Submarines and ships rely on towed sonar arrays(TSAs)for underwater exploration and security operations,but dragging these sensors through water,especially at high cruising speeds,creates excess noise that can mask target signals and compromise the sonar’s detection capabilities.Now,a team of Berkeley engineers is attempting to solve this problem with alittle inspiration from Mother Nature.In astudy recently published in Extreme Mechanics Letters,researchers from Berkeley,in collaboration with MIT Lincoln Laboratory,demonstrate how atextured surface designed to mimic shark skin can reduce drag and mitigate flow-based noise,potentially opening the door to anew generation of more effective and efficient TSAs.“Past studies have shown that the unique patterns on shark skin,known as riblets,can reduce drag,”said Grace Gu,assistant professor of mechanical engineering and principal investigator of this study.“We hypothesized that such bioinspired topographies could similarly reduce noise production in an underwater context and set out to adapt these naturally occurring designs to the surfaces of sonar arrays.”According to the researchers,the idea of using riblets for noise suppression was inspired by yet another natural texture,serrations,which are known to help owls achieve silent flight and used on surfaces to mitigate noise in aeronautic systems.To test their theory,the researchers used computational modeling to simulate riblet surfaces with different shapes and patterns and then simulated the movement of water around these engineered riblet surfaces on the arrays.This virtual testing environment enabled them to assess how different riblet designs affect fluid behavior and the acoustic properties of the sonar arrays under various flow conditions—from smooth,predictable laminar flows to the more common,chaotic turbulent flows encountered in natural marine environments. 查看详细>>

A panel of the nation‘s top particle physicists,chaired by University of California,Berkeley,theoretician Hitoshi Murayama,has issued its final report recommending how the U.S.government should commit its high-energy physics research funds for the next decade and beyond,focusing on neutrinos,dark matter and the cosmic microwave background.The report by the Particle Physics Project Prioritization Panel(P5)was approved on Friday,Dec.8,by the High Energy Physics Advisory Panel(HEPAP)and will be sent to the two main funding agencies for physics in the U.S.—the Department of Energy(DOE)and the National Science Foundation(NSF)—to aid them in their decisions about which research to fund.The HEPAP,a permanent advisory committee to DOE and NSF,constitutes aprioritization panel every 10 years.The panel,consisting of 31 members and one ex-officio member from the U.S.and abroad,considered only large-and medium-sized physics research projects—the kind that can take years or decades to plan and build,enlist contributions from thousands of scientists and cost billions of dollars.To fit within budget constraints—likely less than$5 billion from the two agencies over 10 years for new projects—the panel had to combine or reconfigure many proposed projects and turn down perhaps two-thirds of them."Fiscal responsibility has been abig thing on our mind to make sure that the recommendations are actionable by agencies and can be followed up,"said Murayama,the MacAdams Professor of Physics at the UC Berkeley."We had to be really realistic about our plan."The five recommended projects with estimated budgets exceeding aquarter of abillion dollars each are:The Cosmic Microwave Background Stage IV experiment(CMB-S4),which will use telescopes sited in Chile and Antarctica,supported by U.S.infrastructure at the South Pole,to study the oldest light from the beginning of the universe.The polarization of the CMB can tell cosmologists about the gravitational waves generated during inflation in the early universe and help them understand what was going on when the cosmos was still microscopic.Enhancements,including an upgrade in power and experimental capabilities,to the Deep Underground Neutrino Experiment(DUNE)in South Dakota.The DUNE is the centerpiece of adecades-long program to reveal the mysteries of elusive neutrinos.The U.S.