Computers & Linux News

At Long Last, Mathematical Proof That Black Holes Are Stable

SlashDot - Thu, 2022-08-04 12:00
Steve Nadis, reporting for Quanta Magazine: In 1963, the mathematician Roy Kerr found a solution to Einstein's equations that precisely described the space-time outside what we now call a rotating black hole. (The term wouldn't be coined for a few more years.) In the nearly six decades since his achievement, researchers have tried to show that these so-called Kerr black holes are stable. What that means, explained Jeremie Szeftel, a mathematician at Sorbonne University, "is that if I start with something that looks like a Kerr black hole and give it a little bump" -- by throwing some gravitational waves at it, for instance -- "what you expect, far into the future, is that everything will settle down, and it will once again look exactly like a Kerr solution." The opposite situation -- a mathematical instability -- "would have posed a deep conundrum to theoretical physicists and would have suggested the need to modify, at some fundamental level, Einstein's theory of gravitation," said Thibault Damour, a physicist at the Institute of Advanced Scientific Studies in France. In a 912-page paper posted online on May 30, Szeftel, Elena Giorgi of Columbia University and Sergiu Klainerman of Princeton University have proved that slowly rotating Kerr black holes are indeed stable. The work is the product of a multiyear effort. The entire proof -- consisting of the new work, an 800-page paper by Klainerman and Szeftel from 2021, plus three background papers that established various mathematical tools -- totals roughly 2,100 pages in all. The new result "does indeed constitute a milestone in the mathematical development of general relativity," said Demetrios Christodoulou, a mathematician at the Swiss Federal Institute of Technology Zurich. Shing-Tung Yau, an emeritus professor at Harvard University who recently moved to Tsinghua University, was similarly laudatory, calling the proof "the first major breakthrough" in this area of general relativity since the early 1990s. "It is a very tough problem," he said. He did stress, however, that the new paper has not yet undergone peer review. But he called the 2021 paper, which has been approved for publication, both "complete and exciting."

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This $10 4-Pack of Night Lights Automatically Illuminates Your Path - CNET

CNET News - Thu, 2022-08-04 11:40
Don't trip on your way to a midnight snack -- these nifty plug-ins come on when it's dark so you can always find your way.

Samsung Workers in Vietnam Bear Brunt of Slowdown in Global Demand for Electronics

SlashDot - Thu, 2022-08-04 11:22
Samsung has scaled back production at its massive smartphone plant in Vietnam, employees say, as retailers and warehouses grapple with rising inventory amid a global fall in consumer spending. From a report: America's largest warehouse market is full and major U.S. retailers such as Best Buy and Target warn of slowing sales as shoppers tighten their belts after early COVID-era spending binges. The effect is acutely felt in Vietnam's northern province of Thai Nguyen, one of Samsung's two mobile manufacturing bases in the country where the world's largest smartphone vendor churns out half of its phone output, according to the Vietnam government. Samsung, which shipped around 270 million smartphones in 2021, says the campus has the capacity to make around 100 million devices a year, according to its website. "We are going to work just three days per week, some lines are adjusting to a four-day workweek instead of six before, and of course no overtime is needed," Pham Thi Thuong, a 28-year-old worker at the plant told Reuters. "Business activities were even more robust during this time last year when the COVID-19 outbreak was at its peak. It's so tepid now."

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2023 Volkswagen ID 4 Gets Smaller Battery Option, $3,700 Price Cut - CNET

CNET News - Thu, 2022-08-04 11:00
The entire ID 4 lineup gets a few styling tweaks and larger-battery versions have an increased charging speed, as well.

Shop Sally Beauty's Big Bottle Sale for BOGO Deals on Hair Care - CNET

CNET News - Thu, 2022-08-04 11:00
Get quality shampoo, conditioner and more for less.

Next-Generation Audi RS6 Will Be a Plug-In Hybrid, Report Says - CNET

CNET News - Thu, 2022-08-04 10:59
The PHEV will be the last RS6 to use an internal combustion engine.

