iiinova — where your digital self keeps evolving

Barbara Ryden @bsryden.bsky.social · 29/09/2026

Fat Bear Week comes but once a year. The final round of voting is today; make your vote count!

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Barbara Ryden @bsryden.bsky.social · 12/09/2026

It's a rainy #Caturday here, and the cats are napping.

Two cats sleeping in postures that look goofy to the human eye

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Barbara Ryden @bsryden.bsky.social · 08/08/2026

International Cat Day falls on a #Caturday this year! That means it is time to party like a cat.

An orange tabby cat lounges upside down on the lap of a mere human.

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Barbara Ryden @bsryden.bsky.social · 14/07/2026

January 1921: NGC 584 is inconceivably distant. VP-elect has faith in America's moral fiber. July 2026: NGC 584 is at a distance of ~20 megaparsecs. Current VP is not regarded as an authority on moral fiber.

New York Times, Wednesday, January 19, 1921, page 6. Headlines are: "COOLIDGE HAS FAITH IN OUR MORAL FIBRE" and "DREYER NEBULA NO. 584 INCONVEIVABLY DISTANT"

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Barbara Ryden @bsryden.bsky.social · 12/07/2026

Orange tabby cat (Finn) lies lengthwise on the sofa. Gray and white cat (Trim) lies crosswise.

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Barbara Ryden @bsryden.bsky.social · 21/06/2026

Since the cats have anti-parallel spins, they can both occupy the ground state. (Since they are cats, they are seldom in an excited state.)

Two cats engage in cat napping, side by side.

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Barbara Ryden @bsryden.bsky.social · 14/06/2026

Seen from certain angles, at occasional moments, the OSU campus is lovely.

An egret flies over Mirror Lake, on the main campus of the™ Ohio State University. A fountain plays at the far end of Mirror Lake.

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Barbara Ryden @bsryden.bsky.social · 07/06/2026

Trim and Finn are recovering after their Caturday night party.

A gray and white cat (named Trim) and an orange tabby cat (named Finn) are sprawled side by side on an end table next to a sofa.

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Barbara Ryden @bsryden.bsky.social · 28/05/2026

@benneholwerda.bsky.social is an authority. Pay attention to their words of wisdom!

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Barbara Ryden @bsryden.bsky.social · 28/04/2026

Apparently, I am an author. It says so, right on my label.

An astronomer is wearing a space-cat-themed shirt. A nametag is clipped to the shirt, reading "Barbara Ryden AUTHOR"

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Barbara Ryden @bsryden.bsky.social · 11/04/2026

Although my Friday lecture was on quasars, I decided to spread some Moon joy in the cover slide for the lecture. (The students seemed to tolerate the digression.)

Cover slide for the Friday, April 10 lecture of Ast 2142 (Black Holes) at The Ohio State University. The slide includes two images: on the right, the "Earthset" photo from the Artemis II mission; on the left, the "Earthrise" image from the Apollo 8 mission, cropped to match "Earthset."

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Barbara Ryden @bsryden.bsky.social · 07/04/2026

"I'd like to get away from Earth awhile And then come back to it and begin over." For some reason, Robert Frost keeps running through my head today....

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Barbara Ryden @bsryden.bsky.social · 14/03/2026

Happy #Caturday! Trim and Finn have each others' back, in a fine example of feline solidarity.

A gray and white cat (named Trim) and an orange tabby cat (named Finn) are sleeping back-to-back on a fleece blanket.

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Barbara Ryden @bsryden.bsky.social · 08/02/2026

Finally... some "introverted astronomer" representation in the media!

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Barbara Ryden @bsryden.bsky.social · 24/01/2026

Happy #Caturday. If you are in the path of a winter storm, Trim and Finn recommend that you keep warm.

A gray and white cat and an orange tabby cat are snuggled together atop a fleece blanket.

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Barbara Ryden @bsryden.bsky.social · 14/01/2026

Stellar Structure and Evolution: a very fine textbook.

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Barbara Ryden @bsryden.bsky.social · 08/01/2026

It is not strictly required, when attending a meeting of the American Astronomical Society, to pose in front of the big AAS sign. However, I couldn't resist the opportunity. #aas247

Barbara Ryden (wearing a nametag saying "Barbara Ryden") stands in front of a large sign saying "AAS".

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Barbara Ryden @bsryden.bsky.social · 01/01/2026

I haven't quite decided if this is the ideal epigraph for chapter 8. Too Byronic, do you think, or just Byronic enough?

Epigraph for chapter 8 of Astrophysical Gas Dynamics:

When Newton saw an apple fall, he found
In that slight startle from his contemplation -
'Tis said (for I'll not answer above ground
For any sage's creed or calculation) -
A mode of proving that the earth turn'd round
In a most natural whirl, called "gravitation";
And this is the sole mortal who could grapple,
Since Adam, with a fall or with an apple.

