Jamal Mohammed made it to the 2019 World Athletics Championships after fleeing Darfur as a child.
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Thursday, October 3, 2019
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A new way to corrosion-proof thin atomic sheets
A variety of two-dimensional materials that have promising properties for optical, electronic, or optoelectronic applications have been held back by the fact that they quickly degrade when exposed to oxygen and water vapor. The protective coatings developed thus far have proven to be expensive and toxic, and cannot be taken off.
Now, a team of researchers at MIT and elsewhere has developed an ultrathin coating that is inexpensive, simple to apply, and can be removed by applying certain acids.
The new coating could open up a wide variety of potential applications for these “fascinating” 2D materials, the researchers say. Their findings are reported this week in the journal PNAS, in a paper by MIT graduate student Cong Su; professors Ju Li, Jing Kong, Mircea Dinca, and Juejun Hu; and 13 others at MIT and in Australia, China, Denmark, Japan, and the U.K.
Research on 2D materials, which form thin sheets just one or a few atoms thick, is “a very active field,” Li says. Because of their unusual electronic and optical properties, these materials have promising applications, such as highly sensitive light detectors. But many of them, including black phosphorus and a whole category of materials known as transition metal dichalcogenides (TMDs), corrode when exposed to humid air or to various chemicals. Many of them degrade significantly in just hours, precluding their usefulness for real-world applications.
“It’s a key issue” for the development of such materials, Li says. “If you cannot stabilize them in air, their processability and usefulness is limited.” One reason silicon has become such a ubiquitous material for electronic devices, he says, is because it naturally forms a protective layer of silicon dioxide on its surface when exposed to air, preventing further degradation of the surface. But that’s more difficult with these atomically thin materials, whose total thickness could be even less than the silicon dioxide protective layer.
There have been attempts to coat various 2D materials with a protective barrier, but so far they have had serious limitations. Most coatings are much thicker than the 2D materials themselves. Most are also very brittle, easily forming cracks that let through the corroding liquid or vapor, and many are also quite toxic, creating problems with handling and disposal.
The new coating, based on a family of compounds known as linear alkylamines, improves on these drawbacks, the researchers say. The material can be applied in ultrathin layers, as little as 1 nanometer (a billionth of a meter) thick, and further heating of the material after application heals tiny cracks to form a contiguous barrier. The coating is not only impervious to a variety of liquids and solvents but also significantly blocks the penetration of oxygen. And, it can be removed later if needed by certain organic acids.
“This is a unique approach” to protecting thin atomic sheets, Li says, that produces an extra layer just a single molecule thick, known as a monolayer, that provides remarkably durable protection. “This gives the material a factor of 100 longer lifetime,” he says, extending the processability and usability of some of these materials from a few hours up to months. And the coating compound is “very cheap and easy to apply,” he adds.
In addition to theoretical modeling of the molecular behavior of these coatings, the team made a working photodetector from flakes of TMD material protected with the new coating, as a proof of concept. The coating material is hydrophobic, meaning that it strongly repels water, which otherwise would diffuse into the coating and dissolve away a naturally formed protective oxide layer within the coating, leading to rapid corrosion.
The application of the coating is a very simple process, Su explains. The 2D material is simply placed into bath of liquid hexylamine, a form of the linear alkylamine, which builds up the protective coating after about 20 minutes, at a temperature of 130 degrees Celsius at normal pressure. Then, to produce a smooth, crack-free surface, the material is immersed for another 20 minutes in vapor of the same hexylamine.
“You just put the wafer into this liquid chemical and let it be heated,” Su says. “Basically, that’s it.” The coating “is pretty stable, but it can be removed by certain very specific organic acids.”
The use of such coatings could open up new areas of research on promising 2D materials, including the TMDs and black phosphorous, but potentially also silicene, stanine, and other related materials. Since black phosphorous is the most vulnerable and easily degraded of all these materials, that’s what the team used for their initial proof of concept.
The new coating could provide a way of overcoming “the first hurdle to using these fascinating 2D materials,” Su says. “Practically speaking, you need to deal with the degradation during processing before you can use these for any applications,” and that step has now been accomplished, he says.
