Corey S. Powell
@coreyspowell.bsky.social
8.6K followers 910 following 1.5K posts
Fascinated by things very big, very small, and beyond the limits of the human senses. Founder of OpenMind: www.openmindmag.org Creator of the Invisible Universe column: https://invisibleuniverse.substack.com/
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coreyspowell.bsky.social
In honor of all the new arrivals, I'm sharing one of my favorite videos.

It shows 24 hours of Earth's rotation, with the camera locked to the sky instead of the ground. We're all hanging out on this spinning rock.

Brilliant work by Bartosz Wojczyński. 🧪

artuniverse.eu/gallery/1907...
coreyspowell.bsky.social
"The answer to the Great Question..."
"Yes!"
"Of how to follow up with someone you met in a bar..."
"Yes!"
"Is 'U Up?'" said Deep Thought, with infinite majesty and calm.
coreyspowell.bsky.social
Crazy but true: This is a real image captured by the Cassini spacecraft.
jpmajor.bsky.social
Dione in front of Saturn, captured by Cassini 20 years ago today on October 11, 2005 🌖🪐
Reposted by Corey S. Powell
mcnees.bsky.social
“Why is the night sky dark, if we live in an infinite universe?”

Kepler, Halley, and Cheseaux all pondered this apparent paradox, but the question is commonly attributed to Heinrich Olbers, who was born #OTD in 1758. 🧪 🔭

Images: hyperphysics.phy-astr.gsu.edu/hbase/Astro/..., Wellcome Collection
A diagram shows arrows radiating from a central point, indicating directions, with lots of white disks (stars) surrounding the central point. An etching of Hans Olbers. He wears a heavy coat, vest, and high collared white shirt. His wispy hair is receding.
coreyspowell.bsky.social
This finding comes from the archives of a different project called RadioAstron. It was a collaboration with Russia, back in somewhat more peaceful times.

science.nrao.edu/about/news/r...
RadioAstron Operational
science.nrao.edu
coreyspowell.bsky.social
For those who want to go deeeep:

The full paper about the binary, orbiting supermassive black holes is freely available:

iopscience.iop.org/article/10.3...
The image of OJ 287 at the record-breaking resolution of 12 μas, achieved in space VLBI when the RadioAstron telescope was 15 Earth diameters away from the ground-based telescopes (a distance of about 190,000 km, comparable to about half of the semimajor axis of the Moon orbit).
coreyspowell.bsky.social
Sure it's blobby, but this is our clearest look at two supermassive black holes in orbit around each other. The primary one is 18 billion times the mass of the Sun!

The image was created using a space-based antenna that created a combined telescope 190,000 km wide. 🔭🧪

www.utu.fi/en/news/pres...
Two black holes in orbit around each other in quasar OJ287. On the left is part of an image taken by the system including the RadioAstron satellite (J.L. Gomez and et al., 2022), where the two lower bright spots are the radio emission coming from the two black holes, and the topmost spot is the jet of the smaller black hole. On the right is a theoretical diagram, calculated by Lankeswar Dey, showing where the black holes and the jets emanating from them were at the time when the picture was taken.
coreyspowell.bsky.social
There should be a whole category for ramen, microwave burritos, and hot pockets
coreyspowell.bsky.social
Very true. And there are a number of enablers within the Jewish community who go along with this idea (as I know only too well, being related to some of them).
coreyspowell.bsky.social
An intriguing detail about the asteroid Kamoʻoalewa:

Based on its orbit and composition, some planetary scientists have theorized that it could be a chunk of our Moon that was blasted free by a large impact. We'll know more soon! 🧪🔭

news.arizona.edu/news/researc...
By using the NASA's JPL — Small-body Database Lookup, the orbit of 469219 Kamo'oalewa can be displayed alongside Earth's orbit. The orbits appear to be nearly identical but just shifted. In the bottom-left corner it provides the distance from Kamo'oalewa to Earth and to the Sun. Credit: NASA
coreyspowell.bsky.social
China's Tianwen-2 is on its way to Kamoʻoalewa, an asteroid that currently doubles as a "quasi-moon" of Earth. The spacecraft will collect samples & bring them back home.

On its outward trajectory, Tianwen-2 looked back and got this lovely view of our planet. 🧪🔭

english.news.cn/20251001/ef3...
This image released by the China National Space Administration (CNSA) on Oct. 1, 2025 shows a view of the Tianwen-2 probe alongside Earth, captured by the probe during its deep-space journey. The newly released image, acquired by a monitoring camera mounted on the probe's robotic arm, showcases China's five-starred red flag and the white return capsule against the backdrop of a distant, blue Earth. (Some slight image processing by me.)
coreyspowell.bsky.social
Sure, let's award prizes to the Bunsen burners, Erlenmeyer flasks, and of course the inanimate carbon rods...

