Doug Jerolmack @dougjerolmack.bsky.social · 02/01/2026Jamming, glass transitions, yielding and percolation are key concepts in soft matter that we connect to geophysics problems: soil creep, debris flows, river channel networks, and earthquakes. I also discuss the centrality of randomness and disorder in universality. This lecture pairs with Lecture 8. 010
Doug Jerolmack @dougjerolmack.bsky.social · 02/01/2026"Soft Earth 7: Details don't matter" is the key "theoretical" lecture in the series. I discuss how and why we might expect generality in the behavior of different geophysical systems, especially in the vicinity of critical points. 100
Doug Jerolmack @dougjerolmack.bsky.social · 02/01/2026Sedimentary rocks preserve snippets of these grain and landform memories. We discuss how these memories are stored in landscapes, and how they are erased. 100
Doug Jerolmack @dougjerolmack.bsky.social · 02/01/2026Now up: "Soft Earth 6: Landscapes are memories". From river beds to faults, particles arrange into structures that indicate the direction and magnitude of stresses that act on them. Particles conspire to create landforms such as sand dunes, which encode the history of transport at larger scales. 110
Doug Jerolmack @dougjerolmack.bsky.social · 27/12/2025Dropped "Soft Earth 5: Earth is resilient". Although Earth materials are fragile they're also resilient; soils, for example, evolved to withstand the barrage of environmental stresses under which they formed. This resilience is key to building sustainably using Earth materials. Pairs with Lecture 4. 100
Doug Jerolmack @dougjerolmack.bsky.social · 27/12/2025In a study led by my colleague Hugo Ulloa, we reveal a surprising new mechanism for erosion by raindrops. Sandballs form when rolling drops mop up sand, even reaching a jammed state! #SoftEarthGeophysics 03512
Doug Jerolmack @dougjerolmack.bsky.social · 22/12/2025We explore the consequences of fragility in disordered materials for the Earth's surface, with a special focus on soil creep. This lecture pairs with Lecture 5. 100
Doug Jerolmack @dougjerolmack.bsky.social · 22/12/2025Just dropped: "Soft Earth 4: Earth is fragile". 'Fragile' has a special meaning for materials. It means that particles -- molecules, colloids, sand grains -- form metastable structures that incessantly rearrange, even under very little disturbance. Fragile solids don't stay HOW you put them. 100
Doug Jerolmack @dougjerolmack.bsky.social · 19/12/2025Find out why Plato was right about one of the elements, and how water can be detected on other planets from fractures alone! 110
Doug Jerolmack @dougjerolmack.bsky.social · 19/12/2025Just dropped: "Lecture 3: Things Fall Apart. The Geometry of Failure". I introduce a simple geometric framework for describing the geometry of fracture networks, and show how this lens reveals distinct patterns that are related to the mechanisms of cracking. 110
Doug Jerolmack @dougjerolmack.bsky.social · 16/12/2025I introduce the concept of self organized criticality, and its consequences for the dynamics of the Earth's surface. You'll never look at a sandpile the same! 110
Doug Jerolmack @dougjerolmack.bsky.social · 16/12/2025Just dropped: "Lecture 2: The world is a sandpile. Why everything is threshold, and threshold is everything" in the Soft Earth Chalk Talk series youtube.com/@pennsed?si=... #SoftEarthGeophysics Mountains, faults, rivers & sand dunes are perched on the threshold of failure.youtube.comPennSEDhttps://pennsed.seas.upenn.edu Profile photo: Yukon Delta, satellite image from USGS 110
Doug Jerolmack @dougjerolmack.bsky.social · 12/12/2025New lectures will drop every few days on our PennSED channel: youtube.com/@pennsed?si=... We just posted the prologue to learn what the series is all about, and "Lecture 1. Everything flows: The squishy concept of solid". Please have a look and share!youtube.comPennSEDhttps://pennsed.seas.upenn.edu Profile photo: Yukon Delta, satellite image from USGS 120