The team included researchers in MIT’s departments of Nuclear Science and Engineering, Chemistry, Materials Science and Engineering, Electrical Engineering and Computer Science, and the Research Laboratory of Electronics, as well as others at the Australian National University, the University of Chinese Academy of Sciences, Aarhus University in Denmark, Oxford University, and Shinshu University in Japan. The work was supported by the Center for Excitonics and the Energy Frontier Research Center funded by the U.S. Department of Energy, and by the National Science Foundation, the Chinese Academy of Sciences, the Royal Society, the U.S. Army Research Office through the MIT Institute for Soldier Nanotechnologies, and Tohoku University.
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Deploying drones to prepare for climate change
While doing field research for her graduate thesis in her hometown of Cairo, Norhan Magdy Bayomi observed firsthand the impact of climate change on her local community.
The residents of the low-income neighborhood she was studying were living in small, poorly insulated apartments that were ill-equipped for dealing with the region’s rising temperatures. Sharing cramped quarters — with families in studios less than 500 square feet — and generally lacking air conditioning or even fans, many people avoided staying in their homes altogether on the hottest days.
It was a powerful illustration of one of the most terrible aspects of climate change: Those who are facing its most extreme impacts also tend to have the fewest resources for adapting.
This understanding has guided Bayomi’s research as a PhD student in the Department of Architecture’s Building Technology Program. Currently in her third year of the program, she has mainly looked at countries in the developing world, studying how low-income communities there adapt to changing heat patterns and documenting global heatwaves and populations’ adaptive capacity to heat. A key focus of her research is how building construction and neighborhoods’ design affect residents’ vulnerability to hotter temperatures.
She uses drones with infrared cameras to document the surface temperatures of urban buildings, including structures with a variety of designs and building materials, and outdoor conditions in the urban canyons between buildings.
“When you look at technologies like drones, they are not really designed or commonly used to tackle problems like this. We’re trying to incorporate this kind of technology to understand what kind of adaptation strategies are suitable for addressing climate change, especially for underserved populations,” she says.
Eyes in the sky
Bayomi is currently developing a computational tool to model heat risk in urban areas that incorporates building performance, available urban resources for adaptation, and population adaptive capacity into its data.
“Most of the tools that are available right now are mostly using statistical data about the population, the income, and the temperature. I’m trying to incorporate how the building affects indoor conditions, what resources are available to urban residents, and how they adapt to heat exposure — for instance, if they have a cooling space they could go to, or if there is a problem with the power supplies and they don’t have access to ceiling fans,” she says. “I’m trying to add these details to the equation to see how they would affect risk in the future.”
She recently began looking at similar changes in communities in the Bronx, New York, in order to see how building construction, population adaptation, and the effects of climate change differ based on region. Bayomi says that her advisor, Professor John Fernández, motivated her to think about how she could apply different technologies into her field of research.
Bayomi’s interest in drones and urban development isn’t limited to thermal mapping. As a participant in the School of Architecture and Planning’s DesignX entrepreneurship program, she and her team founded Airworks, a company that uses aerial data collected by the drones to provide developers with automated site plans and building models. Bayomi worked on thermal imaging for the company, and she hopes to continue this work after she finishes her studies.
Bayomi is also working with Fernández’s Urban Metabolism Group on an aerial thermography project in collaboration with Tarek Rakha PhD ’15, an assistant professor at Georgia Tech. The project is developing a cyber-physical platform to calibrate building energy models, using drones equipped with infrared sensors that autonomously detect heat transfer anomalies and envelope material conditions. Bayomi’s group is currently working on a drone that will be able to capture these data and process them in real-time.
Second home
Bayomi says the personal connections that she has developed at MIT, both within her program and across the Institute, have profoundly shaped her graduate experience.
“MIT is a place where I felt home and welcome. Even as an Arabic muslim woman, I always felt home,” she says. “My relationship with my advisor was one of the main unique things that kept me centered and focused, as I was blessed with an advisor who understands and respects my ideas and gives me freedom to explore new areas.”
She also appreciates the Building Technology program’s “unique family vibe,” with its multiple academic and nonacademic events including lunch seminars and social events.
When she’s not working on climate technologies, Bayomi enjoys playing and producing music. She has played the guitar for 20 years now and was part of a band during her undergraduate years. Music serves an important role in Bayomi’s life and is a crucial creative outlet for her. She currently produces rock-influenced trance music, a genre categorized by melodic, electronic sounds. She released her first single under the moniker Nourey last year and is working on an upcoming track. She likes incorporating guitar into her songs, an element not typically heard in trance tunes.