Lord Byron, "Don Juan," Canto X [1823]

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Barbara Ryden @bsryden.bsky.social · 26/12/2025

Happy Boxing Day from Finn the cat!

An orange tabby cats sits inside a cardboard box.

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Barbara Ryden @bsryden.bsky.social · 21/12/2025

Happy #Solstice! I hope everyone in the northern hemisphere is keeping warm (preferably with the help of a cat).

Orange tabby cat, sitting comfortably on a human lap

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Barbara Ryden @bsryden.bsky.social · 13/12/2025

I hope you are having a well-groomed #Caturday (perhaps with a little help from a friend).

A gray and white cat (Trim) licks the head of an orange tabby cat (Finn).

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Barbara Ryden @bsryden.bsky.social · 22/11/2025

Happy #Caturday! At this point, my cats' knowledge of physics is starting to catch up with mine.

An orange tabby cat examines the book Physics for Cats, by Tom Gauld.

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Barbara Ryden @bsryden.bsky.social · 11/10/2025

Advice from Finn and Trim: get plenty of rest this #Caturday, to prepare you for the week ahead.

Two cats snoozing. Finn (on the left) is burrowed into a comforter; Trim (on the right) is curled up on top of a folded blanket.

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Barbara Ryden @bsryden.bsky.social · 28/09/2025

Happy Fat Bear Week to those who celebrate!

Winne the Pooh (after mass consumption of honey and condensed milk) gets wedged in the door of Rabbit's house. Illustration by E. H. Shepard

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Barbara Ryden @bsryden.bsky.social · 22/09/2025

I'm not certain this is the best possible epigraph for a chapter on accretion, but I was feeling Rabelaisian when I chose it.

Epigraph for chapter 7 of Astrophysical Gas Dynamics:
L'appétit vient en mangeant.
(Appetite comes with eating.)
François Rabelais
Gargantua, book 1, chap. 5 (1534)

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Barbara Ryden @bsryden.bsky.social · 17/08/2025

Although a quotation about the incomprehensibility of turbulence (even with divine intervention) is often attributed to Werner Heisenberg, this statement by Horace Lamb seems to have priority.

Epigraph to Chapter 6 of Astrophysical Has Dynamics:
It was at a meeting of the British Association in London in 1933
that I remember that [Horace] Lamb remarked, "I am an old man
now, and when I die and go to Heaven there are two matters on
which I hope for enlightenment. One is quantum electrodynamics,
and the other is the turbulent motion of fluids.
And about the former I am really rather optimistic."
Sydney Goldstein

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Barbara Ryden @bsryden.bsky.social · 16/08/2025

Happy #Caturday! May you have all the cat hugs you desire.

An orange tabby cat sits on a human's lap and hugs them around the waist.

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Barbara Ryden @bsryden.bsky.social · 14/07/2025

For balance, a chapter that contains Maxwell's Equations must start with Maxwell's Poetry.

Epigraph to Chapter 5 (Mangetohydrodynamics):

The world may be utterly crazy,
And life may be labour in vain;
But I'd rather be silly than lazy,
and would not quit life for its pain.

-- James Clerk Maxwell [1858]

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Barbara Ryden @bsryden.bsky.social · 05/07/2025

Remember to take some time to relax this #Caturday (in whatever posture suits your mood).

An orange tabby cat (named Finn) lounges upside down by the front door of a house.

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Barbara Ryden @bsryden.bsky.social · 28/06/2025

I continue my cinematic era with the epigraph to Chapter 4 of Astrophysical Gas Dynamics.

The beginning of Chapter 4 ("Advanced Shocks") of Astrophysical Gas Dynamics, to be published in 2026. The epigraph of the chapter is

Captain Renault: I am shocked, *shocked*, to find that gambling is going on in here.

[Julius Epstein, Philip Epstein, and Howard Koch. Casablanca screenplay, 1942]

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Barbara Ryden @bsryden.bsky.social · 24/05/2025

I cannot guarantee that I will stop crabbing. I will try, however, to stop doing it from pontoons.

View from the pier in St Mawes, Cornwall. A sign states, "Sorry no crabbing from pontoon."

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Barbara Ryden @bsryden.bsky.social · 29/03/2025

Finn the cat is hanging out with his lobster. Happy #caturday!

Finn (an orange tabby cat) with his lobster-shaped cat toy.

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Barbara Ryden @bsryden.bsky.social · 18/03/2025

Given 274 confirmed moons of Saturn, Lucy definitely has a point.

