Though the current project started as a series of posts charting my grief journey after the death of my mother, I am no longer actively grieving. Now, the blog charts a conversation in living, mainly whatever I want it to be. This is an activity that goes well with the theme of this blog (updated 2018). The Sense of Doubt blog is dedicated to my motto: EMBRACE UNCERTAINTY. I promote questioning everything because just when I think I know something is concrete, I find out that it’s not.
Hey, Mom! The Explanation.
Here's the permanent dedicated link to my first Hey, Mom! post and the explanation of the feature it contains.
Hey, Mom! Talking to My Mother #1195 (SoD #1878) - THROWBACK THURSDAY from 1964 with spectacles FOR 2004.09 and the Weekly Hodge Podge
Hey, Mom! Talking to My Mother #1195 (SoD #1878) - THROWBACK THURSDAY from 1964 with spectacles FOR 2004.09 and the Weekly Hodge Podge
Hi Mom,
I have not written to you in a while. My last HEY MOM was back on 2002.28 (February 28th, 2020 for those who do not understand my star date form).
I decided to make this big Throwback and hodge podge dedicated to writing to you. I have been thinking about you a lot lately, Mom. I am glad you are not here for this pandemic. I would be so worried about you. Mostly, I have been thinking about you as I walk the dogs. We used to take so many walks together. You were such a go-go-go trooper before the meningitis, hauling up and down suburban streets. I miss those walks with you, Mom.
I was told today -- as of when I write it's 2004.07 -- that according to FOX News, 98.6% of infected people recover from COVID-19, here's my response:
Lastly, though we watch a lot of CNN, we look at a variety of news networks, including a little Fox for comparison and fairness. The "doom and gloom" is not unwarranted. This pandemic could go on much longer and kill more people than the "good" projections favored by the president. I agree that 100K dying would be a good outcome versus 2.4 million or more. However, Fox News denied a pandemic was coming and claimed it was contained and under control in the US just a month ago. I do not find their coverage to be accurate on anything that would impact opinion of the current hegemony. Also, that statistic about 98.6% recovered is just not accurate. Just do the math. 11K have died in the US as of today. We know of 378K cases, though testing is inadequate so there's likely more infected than that. If 98.6% recover, then the deaths out of 378K would be 1.4%. 11K is not 1.4% of 378K. it's 2.9%. The doom and gloom is very real ...
"There is an increasing probability of a full-blown COVID-19 pandemic that could infect as many as 100 million Americans, with a loss of life of as many as 1-2 million souls," trade adviser Peter Navarro warned in a memo to President Donald Trump way back on February 23. The next morning, Trump told Americans "the coronavirus is very much under control in the USA."
Navarro's February memo followed up on one from January 29. In the earlier memo, Navarro wrote that the economic cost of doing nothing could be as high as $5.7 trillion and suggested that more than half a million Americans could be killed by COVID-19.
A little more than a week after this memo, the Trump administration gave "nearly 18 tons of donated respirator masks, surgical masks, gowns and other medical supplies to China." And throughout the next few weeks, Trump continued to downplay the seriousness of the COVID-19 threat.
Navarro was persistent. In his February memo, he expressed an urgent need for at least $3 billion in appropriations to help prevent, contain, and treat the coronavirus. He said now was not the time to be worried about costs but to start stocking up on ventilators, personal protective equipment for health care providers, and other pandemic-related supplies.
"We can expect to need at least a billion face masks, 200,000 Tyvek suits, and 11,000 ventilator circuits, and 25,000 PAPRs (powered air-purifying respirators)," Navarro wrote.
TRUMP keeps claiming that AMERICA HAS NEVER ramped up a response as massive and impressive as the one to respond to this virus. Um... did we forget WORLD WAR TWO? Well, I did not forget but Trump surely did.
As the globe confronts the coronavirus pandemic, one urgent problem is the shortage of key pieces of equipment, including high-quality masks, test kits and—perhaps most important of all—ventilators. It seems hundreds of thousands of lives might be saved, if only manufacturers could quickly ramp up the production of such equipment, perhaps by a factor of 100 or 1,000, within a few weeks.
The United States has done something similar, on a nationwide scale, once before—eight decades ago during the emergency of World War II. At that time, there was a desperate need to radically accelerate the output of items such as ships, tanks and bombers. With decisive government action, including taking a little bit of control from corporations, this effort was hugely successful.