“'I’m trying to do something using guitars with ambient influences in trance music, which is not very common,” she says.
Bayomi has been a member of the MIT Egyptian Students Association since she arrived at MIT in 2015, and now serves as vice president. The club works to connect Egyptian students at MIT and students in Egypt, to encourage prospective students to apply and provide guidance based on the members’ own experiences.
“We currently have an amazing mix of students in engineering, Sloan [School of Management], Media Lab, and architecture, including graduate and undergraduate members. Also, with this club we try to create a little piece of home here at MIT for those who feel homesick and disconnected due to culture challenges,” she says.
In 2017 she participated in MIT’s Vacation Week for Massachusetts Public Schools at the MIT Museum, and in 2018 she participated in the Climate Changed ideas competition, where her team’s entry was selected as one of the top three finalists.
“I am keen to participate whenever possible in these kind of activities, which enhance my academic experience here,” she says. “MIT is a rich place for such events.”
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Africa's top shots: 27 September - 3 October
Delvin Joyce: Financial Planner Promotes Prosperity In The Community
BE Modern Man: Delvin Joyce
Financial planner; 40; Founder, Prosperity Wealth Group (affiliation: Prudential Advisors)
Twitter: @delvinjoyce33; Instagram: @delvinj33
In my role as a financial planner, I have the awesome opportunity to help first-generation wealth builders, a lot of whom are black Americans, create generational wealth and legacies for their families. I truly feel that the work I’m doing is helping to close the racial wealth gap. A big part of the mission of my practice as a financial planner is promoting prosperity in the community through financial literacy and education, so we spend a lot of time doing seminars for various community organizations, removing the stigma around money talk and empowering people to take control of their financial futures.
WHAT PRACTICES, TOOLS, BOOKS, ETC. DO YOU RELY ON FOR YOUR SUCCESS?
Every morning I do 100 push-ups first thing—before I get dressed, before I brush my teeth or anything. Of course, I also go to the gym but so does everyone else and the 100 push-ups is my way of feeling like I gained a slight advantage. This daily ritual serves as a reminder for me to always go the extra mile in my business and that for me to be successful I have to constantly challenge myself to outwork everyone else. Success is never owned, it is rented and the rent is due every day. The push-ups remind me to pay the rent.
HOW HAVE YOU TURNED STRUGGLE INTO SUCCESS?
In my pre-financial planner life, my path to becoming an NFL player was all about struggle. As someone who had always been considered too small to be taken seriously as a football player, I struggled to gain validity after being snubbed by every college in the country and joining the James Madison University football program as an un-recruited, non-scholarship walk-on. That struggle resulted in an All-American college career. The struggle didn’t end there, as every NFL team passed on me in the draft, which forced me to go to work after college and start my career working toward becoming a financial adviser. With a little nudge from my father-in-law, I decided to take another crack at football and together we created a package with my highlight tape and a résumé with all of my awards and accolades that we sent to every NFL team. I knew it was a long shot and I felt like a rapper sending my mixtape to record labels trying to get a deal. Out of the 32 NFL teams that received my package only one team responded, and after a year of being removed from football altogether, I found myself on the 53 man roster for the New York Football Giants in 2002.
Although I didn’t see it this way at the time, my convoluted journey to the NFL was providential as it allowed me to find my passion and purpose in the financial industry. So when my career came to an abrupt end after three seasons, I knew exactly what I was supposed to do next.
WHO WAS YOUR GREATEST MALE ROLE MODEL AND WHAT DID YOU LEARN FROM HIM?
My dad was my greatest male role model. He was the person who gave me the inspiration at a very young age to pursue my athletic aspirations despite my diminutive stature. That was important to him because he was only 4’10” tall as an adult and he always told me that as a kid he let people talk him out of playing sports because of his size and he was determined not to let that happen to me. I like to say that my Dad taught me sticktoitiveness and I grew up with a chip on my shoulder, believing that I could do or accomplish anything with hard work and perseverance.
HOW DO YOU DEFINE MANHOOD?
I define manhood as having the courage to make tough decisions, the confidence to get it right, and the humility to admit when you’re wrong.
