Lightnews — Scholar-powered news

Christopher Berry @cplberry.bsky.social · 1d

Sounds about right. It's about 8 hours per lecture for me, once I've got the syllabus outlined.

Christopher Berry @cplberry.bsky.social · 1d

Celebrate the full moon with #GravitationalWave candidate #S251006dd

If real, the source is probably a binary black hole (chirp mass ~5.5–11 solar masses)

False alarm rate 1 in 5.9 10^7 yr
GraceDB gracedb.ligo.org/superevents/...
GCN gcn.nasa.gov/circulars/42...
Rating 🐇🏔️🥮

[🧪🔭⚛️]

Initial sky localization. 90% area 110 sq deg.

Initial three-dimensional volume localization. Distance around 710 Mpc.

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Reposted by Christopher Berry

Michael Zingale @michaelzingale.bsky.social · 2d

I like my plot of equipotentials a lot, but I can never shake the fact that @sabinastro.bsky.social calls it the Teenage Mutant Ninja Turtle plot...

zingale.github.io/stars/notebo...

a plot of equipotentials in a binary star system, showing the Roche lobes and Lagrange points. The green color scheme makes it look like a teenage mutant ninja turtle...

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Reposted by Christopher Berry

Graham Doskoch @astrohde.bsky.social · 2d

@giantmolecular.cloud, Bill Smith and I wrote about why the new modification to the eligibility rules for the premier NSF graduate fellowship is actually A Really, Really Big Deal -- and not in a good way.

Astrobites @astrobites.bsky.social · 3d

In this bite, the Astrobites authors discuss recent changes to the NSF’s Graduate Research Fellowship, their impact, and what you can do to help. 🔭✨☄️
astrobites.org/2025/10/04/n...

Big Changes to the NSF’s Graduate Fellowship Mean Big Problems

In this bite, the authors discuss recent changes to the NSF's Graduate Research Fellowship, their impact, and what you can do to help.

astrobites.org

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Reposted by Christopher Berry

Dr Joanne Williams @jowilliams.bsky.social · 6d

This list is astonishing. Individuals recording rainfall for 50, 60, 70 years. 👇All hail the reliable people!

Ed Hawkins @edhawkins.org · 7d

The Rainfall Observers

Over the past three centuries, thousands of people across the British & Irish Isles have recorded rainfall, often every day for decades. Here we recognise some of the individuals who made particularly important contributions.

rmets.onlinelibrary.wiley.com/doi/10.1002/...

The rainfall observers

Over the past three centuries, thousands of people across the British and Irish Isles have regularly recorded rainfall, often every day for decades. Their efforts allow us to reconstruct long-term tr...

rmets.onlinelibrary.wiley.com

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Reposted by Christopher Berry

CIERA @nuciera.bsky.social · 6d

In November 1887, Northwestern’s astronomy journey began with the Dearborn Telescope.

135+ years later, @nuciera.bsky.social leads one of the top 10 astronomy programs in the nation.

🔭 Explore the rich history:
sites.northwestern.edu/highlightsof...

#CIERA #Northwestern #Astronomy #SpaceScience

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Christopher Berry @cplberry.bsky.social · 9d

I'd vote for more cheesecake and less pollution

Paul Waldman @paulwaldman.bsky.social · 9d

1. More Americans work at the Cheesecake Factory than in the entire coal industry, and that won't change. It's because of automation, not snooty libs.

2. Coal energy is now more expensive than wind and solar.

3. So this means: higher energy prices, more pollution, no jobs benefit. Genius!

Aaron Rupar @atrupar.com · 9d

Energy Secretary Chris Wright on Fox: "We're announcing today expanded programs to help the American coal industry. We're helping it because for years it has been under assault. It was out of fashion with the chardonnay set in San Francisco, Boulder, and NYC ... coal just makes the world go round."

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Reposted by Christopher Berry

LIGO Scientific Collaboration @ligo.org · 9d

Count down the top 10 breakthroughs in the 10 years since our first detection with @space.com. Do you agree with their picks?

www.space.com/astronomy/li... by @robleascijorno.bsky.social

#GW10Years 🔭 ⚛️ 🧪

Screenshot: 1. Proving Einstein right! The first gravitational wave detection.

On Sept. 14, 2015, ripples in space-time washed over Earth that were generated by the merger of two black holes, each with a mass of around 30 times that of the sun. This signal, which would come to be known as GW150914 (GW for "gravitational wave" and the following numbers for the date of measurement), had been traveling to our planet for 1.4 billion years.

GW150914's arrival and detection confirmed a theory that was first proposed a century earlier by arguably history's most famous physicist, Albert Einstein, in his 1915 theory of gravity, general relativity.

Screenshot: 10. Proving Einstein ... wrong!?!

The LIGO project operates two detector sites: one near Hanford in eastern Washington, and another near Livingston, Louisiana (shown here). The observatory has four kilometre arms, long concrete tubes surrounded by the greenery of Louisiana. The central building shines white in the middle of the picture. There is LIGO's Science Education Center there is you would like to visit.