-hosted international project will exploit aunique underground laboratory,the Sanford Underground Research Laboratory,now nearing completion,and neutrino beams produced at Fermi National Accelerator Laboratory in Illinois.A Higgs boson factory,located in either Europe or Japan,to advance studies of astill mysterious particle that was only discovered in 2012,yet which gives mass to all other forms of matter.An accelerator that produces lots of Higgs bosons would allow precise measurements of the boson‘s properties and help physicists understand how the particle fits into current models of the universe and whether it is connected with dark matter.A Generation 3(G3)Dark Matter experiment that would combine four different international experiments—including the LZ experiment led by Lawrence Berkeley National Laboratory—into one comprehensive program to probe the enigmatic nature of dark matter,which makes up asignificant portion of the universe’s mass and energy and has been one of the most enduring mysteries in modern physics.The panel recommended that this experiment be built in the U.S.Expansion at the South Pole of aneutrino observatory,which earlier this year mapped for the first time the sources of neutrinos from the Milky Way galaxy and outside our galaxy.Called IceCube-Gen2,it would be an international collaboration operated by the University of Wisconsin–Madison.The observatory now consists of detectors embedded in 1cubic kilometer of ice;the expansion would increase the observatory‘s sensitivity by afactor of 10.The panel also recommended investing in studies of afuture muon collider.While most particle accelerators today rev up electrons or protons and smash them together,a muon collider would accelerate short-lived muons,which are fundamental particles like electrons(they‘re both leptons),but much heavier.A muon collider could explore new frontiers of physics with much less energy input than aproton collider.The panel proposed Fermilab as agood place to build ademonstration collider to test the unique technology. 查看详细>>

Science has been considered apurely objective field of study that has produced research to cure diseases,map out the anatomies of living things and explore our planet and the universe.But UC Berkeley Bioengineering Professor Aaron Streets says it is important for those who conduct that research“to represent the full diversity of human genetic variation.”And while equity and justice are important,he said,it goes beyond that.“Scientific research runs the risk of not comprehensively addressing the broad range of public need if our scientists only represent anarrow range of genotypes,”said Streets,whose bioengineering lab on campus conducts research on microscopy,microfluidics and single-cell genomics.“It matters who is doing the science.”Streets was recently honored with Berkeley’s 2023 Chancellor’s Award for Advancing Institutional Equity and Excellence.While certain states around the country are currently moving to eliminate public education funding for various diversity,equity and inclusion programs—efforts led by politicians who devalue the importance of that work and research—Streets has been atireless advocate for increasing diversity in STEM.Through his Next Generation Faculty Symposium—a joint initiative between Berkeley,Stanford University and UC San Francisco that aims to diversify faculty recruitment pools at universities—Streets has given STEM postdoctoral candidates from underrepresented communities an opportunity to showcase their work and research to the masses.And Streets’Bioengineering Scholars Program has introduced first-year undergraduates—many from historically underrepresented groups—to STEM research through amentoring program focused on recruitment and support.Berkeley News spoke with Streets recently about why Berkeley has become an ideal place for DEI work,how diversity can help bring new and necessary perspectives to STEM research and academia,and the intersection of his two passions,art and science.If researchers represent only anarrow composition of genotypes,then the things that those biologists and those doctors care about might only be applicable to anarrow range of stakeholders.Historically,we have seen researchers focus solely on demographics that reflect their own genotypes.But as we get more into the age of genomics,personalized medicine and rare diseases,there are potentially blind spots to that approach.What are those blind spots,and how do they impact society as awhole?Scientific experts,like biologists and bioengineers,are people that the government looks to for policy decisions and decisions about epidemiological responses,for example.We saw that especially during the COVID-19 pandemic.If they’re looking to our STEM academic community as experts to guide policy decisions,it’s important that we collectively understand the implications of those policy decisions in different ethnic and socioeconomic communities.Another example is if we’re trying to understand the relationship between one’s genome and the likelihood of getting adisease,and we’re only studying one sliver of genotype—one ethnicity,one type of ancestry—then we’re only going to understand the relationship between the disease and that specific group of people.Going even further,if we come up with adrug or therapeutic approach to that disease,and we test the efficacy of that intervention on ahomogeneous sample of human genomes,our data might not apply to abroader population.That is ahuge blind spot,because we won’t know the implications for people with different genotypes or from different ethnic groups or different lifestyle behaviors and diets.Our research is incomplete if our subjects aren’t diverse.And,oftentimes,it takes aresearcher from those underrepresented groups in STEM to point this out. 查看详细>>