WHAT’S THE BEST ADVICE YOU’VE EVER RECEIVED?
The best advice I ever got was from my grandmother who used to say “give people their flowers while they can still smell them.” In 2015, I was inducted into the JMU Sports Hall of Fame and during my acceptance speech, I proceeded to thank virtually everyone who played a role in not just my athletic success but life in general. It was an awesome moment where I got to tell my parents how much they meant to me. Less than a year later, my Dad would be dead at age 64 after suffering a stroke and I’m so happy that I took my Grandma’s advice and gave him his flowers while he could smell them.
WHAT DO YOU LIKE MOST ABOUT BEING A BLACK MAN?
What I like best about being a black male is understanding that I get to drink from a well that I didn’t dig myself. I believe that when you are operating in that awareness it forces you to not take anything for granted and to always strive to be the very best version of yourself.
BE Modern Man is an online and social media campaign designed to celebrate black men making valuable contributions in every profession, industry, community, and area of endeavor. Each year, we solicit nominations in order to select men of color for inclusion in the 100 Black Enterprise Modern Men of Distinction. Our goal is to recognize men who epitomize the BEMM credo “Extraordinary is our normal” in their day-to-day lives, presenting authentic examples of the typical black man rarely seen in mainstream media. The BE Modern Men of Distinction are celebrated annually at Black Men XCEL (www.blackenterprise.com/blackmenxcel/). Click this link to submit a nomination for BE Modern Man: https://www.blackenterprise.com/nominate/. Follow BE Modern Man on Twitter: @bemodernman and Instagram: @be_modernman.
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Cardi B is filming another movie after her debut in Hustlers: ‘I enjoy the checks’
On the heels of her feature film debut in Hustlers, Cardi B seems to already be preparing to make a return to the big screen.
Thursday, the Grammy-winning rapper appeared on The Ellen Show along with T.I. and Chance the Rapper, her fellow judges on Netflix’s new reality music series Rhythm + Flow.
READ MORE: Cardi B outbids herself at Diamond Ball auction, drops $111K on Rihanna’s new book
At one point, host Ellen DeGeneres confessed that she couldn’t let Cardi go without applauding her for how well she did in Hustlers, which has so far grossed nearly $100 million worldwide.
When asked if she enjoyed working on the set, Cardi mused, “I enjoyed it, and I just couldn’t believe I was on set for like 16 hours and then like… is this what actors gotta go through?
“Artists, we have long days but it’s just full of excitement, like we move around we’re doing something,” she continued. “Like, you gotta wait in the trailer until it’s your turn, you gotta do the same scene like 20 times.”
But when DeGeneres teased, “You’re not going to do that again aren’t you,” the Bronx native quipped, “Oh yes I am. Yup. I am going to film for a movie this month.”
When the comedian pointed out that Cardi just admitted she didn’t really enjoy the process of acting, Cardi playfully pushed back, “I enjoy the checks.”
Then she candidly admitted she did Rhythm + Flow for the checks as well, a response that both T.I. and Chance seemed to agree with.
READ MORE: Keke Palmer on perfecting her pole-dancing skills for ‘Hustlers’ and scoring ‘GMA: 3’ gig
“We did it for the check, but once we were there… you know something, I grew a connection to the contestants,” said the mother of one. “I was really emotional the last day. I was so sad.”
T.I. chimed in that they, “came for the check but stayed for the artists,” and Cardi shared that’s why she felt bad because she knew they, “crushed a couple of people’s dreams.”
Rhythm + Flow debuts on Netflix on October 9.
The post Cardi B is filming another movie after her debut in Hustlers: ‘I enjoy the checks’ appeared first on theGrio.
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Engineered viruses could fight drug resistance
In the battle against antibiotic resistance, many scientists have been trying to deploy naturally occurring viruses called bacteriophages that can infect and kill bacteria.
Bacteriophages kill bacteria through different mechanisms than antibiotics, and they can target specific strains, making them an appealing option for potentially overcoming multidrug resistance. However, quickly finding and optimizing well-defined bacteriophages to use against a bacterial target is challenging.
In a new study, MIT biological engineers showed that they could rapidly program bacteriophages to kill different strains of E. coli by making mutations in a viral protein that binds to host cells. These engineered bacteriophages are also less likely to provoke resistance in bacteria, the researchers found.