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Christopher Berry @cplberry.bsky.social · 9d

Overnight #GravitationalWave candidate #S250929c

If real, the source is probably a binary black hole (chirp mass ~11–44 solar masses)

False alarm rate 1 in 1.3 yr
GraceDB gracedb.ligo.org/superevents/...
GCN gcn.nasa.gov/circulars/42...
Rating 🐈‍⬛

[🧪🔭⚛️]

Initial sky localization. 90% area 2,200 sq deg.

Initial three-dimensional volume localization. Distance around 4.4 Gpc.

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Christopher Berry @cplberry.bsky.social · 11d

You wait long enough and you'll find random noise can look like anything

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Christopher Berry @cplberry.bsky.social · 11d

We do extra analyses with longer stretches of data later. We also do in-depth checks of the the state of the instrument to investigate if we can find any potential non-astrophysical causes for the candidate. We may never know if it is a false alarm or not though

🧵/3

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Christopher Berry @cplberry.bsky.social · 11d

Then you evaluate your statistic on lots of background noise. This enables you to calculate how often a candidate that looks at least this signal-like occurs due to noise. That gives you your false alarm rate.

🧵/2

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Christopher Berry @cplberry.bsky.social · 11d

We have a variety of algorithms, and each calculate false alarm rate in a slightly different way. The basic idea is that you construct a statistic (a mix of how loud a signal is and how consistent with a template) that you expect to be higher for most signal-like things.

🧵/1

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Christopher Berry @cplberry.bsky.social · 11d

Second #GravitationalWave candidate of the day #S250927cy

If real, the source is probably a binary black hole (chirp mass ~22–44 solar masses)

False alarm rate 1 in 0.6 yr
GraceDB gracedb.ligo.org/superevents/...
GCN gcn.nasa.gov/circulars/42...
Rating 🍟

[🧪🔭⚛️]

Initial sky localization. 90% area 1,600 sq deg.

Initial three-dimensional volume localization. Distance around 4.1 Gpc.

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Christopher Berry @cplberry.bsky.social · 11d

Remember to check your battery!

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Christopher Berry @cplberry.bsky.social · 11d

Saturday #GravitationalWave candidate #/S250927ck

If real, the source is probably a binary black hole (chirp mass ~44–88 solar masses)

False alarm rate 1 in 1.0 yr
GraceDB gracedb.ligo.org/superevents/...
GCN gcn.nasa.gov/circulars/42...
Rating 🖌️

[🧪🔭⚛️]

Initial sky localization. 90% area 180 sq deg.

Initial three-dimensional volume localization. Distance around 4.3 Gpc.

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Reposted by Christopher Berry

Jellybox @jellybox.bsky.social · 12d

This is FINE, everything is FINE

We worked with a bunch of talented animators and artists on a music video for The Living Tombstone’s remix of Everything is Fine!!!

CHECK IT OUT NOW!

The Living Tombstone - "Everything Is Fine (Remix)"

YouTube video by The Living Tombstone

www.youtube.com

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Reposted by Christopher Berry

Shanika Galaudage @astronerdika.bsky.social · 13d

Mirror, mirror, reflecting our [LASER] beam...
What is the loudest [gravitational wave] signal that we've seen?

It’s #GW250114!

(Yes, it’s been two weeks since it was announced, but I can still celebrate! 🎉 )

#EinsteinWasRight #HawkingWasRight
@ligo.org @egovirgo.bsky.social

An infographic created by @astronerdika titled “MIRROR, MIRROR, reflecting our LASER beam… what’s the LOUDEST signal gravitational wave we’ve seen?” explaining the gravitational-wave discovery GW250114 and how the observation confirms Hawking’s area law. The visual shows the mirrors in a gravitational-wave interferometer speaking about the loudest event they have seen. There are several illustrations as follows:

1. A simplified diagram of a laser interferometer. A red laser beam from a labeled “LASER source” hits a beam splitter, travels down two perpendicular arms, reflects off round mirrors, and recombines at a labeled “detector.” A label near the top-right mirror reads: “the DETECTOR, signal seen by LIGO Hanford & LIGO Livingston.” 
2. An illustration of a binary black hole merger, with two black circles spiraling inward. They are labeled ~34 solar masses and ~32 solar masses. Surrounding spiral lines represent gravitational waves. A nearby caption reads: “the SOURCE, Discovered in 2025, on January 14, at 08:22:03 UTC.”

3. A prominent speech bubble with white text on a purple background states: “GW250114 is the loudest & clearest signal we’ve seen!” A smaller note below reads: “as of January 2025.”

4. Another speech bubble reads: “AND we saw that Hawking was right too!”

5. Visual explanation of Hawking’s Area Law. Two small circles labeled “this BH” + “this BH” are shown to the left of a “<” symbol, pointing to a larger circle labeled “the surface area of the merged BH.” Below there is the explanatory sentence: “GW250114’s remnant event horizon area is larger than the sum of the individual areas.”

