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Keith Smith @drkeithsmith.bsky.social · 4h

Editor's choice: little red dots (LRDs) are compact distant galaxies with unusual properties, of uncertain origin. Taylor et al. have found an LRD at redshift 9.2, and show it contains a supermassive black hole >5% of the stellar mass in the galaxy. ☄️ #extragalactic
www.science.org/doi/10.1126/...

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Reposted by Keith Smith

Keith Smith @drkeithsmith.bsky.social · 1d

Please don't vandalise @wikipedia.org. It's one of the most useful resources ever produced. Don't deliberately damage it.

You might think you're just having a laugh, but you're making the encyclopaedia worse for everyone else, and wasting the time of other users who have to tidy up after you.

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Keith Smith @drkeithsmith.bsky.social · 1d

Please don't vandalise @wikipedia.org. It's one of the most useful resources ever produced. Don't deliberately damage it.

You might think you're just having a laugh, but you're making the encyclopaedia worse for everyone else, and wasting the time of other users who have to tidy up after you.

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Reposted by Keith Smith

Science Magazine @science.org · 1d

This year’s #NobelPrize in Physics honors researchers who demonstrated quantum mechanical effects in electric circuits on a chip. https://scim.ag/46T4qQK

Physics Nobel awarded for macro demonstration of quantum effects

John Clarke, Michel Devoret, and John Martinis honored for work demonstrating quantum mechanical tunneling in electrical circuits

scim.ag

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Reposted by Keith Smith

Jake Yeston @jakeyeston.bsky.social · 1d

Quantum mechanics of a macroscopic variable, published by today’s laureates in @science.org in 1988. In addition to the science, it’s remarkably lucid writing

www.science.org/doi/10.1126/...

🧪

ARE MACROSCOPIC DEGREES OF FREEDOM GOVERNED BY quantum mechanics? Our everyday experience tells us that a classical description appears to be entirely adequate. The trajectory of the center of mass of a billiard ball is predicted wonderfully well by classical mechanics. Even the Brownian motion
of a tiny speck of dust in a drop of water is a purely classical phenomenon. Until recently, quantum mechanics manifested itself at the macroscopic level only through such collective phenomena as
superconductivity, flux quantization, or the Josephson effect. However, these "macroscopic" effects actually arise from the coherent superposition of a large number of microscopic variables each
governed by quantum mechanics. Thus, for example, the current through a Josephson tunnel junction and the phase difference across it are normally treated as classical variables.

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Keith Smith @drkeithsmith.bsky.social · 1d

⚛️

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Reposted by Keith Smith

Science Magazine @science.org · 2d

This year’s #NobelPrize in Physiology or Medicine has been awarded to three scientists for discovering how the immune system distinguishes friend from foe. https://scim.ag/3Wt5rdi

Medicine Nobel goes to three researchers who identified immune system’s security guards

Mary Brunkow, Fred Ramsdell, and Shimon Sakaguchi discovered regulatory T cells that prevent autoimmune disease

scim.ag

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Keith Smith @drkeithsmith.bsky.social · 2d

That's a bit harsh. The authors do explain their reasoning e.g. "The inability of models to consistently explain all these sources indicates an incomplete understanding of phosphorus chemistry in low-temperature atmospheres."

You might disagree with that logic, but the referees accepted it.

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Keith Smith @drkeithsmith.bsky.social · 2d

I did not mention Venus, and nor does the paper. It does discuss the abundances on Jupiter, Saturn and other brown dwarfs.

The authors' point about biosignatures arises from the difficulty in explaining the varying phosphine abundances in different targets using atmospheric models.

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Keith Smith @drkeithsmith.bsky.social · 2d

In @aunz.theconversation.com , Laura McKemmish discusses why astronomers are interested in phosphine. How should we interpret its abundance in planets and brown dwarfs? #stellarastro #exoplanet #chemsky ☄️
theconversation.com/mysterious-m...

Mysterious molecule found on brown dwarf casts further doubt on potential signs of life on Venus

A failed star just taught us something new about the search for alien life.

theconversation.com

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Keith Smith @drkeithsmith.bsky.social · 2d

The phosphine molecule, PH3, has been proposed as a biosignature in rocky planets. In @science.org, Burgasser et al. report phosphine in a brown dwarf atmosphere. "We therefore caution against the use of phosphine as a biosignature". #stellarastro #exoplanet ☄️
www.science.org/doi/10.1126/...

Observation of undepleted phosphine in the atmosphere of a low-temperature brown dwarf

The atmospheres of low-temperature brown dwarfs and gas giant planets are expected to contain the phosphine molecule, PH3. However, previous observations have shown much lower abundances of this molec...

www.science.org

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Keith Smith @drkeithsmith.bsky.social · 9d

For the UK, I’m sure the current number is substantially lower than 20%, and has been since at least the 2008 financial crisis.