“As we’re seeing in the news more and more now, bacterial resistance is continuing to evolve and is increasingly problematic for public health,” says Timothy Lu, an MIT associate professor of electrical engineering and computer science and of biological engineering. “Phages represent a very different way of killing bacteria than antibiotics, which is complementary to antibiotics, rather than trying to replace them.”
The researchers created several engineered phages that could kill E. coli grown in the lab. One of the newly created phages was also able to eliminate two E. coli strains that are resistant to naturally occurring phages from a skin infection in mice.
Lu is the senior author of the study, which appears in the Oct. 3 issue of Cell. MIT postdoc Kevin Yehl and former postdoc Sebastien Lemire are the lead authors of the paper.
Engineered viruses
The Food and Drug Administration has approved a handful of bacteriophages for killing harmful bacteria in food, but they have not been widely used to treat infections because finding naturally occurring phages that target the right kind of bacteria can be a difficult and time-consuming process.
To make such treatments easier to develop, Lu’s lab has been working on engineered viral “scaffolds” that can be easily repurposed to target different bacterial strains or different resistance mechanisms.
“We think phages are a good toolkit for killing and knocking down bacteria levels inside a complex ecosystem, but in a targeted way,” Lu says.
In 2015, the researchers used a phage from the T7 family, which naturally kills E.coli, and showed that they could program it to target other bacteria by swapping in different genes that code for tail fibers, the protein that bacteriophages use to latch onto receptors on the surfaces of host cells.
While that approach did work, the researchers wanted to find a way to speed up the process of tailoring phages to a particular type of bacteria. In their new study, they came up with a strategy that allows them to rapidly create and test a much greater number of tail fiber variants.
From previous studies of tail fiber structure, the researchers knew that the protein consists of segments called beta sheets that are connected by loops. They decided to try systematically mutating only the amino acids that form the loops, while preserving the beta sheet structure.
“We identified regions that we thought would have minimal effect on the protein structure, but would be able to change its binding interaction with the bacteria,” Yehl says.
They created phages with about 10,000,000 different tail fibers and tested them against several strains of E. coli that had evolved to be resistant to the nonengineered bacteriophage. One way that E. coli can become resistant to bacteriophages is by mutating “LPS” receptors so that they are shortened or missing, but the MIT team found that some of their engineered phages could kill even strains of E. coli with mutated or missing LPS receptors.
This helps to overcome one of the limiting factors in using phages as antimicrobials, which is that bacteria can generate resistance by mutating receptors that the phages use to enter bacteria, says Rotem Sorek, a professor of molecular genetics at the Weizmann Institute of Science.
“Through deep understanding of the biology entailing the phage-bacteria recognition, together with smart bioengineering approaches, Lu and his team managed to design a large library of phage variants, each of which has the potential to recognize a slightly different receptor. They show that treating bacteria with this library rather than with a single phage limits the emergence of resistance,” says Sorek, who was not involved in the study.
Other targets
Lu and Yehl now plan to apply this approach to targeting other resistance mechanisms used by E. coli, and they also hope to develop phages that can kill other types of harmful bacteria. “This is just the beginning, as there are many other viral scaffolds and bacteria to target,” Yehl says. The researchers are also interested in using bacteriophages as a tool to target specific strains of bacteria that live in the human gut and cause health problems.
“Being able to selectively hit those nonbeneficial strains could give us a lot of benefits in terms of human clinical outcomes,” Lu says.
The research was funded by the Defense Threat Reduction Agency, the National Institutes of Health, the U.S. Army Research Laboratory/Army Research Office through the MIT Institute for Soldier Nanotechnologies, and the Koch Institute Support (core) Grant from the National Cancer Institute.
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This is how a “fuzzy” universe may have looked
Dark matter was likely the starting ingredient for brewing up the very first galaxies in the universe. Shortly after the Big Bang, particles of dark matter would have clumped together in gravitational “halos,” pulling surrounding gas into their cores, which over time cooled and condensed into the first galaxies.
Although dark matter is considered the backbone to the structure of the universe, scientists know very little about its nature, as the particles have so far evaded detection.
Now scientists at MIT, Princeton University, and Cambridge University have found that the early universe, and the very first galaxies, would have looked very different depending on the nature of dark matter. For the first time, the team has simulated what early galaxy formation would have looked like if dark matter were “fuzzy,” rather than cold or warm.
