Slashdot reader the_newsbeagle writes: At the beginning of the pandemic, modelers pulled out everything they had to predict the spread of the virus. This article explains the three main types of models used: 1) compartmental models that sort people into categories of exposure and recovery, 2) data-driven models that often use neural networks to make predictions, and 3) agent-based models that are something like a Sim Pandemic.
"Researchers say they've learned a lot of lessons modeling this pandemic, lessons that will carry over to the next..." the article points out: Finally, researchers emphasize the need for agility. Jarad Niemi, an associate professor of statistics at Iowa State University who helps run the forecast hub used by the CDC, says software packages have made it easier to build models quickly, and the code-sharing site GitHub lets people share and compare their models. COVID-19 is giving modelers a chance to try out all their newest tools, says biologist Lauren Ancel Meyers, the head of the COVID-19 Modeling Consortium at the University of Texas at Austin. "The pace of innovation, the pace of development, is unlike ever before," she says. "There are new statistical methods, new kinds of data, new model structures."

"If we want to beat this virus," says Mikhail Prokopenko, a computer scientist at the University of Sydney, "we have to be as adaptive as it is."

University of Queensland student Germain Tobar who worked with UQ physics professor Fabio Costa on a new peer-reviewed paper "says he has mathematically proven the physical feasibility of a specific kind of time travel" without paradoxes, reports Popular Mechanics: Time travel discussion focuses on closed time-like curves, something Albert Einstein first posited. And Tobar and Costa say that as long as just two pieces of an entire scenario within a closed time-like curve are still in "causal order" when you leave, the rest is subject to local free will... In a university statement, Costa illustrates the science with an analogy


"Say you travelled in time, in an attempt to stop COVID-19's patient zero from being exposed to the virus. However if you stopped that individual from becoming infected, that would eliminate the motivation for you to go back and stop the pandemic in the first place. This is a paradox, an inconsistency that often leads people to think that time travel cannot occur in our universe. [L]ogically it's hard to accept because that would affect our freedom to make any arbitrary action. It would mean you can time travel, but you cannot do anything that would cause a paradox to occur...."


But the real truth, in terms of the mathematical outcomes, is more like another classic parable: the monkey's paw. Be careful what you wish for, and be careful what you time travel for. Tobar explains in the statement:


"In the coronavirus patient zero example, you might try and stop patient zero from becoming infected, but in doing so you would catch the virus and become patient zero, or someone else would. No matter what you did, the salient events would just recalibrate around you. Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency."

Researchers will be able to gain a deeper understanding of what's considered the world's oldest surviving (digital) computer after its long-lost user manual was unearthed. Engadget reports: The Z4, which was built in 1945, runs on tape, takes up most of a room and needs several people to operate it. The machine now takes residence at the Deutsches Museum in Munich, but it hasn't been used in quite some time. An archivist at ETH Zurich, Evelyn Boesch, discovered the manual among her father's documents in March, according to retired lecturer Herbert Bruderer. Rene Boesch worked with the Swiss Aeronautical Engineering Association, which was based at the university's Institute for Aircraft Statics and Aircraft Construction. The Z4 was housed there in the early 1950s.

Among Boesch's documents were notes on math problems the Z4 solved that were linked to the development of the P-16 jet fighter. "These included calculations on the trajectory of rockets, on aircraft wings, on flutter vibrations [and] on nosedive," Bruderer wrote in a Association of Computing Machinery blog post.

Slashdot has featured "the 61 books Elon Musk has recommended on Twitter" as well as the 41 books Mark Zuckerberg recommended on Facebook. Both lists were compiled by a slick web site (with Amazon referrer codes) called "Most Recommended Books." But they've also created pages showing books recommended by over 400 other public figures — incuding Bill Gates and the late Steve Jobs — which provide surprisingly revealing glimpses into the minds of two very different men.

Here's some of the highlights...