The Biden Administration today(Tuesday,March 28)named Darleane C.Hoffman and Gabor A.Somorjai as recipients of the Enrico Fermi Presidential Award,one of the oldest and most prestigious science and technology honors bestowed by the U.S.government.“Dr.Hoffman and Dr.Somorjai’s work to open the frontiers of radiochemistry and surface chemistry helped change what was possible,and advanced efforts to tackle some of the world’s greatest challenges,”said Arati Prabhakar,assistant to the President and director of the White House Office of Science and Technology Policy.“They are world-class innovators and an inspiration to future generations of scientists,and Icongratulate each of them for alifetime of achievement.”“It is an honor to be able to recognize the outstanding achievements of Dr.Hoffman and Dr.Somorjai,”said Energy Secretary Jennifer Granholm.“Their commitment to pushing the boundaries of science is not only inspiring,but will help us respond to the big challenges we anticipate in the future.We need leaders of this kind to provide the scientific foundation for the next generation.”Hoffman,UC Berkeley professor emerita of chemistry and former faculty senior scientist at Lawrence Berkeley National Laboratory(Berkeley Lab),is anuclear chemist known for the study of transuranic elements—quickly decaying elements that are heavier than uranium.In 1993,she was among agroup of researchers who confirmed the existence of anew element,seaborgium 106,and was awarded the National Medal of Science in 1997.Hoffman,96,is recognized with the Fermi Award for scientific discoveries advancing the field of nuclear and radiochemistry,for distinguished service to the Department of Energy’s missions in national security and nuclear waste management,and for sustained leadership in radiochemistry research and education.Somorjai,a University Professor in Berkeley’s College of Chemistry and former faculty senior scientist at Berkeley Lab,conducted research that has advanced surface chemistry important for energy and clean water,in addition to arange of other contributions.He has been aleader in catalysis for more than 50 years and was awarded the National Medal of Science in 2001.Somorjai,87,is recognized with the Fermi Award for key contributions in molecular studies of surfaces through the use of single crystals,the development of techniques for quantitative determinations of surface structure,and establishing the molecular foundations of heterogeneous metal catalysis.The Enrico Fermi Presidential Award was established in 1956 as amemorial to the legacy of Enrico Fermi,an Italian-born naturalized American citizen and 1938 Nobel laureate in physics who achieved the first nuclear chain reaction in 1942.It is given to encourage excellence in research in energy science and technology benefiting humanity;recognize scientists,engineers and science policymakers who have given unstintingly over their careers to advance energy science and technology;and inspire people of all ages through the examples of Fermi,and the Fermi Award laureates who followed in his footsteps,to explore new scientific and technological horizons.Winners receive acitation signed by the President and the Secretary of Energy,a gold-plated medal bearing the likeness of Enrico Fermi,and an honorarium of$100,000.In the event the award is given to more than one individual in the same year,the recipients share the honorarium equally.The Fermi Award is administered on behalf of the White House by the U.S.Department of Energy. 查看详细>>

A dense,collapsed star spinning 707 times per second—making it one of the fastest spinning neutron stars in the Milky Way galaxy—has shredded and consumed nearly the entire mass of its stellar companion and,in the process,grown into the heaviest neutron star observed to date.Weighing this record-setting neutron star,which tops the charts at 2.35 times the mass of the sun,helps astronomers understand the weird quantum state of matter inside these dense objects,which—if they get much heavier than that—collapse entirely and disappear as ablack hole.“We know roughly how matter behaves at nuclear densities,like in the nucleus of auranium atom,”said Alex Filippenko,Distinguished Professor of Astronomy at the University of California,Berkeley.