Amazon Discount Shaves up to $50 off the Latest 10.2-inch iPad - CNET

CNET News - Thu, 2022-08-04 10:43
It's not every day that we see deals on the newest versions of Apple devices.

Tencent Seeks Bigger Stake in 'Assassin's Creed' Maker Ubisoft

SlashDot - Thu, 2022-08-04 10:42
Tencent plans to raise its stake in French video game group Ubisoft Entertainment as the Chinese gaming giant pivots to the global gaming market, Reuters reported Thursday, citing four sources with direct knowledge of the matter. From the report: China's largest social network and gaming firm, which bought a 5% stake in Ubisoft in 2018, has reached out to the French firm's founding Guillemot family and expressed interest in increasing its stake in the firm, the sources said. It is not clear how much more Tencent wants to own in Ubisoft, valued at $5.3 billion, but Tencent aims to become the single largest shareholder of the French company with an additional stake purchase, two of the sources said, speaking on condition of anonymity. Tencent is hoping to buy a part of the additional stake in Ubisoft, the maker of the blockbuster "Assassin's Creed" video game franchise, from the Guillemot family, which owns 15% of the firm, three of the sources said. Tencent could offer up to 100 euros ($101.84) per share to acquire the additional stake, two of the sources with knowledge of the internal discussions, said. It paid 66 euros per share for the 5% stake in 2018.

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Microsoft Justifies Activision Blizzard's $69 Billion Acquisition By Telling Regulator Call of Duty Publisher Doesn't Release 'Unique' Games

SlashDot - Thu, 2022-08-04 10:09
Microsoft has recently tried to justify its $68.7 billion acquisition of Activision Blizzard by telling regulators that the deal with the Call of Duty publisher will not negatively impact the market and other platforms because it does not release "unique" or "must have" games. From a report: In a document presented to the New Zealand Business Acquisitions and Authorisations Commerce Commission, Microsoft claimed that no Activision Blizzard game has "unique" characteristics, so its rivals would do well without Activision Blizzard titles and would be able to compete in the gaming market. "With respect to Activision Blizzard video games, there is nothing unique about the video games developed and published by Activision Blizzard that is a "must have" for rival PC and console video game distributors that could give rise to a foreclosure concern," the company said.

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Midsize Cars Struggle in Updated IIHS Side Crash Test - CNET

CNET News - Thu, 2022-08-04 10:07
Less than half of the field earned a rating high enough to earn future accolades.

Google Pixel 6A Sees First Price Drop to $399, Save $50 Today - CNET

CNET News - Thu, 2022-08-04 10:05
Snag this deal on the device CNET's Lisa Eadicicco called the best Android phone under $500.

This Under Armour Sale Has Back-To-School Gear for Up to 25% Off - CNET

CNET News - Thu, 2022-08-04 10:02
Prep for school sports with new athletic gear.

SpaceX, Blue Origin Headline 4 Major Space Launches Thursday - CNET

CNET News - Thu, 2022-08-04 09:55
It's one of the busiest days in space for Florida in half a century, and that's not the only place the launches are leaving from.

Porsche Actually Built a Cayenne Convertible, and It's Wild - CNET

CNET News - Thu, 2022-08-04 09:26
This one-of-one prototype looks just a little chunky.

Save $50 On Ninja's Compact Kitchen System and Pay Just $110 -- Today Only - CNET

CNET News - Thu, 2022-08-04 09:23
Cut the hassle of prep work with this versatile food processor, blender and ice crusher combo.

New Technique Brings Quantum Computers Closer to Their Promise - CNET

CNET News - Thu, 2022-08-04 09:00
Quantinuum proves decades-old ideas about quantum computing error correction really do work.

Mortgage Rates on Aug. 4, 2022: Fixed Rates Decline - CNET

CNET News - Thu, 2022-08-04 09:00
If you're in the market for a mortgage, see how your payments might be affected by interest rate hikes.

Here Are Today's Refinance Rates, Aug. 4, 2022: Rates Drop - CNET

CNET News - Thu, 2022-08-04 09:00
Several important refinance rates tapered off today, continuing a recent downward trend.

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