Certainly nobody likes having the family car put up on blocks for the duration of the war. Pleasure drives in the countryside were more or less outlawed. The government wanted the rubber from your tires. You weren’t going to be able to get gas. What’s a better sign of American prosperity than the family car? That’s the first thing you had to sacrifice in World War II. By and large, most Americans went through with that. Did they grumble? Certainly. If you look at the ration system, you had to make decisions like, “Do I want to have a pound of ground meat or do I want a jar of cheese spread?” We didn’t have enough sugar or butter or lard, because they were used to make explosives. But people understood that. It’s an intellectual proposition, but that’s not to say it made anybody happy. Workers weren’t happy about wage controls. Businesses weren’t happy about price controls. Landlords weren’t happy about rent controls. It’s a big country, so there’s always going to be anomalies, but most Americans realized these things were probably necessary for the war effort and were willing to go along. this one, too.... What World War II CanTeach Us About Fighting the Coronavirus
Some
manufacturers are racing to make ventilators, respirators, and face shields.
But the situation is nothing like it was in the 1940s.
During World War II, the US government paid to build plants, owned them, hired companies to use them, and bought all the output. That allowed companies to expand their footprint without worrying about a return on their investment, and ensured that the government got what it needed, when it needed it. That’s how road-building company Brown & Root ended up with a $90 million Naval Air Station in Corpus Christi, Texas, and how Ford got the mile-long assembly line at the Willow Run bomber plant.
This effort “was really at the core of US mobilization,” says Wilson. Instead of waiting for corporate executives to decide if a plant made financial sense, “the government just threw money at the problem and said, ‘Don’t worry about that, we’ll absorb the risk.’”
The economics aren’t as clear for companies enlisting in the fight against the coronavirus. “We haven't talked to anybody about any kind of reimbursement or anything like that,” Bill Ford told CNBC. But it’s hard to imagine any company launching a large-scale effort to boost production of ventilators or other products without considering how it will recover the costs. During the war, the feds made helping out rather tempting, promising its business partners profit margins of 8 percent, says Citino of the World War II museum. It wasn’t just patriotism that won the war, an old joke went—it was patriotism and that 8 percent.
The key to winning a global fight—in the 1940s and maybe today too—was finding the right incentives to push every needed effort in the right direction, Citino adds: “You get to do good and do well at the same time.”
This is difficult to define. What constitutes an album that is not mentioned often? Where? By whom?
Does Exile on Main Street (best cover ever?) count or is that mentioned too much? What about The Rise and Fall of Ziggy Stardust and the Spider From Mars?
I liked this guy's answer:
Thanks for the question Phil, I’ll do my best to list albums that not only are “hardly ever mentioned” but albums that are almost never mentioned. You can find the albums so I’ll just do a song off each.
First, Julian Cope with “World Shut Your Mouth” and “My Nation Underground” We’ll do the title tracks.
His Teardrop Explodes albums should also be mentioned once in a while.
Bauhaus “The Sky’s Gone Out” Let’s do “In The Night”
Robyn Hitchcock And The Egyptians “Perspex Island” An album that defies description other than to say it’s classic Robyn, this is “Oceanside.”
James Gang“Miami”
Recorded before Tommy Bolin left James Gang to join Deep Purple this album never gets mentioned.
That’s a special three track binge. “Cruisin’ Down The Highway” “Do It (The Way You Do It)” “Wildfire”
Ya’ know, I’m going through racks of CD’s, seeing so many albums that are mentioned quite frequently and I finally found an album and a band I like that NEVER gets mentioned here on quora. Maybe it’s just me that likes it but this album is noisy, clever, and seemingly unknown. (although I know it really isn’t)
I’m talking about The Screaming Blue Messiahs“Bikini Red” check out two tracks, “Jesus Chrysler Drives A Dodge” and “I Can Speak American”
I won’t post “I Wanna Be A Flintstone” but damn, that’s kinda fun!
Jazz Butcher “Bloody Nonsense” I’ll do “Jazz Butcher vs Prime Minister” and “Drink”
I guess that’s plenty, I could keep going through these racks all day but I won’t.
Everything is so dark, but the internet -- for all its bad and broken parts -- is helping to keep us together in a way that has never happened before, writes Joshua Topolsky in an essay on Input Mag. Two excerpts from the essay:What the hell would we do right now without the internet? How would so many of us work, stay connected, stay informed, stay entertained? For all of its failings and flops, all of its breeches and blunders, the internet has become the digital town square that we always believed it could and should be. At a time when politicians and many corporations have exhibited the worst instincts, we're seeing some of the best of what humanity has to offer -- and we're seeing it because the internet exists.