It's getting harder and harder to separate satire from bad AI takes
Homer Simpson's inanimate carbon rod gets its day of honor
coreyspowell.bsky.social
1 word? Halos.

It could tell us how dark matter forms clumpy structures in the halos that seem to surround visible galaxies. Which in turn could provide some clues about what the hell dark matter even is.
coreyspowell.bsky.social
In that case you'll definitely enjoy the "is it a banana or is it a penguin?" galaxy.

esahubble.org/images/heic1...
This image shows the two galaxies interacting. NGC 2936, once a standard spiral galaxy, and NGC 2937, a smaller elliptical, bear a striking resemblance to a penguin guarding its egg. This image is a combination of visible and infrared light, created from data gathered by the NASA/ESA Hubble Space Telescope Wide Field Planetary Camera 3 (WFC3).
coreyspowell.bsky.social
Astronomers have detected a dark blob of...something, billions of light years away. It's as massive as a million Suns & it emits no detectable radiation.

It might be a clump of dark matter, revealing new details about the structure of the invisible universe. 🧪🔭

www.ucdavis.edu/news/astrono...
Left, our best surface brightness model of the 1.7-GHz global VLBI observation used here, which has been reconvolved with the main lobe of the interferometer’s point spread function and added to the residuals (34 μJy per beam r.m.s.). For reference, red contours show the surface brightness at 2.1 μm observed by the W. M. Keck Observatory adaptive optics system30. The positions of two low-mass perturbers are each marked with a black X. The 2 × 108 M⊙ object first detected by ref. 24 is labelled , and the 1.13 × 106 M⊙ detection reported here is labelled . The zoomed-in region shown in the right-hand two panels is indicated by the black square, which has a side length of 60 mas. Top right, detail of the bright arc around , with the colour scale modified to emphasize the gap in the arc produced by the gravitational perturbation of . Bottom right, GI corrections to the lensing convergence (expressed in units of lens-plane surface mass density), showing a compact, positive feature whose position and mass are consistent with the independent parametric modelling results for . The dashed black circle has a radius of 80 pc and the lensed emission is indicated by the black contours.
coreyspowell.bsky.social
Photo from Toronto, more than a decade ago, but I appreciate the joke
coreyspowell.bsky.social
What's out there in the universe? We don't know until we look.

The COWLS project scanned 42,000 galaxies and found hundreds of previously unknown gravitational lenses -- places where the pull of massive galaxies has warped space & bent starlight into arcs and rings. 🧪🔭

esawebb.org/images/potm2...
This ESA/Webb Picture of the Month shows eight stunning examples of gravitational lensing. Gravitational lensing, which was first predicted by Einstein, occurs because massive objects like galaxies and clusters of galaxies dramatically warp the fabric of spacetime. When a massive foreground object lines up just so with a background galaxy, the light from the background galaxy bends as it navigates the warped spacetime on its way to our telescopes.

Depending on how perfect the alignment is, the light from the background galaxy can be bent into an arc, a circle (a phenomenon called an ‘Einstein ring’) or even split into multiple images.
coreyspowell.bsky.social
I understand the objection to awarding a prize for pure theory. But I didn't know about all the personal politics brewing behind the scenes as well!
coreyspowell.bsky.social
In 1912, the Nobel Prize in physics might have honored special relativity, or the photoelectric effect, or the liquefaction of helium. Instead, it recognized an advance in...the design of lighthouses. 🧪

physicsworld.com/a/nobel-priz...
The first light designed to use Gustav Dalén’s technology is located near Djurgården in Stockholm, Sweden. It has since been converted to run on electricity.
coreyspowell.bsky.social
The Nobel Prize, widely considered the ultimate indicator of important science, has often gone off in weird directions due to politics & personalities.

Like that year when an obsolete form of color photography beat out quantum physics for the physics Nobel. 🧪

physicsworld.com/a/nobel-priz...
A still life taken by Lippmann using his method between 1890 and 1910. By the latter part of this period, the method had fallen out of favour, superseded by the simpler Autochrome process. (Photo in public domain)
coreyspowell.bsky.social
Amazing: Comet ATLAS formed some 8 billion years ago. It made about 3 dozen circuits around our galaxy. It entered our our solar system & just passed 30 million kilometers from Mars...

...where ESA's ExoMars orbiter captured these images of the interstellar comet! 🧪🔭

www.esa.int/Science_Expl...
Reposted by Corey S. Powell
physicstoday.bsky.social
You can add John Clarke to the list of Nobel laureates who have published in Physics Today! 🥳

Here's a feature article he wrote in 1971 on quantum tunneling, Josephson junctions, and superconductivity.
Electronics with superconducting junctions
As ultracold becomes easier to maintain, highly sensitive devices based on the Josephson effects may find wider and wider use to measure tiny high‐frequency vol
pubs.aip.org