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Keith Smith @drkeithsmith.bsky.social · 19d

This video is now a decade old, but it's still the most thought-provoking discussion of #AI that I've ever seen.

(By @computerphile.bsky.social, which doesn't seem to be active here yet.)
www.youtube.com/watch?v=tcdV...

Deadly Truth of General AI? - Computerphile

YouTube video by Computerphile

www.youtube.com

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Keith Smith @drkeithsmith.bsky.social · 19d

An amusing footnote in a preprint:
"for brevity, we refer to this as the Ravasio Line, following the established tradition in our field [gamma-ray bursts] of naming things after Italians."
☄️ #HighEnergyAstro
arxiv.org/abs/2410.00286

Fermi-GBM Team Analysis on The Ravasio Line

The prompt spectra of gamma-ray bursts are known to follow broadband continuum behavior over decades in energy. GRB 221009A, given the moniker the brightest of all time (BOAT), is the brightest gamma-...

arxiv.org

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Keith Smith @drkeithsmith.bsky.social · 19d

I have *never* heard anyone say ‘question mark’ out loud when asking a question. Surely that isn’t a thing people do?

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Reposted by Keith Smith

Science Magazine @science.org · 22d

Increasing the breadth of researchers trained as peer reviewers is crucial to upholding quality in academic publishing. Last year, the Science journals began a pilot in which invited peer reviewers could add trainees as co-reviewers, with more than 2200 scientists participating. #PeerReviewWeek

White text on a red background: Science thanks each of our reviewers for their critical contribution. #PeerReviewWeek

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Keith Smith @drkeithsmith.bsky.social · 24d

Disproven decades ago. It was a reasonable idea when it was first proposed, but subsequent observational evidence is overwhelmingly incompatible with it.

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Keith Smith @drkeithsmith.bsky.social · 24d

This is in the library of St John’s College, Cambridge, during a public open day. Hoyle was a fellow of that college and many of his papers are in the library collection.

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Keith Smith @drkeithsmith.bsky.social · 25d

… and saw Isaac Newton’s own copy of the first edition Principia Mathematica, with his hand-written corrections for the second edition. 🔭⚛️🧪

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Keith Smith @drkeithsmith.bsky.social · 25d

Today I looked through Fred Hoyle’s telescope… 🔭⚛️

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Keith Smith @drkeithsmith.bsky.social · 26d

3/3 Ancient pollution from mines and smelting shows that Britain's economy did not suffer when the Romans left in 410 AD. Metal production rose for the following two centuries. A fascinating mix of #geochemistry and #archaeology 🏺 reported by @evoscribe.bsky.social.
www.science.org/doi/10.1126/...

Great Britain’s economy didn’t completely tank after Romans left, countering conventional wisdom

“Completely surprising” discovery based on ancient pollutants suggests mining and smelting continued apace for centuries

www.science.org

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Keith Smith @drkeithsmith.bsky.social · 26d

2/3 Two recent studies of marsquakes recorded by the InSight lander provide new information on Mars' interior, reports @voosen.me. One study probed the planet's mantle, the other its core. #planetsci #seismology #earthquake
www.science.org/doi/10.1126/...

Data from defunct NASA lander paint a radical new picture of Mars’s interior

Studies identify a solid inner core and buried remnants of giant impacts

www.science.org

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Keith Smith @drkeithsmith.bsky.social · 26d

Lots of interesting reporting in this week's issue of @science.org:

1/3 The loudest gravitational wave event observed by @ligo.org determined the surface areas of the black holes. The results confirm Stephen Hawking's theoretical predictions, writes Adrian Cho. ⚛️☄️🧪
www.science.org/doi/10.1126/...

Strongest black hole collision yet confirms theories of Einstein, Hawking

Observation confirms that a black hole’s area can only grow and never shrink

www.science.org

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Keith Smith @drkeithsmith.bsky.social · Sep 8

Not quite what I was thinking of (which was HVCs in radio), but section 4.4 of this paper ascribes variable optical absorption lines in quasar spectra to the motion of the Sun relative to the Milky Way ISM - which is just the inverse of the ISM proper motion.
www.aanda.org/articles/aa/...

Time variations of narrow absorption lines in high resolution quasar spectra | Astronomy & Astrophysics (A&A)

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics

www.aanda.org

Keith Smith @drkeithsmith.bsky.social · Sep 8

It's a long time since I worked on time-varying interstellar lines; for stars we could never disentangle the motion of the star vs gas (e.g. Smith+ 2013).

Still, I thought there were quasars with variable absorption lines ascribed to the proper motion of foreground clouds within the Milky Way.

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