Lanodonal writes: A mathematician who tamed a nightmarish family of equations that behave so badly they make no sense has won the most lucrative prize in academia. Martin Hairer, an Austrian-British researcher at Imperial College London, is the winner of the 2021 Breakthrough prize for mathematics, an annual $3m award that has come to rival the Nobels in terms of kudos and prestige. Hairer landed the prize for his work on stochastic analysis, a field that describes how random effects turn the maths of things like stirring a cup of tea, the growth of a forest fire, or the spread of a water droplet that has fallen on a tissue into a fiendishly complex problem. His major work, a 180-page treatise that introduced the world to "regularity structures," so stunned his colleagues that one suggested it must have been transmitted to Hairer by a more intelligent alien civilisation.

Hairer, who rents a London flat with his wife and fellow Imperial mathematician, Xue-Mei Li, heard he had won the prize in a Skype call while the UK was still in lockdown. "It was completely unexpected," he said. "I didn't think about it at all, so it was a complete shock. We couldn't go out or anything, so we celebrated at home." The award is one of several Breakthrough prizes announced each year by a foundation set up by the Israeli-Russian investor Yuri Milner and Facebook's Mark Zuckerberg. A committee of previous recipients chooses the winners who are all leading lights in mathematics and the sciences. Other winners announced on Thursday include a Hong Kong scientist, Dennis Lo, who was inspired by a 3D Harry Potter movie to develop a test for genetic mutations in DNA shed by unborn babies, and a team of physicists whose experiments revealed that if extra dimensions of reality exist, they are curled up smaller than a third of a hair's width.

NCamero (Slashdot reader #35,481) brings some news from the world of 12-sided dodecahedrons: Quanta magazine reports that a trio of mathematicians has resolved one of the most basic questions about the dodecahedron. The cube, tetrahedron, octahedron and icosahedron cannot have a straight path you could take [starting from a corner] that would eventually return you to your starting point without passing through any of the other corners. The dodecahedron can.
Mathematicians studied dodecahedrons for over 2,000 years without solving the problem, reports Quanta magazine. But now... Jayadev Athreya, David Aulicino and Patrick Hooper have shown that an infinite number of such paths do in fact exist on the dodecahedron. Their paper, published in May in Experimental Mathematics, shows that these paths can be divided into 31 natural families. The solution required modern techniques and computer algorithms.

"Twenty years ago, [this question] was absolutely out of reach; 10 years ago it would require an enormous effort of writing all necessary software, so only now all the factors came together," wrote Anton Zorich, of the Institute of Mathematics of Jussieu in Paris, in an email.

It took five decades, but the Democratic Party has finally changed its stance on nuclear energy. In its recently released party platform, the Democrats say they favor a "technology-neutral" approach that includes "all zero-carbon technologies, including hydroelectric power, geothermal, existing and advanced nuclear, and carbon capture and storage." Robert Bryce writes via Forbes: That statement marks the first time since 1972 that the Democratic Party has said anything positive in its platform about nuclear energy. The change in policy is good -- and long overdue -- news for the American nuclear-energy sector and for everyone concerned about climate change. The Democrats' new position means that for the first time since Richard Nixon was in the White House, both the Republican and Democratic parties are officially on record in support of nuclear energy. That's the good news.

About a decade ago, a high-ranking official at the Department of Energy told me that a big problem with nuclear energy is that it needs bipartisan support in Congress. That wasn't happening, he said, because "Democrats are pro-government and anti-nuclear. Republicans are pro-nuclear and anti-government." That partisan divide is apparent in the polling data. A 2019 Gallup poll found that 65 percent of Republicans strongly favored nuclear energy but only 42 percent of Democrats did so. The last time the Democratic Party's platform contained a positive statement about nuclear energy was in 1972, when the party said it supported "greater research and development" into "unconventional energy sources" including solar, geothermal, and "a variety of nuclear power possibilities to design clean breeder fission and fusion techniques."

