wednesday, February 20, 2019

The galactic river

I was an amateur stargazer as a kid.  I had a small refracting telescope and spent many hours out in my parents' front yard, looking at stars and planets and whatever else I could find.  My favorite astronomical object was (and, in fact, still is) the Pleiades, a star cluster and "stellar nursery" in the constellation Taurus:

[Image courtesy of NASA/JPL]

I pondered many times whether the stars I looked at hosted planets, and those planets intelligent life -- and whether there might be a little alien boy looking back at me through his telescope.  I also sometimes liked to stand on my head (I was a bit of a strange kid, a fact that should shock no one) and I remember thinking that when I did that at night, I had the stars beneath my feet.  And if I started falling upward, I would fall forever.

Such are the musings of a whimsical ten-year-old wannabe science nerd.

I still have a sense of wonder whenever I look up into the sky.  The sheer scale of it leaves me breathless.  And with every new discovery made about the universe we live in, the awe I feel becomes that much stronger.  Take, for example, the bit of research published last week in the journal Astronomy & Astrophysics, that many of the stars in the Southern Hemisphere of the sky are part of a stellar cluster that is in the process of being torn apart by tidal forces from the Milky Way.

The paper is entitled, "Extended Stellar Systems in the Solar Neighborhood: Discovery of a Nearby 120° Stellar Stream in Gaia DR2," by Stefan Meingast and Verena Fürnkranz of the University of Vienna and João Alves of Harvard University, and describes a startling finding -- an estimated 4,000 of the stars visible from southern latitudes are part of a "river of stars" produced when what was a compact cluster is stretched out into a long stellar stream.

These things aren't common, so to find one only (only!) 326 light years away is pretty phenomenal.  "Identifying nearby disc streams is like looking for the proverbial needle in a haystack," Alves said in an interview with Science Alert.  "Astronomers have been looking at, and through, this new stream for a long time, as it covers most of the night sky, but only now realise it is there, and it is huge, and shockingly close to the Sun.  Finding things close to home is very useful, it means they are not too faint nor too blurred for further detailed exploration, as astronomers dream."

The southern stellar stream -- stars that are part of it are highlighted in red [Image from Gaia DR2 Skymap]

The researchers think that the stars in the stream (and therefore the cluster in which they originated) is about a billion years old, meaning it's had time for about four complete revolutions around the galactic center.  This is time enough for tidal forces exerted by the Milky Way to stretch the cluster out from its original shape -- which was possibly something like the Pleaides -- into a streamer going nearly halfway around the night sky.

I wish I could see those stars, but none of them are visible from my perspective here in the frozen North.  I know they don't look any different from the stars I see at night, but still, the idea that I'd be looking at a stellar river that came from a billion-year-old cluster is pretty awe-inspiring.  But since I don't have any trips to the Southern Hemisphere planned, I'll just have to stick with the ones in my own neighborhood, which are wonderful enough.

Maybe they'll even inspire me to stand on my head.


You can't get on social media without running into those "What Star Trek character are you?" and "Click on the color you like best and find out about your personality!" tests, which purport to give you insight into yourself and your unconscious or subconscious traits.  While few of us look at these as any more than the games they are, there's one personality test -- the Myers-Briggs Type Indicator, which boils you down to where you fall on four scales -- extrovert/introvert, sensing/intuition, thinking/feeling, and judging/perceiving -- that a great many people, including a lot of counselors and psychologists, take seriously.

In The Personality Brokers, author Merve Emre looks not only at the test but how it originated.  It's a fascinating and twisty story of marketing, competing interests, praise, and scathing criticism that led to the mother/daughter team of Katharine Briggs and Isabel Myers developing what is now the most familiar personality inventory in the world.

Emre doesn't shy away from the criticisms, but she is fair and even-handed in her approach.  The Personality Brokers is a fantastic read, especially for anyone interested in psychology, the brain, and the complexity of the human personality.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

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