Doug Jerolmack @dougjerolmack.bsky.social · 12/12/2025If you wanna find out why soil is creepy, why rocks are soft, why the world is a sandpile, why earth is made of cubes, why details don't matter until they very much do, and why i'm the Nas of geophysics...then dive in! 100
Doug Jerolmack @dougjerolmack.bsky.social · 12/12/2025Each lecture has a theme that links concepts in soft matter to problems in geophysics. Target audience is geoscientists and physicists looking for new approaches and problems, but hopefully is accessible to anyone passionate about science learning. 100
Doug Jerolmack @dougjerolmack.bsky.social · 12/12/2025🧪Today we begin releasing the #SoftEarthGeophysics Chalk Talks, INFORMAL lectures laying out how to think of Earth's surface as a soft matter landscape. This labor of love started w/ a @kitp-ucsb.bsky.social blackboard talk, and grew with support across @sas.upenn.edu @pennengineering.bsky.social 170
Doug Jerolmack @dougjerolmack.bsky.social · 23/10/2025Building momentum for our @kitp-ucsb.bsky.social conference "Hard problems in soft Earth geophysics" this January. Sign up, and bring your friends! www.kitp.ucsb.edu/activities/s...kitp.ucsb.eduKITP 010
Doug Jerolmack @dougjerolmack.bsky.social · 23/10/2025I am beyond honored to be recognized by @apsphysics.bsky.social ! Being an "adult learner" in physics is hard, but the community has been so supportive! More important, to me, is the recognition of #SoftEarthGeophysics and its home in APS. 2100
Reposted by Doug JerolmackPenn Arts & Sciences @sas.upenn.edu · 21/09/2025Recently, NASA announced that samples from an ancient dry riverbed on Mars may contain potential biosignatures, possible evidence of ancient microbial life. On CBS News, @dougjerolmack.bsky.social of the Department of Earth and Environmental Science discussed the exciting news.buff.lyThe significance of Mars rover's latest discoveryThis week, NASA said scientists took the biggest step yet toward discovering whether there was ever life on Mars when a rock sample collected by the Mars rover Perseverance contained potential… 021
Doug Jerolmack @dougjerolmack.bsky.social · 29/09/2025On the "seminar circuit" I keep finding people who didn't know about our #SoftEarthGeophysics conference at @kitp-ucsb.bsky.social and that want to come. Please share with your colleagues and research groups. Details below. 001
Doug Jerolmack @dougjerolmack.bsky.social · 13/09/2025Check me out on @cbsnews.com talking about Mars rocks and using landscape patterns to search for life on other planets. #SoftEarthGeophysics @upenn.edu www.cbsnews.com/video/the-si... 040
Doug Jerolmack @dougjerolmack.bsky.social · 01/09/2025If there was ever a time where deep and original thinking in science is needed. Thanks @davidjonfurbish.bsky.social 020
Reposted by Doug JerolmackJill A Marshall she/her 🇺🇸 @happygeojill.bsky.social · 21/08/2025Can forests damp earthquake waves and thus limit co-seismic landslides? What does this mean for Critical Zone development? Postdoctoral position with Will Struble and a multi-disciplinary team (including me🌲🌲🌊🌳). Position is open until filled. willstruble.com #CZScience #Postdocwillstruble.comWill StrubleTectonic Geomorphology and Surface Processes at the University of Houston 195
Doug Jerolmack @dougjerolmack.bsky.social · 20/08/2025KITP conferences are special. Early career researchers will find ample opportunities to interact and build new relationships, and more senior scientists will find themselves rejuvenated. Hit me up if you have questions, and please SPREAD THE WORD! 021
Doug Jerolmack @dougjerolmack.bsky.social · 20/08/2025Ezequiel Ferrero, Centro Atómico Bariloche Rachel Glade, U. Rochester Jill Marshall, Portland State Olivia Meng, Purdue Tejas Murthy, IIT Bangalore Shravan Pradeep, Penn David Weitz, Harvard 120