“A neutron star is like one giant nucleus,but when you have one-and-a-half solar masses of this stuff,which is about 500,000 Earth masses of nuclei all clinging together,it’s not at all clear how they will behave.”Roger W.Romani,professor of astrophysics at Stanford University,noted that neutron stars are so dense—1 cubic inch weighs over 10 billion tons—that their cores are the densest matter in the universe short of black holes,which because they are hidden behind their event horizon are impossible to study.The neutron star,a pulsar designated PSR J0952-0607,is thus the densest object within sight of Earth.The measurement of the neutron star’s mass was possible thanks to the extreme sensitivity of the 10-meter Keck Itelescope on Maunakea in Hawai’i,which was just able to record aspectrum of visible light from the hotly glowing companion star,now reduced to the size of alarge gaseous planet.The stars are about 3,000 light years from Earth in the direction of the constellation Sextans.Discovered in 2017,PSR J0952-0607 is referred to as a“black widow”pulsar—an analogy to the tendency of female black widow spiders to consume the much smaller male after mating.Filippenko and Romani have been studying black widow systems for more than adecade,hoping to establish the upper limit on how large neutron stars/pulsars can grow.“By combining this measurement with those of several other black widows,we show that neutron stars must reach at least this mass,2.35 plus or minus 0.17 solar masses,”said Romani,who is aprofessor of physics in Stanford’s School of Humanities and Sciences and member of the Kavli Institute for Particle Astrophysics and Cosmology.“In turn,this provides some of the strongest constraints on the property of matter at several times the density seen in atomic nuclei.Indeed,many otherwise popular models of dense-matter physics are excluded by this result.”If 2.35 solar masses is close to the upper limit of neutron stars,the researchers say,then the interior is likely to be asoup of neutrons as well as up and down quarks—the constituents of normal protons and neutrons—but not exotic matter,such as“strange”quarks or kaons,which are particles that contain astrange quark.“A high maximum mass for neutron stars suggests that it is amixture of nuclei and their dissolved up and down quarks all the way to the core,”Romani said.“This excludes many proposed states of matter,especially those with exotic interior composition.”Romani,Filippenko and Stanford graduate student Dinesh Kandel are co-authors of apaper describing the team’s results that has been accepted for publication by The Astrophysical Journal Letters. 查看详细>>

Tuskegee University and UC Berkeley recently announced the Berkeley-Tuskegee Data Science Initiative,a multi-year partnership to develop curriculum and collaborative research opportunities for students and faculty at both institutions.On June 21,Charlotte Morris,president of Tuskegee University,met with Berkeley Chancellor Carol Christ to discuss the new initiative.In areception at University House,Chancellor Christ greeted the Tuskegee delegation,including four faculty and staff representatives and the first cohort of Tuskegee Scholars,13 students in residence at Berkeley for eight weeks to take Data 6or Data 8courses.“We‘re excited to create our partnership with Tuskegee around the theme of community–community in the classroom,how we teach our students community in our research,how we explore challenging issues and fields at the intersection of data science and society and community at the university level between UC Berkeley and Tuskegee University,”said Chancellor Christ.President Morris noted Tuskegee’s pioneering legacy as atop historically Black college and university(HBCU),including atrack record for excellence in STEM fields.“We want to go beyond that legacy and take Tuskegee to the next level in terms of technology,in terms of what’s going on in the world today,so that our students will be marketable when they go across that stage at graduation,”she said.On June 28,faculty at both universities discussed the collaboration at the National Workshop on Data Science Education in both online and in-person sessions on the Berkeley campus.The Berkeley-Tuskegee Data Science Initiative events this summer are the culmination of two years of conversation and planning.In 2021,Google contributed$5 million to Tuskegee University in support of STEM initiatives,including the development of adata science program.The initial phases of the initiative are funded by part of this contribution.Deborah Nolan,emeritus professor of statistics and associate dean for faculty at the Division of Computing,Data Science,and Society(CDSS),was involved in the project from the outset.She and collaborators at Tuskegee and Berkeley have been exploring what shape educational and research collaborations could take between the two universities.Nolan said the initiative’s events last week were both alaunch and acelebration of this shared endeavor. 查看详细>>