Since then, the Democratic Party has either ignored or professed outright opposition to nuclear energy. In 2016, the party's platform said climate change "poses a real and urgent threat to our economy, our national security, and our children's health and futures." The platform contained 31 uses of the word "nuclear" including "nuclear proliferation," "nuclear weapon," and "nuclear annihilation." It did not contain a single mention of "nuclear energy." That stance reflected the orthodoxy of the climate activists and environmental groups who have dominated the Democratic Party's discussion on energy for decades. What changed the Democrats' stance on nuclear? I cannot claim any special knowledge about the drafting of the platform, but it appears that science and basic math finally won out. While vying for their party's nomination, two prominent Democratic presidential hopefuls -- Cory Booker and Andrew Yang -- both endorsed nuclear energy. In addition, Joe Biden's energy plan included a shout-out to nuclear.

A decimal point error at e-commerce site Etsy briefly caused the company to overcharge for shipping labels by thousands of dollars. PCMag reports: Etsy sellers took to social media on Monday to notify the company about the problem. Apparently, the e-commerce site's accounting system failed to notice the decimal point when charging for the total cost for shipping labels. As a result, one merchant who thought they were paying $11.64 for postage ended up being billed $1,164. In other cases, the glitch caused Etsy to accidentally empty bank accounts.

"I just lost $11k. Emptied my Etsy account, drained my bank account, maxxed out my overdraft protection, and maxxed out my credit card.... all for what should have been $110 in labels," tweeted one seller. "Do not ship through Etsy," wrote another seller. "Right now they are charging you $350 for $3.50 shipping labels, their system is fucking up a decimal." The glitch also caused many merchants to stop sending out packages with labels printed from Etsy, which has over 2.8 million active sellers. Fortunately, the company began fixing the problem last night. "This issue has now been resolved and we have credited impacted sellers for the incorrect fees," the company said in a customer support ticket. "Accurate charges are now reflected in affected sellers' payment accounts. For the small group of sellers that were autobilled, we have refunded any resulting card charges."

Sphere packing might seem like a topic only a mathematician could love. Who else could get excited about finding the most efficient way to arrange circles in the plane, or spheres in space? But right now, millions of people all over the world are thinking about this very problem. From a report: Determining how to safely reopen buildings and public spaces under social distancing is in part an exercise in geometry: If each person must keep six feet away from everyone else, then figuring out how many people can sit in a classroom or a dining room is a question about packing non-overlapping circles into floor plans. Of course there's a lot more to confronting COVID than just this geometry problem. But circle and sphere packing plays a part, just as it does in modeling crystal structures in chemistry and abstract message spaces in information theory.

It's a simple-sounding problem that's occupied some of history's greatest mathematicians, and exciting research is still happening today, particularly in higher dimensions. For example, mathematicians recently proved the best way to pack spheres into 8- and 24-dimensional space -- a technique essential for optimizing the error-correcting codes used in cell phones or for communication with space probes. So let's take a look at some of the surprising complications that arise when we try to pack space with our simplest shape. If your job involves packing oranges in a box or safely seating students under social distancing, the size and shape of your container is a crucial component of the problem. But for most mathematicians, the theory of sphere packing is about filling all of space. In two dimensions, this means covering the plane with same-size circles that don't overlap.

The American Mathematical Society has announced the passing of Ronald Graham, "one of the principal architects of the rapid development worldwide of discrete mathematics in recent years." He died July 6th at the age of 84. From the report: Graham published more than 350 papers and books with many collaborators, including more than 90 with his wife, Fan Chung, and more than 30 with Paul Erdos. In addition to writing articles with Paul Erdos, Graham had a room in his house reserved for Erdos's frequent visits, he administered the cash prizes that Erdos created for various problems, and he created the Erdos number, which is the collaboration distance between a mathematician and Erdo's. He also created Graham's number in a 1971 paper on Ramsey theory written with Bruce Rothschild, which was for a time the largest number used in a proof.