In the most widely accepted scenario, dark matter is cold, made up of slow-moving particles that, aside from gravitational effects, have no interaction with ordinary matter. Warm dark matter is thought to be a slightly lighter and faster version of cold dark matter. And fuzzy dark matter, a relatively new concept, is something entirely different, consisting of ultralight particles, each about 1 octillionth (10-27) the mass of an electron (a cold dark matter particle is far heavier — about 105 times more massive than an electron).
In their simulations, the researchers found that if dark matter is cold, then galaxies in the early universe would have formed in nearly spherical halos. But if the nature of dark matter is fuzzy or warm, the early universe would have looked very different, with galaxies forming first in extended, tail-like filaments. In a fuzzy universe, these filaments would have appeared striated, like star-lit strings on a harp.
As new telescopes come online, with the ability to see further back into the early universe, scientists may be able to deduce, from the pattern of galaxy formation, whether the nature of dark matter, which today makes up nearly 85 percent of the matter in the universe, is fuzzy as opposed to cold or warm.
“The first galaxies in the early universe may illuminate what type of dark matter we have today,” says Mark Vogelsberger, associate professor of physics in MIT’s Kavli Institute for Astrophysics and Space Research. “Either we see this filament pattern, and fuzzy dark matter is plausible, or we don’t, and we can rule that model out. We now have a blueprint for how to do this.”
Vogelsberger is a co-author of a paper appearing today in Physical Review Letters, along with the paper’s lead author, Philip Mocz of Princeton University, and Anastasia Fialkov of Cambridge University and previously the University of Sussex.
Fuzzy waves
While dark matter has yet to be directly detected, the hypothesis that describes dark matter as cold has proven successful at describing the large-scale structure of the observable universe. As a result, models of galaxy formation are based on the assumption that dark matter is cold.
“The problem is, there are some discrepancies between observations and predictions of cold dark matter,” Vogelsberger points out. “For example, if you look at very small galaxies, the inferred distribution of dark matter within these galaxies doesn’t perfectly agree with what theoretical models predict. So there is tension there.”
Enter, then, alternative theories for dark matter, including warm, and fuzzy, which researchers have proposed in recent years.
“The nature of dark matter is still a mystery,” Fialkov says. “Fuzzy dark matter is motivated by fundamental physics, for instance, string theory, and thus is an interesting dark matter candidate. Cosmic structures hold the key to validating or ruling out such dark matter modles.”
Fuzzy dark matter is made up of particles that are so light that they act in a quantum, wave-like fashion, rather than as individual particles. This quantum, fuzzy nature, Mocz says, could have produced early galaxies that look entirely different from what standard models predict for cold dark matter.
“Even though in the late universe these different dark matter scenarios may predict similar shapes for galaxies, the first galaxies would be strikingly different, which will give us a clue about what dark matter is,” Mocz says.
To see how different a cold and a fuzzy early universe could be, the researchers simulated a small, cubic space of the early universe, measuring about 3 million light years across, and ran it forward in time to see how galaxies would form given one of the three dark matter scenarios: cold, warm, and fuzzy.
The team began each simulation by assuming a certain distribution of dark matter, which scientists have some idea of, based on measurements of the cosmic microwave background — “relic radiation” that was emitted by, and was detected just 400,000 years after, the Big Bang.
“Dark matter doesn’t have a constant density, even at these early times,” Vogelsberger says. “There are tiny perturbations on top of a constant density field.”
The researchers were able to use existing algorithms to simulate galaxy formation under scenarios of cold and warm dark matter. But to simulate fuzzy dark matter, with its quantum nature, they needed a new approach.
A map of harp strings
The researchers modified their simulation of cold dark matter, enabling it to solve two extra equations in order to simulate galaxy formation in a fuzzy dark matter universe. The first, Schrödinger’s equation, describes how a quantum particle acts as a wave, while the second, Poisson’s equation, describes how that wave generates a density field, or distribution of dark matter, and how that distribution leads to gravity — the force that eventually pulls in matter to form galaxies. They then coupled this simulation to a model that describes the behavior of gas in the universe, and the way it condenses into galaxies in response to gravitational effects.
