Cara Giovanetti
@idontevencara.bsky.social
I study dark matter, cosmology, and particle physics for a living at UC Berkeley and Lawrence Berkeley National Lab. On the weekends I write explainers about surprising places physics shows up in the natural world.
caragiovanetti.com
caragiovanetti.com
When I was a kid I used to have nightmares about giant beetles breaking in through the windows of my school cafeteria.
Today I am relieved to put those fears to rest: the laws of physics limit the maximum size insects can grow to.
🧵⚛️🧪
Today I am relieved to put those fears to rest: the laws of physics limit the maximum size insects can grow to.
🧵⚛️🧪
October 11, 2026 at 9:47 PM
When I was a kid I used to have nightmares about giant beetles breaking in through the windows of my school cafeteria.
Today I am relieved to put those fears to rest: the laws of physics limit the maximum size insects can grow to.
🧵⚛️🧪
Today I am relieved to put those fears to rest: the laws of physics limit the maximum size insects can grow to.
🧵⚛️🧪
Supernovae are violent explosions, spewing hot, radioactive material in the death throes of massive stars.
You might think life wouldn’t stand a chance against one. But it turns out life on Earth has withstood *multiple* nearby supernovae.
🧵⚛️🧪
You might think life wouldn’t stand a chance against one. But it turns out life on Earth has withstood *multiple* nearby supernovae.
🧵⚛️🧪
October 4, 2026 at 11:47 PM
Supernovae are violent explosions, spewing hot, radioactive material in the death throes of massive stars.
You might think life wouldn’t stand a chance against one. But it turns out life on Earth has withstood *multiple* nearby supernovae.
🧵⚛️🧪
You might think life wouldn’t stand a chance against one. But it turns out life on Earth has withstood *multiple* nearby supernovae.
🧵⚛️🧪
Reposted by Cara Giovanetti
What guides a bat’s internal compass? It’s not the stars in the sky, or the Earth’s magnetic field. https://www.quantamagazine.org/how-animals-build-a-sense-of-direction-20260121/
How Animals Build a Sense of Direction | Quanta Magazine
Researchers documented the activity of neurons that shape directional navigation as bats explored a remote island off the coast of Tanzania.
www.quantamagazine.org
October 3, 2026 at 6:00 PM
What guides a bat’s internal compass? It’s not the stars in the sky, or the Earth’s magnetic field. https://www.quantamagazine.org/how-animals-build-a-sense-of-direction-20260121/
Reposted by Cara Giovanetti
With a simple tweak, scientists can reverse the flow of turbulence in a 2D system. https://www.quantamagazine.org/sea-monkeys-show-scientists-how-to-rewrite-a-rule-of-turbulence-20261002/
Sea Monkeys Show Scientists How To Rewrite a Rule of Turbulence | Quanta Magazine
Scientists assumed that energy flows in only one direction in a turbulent system. What they didn’t know, until they looked closely at brine shrimp, was that a simple factor can reverse the flow.
www.quantamagazine.org
October 3, 2026 at 8:25 PM
With a simple tweak, scientists can reverse the flow of turbulence in a 2D system. https://www.quantamagazine.org/sea-monkeys-show-scientists-how-to-rewrite-a-rule-of-turbulence-20261002/
Ultimately necessary and the right move ⚛️🧪 I can only see this slightly inconveniencing job seekers who might be trying to push out many works-in-progress close to an application deadline. Plan ahead and ask your collaborators to submit!
Fair Moderation, Equitable Access, and AI: arXiv’s Updated Rate Limit Policy
arXiv, and the scientific community at large, are facing a watershed moment. Scholarly publishing is currently changing at a rapid pace, and we are seeing a…
blog.arxiv.org
October 1, 2026 at 8:38 PM
Ultimately necessary and the right move ⚛️🧪 I can only see this slightly inconveniencing job seekers who might be trying to push out many works-in-progress close to an application deadline. Plan ahead and ask your collaborators to submit!