Graham received his PhD from the University of California, Berkeley in 1962 under the direction of D.H. Lehmer. He worked at Bell Laboratories until 1999, starting as director of information sciences and ending his tenure there as chief scientist. Graham then joined the faculty at the University of California, San Diego and later became chief scientist at the California Institute for Telecommunications and Information Technology, a joint operation between the university and the University of California, Irvine. [...] Graham was an AMS member since 1961. For more information, see his "special page," these video interviews by the Simons Foundation, an audio interview about the mathematics of juggling, and his page at the MacTutor website. Graham's most recent appearance on Slashdot was in 2016, when a trio of researchers used a supercomputer to generate the largest math proof ever at 200 terabytes in size. The math problem was named the boolean Pythagorean Triples problem and was first proposed back in the 1980's by mathematician Ronald Graham.

Forbes reports on ThreeFold, an ambitious new "long-term project to rewire the internet in the image of its first incarnation: decentralized, unowned, accessible, free." "We have 18,000 CPU cores and 90 million gigabytes, which is a lot of capacity," founder Kristof de Spiegeleer told me recently on the TechFirst podcast. "It's probably between five and ten times more than all of the capacity of all the blockchain projects together..."

"It's a movement," de Spiegeleer says about ThreeFold. "It's where we invite a lot of people to...basically help us to build a new internet. Now it sounds a little bit weird building a new internet. We're not trying to replace the cables... what we need help with is that we get more compute and storage capacity close to us." That would be a fundamentally different kind of internet: one we all collectively own rather than just one we all just use.

It requires a lot of different technology for backups and storage, for which ThreeFold is building a variety of related technologies: peer-to-peer technology to create the grid in the first place; storage, compute, and network technologies to enable distributed applications; and a self-healing layer bridging people and applications. Oh, and yes. There is a blockchain component: smart contracts for utilizing the grid and keeping a record of activities. "Farmers" (read: all of us) provide capacity and get micropayments for usage.

So instead of a Bitcoin scenario where some of the fastest computers in the world waste country-scale amounts of electricity doing arcane math to create an imaginary currency with dubious value (apologies, are my biases showing?) you have people providing actual tangible services for others in exchange for some degree of cryptocurrency reward. Which, in my (very) humble opinion, offers a lot more social utility...

ThreeFold and partners have invested more than $40 million in make it happen, de Spiegeleer says, and there are more than 30 partners working on the project or onboarding shortly. "So it's happening," he says.
In the interview, de Spiegeleer points out 80% of current internet capacity is owned by less than 20 companies, arguing on the podcast that "It really needs to be something like electricity.

"It needs to be everywhere and everyone needs to have access to it. It needs to be cost effective, it needs to be reliable, it needs to be independent..."

Representation theory was initially dismissed. Today, it's central to much of mathematics. From a report: When representation theory emerged in the late 19th century, many mathematicians questioned its worth. In 1897, the English mathematician William Burnside wrote that he doubted that this unorthodox perspective would yield any new results at all. "Basically what [Burnside was] saying is that representation theory is useless," said Geordie Williamson of the University of Sydney in a 2015 lecture. More than a century since its debut, representation theory has served as a key ingredient in many of the most important discoveries in mathematics. Yet its usefulness is still hard to perceive at first. "It doesn't seem immediately clear that this is a reasonable thing to study," said Emily Norton of the Technical University of Kaiserslautern in Germany.

Representation theory is a way of taking complicated objects and "representing" them with simpler objects. The complicated objects are often collections of mathematical objects -- like numbers or symmetries -- that stand in a particular structured relationship with each other. These collections are called groups. The simpler objects are arrays of numbers called matrices, the core element of linear algebra. While groups are abstract and often difficult to get a handle on, matrices and linear algebra are elementary. "Mathematicians basically know everything there is to know about matrices. It's one of the few subjects of math that's thoroughly well understood," said Jared Weinstein of Boston University.