In all three scenarios, galaxies formed wherever there were over-densities, or large concentrations of gravitationally collapsed dark matter. The pattern of this dark matter, however, was different, depending on whether it was cold, warm, or fuzzy.
In a scenario of cold dark matter, galaxies formed in spherical halos, as well as smaller subhalos. Warm dark matter produced first galaxies in tail-like filaments, and no subhalos. This may be due to warm dark matter’s lighter, faster nature, making particles less likely to stick around in smaller, subhalo clumps.
Similar to warm dark matter, fuzzy dark matter formed stars along filaments. But then quantum wave effects took over in shaping the galaxies, which formed more striated filaments, like strings on an invisible harp. Vogelsberger says this striated pattern is due to interference, an effect that occurs when two waves overlap. When this occurs, for instance in waves of light, the points where the crests and troughs of each wave align form darker spots, creating an alternating pattern of bright and dark regions.
In the case of fuzzy dark matter, instead of bright and dark points, it generates an alternating pattern of over-dense and under-dense concentrations of dark matter.
“You would get a lot of gravitational pull at these over-densities, and the gas would follow, and at some point would form galaxies along those over-densities, and not the under-densities,” Vogelsberger explains. “This picture would be replicated throughout the early universe.”
The team is developing more detailed predictions of what early galaxies may have looked like in a universe dominated by fuzzy dark matter. Their goal is to provide a map for upcoming telescopes, such as the James Webb Space Telescope, that may be able to look far enough back in time to spot the earliest galaxies. If they see filamentary galaxies such as those simulated by Mocz, Fialkov, Vogelsberger, and their colleagues, it could be the first signs that dark matter’s nature is fuzzy.
“It’s this observational test we can provide for the nature of dark matter, based on observations of the early universe, which will become feasible in the next couple of years,” Vogelsberger says.
This research was supported, in part, by NASA.
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Credit Card Debt is Delaying Millennials’ Dreams
Are you seeking to buy a new home? Is a new car on your wish list? Do you need to take out a personal loan? Well, credit card debt may be standing in your way and limiting your ability to create the life of your dreams.
It’s 2019 and Americans are diving deeper into credit card debt with no visible escape plan. According to Federal Reserve data, outstanding consumer debt is at an all-time high, exceeding $4 trillion as of July 2019.
Research from Clever has found that millennials are greatly impacted by credit card debt. While student loan debt may be the main culprit of millennial financial stress, credit card debt doesn’t rank too far behind in the list of financial frustrations. Forty-one percent of millennials say their credit card debt has prevented them from making a major life purchase.
Millennials are struggling with the homeownership process due to waning credit scores and increased debt obligations. The most important thing millennials can do right now is to take control of their financial situation and eliminate any debt that may be standing in their way.
Here are three tips to take control of credit card debt and move closer to your dreams.
Understand Your Credit Score
Don’t just grab the free credit reports and memorize your credit score. Try to understand why your credit score is what it is and improve it. Traditionally, credit scores are divided into five components: payment history (35%), amounts owed (30%), length of credit history (15%), new credit (10%), and credit mix (10%).
Find out your grade for each piece of your credit score and determine the best ways to increase your score in the shortest amount of time. Most FICO scores range from 300 to 850, and the highest scores get access to the best rates for homes and cars.
Don’t Become a Credit Card Junkie
If you can’t control your credit card spending habits, leave the cards at home. Discipline is a key component to achieving your dreams. Don’t spend more money on a credit card than you have available. If you do use your credit card for an emergency, make sure you have a reliable action plan to pay it off before the interest payments get out of control.
Talk to a financial coach as soon as possible to help you create a game plan that will save you tons of money. “Working with a financial coach is the smartest move you can make to avoid wasting time and money on credit card debt,” says Jeff Wilson II, author of The Lies Our Parents Were Sold and Told Us and principal CPA at The W2 Group accounting firm. “Those who wait to take action end up in a cycle of debt that starts to control every aspect of their lives.”
Pay Balances in Full
Don’t fall for the minimum balance trick. Paying a minimum amount sounds very enticing but doing so will extend the length of your credit card payments. You don’t want to be paying the same credit card balance for more than 10 years because of interest accumulation!
Be financially responsible and pay your balances in full. If a monthly payment system is too much for you to handle, start paying your credit card bill weekly to make it more manageable.
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