I was 12 the first time I logged onto whatever was called the internet then. There were no websites to speak of, not really. No ecommerce, no banner ads, no data tracking, no spyware. iPhones hadn't been invented yet; we called apps "programs"; and I had an EGA monitor on my PC (a whole 16 colors of range). But the first time I telnetted into a chatroom about raves, made new friends in Australia, or downloaded files to load into a music tracker, I felt the same elation that I feel now. This force, propelled by people, connected by copper and light, letting us make new connections. Connections we need now more than ever. We're here together, for how long we don't know. But we're not alone. Not anymore.
A New York Times analysis of internet usage in the United States from SimilarWeb and Apptopia, two online data providers, reveals that our behaviors shifted, sometimes starkly, as the virus spread and pushed us to our devices for work, play and connecting. From the report:With nearly all public gatherings called off, Americans are seeking out entertainment on streaming services like Netflix and YouTube, and looking to connect with one another on social media outlets like Facebook. In the past few years, users of these services were increasingly moving to their smartphones, creating an industrywide focus on mobile. Now that we are spending our days at home, with computers close at hand, Americans appear to be remembering how unpleasant it can be to squint at those little phone screens.
Facebook, Netflix and YouTube have all seen user numbers on their phone apps stagnate or fall off as their websites have grown, the data from SimilarWeb and Apptopia indicates. While traditional social media sites have been growing, it seems that we want to do more than just connect through messaging and text -- we want to see one another. This has given a big boost to apps that used to linger in relative obscurity, like Google's video chatting application, Duo, and Houseparty, which allows groups of friends to join a single video chat and play games together
A dude told me I hacked like a girl. I told him if he popped shells a little faster, he could too. pic.twitter.com/PgiyYw41oo
"The Eclipse Foundation just released version 1.0 of an open-source alternative to Visual Studio Code called Eclipse Theia," reports SD Times:Theia is an extensible platform that allows developers to create multi-language cloud and desktop IDEs, allowing them to create entirely new developer experiences.
According to the Eclipse Foundation, the differences between Theia and Visual Studio Code are that Theia has a more modular architecture, Theia was designed from the ground to run on desktop and cloud, and Theia was developed under community-driven and vendor-neutral governance of the Eclipse Foundation. The Theia project was started by Ericsson and TypeFox in 2016, and since then it has become an integral part of cloud solutions globally. The project approached the Eclipse Foundation about becoming a potential host in 2019.
Early contributors to the project include ARM, Arduino, EclipseSource, Ericsson, Google Cloud, IBM, Red Hat, SAP, and TypeFox.
"We are thrilled to see Eclipse Theia deliver on its promise of providing a production-ready, vendor-neutral, and open source framework for creating custom and white-labeled developer products," announced Mike Milinkovich, the Eclipse Foundation's executive director. "Visual Studio Code is one of the world's most popular development environments. Not only does Theia allow developers to install and reuse VS Code extensions, it provides an extensible and adaptable platform that can be tailored to specific use cases, which is a huge benefit for any organization that wants to deliver a modern and professional development experience. Congratulations to all the Theia committers and contributors on achieving this milestone."
Posted by BeauHD from the practice-makes-perfect dept.
For a third time, SpaceX lost one of its Starship prototype spacecrafts during a pressure test at the company's test site in Boca Chica, Texas. Ars Technica reports:This week, SpaceX workers in South Texas loaded the third full-scale Starship prototype -- SN3 -- onto a test stand at the company's Boca Chica launch site. On Wednesday night, they pressure-tested the vehicle at ambient temperature with nitrogen, and SN3 performed fine. On Thursday night SpaceX began cryo-testing the vehicle, which means it was loaded again with nitrogen, but this time it was chilled to flight-like temperatures and put under flight-like pressures. Unfortunately, a little after 2am local time, SN3 failed and began to collapse on top of itself. It appeared as if the vehicle may have lost pressurization and become top-heavy. Multiple sources indicated that had these preliminary tests succeeded, SN3 would have attempted a 150-meter flight test as early as next Tuesday.SpaceX founder Elon Musk said on Twitter: "We will see what data review says in the morning, but this may have been a test configuration mistake." A testing issue would be good in the sense that it means the vehicle itself performed well, and the problem can be more easily addressed.