"This spring, America took an involuntary crash course in remote learning," writes the Wall Street Journal, noting it affected 50 million students from kindergarten through 12th grade.

"With the school year now winding down, the grades from students, teachers, parents and administrators is already in: It was a failure..." The problems began piling up almost immediately... Soon many districts weren't requiring students to do any work at all, increasing the risk that millions of students would have big gaps in their learning... Preliminary research suggests students nationwide will return to school in the fall with roughly 70% of learning gains in reading relative to a typical school year, and less than 50% in math, according to projections by NWEA, an Oregon-based nonprofit that provides research to help educators tailor instruction. It expects a greater learning loss for minority and low-income children who have less access to technology, and for families more affected by the economic downturn.... About 9.7 million students aren't connected to the internet, according to an estimate by the EducationSuperHighway, a nonprofit focused on connectivity in public schools. [The national average for unconnected students is 20%] "As a nation, we were not prepared to take learning online," said founder and CEO Evan Marwell...

School districts didn't realize the number of students without access to devices and the internet until they surveyed parents. Districts that could afford to do so hurried to buy the technology needed to get students online. Some, such as those in Austin and Belleville, Illinois, put Wi-Fi wired buses in parking lots for students to connect from their parents' cars. Many districts prepared printed packets of work for students without online access, which were handed out in food drive-through lines at schools....

Remote learning has turned the simple task of taking attendance into a challenge. Many count students as present if they log in to do work in programs like Google Classroom, an online classroom manager. Some give attendance credit for weekly progress on completed work, while others allow parents to call in to vouch for their children. Some districts aren't bothering with attendance at all. Those that have been able to track attendance say it has been below regular levels. Some students have simply gone missing. Early into the shutdown, the Los Angeles Unified School District estimated that on any given day in a week span, 32% of high-school students didn't log in to learn.

"Having re-open-sourced MS-DOS on GitHub in 2018, Microsoft has now released the source code for GW-BASIC, Microsoft's 1983 BASIC interpreter," reports ZDNet, adding that GW-BASIC "can trace its roots back to Bill Gates' and Paul Allen's implementation of Microsoft's first product, the BASIC interpreter for the Altair 8800 computer."

"Interested to look at thousands of lines of glorious 8088 assembly code for the original 1983 GW-BASIC...?" writes Slashdot reader sonofusion82, adding "there are not Makefiles or build scripts, just a bunch of 8088 ASM files."

Or as Hackaday jokes, "Microsoft releases the source code you wanted almost 30 years ago." In the late 1970s and early 1980s, if you had a personal computer there was a fair chance it either booted into some version of Microsoft Basic or you could load and run Basic... Now you can get the once-coveted Microsoft Basic source code...

They put up a read only GW-BASIC repository, presumably to stop a flood of feature requests for GPU acceleration...

From what we understand, GW-Basic was identical to IBM's BASICA, but didn't require certain IBM PC ROMs to operate. Of course, BASICA, itself, came from MBASIC, Microsoft's CP/M language that originated with Altair Basic... We did enjoy the 1975 copyright message, though:

ORIGINALLY WRITTEN ON THE PDP-10 FROM FEBRUARY 9 TO APRIL 9 1975

BILL GATES WROTE A LOT OF STUFF.
PAUL ALLEN WROTE A LOT OF OTHER STUFF AND FAST CODE.
MONTE DAVIDOFF WROTE THE MATH PACKAGE (F4I.MAC).
Bill Gates was 19 years old, Paul Allen was 22.

Yes, economist Tyler Cowen and former world chess champion Garry Kasparov (now the chairman of the nonprofit Renew Democracy Initiative) co-authored an opinion piece this week arguing that Covid-19 "is illustrating that some aspects of a Universal Basic Income may be more necessary and more workable than previously thought. But there is one big piece missing: The economic output required to pay for such policies."