Reposted by Cara Giovanetti
Postdoc appreciation week is over, so please, STOP appreciating postdocs. They will get some more appreciation next year
September 27, 2026 at 10:37 PM
Postdoc appreciation week is over, so please, STOP appreciating postdocs. They will get some more appreciation next year
Hot rocks can stay warm for ludicrous amounts of time—maybe you’ve seen that video of a guy who heats the interior of his truck by putting a rock in a fire and then moving it to his truck’s cabin.
Turns out the same physics keeps planets’ cores warm—even bodies as small as the moon!
🧵⚛️🧪
Turns out the same physics keeps planets’ cores warm—even bodies as small as the moon!
🧵⚛️🧪
September 27, 2026 at 4:07 PM
Hot rocks can stay warm for ludicrous amounts of time—maybe you’ve seen that video of a guy who heats the interior of his truck by putting a rock in a fire and then moving it to his truck’s cabin.
Turns out the same physics keeps planets’ cores warm—even bodies as small as the moon!
🧵⚛️🧪
Turns out the same physics keeps planets’ cores warm—even bodies as small as the moon!
🧵⚛️🧪
An overlooked era of cosmology is stealing the show in the quest to understand the cosmos. I wrote about it and exciting implications for physics in The Conversation:
⚛️🧪
⚛️🧪
An overlooked era of cosmology is stealing the show in the quest to understand the cosmos
The early universe was kind of like a big game of musical chairs – scientists are figuring out how many particles were able to find ‘seats’ to understand the cosmos.
theconversation.com
September 25, 2026 at 2:26 PM
An overlooked era of cosmology is stealing the show in the quest to understand the cosmos. I wrote about it and exciting implications for physics in The Conversation:
⚛️🧪
⚛️🧪
Reposted by Cara Giovanetti
Tyrannosaurus rex was warm-blooded, new study confirms www.popsci.com/science/tyra...
Tyrannosaurus rex was warm-blooded, new study confirms
The King of the Dinosaurs had an internal temperature similar to you.
www.popsci.com
September 16, 2026 at 7:11 PM
Tyrannosaurus rex was warm-blooded, new study confirms www.popsci.com/science/tyra...
Reposted by Cara Giovanetti
Doing my part to make physics a kinder field, I tell myself as I go grab some chocolate to ensure I'm not grumpy when reviewing
September 15, 2026 at 6:27 PM
Doing my part to make physics a kinder field, I tell myself as I go grab some chocolate to ensure I'm not grumpy when reviewing
evidence of her crimes
September 13, 2026 at 4:22 PM
evidence of her crimes
Reposted by Cara Giovanetti
Brown pelican doing what is called wave slope soaring using updrafts created by breaking waves to conserve valuable energy without flapping, sometimes over a considerable distance. Very cool. 🪶🌿
September 9, 2026 at 1:44 PM
Brown pelican doing what is called wave slope soaring using updrafts created by breaking waves to conserve valuable energy without flapping, sometimes over a considerable distance. Very cool. 🪶🌿
Heard a suggestion today to ask only for a researcher's top ~five most important publications as part of postdoc/faculty applications, to disincentivize cranking out as many LLM-assisted papers as possible. Apparently this strategy is gaining traction in Europe, US has yet to catch on. ⚛️🧪
September 8, 2026 at 6:52 PM
Heard a suggestion today to ask only for a researcher's top ~five most important publications as part of postdoc/faculty applications, to disincentivize cranking out as many LLM-assisted papers as possible. Apparently this strategy is gaining traction in Europe, US has yet to catch on. ⚛️🧪
Reposted by Cara Giovanetti
"Bayesian" means "from the Bay Area".
September 5, 2026 at 4:22 PM
"Bayesian" means "from the Bay Area".