Coming from along line of Iowa farmers,David Savage always thought he would do research to improve crops.That dream died in college,when it became clear that any genetic tweak to acrop would take at least ayear to test;for some perennials and trees,it could take five to 10 years.Faced with such slow progress,he chose to study the proteins in photosynthetic bacteria instead.But the advent of CRISPR changed all that.Savage is now pivoting to molecular crop breeding,hoping to find ways to improve their carbon uptake and the amount of carbon they return to the soil.And he hopes to see these improved crops in fields within his lifetime,helping to boost crop yields but also to draw down the excess carbon in the atmosphere that is warming the planet and stash it underground.“The advent of CRISPR basically allowed us to create new molecular tools for potentially skipping the slow aspects of plant tissue culture and plant genetic engineering,which are large barriers to doing experiments in plants,”said Savage,associate professor of molecular and cell biology at the University of California,Berkeley,an investigator in the Howard Hughes Medical Institute,and member of the Innovative Genomics Institute(IGI),which focuses on the myriad uses of CRISPR-Cas9 genome editing.One of his collaborators,Krishna Niyogi,UC Berkeley professor of plant and microbial biology,estimates that the suboptimal photosynthetic reactions in plants could be improved with CRISPR editing to be between 20%and 50%more efficient.That means more carbon captured from the air,complementing other efforts—in particular,halting the burning of fossil fuels—to reduce greenhouse gases.Agriculture could potentially sequester billions of tons of carbon each year.“Now,I’m really excited to create tools to eliminate the slow bottleneck,”Savage said.“Then we can start to do more molecular experiments again,like trying to improve photosynthesis in away that you could never do before.CRISPR enabled that.”A$11 million commitment from the Chan Zuckerberg Initiative(CZI)announced this month will help Savage and IGI researchers at UC Berkeley,UC Davis and Lawrence Livermore National Laboratory(LLNL)rapidly assess CRISPR gene editing in plants,primarily rice and sorghum,and hopefully get improved varieties into field trials in three to five years.“In crop breeding,a typical graduate student for their Ph.D.project might make mutations in 10 or 20 plants—they get 10 or 20 shots on goal.We know that’s not enough,”Savage said.“The power of CRISPR is,we now have the ability to essentially make all possible mutations,determine in the lab what the most promising mutations might be,then take that prioritized list and move it into the field and assess from there what would work.So,we still take 10 shots on goal,but they’re 10 really good shots on goal.” 查看详细>>

If,as astronomers believe,the death of large stars leave behind black holes,there should be hundreds of millions of them scattered throughout the Milky Way galaxy.The problem is,isolated black holes are invisible.Now,a team led by University of California,Berkeley,astronomers has for the first time discovered what may be afree-floating black hole by observing the brightening of amore distant star as its light was distorted by the object’s strong gravitational field—so-called gravitational microlensing.The team,led by graduate student Casey Lam and Jessica Lu,a UC Berkeley associate professor of astronomy,estimates that the mass of the invisible compact object is between 1.6 and 4.4 times that of the sun.Because astronomers think that the leftover remnant of adead star must be heavier than 2.2 solar masses in order to collapse to ablack hole,the UC Berkeley researchers caution that the object could be aneutron star instead of ablack hole.Neutron stars are also dense,highly compact objects,but their gravity is balanced by internal neutron pressure,which prevents further collapse to ablack hole.Whether ablack hole or aneutron star,the object is the first dark stellar remnant—a stellar“ghost”—discovered wandering through the galaxy unpaired with another star.“This is the first free-floating black hole or neutron star discovered with gravitational microlensing,”Lu said.“With microlensing,we’re able to probe these lonely,compact objects and weigh them.I think we have opened anew window onto these dark objects,which can’t be seen any other way.”Determining how many of these compact objects populate the Milky Way galaxy will help astronomers understand the evolution of stars—in particular,how they die—and of our galaxy,and perhaps reveal whether any of the unseen black holes are primordial black holes,which some cosmologists think were produced in large quantities during the Big Bang.The analysis by Lam,Lu and their international team has been accepted for publication in The Astrophysical Journal Letters.The analysis includes four other microlensing events that the team concluded were not caused by ablack hole,though two were likely caused by awhite dwarf or aneutron star.The team also concluded that the likely population of black holes in the galaxy is 200 million—about what most theorists predicted. 查看详细>>