Doug Jerolmack @dougjerolmack.bsky.social · 20/08/2025Paulo Arratia, Penn Mahesh Bandi, OIST Katie Barnhardt, USGS Cacey Bester, Swarthmore Justin Burton, Emory Karen Daniels, NC State Emanuela Del Gado, Georgetown Itai Einav, U. Sydney Ahmed Elbanna, USC 120
Doug Jerolmack @dougjerolmack.bsky.social · 20/08/2025There will be lively, long and luxurious poster sessions -- with great interactions and snacks. There will be surf lessons! We will be building the community of #SoftEarthGeophysics and defining problems TOGETHER, that will feed a 3-month program to follow. CHECK OUT INCREDIBLE CONFIRMED SPEAKERS: 120
Doug Jerolmack @dougjerolmack.bsky.social · 20/08/2025Check out the @kitp-ucsb.bsky.social conference we're (Vashan Wright, Sujit Datta, Nathalie Vriend) organizing: www.kitp.ucsb.edu/activities/s... for THIS JANUARY 6-9! Geoscientists, physicists and engineers: are you intellectually adventurous and been wondering "is this all there is?" 🧪kitp.ucsb.eduKITP 178
Doug Jerolmack @dougjerolmack.bsky.social · 05/06/2025🧪 idea for 1 way to address federal cuts to science funding: if the big dumb bill passes and >middle class people get tax breaks they don't need, can we organize a system to divert these to private foundations that already fund science? I'm serious. Anybody got ideas on if and how to do this? 032
Reposted by Doug JerolmackPenn Center for Science, Sustainability & the Media @penncssm.bsky.social · 02/06/2025Check out PCSSM postdoc @asinclair.bsky.social's latest paper with collaborators in @nathumbehav.nature.com on their SCIMaP project that visualizes cuts to NIH funding & how that impacts economy and employment nationwide. And check out the map here: scienceimpacts.org @michaelemann.bsky.social 02013
Reposted by Doug JerolmackMatt Shipman (he/him) @shiplives.bsky.social · 16/05/2025I think most people don't understand exactly what universities do or how they are funded. It's worth reading this and then talking with folks you know about it.🧪 www.npr.org/2025/04/25/n...npr.orgWhat losing billions in federal grants means for universities, and the nationThe Trump administration has so far frozen about $11 billion in research funding. University leaders say no other source can fill the void. 17742
Reposted by Doug JerolmackStand Up for Science! @standupforscience.net · 15/05/2025Over 90% of Americans rely on federally funded science, But only 10% are worried about losing access to it. That’s a dangerous disconnect. Help us close the gap. Join our #SummerFightForScience and help spread the word about how essential science is to everyday lives. www.npr.org/2025/05/06/n...npr.orgMost Americans use federal science information on a weekly basis, a new poll findsMost Americans frequently use federal science information. But few are concerned that cuts to federal science spending could affect their access to such information, a new poll finds. 6257102
Reposted by Doug JerolmackMichael E. Mann @michaelemann.bsky.social · 15/05/2025Seen on @cnn.com @andersoncooper360.bsky.social this evening, courtesy of my #ScienceUnderSiege co-author @peterhotezmdphd.bsky.social 39421
Doug Jerolmack @dougjerolmack.bsky.social · 15/05/2025Amen. I'm an adult learner in this area, but let's try to envision a better future out of the ashes of this, rather than fighting for a status quo we didn't love 010
Reposted by Doug JerolmackDr. David Miller 🏳️🌈 @davidimiller.bsky.social · 14/05/2025🧪 YASSSSS!!! 👏👏👏 Sooo excited to see this. Time *for us* to flood the zone! I'm especially excited to hear about the formation of Stand Up For Science **LOCAL**. Who will lead each local chapter? Could be you. We're the leaders we've all been waiting for to #StandUpForScience. 07726