Posted by EditorDavid from the rest-of-the-story dept.
Thursday an Opinion piece in the Washington Post touted what the paper's own health policy reporter has described as "a conspiracy theory that has been repeatedly debunked by experts." That conspiracy theory argues that instead of originating in the wild, the COVID-19 virus somehow escaped from a research lab.
Now the fact-checking web site Snopes has also weighed in this week, pointing out that the lab nearest the Wuhan market hadn't even published any coronavirus-related research prior to the outbreak. Instead the nearest coronavirus-researching lab was about 7 miles away, a maximum security "biosafety level 4 (BSL-4) laboratory certified to handle the world's most deadly pathogens."A February 2020 document erroneously described by several media outlets as a "scientific study" provides the supposedly science-based evidence of a virus escaping from a lab. This paper, such as it is, merely highlights the close distance between the seafood market and the labs and falsely claimed to have identified instances in which viral agents had escaped from Wuhan biological laboratories in the past... While SARS viruses have escaped from a Beijing lab on at least four occasions, no such event has been documented in Wuhan.
The purported instances of pathogens leaking from Wuhan laboratories, according to this "study," came from a Chinese news report (that we believe, based on the similarity of the research described and people involved, to be reproduced here) that profiled a Wuhan Center for Disease Control and Prevention researcher named Tian Junhua. In 2012 and 2013, he captured and sampled nearly 10,000 bats in an effort to decode the evolutionary history of the hantavirus. In two instances, this researcher properly self-quarantined either after being bitten or urinated on by a potentially infected bat, he told reporters. These events, according to the 2013 study his research produced, occurred in the field and have nothing to do with either lab's ability to contain infective agents...
In sum, this paper -- which was first posted on and later deleted from the academic social networking website ResearchGate -- adds nothing but misinformation to the debate regarding the origins of the novel coronavirus and is not a real scientific study.
In February the Washington Post had quoted Vipin Narang, an associate professor at the Massachusetts Institute of Technology, as saying that it's "highly unlikely" the general population was exposed to a virus through an accident at a lab. "We don't have any evidence for that," said Narang, a political science professor with a background in chemical engineering.
Imagine all the people...
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In life, there are so many things that divide us. Religion, race, politics, social status and so much more....But today a global pandemic brings us all together as one.
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Over the next few months our health care system will be tested. Many lives will be lost. Health care providers will be under an incredible amount of stress to save thousands of people. But when times are as dark as they are today, nothing shines brighter than the human spirit.
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There is something beautiful about a collective struggle. And the beauty in what we are facing today is that the only way to overcome this pandemic is for us to all come together as one.
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Nurses, doctors, students, research scientists, politicians, Uber eats drivers, cashiers, factory workers etc.....Getting through this will be hard but one thing is certain...the only way we will get through it is together, as one
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“You might say that I’m a dreamer. But I’m not the only one. I hope some day that you will join us...and the world will live as one....”
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Thankful for my brother Dr. William Robinson on the piano
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Much love to all 7.53 billion people out there,
Doctor Elvis
In the video linked above, WIRED senior writers Adam Rogers and Lauren Goode unpack what’s going on with Covid-19 tests: how the tests work and the biochemical ingredients that are required in order for them to be effective; how murky bureaucratic issues and equipment shortages are contributing to the delays; and what the next phase of coronavirus testing might look like.
Calorie restriction increases life span
Why we need to restrict calories right now.
The former CIA contractor who exposed NSA surveillance programs, Edward Snowden, is especially concerned about the long-term implications of strengthening the national surveillance infrastructure. While some measures might help slow the transmission of COVID-19, they could also serve as stepping stones to a new normal of surveillance.
"Giving the government access to biometrics could open up alarming new ways for governments to spy on citizens, Snowden said. ‘They already know what you're looking at on the internet,’ he said. ‘They already know where your phone is moving. Now they know what your heart rate is, what your pulse is. What happens when they start to mix these and apply artificial intelligence to it?’ Snowden offered an example: A man in the U.S. watches a YouTube video of a federal official giving a speech. The speech angers him. His pulse and heart-rate shoot up, and this biometric data gets recorded by his smartphone. The government, using algorithms that compare biometrics with online activity and other data, puts this man on a watch-list for people deemed to be potential terrorists or other undesirables.”
Erykah Badu is finally getting to play her dream stage while under quarantine at her home in Dallas, Texas. She kicked off her “Quarantine Concert Series: Apocalypse One” two weeks ago, charging fans $1 per ticket to watch her and her band perform songs from her bedroom.