Their suggestion is to boost "abilities to succeed with major projects" and "to invest ambitiously in innovation." And TechCrunch recently hinted at one very specific suggestion. "If policymakers want to do more than just keep the floor from falling out and start laying the groundwork for an actual recovery, then they ought to be discussing a different UBI as well: Universal Basic Internet." The government has delegated providing access to internet to the private sector for far too long. Only the "more prosperous" have been able to enjoy the full benefits of high-speed internet...

[T]he math makes clear that closing the digital divide will generate a digital dividend. There's no easy to way to measure the impact of broadband access on the economy, but several studies indicate that this is exactly the sort of investment we should make in a time of crisis: some have estimated that doubling broadband speeds adds around 0.3% to GDP growth; others forecast that every broadband-related job generates between 2.5 and 4.0 additional jobs; and, yet another study determined that a 10 percentage point increase in broadband access could increase GDP per capita by $13,036. Simply put, there's a high ROI — return on internet — associated with increasing broadband access.
The article points out that somewhere between 23% and 28% of Americans currently don't have broadband internet access. And it also suggests "trainers to increase digital literacy around the nation.

"This approach to closing the digital divide will go a long way in helping the nation recover from the COVID collapse."

Electric car maker Tesla plans to introduce a new low-cost, long-life battery in its Model 3 sedan in China later this year or early next that it expects will bring the cost of electric vehicles in line with gasoline models, and allow EV batteries to have second and third lives in the electric power grid. Reuters reports: For months, Tesla Chief Executive Elon Musk has been teasing investors, and rivals, with promises to reveal significant advances in battery technology during a "Battery Day" in late May. New, low-cost batteries designed to last for a million miles of use and enable electric Teslas to sell profitably for the same price or less than a gasoline vehicle are just part of Musk's agenda.

With a global fleet of more than 1 million electric vehicles that are capable of connecting to and sharing power with the grid, Tesla's goal is to achieve the status of a power company, competing with such traditional energy providers as Pacific Gas & Electric and Tokyo Electric Power. The new "million mile" battery at the center of Tesla's strategy was jointly developed with China's Contemporary Amperex Technology Ltd and deploys technology developed by Tesla in collaboration with a team of academic battery experts recruited by Musk. Eventually, improved versions of the battery, with greater energy density and storage capacity and even lower cost, will be introduced in additional Tesla vehicles in other markets, including North America. Tesla's plan to launch the new battery first in China and its broader strategy to reposition the company have not previously been reported. "Tesla's new batteries will rely on innovations such as low-cobalt and cobalt-free battery chemistries, and the use of chemical additives, materials and coatings that will reduce internal stress and enable batteries to store more energy for longer periods," the report adds. The company is also employing new high-speed, heavily automated battery manufacturing processes to reduce labor costs and increase production. According to the report, Tesla will produce the new batteries "in massive 'terafactories' about 30 times the size of the company's sprawling Nevada 'gigafactory.'"

Finally, in addition to improving the recycling and recovery of expensive metals, Tesla is working on new "second life" applications of electric vehicle batteries in grid storage systems. "The automaker also has said it wants to supply electricity to consumers and businesses, but has not provided details," Reuters reports.

"Data from connected scale users suggests Americans, on average, are not gaining weight during lockdowns," writes long-time Slashdot reader pfhlick.

The Washington Post reports: Withings, the maker of popular Internet-connected scales and other body-measurement devices, studied what happened to the weight of some 450,000 of its American users between March 22 — when New York ordered people home — and April 18. Despite concerns about gaining a "quarantine 15," the average user gained 0.21 pounds during that month... Over the same March-April period in 2019, Withings said its American users gained slightly less weight — 0.19 pounds on average — though fewer people had the scales last year...