The more definitive mass means that the most common type of experiment to detect these elusive particles—a microwave resonance chamber containing astrong magnetic field,in which scientists hope to snag the conversion of an axion into afaint electromagnetic wave—won’t be able to detect them,no matter how much the experiment is tweaked.The chamber would have to be smaller than afew centimeters on aside to detect the higher-frequency wave from ahigher-mass axion,Safdi said,and that volume would be too small to capture enough axions for the signal to rise above the noise.“Our work provides the most precise estimate to date of the axion mass and points to aspecific range of masses that is not currently being explored in the laboratory,”he said.“I really do think it makes sense to focus experimental efforts on 40 to 180μeV axion masses,but there’s alot of work gearing up to go after that mass range.”One newer type of experiment,a plasmonic haloscope,which looks for axion excitations in ametamaterial—a solid-state plasma—should be sensitive to an axion particle of this mass,and could potentially detect one.“The basic studies of these three-dimensional arrays of fine wires have worked out amazingly well,much better than we ever expected,”said Karl van Bibber,a UC Berkeley professor of nuclear engineering who is building aprototype of the plasmonic haloscope while also participating in amicrowave cavity axion search called the HAYSTAC experiment.“Ben’s latest result is very exciting.If the post-inflation scenario is right,after four decades,discovery of the axion could be greatly accelerated.”If axions really exist.The work was published today(Feb.25)in the journal Nature Communications.Axion top candidate for dark matter Dark matter is amysterious substance that astronomers know exists—it affects the movements of every star and galaxy—but which interacts so weakly with the stuff of stars and galaxies that it has eluded detection.That doesn’t mean dark matter can’t be studied and even weighed.Astronomers know quite precisely how much dark matter exists in the Milky Way Galaxy and even in the entire universe:85%of all matter in the cosmos.Safdi’s colleagues include Malte Buschmann of Princeton;MIT postdoctoral fellow Joshua Foster;Anson Hook of the University of Maryland;and Adam Peterson,Don Willcox and Weiqun Zhang of Berkeley Lab’s Center for Computational Sciences and Engineering.The research was largely funded by the U.S.Department of Energy through the Exascale Computing Project(17-SC-20-SC)and through the Early Career program(DESC0019225). 查看详细>>

The field of synthetic biology has had great success engineering yeast and bacteria to make chemicals—biofuels,pharmaceuticals,fragrances,even the hoppy flavors of beer—cheaply and more sustainably,with only sugar as the energy source.Yet,the field has been limited by the fact that microbes,even with genes thrown in from plants or other animals,can only make molecules by using the chemical reactions of nature.Much of chemistry and the chemical industry is focused on making substances that are not found in nature with reactions invented in alaboratory.A collaboration between synthetic chemists and synthetic biologists at the University of California,Berkeley,and Lawrence Berkeley National Laboratory has now overcome that hurdle,engineering bacteria that can make amolecule that,until now,could only be synthesized in alaboratory.While the biosynthesis in the bacteria E.coli produced asubstance of low value—and in small quantities,at that—the fact that the researchers could engineer amicrobe to produce something unknown in nature opens the door to production of abroader range of chemicals from yeast and bacterial fermentation,the researchers said.“It’s acompletely new way of doing chemical synthesis.The idea of creating an organism that makes such an unnatural product,that combines laboratory synthesis with synthetic biology within aliving organism—it is just afuturistic way to make organic molecules from two separate fields of science in away nobody’s done before,”said John Hartwig,UC Berkeley professor of chemistry and one of four senior authors of the study.The findings were published online today(Oct.14)in the journal Nature Chemistry.The achievement could greatly expand the applications of synthetic biology,which is agreener,more sustainable way to make chemicals for consumers and industry,said co-author Aindrila Mukhopadhyay,a Berkeley Lab senior scientist and vice president of the Biofuels and Bioproducts Division at the Joint BioEnergy Institute(JBEI)in Emeryville,California.“There is just so much need in our lives right now for sustainable materials,materials that won’t impact the environment.This technology opens up possibilities for fuels with desirable properties that can be produced renewably,as well as new antibiotics,new nutraceuticals,new compounds that would be exceedingly challenging to make using only biology or only chemistry,”she said.“I think that is the real power of this—it expands the range of molecules we can address.We really need disruptive new technologies,and this most definitely is one of them.” 查看详细>>