“I’m the laziest artist in the world. My dream was always to perform from my bed and guess what? It came through!” she quipped in an interview with Page Six.
Badu returns on Sunday with “Apocalypse Two: The Rooms,” where virtual concertgoers can pay $2 to stream Badu and the band performing from multiple rooms inside her home.
Erykah Badu charged fans just $1 to livestream a concert that she performed in her bedroom — with a band wearing surgical masks.
Her “Quarantine Concert Series: Apocalypse One” show — which will help support her band while their shows are indefinitely on hold — streamed on her BaduWorld Market site Monday night.
I’m currently working from Jeep in an empty parking lot because being trapped in a house with other people with no end in sight has pushed me to my limit and holy shit I’m suffocating. How’s your Friday going? pic.twitter.com/UaUqFx7M6a
[Editor’s Note: This guide was first published on January 24, 2017. We are featuring it again to honor John Prine’s memory.]
When John Prine began his career in 1969, he was a 23 year-old mailman just home from a stint in the army as a mechanic in West Germany. After he moved back to his suburban Chicago hometown of Maywood, Illinois, he began writing simple three-chord folk songs about lonesome elderly couples (“Hello in There”), morphine-addicted veterans (“Sam Stone”), and the strip mining that destroyed his father’s Kentucky hometown (“Paradise”). Prine began playing open mics in Chicago folk clubs like the Fifth Peg and the Earl of Old Town, eventually earning a weekly residency, before being discovered one night by Kris Kristofferson. Within two years of stepping on a stage, Prine released a debut album for Atlantic Records, and the plainspoken Midwesterner was being hailed as the latest in a long line of “new Dylan”s.
Prine’s stint with Atlantic, however, lasted only four years and as many studio albums. Two years after releasing his final Atlantic album, 1975’s Common Sense, Prine signed a three-album deal with the more singer-songwriter-oriented Asylum Records, which would release his late ’70s masterpiece Bruised Orange in 1978. But Prine soon realized that he was not interested in being in a relationship with any sort of traditional label.
By 1981, immediately following his three Asylum albums, he’d founded his own label, Oh Boy Records, and by 1984 he was self-releasing full-length records by mail order. That way, as Prine explained at the time to Bobby Bare on The Nashville Network, “There ain’t no middleman… no swarthy little character in Cleveland that gets the money from the people that want the music, and then… takes most of it, twirls his mustache, and sends me 12 cents.”
Since founding Oh Boy, Prine has released a total of 14 albums, including some of the most renowned of his career: From his 1991 comeback album The Missing Years, to his 1999 country duets collection In Spite of Ourselves, to his most recent masterpiece, 2005’s Fair & Square. Almost all of Prine’s Oh Boy discography can be found on Bandcamp.
Photo by Kyle Dean Reinford
By the time he went out on his own in the ’80s, Prine had developed enough of a dedicated following to directly support his music—primarily, by buying tickets to his regularly sold-out theater shows around the country—without the financial backing of a label. As Prine put it in 1995, “I just didn’t want to continue recording unless it was in a manner that seemed to make more sense to what I actually did, which was pack my suitcase and go on the road for a living.”
Although Prine is still best known for the modern-day country-folk standards on his debut 1971 self-titled album, the latter half of his career is populated with exemplary moments of song craftsmanship every bit as moving and profound as “Angel From Montgomery” or “Sam Stone.”
Here are eight highlights from Prine’s Oh Boy collection.
Highlights on 1984’s Aimless Love, Prine’s Oh Boy debut, include the surrealist road trip travelogue “The Bottomless Lake” and “Unwed Fathers,” the story of a young mother roaming through a land of harsh judgment and sexist double standards. But the album’s emotional centerpiece is “Maureen, Maureen,” an understated account of a crumbling relationship told from the perspective of a troubled man who’s become increasingly, as he puts it, “nervous and mean.” “I may have lied to myself/But I tried to tell God how I love you,” Prine sings in the devastating second verse. “But even He don’t answer/ His phone anymore when I pray.”
“You come home straight and you come home curly,” Prine sings on his second Oh Boy LP. “Sometimes you don’t come home at all.” That line is from “Speed of the Sound of Loneliness,” an account of the dissolution of Prine’s second marriage and one of the most heartbreaking songs in his entire body of work. But “Speed of Sound” is the exception on German Afternoons, an otherwise up-tempo collection in which the singer-songwriter embraces his bluegrass and country influences more fully than ever before on fingerpicking Doc Watson-inspired rousers like “Lulu Walls,” “Out of Love,” and “Love, Love, Love.”