Cool find! ⚛️🧪
Scientists find a huge 10-sided wave pattern swirling in the clouds over Saturn's south pole
Scientists have discovered an enormous 10-sided wave pattern in the icy ammonia clouds over Saturn's south pole.
apnews.com
September 3, 2026 at 2:01 PM
Cool find! ⚛️🧪
Reposted by Cara Giovanetti
Brand new #research found that iron-containing cells in pigeons' livers may help them sense the Earth's magnetic field.
#Nature is weird. 🤯 #Birds are amazing. 🐦
👇 Read the full story in my latest Beaks & Bones post.
beaksandbones.substack.com/p/pigeon-mac...
#scicomm #ornithology #pigeons 🧪🪶
#Nature is weird. 🤯 #Birds are amazing. 🐦
👇 Read the full story in my latest Beaks & Bones post.
beaksandbones.substack.com/p/pigeon-mac...
#scicomm #ornithology #pigeons 🧪🪶
Pigeons sense the Earth's magnetic field—with their livers
Superparamagnetic cells in their livers help homing pigeons navigate on cloudy days.
beaksandbones.substack.com
September 2, 2026 at 9:05 AM
Brand new #research found that iron-containing cells in pigeons' livers may help them sense the Earth's magnetic field.
#Nature is weird. 🤯 #Birds are amazing. 🐦
👇 Read the full story in my latest Beaks & Bones post.
beaksandbones.substack.com/p/pigeon-mac...
#scicomm #ornithology #pigeons 🧪🪶
#Nature is weird. 🤯 #Birds are amazing. 🐦
👇 Read the full story in my latest Beaks & Bones post.
beaksandbones.substack.com/p/pigeon-mac...
#scicomm #ornithology #pigeons 🧪🪶
Reposted by Cara Giovanetti
What are the backgrounds for our event of interest LZ230616, and why can't they currently explain it? 🤔 A thread: 🧵
[Images from the TeVPA talk, available on our website https://lz.lbl.gov] #darkmatter #LZ230616
[Images from the TeVPA talk, available on our website https://lz.lbl.gov] #darkmatter #LZ230616
September 2, 2026 at 11:58 AM
What are the backgrounds for our event of interest LZ230616, and why can't they currently explain it? 🤔 A thread: 🧵
[Images from the TeVPA talk, available on our website https://lz.lbl.gov] #darkmatter #LZ230616
[Images from the TeVPA talk, available on our website https://lz.lbl.gov] #darkmatter #LZ230616
Reposted by Cara Giovanetti
Neat little thread with lots of easy to understand language on the potentially exciting (yet, still to be very studied) #DarkMatter announcement from last night. 👇
Hopefully today you caught wind of the exciting possible dark matter detection at the LZ experiment.
But what’s dark matter again? What’s LZ? What does all of this mean???
1/10 ⚛️🧪
But what’s dark matter again? What’s LZ? What does all of this mean???
1/10 ⚛️🧪
September 1, 2026 at 10:36 PM
Neat little thread with lots of easy to understand language on the potentially exciting (yet, still to be very studied) #DarkMatter announcement from last night. 👇
Hopefully today you caught wind of the exciting possible dark matter detection at the LZ experiment.
But what’s dark matter again? What’s LZ? What does all of this mean???
1/10 ⚛️🧪
But what’s dark matter again? What’s LZ? What does all of this mean???
1/10 ⚛️🧪
September 1, 2026 at 10:24 PM
Hopefully today you caught wind of the exciting possible dark matter detection at the LZ experiment.
But what’s dark matter again? What’s LZ? What does all of this mean???
1/10 ⚛️🧪
But what’s dark matter again? What’s LZ? What does all of this mean???
