Sensitive content Clicca per aprire/chiudere

The famous Alcubierre warp drive, introduced in 1994, has long been considered unphysical because it requires enormous amounts of theoretical negative mass or energy density to function . The authors of this study, Bobrick and Martire, suggest that this negative energy problem may not be a fundamental rule for all warp drives, but rather a specific flaw in Alcubierre's original design.

The researchers identify key artificial constraints in the Alcubierre model that mathematically force the need for negative energy. The Alcubierre model assumes the warp bubble has no gravitational effect on the spacetime outside of it, effectively "truncating" the gravitational field. The authors show that this assumption is a likely reason it requires negative energy . Furthermore, Alcubierre designed his drive so a passenger's clock ticks at the same rate as a stationary observer far away . This means the passenger's time is actually accelerated compared to an observer moving alongside the drive, another feature that requires negative energy .

By removing these artificial constraints, the authors developed a new, general model for a warp drive that can be constructed using purely positive energy, or regular matter. This new, physical warp drive is, however, strictly subluminal, meaning it can only travel slower than the speed of light. It is essentially a massive, hollow, spherically symmetric shell of ordinary matter. Unlike the Alcubierre drive, it would have a normal gravitational field outside of it, just like a planet. A passenger inside this shell would be in "flat spacetime," experiencing no gravity due to the Shell Theorem, a principle where the gravitational pull from all parts of the shell perfectly cancels out in the interior. The "warp" effect comes from its enormous mass, which causes time to run slower for the passenger compared to an outside observer. The mass requirements are vast; the paper calculates that an Earth-mass shell compressed to a 10-meter radius would only slow time by a tiny 0.04%.

This paper also clarifies a major misconception about how warp drives work. The original Alcubierre paper suggested the drive's velocity could just be changed as a function of time, but the new study points out that this violates the conservation of energy . The authors stress that a warp drive is an object, specifically a "shell of regular or exotic material moving inertially". Because it is a massive object, it is not a propulsion system itself. It cannot magically accelerate. To move or change velocity, it would require an external form of propulsion, such as a "propellant exhaust system" (like rockets) attached to it.

While this new positive-energy solution is limited to subluminal speeds, the paper reinforces that faster-than-light travel still appears to require negative energy. The authors also note that even for the unphysical Alcubierre drive, the most energy-efficient shape would be a flattened disc, not a sphere. This research is significant because it moves the warp drive concept from a purely unphysical fantasy to an extremely difficult but not theoretically impossible engineering challenge, suggesting a path to construct such spacetimes based on the laws of physics as we know them.

Introducing Physical Warp Drives

The Alcubierre warp drive is an exotic solution in general relativity. It allows for superluminal travel at the cost of enormous amounts of matter with negative mass density.

^arXiv.org

The reason that the so-called booming economy feels like a complete lie to most people is because the economy is bifurcated. There’s the economy for the rich, which is absolutely soaring, and the economy for everyone else, which is basically in a recession. The scary part is that the entire illusion of national prosperity is being propped up by one of the biggest financial bubbles we have ever seen.

This all starts with a deep split. The spending of the wealthiest 10% of Americans now makes up one third of the entire country’s GDP. They are responsible for nearly half of all consumer spending. Meanwhile, for the vast majority, things feel stagnant because they are. The national GDP number is a mathematical trick, buoyed by a few powerhouse states, while regions representing nearly a third of the nation’s economic output, like the Rust Belt, are in or near a recession. The reason for this divide is simple. The stock market gains you hear about on the news only benefit a tiny slice of the population. The top one percent own half of all stocks. The top ten percent collectively own nearly ninety percent. The bottom half of the country owns just one percent. So when the market hits a new high, it is overwhelmingly just the rich getting richer.

Now, let’s talk about that bubble. By the classic Buffett Indicator, which compares the total stock market value to the size of the economy, the US is in unprecedented territory. This indicator is now over 219%. To put that in perspective, it was only 138% at the peak of the dotCom bubble and 105% before the 2008 crash. This is the largest stock market bubble in US history.

But the real insanity is what’s inside this bubble. The market is being carried by a handful of tech companies, often called the Ten Titans. These ten firms represent just a tiny fraction of all public companies, yet they make up over 30% of the entire US stock market’s value. In recent months, they alone were responsible for over half of all market growth. The entire system is dangerously concentrated in a few names. The fuel for this run up is the artificial intelligence boom. But now, even the leaders of the AI revolution admit it is a bubble. Furthermore, recent studies show that 95% of corporate AI projects are failing, and the rest are making very little money. It is pure speculation that's driving this frenzy.

The most critical part of this story is that this AI bubble is now masking a severe weakness in the real economy. The overall GDP growth number for 2025 looks okay, but a deeper look paints a different picture. One analysis found that investment in AI and information processing, a sector that is only 4% of the economy, accounted for a staggering 92% of all GDP growth in the first half of the year. Without the sugar rush of AI spending, the rest of the US economy grew at a near flat rate of just 0.1%. The real economy for most Americans is already on life support, and the AI bubble is the ventilator.