The Missing YearsJohn Prine
It took Prine five years to release his follow up to German Afternoons in 1991, his longest-ever break between albums to that point. A lot happened during that period: Prine divorced his second wife, met his third, and enlisted A-listers like Bruce Springsteen, Tom Petty, and Bonnie Raitt for his triumphant return on The Missing Years. Here, the Singing Mailman tackles divorce with empathy (“All the Best”), rewrites Jesus Christ’s biography (“Jesus, The Missing Years),” and contemplates life’s existential absurdities (“It’s a Big Old Goofy World”). Amidst all the highpoints, there’s no more heartwarming moment than “You Got Gold,” which finds Prine reveling in newfound love and pulling off the near-impossible: finding profundity in contentment, “Life is a blessin’,’” he sings, “It’s a delicatessen.”
“Lake Marie” and “Humidity Built the Snowman,” two of the most expertly-crafted songs of Prine’s career, can both be found on his 1995 album Lost Dogs & Mixed Blessings. But the followup to The Missing Years, which further expanded on the slick sound favored by producer Howie Epstein on The Missing years, suffocates its most poignant moments in chaotic overproduction. Prine’s subsequent 1997 Live on Tour, however, presents definitive versions of both latter-day gems. In concert, the twisted three-act noir epic of “Lake Marie” is the singer-songwriter’s frequent showstopper, culminating in several minutes of a fierce, single-chord guitar solo. This 1997 version does the epic justice.
A still image from a simulation of the formation of dark matter structures from the early universe until today. Gravity makes dark matter clump into dense halos, indicated by bright patches, where galaxies form. In this simulation, a halo like the one that hosts the Milky Way forms, and a smaller halo resembling the Large Magellanic Cloud falls toward it. SLAC and Stanford researchers, working with collaborators from the Dark Energy Survey, have used simulations like these to better understand the connection between dark matter and galaxy formation. Credit: Ralf Kaehler/SLAC National Accelerator Laboratory
Just as the sun has planets and the planets have moons, our galaxy has satellite galaxies, and some of those might have smaller satellite galaxies of their own. To wit, the Large Magellanic Cloud (LMC), a relatively large satellite galaxy visible from the Southern Hemisphere, is thought to have brought at least six of its own satellite galaxies with it when it first approached the Milky Way, based on recent measurements from the European Space Agency's Gaia mission.
Astrophysicists believe that dark matter is responsible for much of that structure, and now researchers at the Department of Energy's SLAC National Accelerator Laboratory and the Dark Energy Survey have drawn on observations of faint galaxies around the Milky Way to place tighter constraints on the connection between the size and structure of galaxies and the dark matter halos that surround them. At the same time, they have found more evidence for the existence of LMC satellite galaxies and made a new prediction: If the scientists' models are correct, the Milky Way should have an additional 150 or more very faint satellite galaxies awaiting discovery by next-generation projects such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time.
The new study, forthcoming in the Astrophysical Journal and available as a preprint here, is part of a larger effort to understand how dark matter works on scales smaller than our galaxy, said Ethan Nadler, the study's first author and a graduate student at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) and Stanford University.
"We know some things about dark matter very well—how much dark matter is there, how does it cluster—but all of these statements are qualified by saying, yes, that is how it behaves on scales larger than the size of our local group of galaxies," Nadler said. "And then the question is, does that work on the smallest scales we can measure?"
Shining galaxies' light on dark matter
Astronomers have long known the Milky Way has satellite galaxies, including the Large Magellanic Cloud, which can be seen by the naked eye from the Southern Hemisphere, but the number was thought to be around just a dozen or so until around the year 2000. Since then, the number of observed satellite galaxies has risen dramatically. Thanks to the Sloan Digital Sky Survey and more recent discoveries by projects including the Dark Energy Survey (DES), the number of known satellite galaxies has climbed to about 60.
Such discoveries are always exciting, but what's perhaps most exciting is what the data could tell us about the cosmos. "For the first time, we can look for these satellite galaxies across about three-quarters of the sky, and that's really important to several different ways of learning about dark matter and galaxy formation," said Risa Wechsler, director of KIPAC. Last year, for example, Wechsler, Nadler and colleagues used data on satellite galaxies in conjunction with computer simulations to place much tighter limits on dark matter's interactions with ordinary matter.