6. A section titled “the PAPERS” lists two arXiv references: https://arxiv.org/abs/2509.08054 and https://www.arxiv.org/abs/2509.08099

Note: This infographic plays off the classic line from Snow White, “Mirror, mirror on the wall…” Here, the “mirrors” are the ones inside the laser interferometer, reflecting light to detect passing gravitational waves.

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Reposted by Christopher Berry

Robert “The Bobby Yaga” McNees @mcnees.bsky.social · 14d

I missed everyone talking about the 100th anniversary of Cecilia Payne-Gaposchkin’s dissertation yesterday.

BUT, just four short months ago I wrote a whole thread about her and work, so idk maybe I was early?

Robert “The Bobby Yaga” McNees @mcnees.bsky.social · May 10

“There is no joy more intense than that of coming upon a fact that cannot be understood in terms of currently accepted ideas."

Astronomer Cecilia Payne-Gaposchkin, who decoded spectral lines to deduce the elemental composition of stars, was born #OTD in 1900. 🧪 🔭 ⚛️ 👩‍🔬

Image: Harvard Observatory

A black and white photo of Cecilia Payne-Gaposchkin. She is sitting at her desk and looking up at the camera, which is in front of her and to her left. Payne-Gaposchkin is wearing a baggy, ribbed sweater and has a wristwatch on her right arm. A pair of glasses rests on the desk in front of her, next to open books and papers which are just visible at the bottom of the photogaph. Filing cabinets, drawers, and another desk are visible in the background. She has short, dark hair which is no longer than chin-length, pulled out of her face behind her left ear.

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Reposted by Christopher Berry

Linn Boldt-Christmas @nplinnspace.bsky.social · 15d

We *absolutely* should celebrate it. Do your part by enjoying the 200+ page masterpiece in its entirety on ADS! ui.adsabs.harvard.edu/abs/1925PhDT... 🔭

Special shoutout to Figure 2, an incredible piece of art that I want on my wall (and suspect could even make an excellent tattoo if executed well?)

Figure caption:

Figure 2. The hydrogen atom. The ten innermost orbits possible for the single electron of the atom of hydrogen are diagrammatically represented. All possible quantum transitions are included as follows: — short dashes, Lyman series, terminating at a 1-quantum orbit; full lines, Balmer series, terminating at a 2-quantum orbit; long dashes, Paschen series, terminating at a 3-quantum orbit. Transfers are only possible between orbits with azimuthal quantum numbers differing by ±1.

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Christopher Berry @cplberry.bsky.social · 14d

Things I Google after eating perhaps one too many biscuits:

arxiv.org/abs/2509.18903

arXiv screenshot for a preprint entitled:

"Can you fall into a McVittie black hole? Will you survive?"
by Brien C. Nolan

arXiv:2509.18903 [gr-qc]

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Reposted by Christopher Berry

Andy Rivkin @asrivkin.bsky.social · 15d

depths of wikipedia @depthsofwikipedia.bsky.social · 16d

imagine if a family of beavers randomly showed up right now and finished whatever thing you've been putting off

In early 2025, beaver activity in the Brdy Protected Landscape Area, Czech Republic, contributed to the restoration of a wetland ecosystem. A family of beavers constructed a series of dams that coincidentally accomplished environmental goals of the Czech government, which had delayed its proposed project since 2018 for bureaucratic and financial reasons. The beaver-built dams saved the Czech government approximately US$1.2 million,

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Reposted by Christopher Berry

Astronomer Royal for Scotland | Catherine Heymans @astroroyalscot.bsky.social · 16d

⏰ Start your countdown clock for the exact moment of the autumn #equinox, 19:19 (UK) 22nd Sept, when the Northern hemisphere and Southern hemisphere are equally illuminated. Today the day length in 🏴󠁧󠁢󠁳󠁣󠁴󠁿Scotland is ~the same as in 🇳🇿New Zealand 🤓🧪🔭

📷: National Maritime Museum, Greenwich

The main diagram shows the Earth's annual rotation around the Sun, surrounded by a zodiacal scale that gives the names, symbols and images of the signs of the zodiac. The seasons and the positions of the equinoxes and solstices are marked. Text at the corners describes the Zodiac and the Earth, and a longer text at the bottom explains the Phenomena of the Seasons.

From https://collections.rmg.co.uk/media/501/182/l1073_001.jpg

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Reposted by Christopher Berry

Laurence Datrier @asleepywanderer.bsky.social · 17d

The #GR24Amaldi16 art gallery is now online! Some really amazing pieces on display - I especially like the papier mâché and clay one by Riccardo Buscicchio
(And of course all of @theastrophoenix.bsky.social's art but does that need to be said?)

🐡🔭🧪

uofgravity.github.io/amaldi-art/

GR AMALDI 2025 ART SHOW

uofgravity.github.io

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Reposted by Christopher Berry

David Ho @davidho.bsky.social · Jul 29

The climate impacts of fossil fuel CO₂ will last longer than nuclear waste.

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