Peanuts cartoon for 1977 Jul 13

panel 1: Lucy, wearing a baseball glove, misses a fly ball.
panel 2: Charlie Brown tells Lucy, "There's no excuse for missing a ball like that! There's absolutely no excuse!"
panel 3: Lucy responds, "The moons of Saturn got in my eyes!"
panel 4: Charlie Brown concedes, "I take it back... That wasn't a bad excuse..."

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Barbara Ryden @bsryden.bsky.social · 15/03/2025

I am entering my cinematic era with the epigraph for Chapter 3 of Astrophysical Gas Dynamics.

epigraph for chapter 3 of Astrophysical Gas Dynamics: "In space, no one can hear you scream." [Barbara Solinger Gips, advertising tagline for Alien]

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Barbara Ryden @bsryden.bsky.social · 23/02/2025

I have chosen an epigraph for Chapter 2, and I think I have found a good illustration for the difference between Lagrangian and Eulerian observers. (I still have to negotiate the rights from the Shepard Trust, however.)

Epigraph for Chapter 2 of Astrophysical Gas Dynamics: "When the gap between ideal and real becomes too wide, the system breaks down" Barbara Tuchman (1912-1989) A Distant Mirror, Foreword [1978]

Figure 2.1 from Astrophysical Gas Dynamics: panel (a) show Eeyore drifting downstream, panel (b) shows Pooh, Piglet, Roo, and Rabbit watching from a bridge [illustration from The House at Pooh Corner, chapter 6, E. H. Shepard, artist]

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Barbara Ryden @bsryden.bsky.social · 06/02/2025

The latest volume in The Ohio State Astrophysics Series has been published! Thanks go to everyone in The Ohio State Astronomy Department, but especially to the students in the graduate dynamics class.

A copy of Celestial and Stellar Dynamics, by Barbara Ryden (part of The Ohio State Astrophysics Series). A teddy bear wearing a sweater with the motto "Density is Destiny!" sits behind the book.

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Barbara Ryden @bsryden.bsky.social · 06/02/2025

Opposing fascism and defying gender stereotypes: it's as American as apple pie, the Saturday Evening Post, and Norman Rockwell.

Saturday Evening Post cover, January 2, 1943: a baby (symbolizing the new year) bayonets a swastika. [J. C. Leyendecker, artist]

Saturday Evening Post cover, May 29, 1943: Rosie the Riveter eats a sandwich on her lunch break, in front of an American flag. [Norman Rockwell, artist]

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Barbara Ryden @bsryden.bsky.social · 18/01/2025

When a polar vortex is on its way, it is important to be prepared.

Finn the cat is snuggled within a folded comforter, with only his head and front legs sticking out.

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Barbara Ryden @bsryden.bsky.social · 12/01/2025

Are you attending #aas245? Stop by the Cambridge University Press display and get 30% off their featured books (including my latest, Celestial and Stellar Dynamics). Not attending? You can still get the discount online.

cambridge.org

American Astronomical Society Winter Meeting

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Barbara Ryden @bsryden.bsky.social · 31/12/2024

This is the time of year when I always think of the Ogden Nash poem "Good Riddance, But Now What?" It ends with the couplet: Hark! It's midnight, children dear. Duck! Here comes another year. (I am preparing to duck 2025.)

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Barbara Ryden @bsryden.bsky.social · 25/12/2024

With Christmas lunch, there is nothing like a snowman-shaped glass filled with Guinness. ("I didn't say there was nothing better. I said there was nothing like it.")

Snowman-shaped glass is filled with Guinness stout; can from which the Guinness was poured is next to it.

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Barbara Ryden @bsryden.bsky.social · 24/12/2024

Progress! I have chosen the epigraph for the first chapter of my next book (Astrophysical Gas Dynamics, to be published in 2026). May I have a cookie now?

Start of first chapter of "Astrophysical Gas Dynamics" (to be published 2026). Chapter epigraph is from Margaret Atwood's poem "Variation on the word Sleep":
I would like to be the air
that inhabits you for a moment
only. I would like to be that unnoticed
& that necessary.

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Barbara Ryden @bsryden.bsky.social · 14/12/2024

Best Caturday wishes. I hope you are able to spend some time hanging out with your buddies.

Two cats and a teddy bear, hanging out together on a futon

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Barbara Ryden @bsryden.bsky.social · 06/12/2024

The two people on the right when the clip begins are LePrince's parents-in-law, who were both born in 1816. Yes, there exists video footage of people born during the reign of George III.

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Barbara Ryden @bsryden.bsky.social · 06/12/2024

What's your favorite 80's movie? Mine is the Roundhay Garden Scene (Louis LePrince, director: October 1888)

youtu.be

Roundhay Garden Scene (1888)

YouTube video by Classic Film Channel

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