Now, Wechsler, Nadler and the DES team are using data from a comprehensive search over most of the sky to ask different questions, including how much dark matter it takes to form a galaxy, how many satellite galaxies we should expect to find around the Milky Way and whether galaxies can bring their own satellites into orbit around our own—a key prediction of the most popular model of dark matter.
Hints of galactic hierarchy
The answer to that last question appears to be a resounding "yes."
The possibility of detecting a hierarchy of satellite galaxies first arose some years back when DES detected more satellite galaxies in the vicinity of the Large Magellanic Cloud than they would have expected if those satellites were randomly distributed throughout the sky. Those observations are particularly interesting, Nadler said, in light of the Gaia measurements, which indicated that six of these satellite galaxies fell into the Milky Way with the LMC.
To study the LMC's satellites more thoroughly, Nadler and team analyzed computer simulations of millions of possible universes. Those simulations, originally run by Yao-Yuan Mao, a former graduate student of Wechsler's who is now at Rutgers University, model the formation of dark matter structure that permeates the Milky Way, including details such as smaller dark matter clumps within the Milky Way that are expected to host satellite galaxies. To connect dark matter to galaxy formation, the researchers used a flexible model that allows them to account for uncertainties in the current understanding of galaxy formation, including the relationship between galaxies' brightness and the mass of dark matter clumps within which they form.
An effort led by the others in the DES team, including former KIPAC students Alex Drlica-Wagner, a Wilson Fellow at Fermilab and an assistant professor of astronomy and astrophysics at the University of Chicago, and Keith Bechtol, an assistant professor of physics at the University of Wisconsin-Madison, and their collaborators produced the crucial final step: a model of which satellite galaxies are most likely to be seen by current surveys, given where they are in the sky as well as their brightness, size and distance.
Those components in hand, the team ran their model with a wide range of parameters and searched for simulations in which LMC-like objects fell into the gravitational pull of a Milky Way-like galaxy. By comparing those cases with galactic observations, they could infer a range of astrophysical parameters, including how many satellite galaxies should have tagged along with the LMC. The results, Nadler said, were consistent with Gaia observations: Six satellite galaxies should currently be detected in the vicinity of the LMC, moving with roughly the right velocities and in roughly the same places as astronomers had previously observed. The simulations also suggested that the LMC first approached the Milky Way about 2.2 billion years ago, consistent with high-precision measurements of the motion of the LMC from the Hubble Space Telescope.
Galaxies yet unseen
In addition to the LMC findings, the team also put limits on the connection between dark matter halos and galaxy structure. For example, in simulations that most closely matched the history of the Milky Way and the LMC, the smallest galaxies astronomers could currently observe should have stars with a combined mass of around a hundred suns, and about a million times as much dark matter. According to an extrapolation of the model, the faintest galaxies that could ever be observed could form in halos up to a hundred times less massive than that.
And there could be more discoveries to come: If the simulations are correct, Nadler said, there are around 100 more satellite galaxies—more than double the number already discovered—hovering around the Milky Way. The discovery of those galaxies would help confirm the researchers' model of the links between dark matter and galaxy formation, he said, and likely place tighter constraints on the nature of dark matter itself.
The research was a collaborative effort within the Dark Energy Survey, led by the Milky Way Working Group, with substantial contributions from junior members including Sidney Mau, an undergraduate at the University of Chicago, and Mitch McNanna, a graduate student at UW-Madison. The research was supported by a National Science Foundation Graduate Fellowship, by the Department of Energy's Office of Science through SLAC, and by Stanford University.
Another example of success: New Zealand - national lockdown and immediate mass testing. They have had just 1 death, and have patients recovering faster than adding cases. https://t.co/9070Ci9NpN
- Bloggery committed by chris tower - 2004.09 - 10:10
NEW (written 1708.27 and 1907.04) NOTE on time: I am now in the same time zone as Google! So, when I post at 10:10 a.m. PDT to coincide with the time of your death, Mom, I am now actually posting late, so it's really 1:10 p.m. EDT. But I will continue to use the time stamp of 10:10 a.m. to remember the time of your death, Mom. I know this only matters to me, and to you, Mom. Dropped "Talk to you tomorrow, Mom" in the sign off on 1907.04. Should have done it sooner as this feature is no longer daily.
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