Doug Jerolmack @dougjerolmack.bsky.social · 14/05/2025In panel discussion at Penn "How did we get here and what do we do?", I answered that generations of increasing competition for funding has narrowed our communication to very small numbers of other scientists... And that an era of direct communication with the pubic is needed. Let's do it!!! 120
Reposted by Doug JerolmackStand Up for Science! @standupforscience.net · 14/05/2025☀️THE SUMMER FIGHT FOR SCIENCE☀️ 🫵 WHO: You + all our friends 🧪 WHAT: Share science with your neighbors and tell them about the impact of proposed budget cuts. 🇺🇸 WHERE: Your local community 🏖️ WHEN: Now to Sept 30th 🔬 WHY: The 9/30 budget vote will determine the future of science in America. 11618347
Reposted by Doug JerolmackClimateBook @climatebook.bsky.social · 09/05/2025To get an idea of what the 37 existing divisions of NSF do, and what is likely to be lost, see the current NSF web site www.nsf.gov/about/direct... But hurry, since this list is apt to disappear at any time.nsf.govOur Directorates and Offices 071
Doug Jerolmack @dougjerolmack.bsky.social · 09/05/2025Join, or Die. If the Big 10 can create a "mutual defense pact", why can't the Ivy League? As Trump takes away all federal money for research, they have less leverage over us. We have nothing to lose by joining Harvard and saying "No compromise. Bring it". 010
Reposted by Doug JerolmackColette Delawalla, PhD @cdelawalla.bsky.social · 09/05/2025Dorks, it’s time to throw sand in the gears. They want us to stop teaching, we will teach in the streets. They want us to stop our research, we will use archival data. They want to send us back to the dark ages, we will be a light. We will not lay down and take this. 6564169
Doug Jerolmack @dougjerolmack.bsky.social · 06/05/2025The drawing features 8 of the colonies that Franklin considered to share common values. There are 8 Ivy League universities, that supposedly share common values and histories. I don't care about the Ivy League per se, but if that title means anything to the universities they must join Harvard. 120
Doug Jerolmack @dougjerolmack.bsky.social · 06/05/2025www.reuters.com/world/us/tru... It is time to "Join, or Die". Founding father of the USA, and Penn, recognized the unorganized colonies had to unite for common cause or face destruction. This is where American Universities are now. en.m.wikipedia.org/wiki/Join,_o...reuters.comTrump administration freezes future grants to HarvardThe U.S. Department of Education informed Harvard University on Monday that it was freezing billions of dollars in future research grants and other aid until the nation's oldest and wealthiest college concedes to a number of demands from the Trump administration, a senior department official said. 120
Doug Jerolmack @dougjerolmack.bsky.social · 03/05/2025Australia and Canada in one week!! Trump may have single handedly reversed a global political trend. I wish my country wasn't sacrificed in the process... 020
Doug Jerolmack @dougjerolmack.bsky.social · 03/05/2025Open letter from NSF Union: www.savensf.com/_files/ugd/e... 🧪 They are trying to destroy American science. They can't without our permission. Science without funding sucks, but science without truth isn't science at all.savensf.com 25317
Reposted by Doug JerolmackColette Delawalla, PhD @cdelawalla.bsky.social · 26/04/2025GOOD EVENING, DORKS. Did you know you can call your senators and house rep and ask for specific grants to be restored? You can ask for specific jobs to be restored. You can ask for data to be restored. You can ask for teams tracking food safety to be restored. Do what you want with this info! 315363
Reposted by Doug JerolmackEos @eos.org · 17/04/2025⬆️New research from @dougjerolmack.bsky.social @upenn.bsky.social, Gábor Domokos at Budapest University of Technology and Economics, & others; comments from Lucas Goehring at Nottingham Trent University and Nina Lanza at Los Alamos National Laboratory. 021