1/10 ⚛️🧪
One detail that seems to be escaping some of the coverage of the possible dark matter signal in LZ: the analysis they ran was not blind. They attempted to blind, but the procedure failed. This means there are fewer protections against investigator bias that could have crept into the analysis. ⚛️🧪
![An attempt to mitigate possible analyzer bias by injecting the dataset with artificial signal-like events, a process known as “salting”, was unsuccessful. Drawn from
a distribution consisting of a sum of a WIMP SI-like exponential and a flat NR spectrum out to 250 ± 25 keV,
the salt events followed a NR model defined before the
AmBe calibration was conducted and did not adequately
cover the signal region at high energies. Despite the lack
of coverage, the analysis selections and likelihood models
were finalized before four salt events were revealed (in addition to the seven salt events previously removed as part
of the analysis in Ref. [5]). Three of the salt events fell in
the WS ROI with one just above, but all four fall outside
the 90% containment region for the calibrated NR band.
The salt can be seen in the Supplemental Material. Bias
mitigation in the region above 55 keV therefore relies primarily on the use of unchanged analysis selections from
Ref. [5]. Ultimately, we consider the analysis described here to be a non-blind analysis.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:rwkqaqshvv5zumjldji2scrz/bafkreihiidgvhmmwuhywno2mmytfhf7y6lxm25advg2rttodamhjqjqrke)
September 1, 2026 at 9:29 PM
One detail that seems to be escaping some of the coverage of the possible dark matter signal in LZ: the analysis they ran was not blind. They attempted to blind, but the procedure failed. This means there are fewer protections against investigator bias that could have crept into the analysis. ⚛️🧪
this is good, everyone was getting a bit weepy about the whole new-physics thing so maybe a good ambulance chase will restore morale
September 1, 2026 at 4:14 PM
this is good, everyone was getting a bit weepy about the whole new-physics thing so maybe a good ambulance chase will restore morale
⚛️🧪
An interesting result out today from LZ. Definitely not a standard wimp, but maybe an inelastic scattering or momentum dependent scattering? (1/n) www.sciencenews.org/article/dark...
Have scientists glimpsed the first dark matter particle?
Shadowy dark matter has eluded scientists for decades. The LZ experiment may have spotted one particle, called a WIMP, but more data is needed to check.
www.sciencenews.org
September 1, 2026 at 3:11 PM
⚛️🧪
Reposted by Cara Giovanetti
Exciting dark matter news from @lzdarkmatter.bsky.social !
We see one event consistent with a 248 keV nuclear recoil, in tension with our background model at 2.6 sigma.
Paper is now available here:
lz.lbl.gov/wp-content/u...
🧪⚛️
We see one event consistent with a 248 keV nuclear recoil, in tension with our background model at 2.6 sigma.
Paper is now available here:
lz.lbl.gov/wp-content/u...
🧪⚛️
lz.lbl.gov
September 1, 2026 at 2:10 PM
Exciting dark matter news from @lzdarkmatter.bsky.social !
We see one event consistent with a 248 keV nuclear recoil, in tension with our background model at 2.6 sigma.
Paper is now available here:
lz.lbl.gov/wp-content/u...
🧪⚛️
We see one event consistent with a 248 keV nuclear recoil, in tension with our background model at 2.6 sigma.
Paper is now available here:
lz.lbl.gov/wp-content/u...
🧪⚛️
Reposted by Cara Giovanetti
🔭 Our new policy blog post shows that the number of astronomical sciences research awards made by NSF has decreased by 57% since last year, corresponding to a 51% reduction in funding. (1/2)
August 31, 2026 at 6:46 PM
🔭 Our new policy blog post shows that the number of astronomical sciences research awards made by NSF has decreased by 57% since last year, corresponding to a 51% reduction in funding. (1/2)
Reposted by Cara Giovanetti
The tour-bus-sized telescope aims to unravel cosmic mysteries and identify more than 100,000 planets beyond our solar system. n.pr/4xpmKNr
NASA has successfully launched its newest space telescope
The tour-bus-sized telescope aims to unravel cosmic mysteries and identify more than 100,000 planets beyond our solar system.
n.pr
August 30, 2026 at 2:08 PM
The tour-bus-sized telescope aims to unravel cosmic mysteries and identify more than 100,000 planets beyond our solar system. n.pr/4xpmKNr