Dariush Mozaffarian, dean of the School of Nutrition Science and Policy at Tufts University — who wasn't involved with the Withings analysis — said he found the results a bit disappointing. "With the shutdown of the restaurants, I thought the numbers would have gotten better," he said. Home-cooked meals tend to be healthier than dining out.
Withings' numbers varied slightly for other countires. But citing a professor of medicine at Stanford, the article notes that average weight gains may be misleading, since some people "may be hitting their groove during stay-at-home orders by embracing cooking and taking up jogging. But others could be using food to cope with stress and gaining large amounts of weight." In fact, 37% of the scale owners gained more than a pound. (Which, if my math is correct, suggests that the other 63% had to lose at least .13 pounds.)

The article also notes that for buyers of Withings' scales, "contributing aggregate data is a condition included in its terms of service; its customers don't get the option to opt out if they want to use Withings products."

"What are the implications if 'space-time' (as conceived of in the Einstein Theory of General Relativity) is quantized like all other aspects of matter and energy?" asks Slashdot reader sixoh1. Space.com reports of a new study that tried to find out: In order for the math of general relativity to work, this fabric of space-time has to be absolutely smooth at the tiniest of scales. No matter how far you zoom in, space-time will always be as wrinkle-free as a recently ironed shirt. No holes, no tears, no tangles. Just pure, clean smoothness. Without this smoothness, the mathematics of gravity simply break down. But general relativity isn't the only thing telling us about space-time. We also have quantum mechanics (and its successor, quantum field theory). In the quantum world, everything microscopic is ruled by random chance and probabilities. Particles can appear and disappear at a moment's notice (and usually even less time than that). Fields can wiggle and vibrate with a will all their own. And nothing can ever be known for certain. [...]

That's exactly what a team of astronomers did, submitting their results for publication in the Monthly Notices of the Royal Astronomical Society, and also posting their work to the online preprint site arXiv. And in a perfect coincidence, they searched for the frothiness of space-time using ... espresso. No, not the drink. ESPRESSO, the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, an instrument based at the European Southern Observatory's Very Large Telescope. As its name suggests, ESPRESSO was not designed to search for space-time frothiness, but it turned out to be the best tool for the job. And the astronomers pointed it at a perfect source: a run-of-the-mill gas cloud sitting over 18 billion light-years away. What makes this particular gas cloud especially useful is two facts. One, there is a bright source sitting just behind it, illuminating it. And two, there's iron in the cloud, which absorbs the background light at a very specific wavelength.

So from our vantage point on Earth, if space-time is perfectly smooth, that gap in the background light caused by the gas cloud should be just as narrow as if the cloud was sitting right next to us. But if space-time is frothy, then the light traveling over the billions of light-years will spread out, changing the width of the gap. The astronomers didn't find any hint of frothiness, which doesn't mean that it doesn't exist -- it just means that if space-time is frothy, we need more than 18 billion light-years to see it with our current technology. But the results were able to rule out some models of quantum gravity, sending them into the proverbial dustbin of physics history.

New submitter wattersa writes: Mathematician/Physicist Stephen Wolfram, founder of Wolfram Research and creator of the technical computation program Mathematica, has announced a discovery in the area of theoretical physics. His long-form blog post discusses the emergence of physical properties of our universe from what he describes as simple, universal, computable rules. He claims the emergent properties are consistent with relativity and quantum mechanics through a 448-page technical paper on the subject, which is posted on a completely new website that just went online.

kbahey shares a report from Planet Princeton: Renowned mathematician and Princeton University professor John Horton Conway died April 11 as a result of complications from the coronavirus. He was 82. Conway made contributions to many areas of mathematics, including game theory, but was most well known for the invention of the cellular automaton called the Game of Life. The Guardian once called Conway the world's most charismatic mathematician. "John Horton Conway is a cross between Archimedes, Mick Jagger and Salvador Dali. For many years, he worried that his obsession with playing silly games was ruining his career -- until he realized that it could lead to extraordinary discoveries," wrote journalist Siobhan Roberts in a 2015 profile.