This sets up a perfect storm for stagflation, meaning a stagnant economy combined with persistent inflation. Prices remain high due to supply chain issues and trade policies, while the real economy struggles. To make matters worse, the AI boom is actively making inflation worse by consuming enormous amounts of electricity and driving up power costs for everyone. So we are left with a terrifying situation. A historic bubble concentrated in a few tech stocks is creating a mirage of prosperity, hiding a recession that most people are already living through. Everyone will suffer when this bubble inevitably pops.

A pardoned Capitol rioter was arrested last weekend for allegedly threatening to kill House Minority Leader Hakeem Jeffries.

Court documents obtained by CBS News said Christopher Moynihan was arrested Sunday after saying in text messages that he planned to "eliminate" Jeffries when the top House Democrat spoke at an event in New York City on Monday.

According to a court filing by prosecutors in the New York state criminal case, Moynihan wrote, "Hakeem Jeffries makes a speech in a few days in NYC I cannot allow this terrorist to live."

Pardoned Capitol rioter charged with threatening to kill Hakeem Jeffries at NYC event this week

A pardoned Capitol rioter was arrested last weekend for allegedly threatening to kill the top House Democrat.

^{Scott MacFarlane (CBS News)}

Images of the demolition of parts of the East Wing went viral on Monday, and Treasury’s headquarters next door to the White House has a front-row seat

The Treasury Department instructed employees not to share photos of the demolition of parts of the White House’s East Wing after images of construction equipment dismantling the facade of the building went viral online.

Treasury’s headquarters is located next door to the East Wing, giving employees there a front-row seat to the construction of Trump’s $250 million ballroom. The new project is set to replace parts of the East Wing.

https://www.wsj.com/politics/policy/treasury-tells-employees-not-to-share-photos-of-white-house-ballroom-construction-1d4f2c49

Virginia Giuffre's posthumous book has revealed her grief at not being allowed to testify against Ghislaine Maxwell because her narrative was seen as too complicated for the jury: "I'd named so many names."

Nobody's Girl, published Tuesday by Knopf, gives the most detailed account yet of Giuffre's life, her abuse at the hands of Jeffrey Epstein, her allegations against Prince Andrew and her battle for justice through the U.S. civil courts.

But she also describes her response to not being called as a witness in the sex trafficking trial that saw Epstein's ex-girlfriend Ghislaine Maxwell jailed for her role in facilitating Epstein's campaign of abuse.

Giuffre died in Australia in April after what her family described as a suicide. Knopf said she had made it clear she wanted the book to be released.

https://www.newsweek.com/virginia-giuffre-ghislaine-maxwell-case-names-epstein-nobodys-girl-10910964

Virginia Giuffre's posthumous book has revealed her grief at not being allowed to testify against Ghislaine Maxwell because her narrative was seen as too complicated for the jury: "I'd named so many names."

Nobody's Girl, published Tuesday by Knopf, gives the most detailed account yet of Giuffre's life, her abuse at the hands of Jeffrey Epstein, her allegations against Prince Andrew and her battle for justice through the U.S. civil courts.

But she also describes her response to not being called as a witness in the sex trafficking trial that saw Epstein's ex-girlfriend Ghislaine Maxwell jailed for her role in facilitating Epstein's campaign of abuse.

Giuffre died in Australia in April after what her family described as a suicide. Knopf said she had made it clear she wanted the book to be released.

https://www.newsweek.com/virginia-giuffre-ghislaine-maxwell-case-names-epstein-nobodys-girl-10910964

Hi everyone, I am planning to install linux on my friends laptop and I am not sure which distro to install for them.

The options I am considering:

• Fedora: I have it on my PC and since I will be the first person to be asked, I thought it would be best if I know the distro well
• Mint: is a default suggestion, but I am not sure if it is different enough from the Windows look that one does not expect it to behave the same as Windows
• Ubuntu: most widely available in forums, etc. And a good starting point in my opinion
  What do you guys think?

EDIT: Thanks for all the suggestions, I think I'll stick with Fedora and let them try Gnome, KDE and Cinnamon 😀

cross-posted from: lemmy.ml/post/37847733

How do you make a great desktop into a fantastic desktop? Easy — chip away at the rough bits, polish the good stuff, and add awesomeness. After 29 years of development, KDE’s got the foundation nailed down. Plasma 6.5 is all about fine-tuning, fresh features, and a making everything smooth and sleek for everyone.

Ready to see what’s new? Let’s dive into Plasma 6.5!

Highlights:
- Automatic Theme Transitions: Configure when your theme will transition from light to dark and back.
- Caret Text Navigation: Zoom now swoops in to where you type
- KRunner Fuzzy Search: Even if you type it wrong, KRunner will find it!

Jure Repinc

2025-10-21 09:55:08

KDE Plasma 6.5 released

How do you make a great desktop into a fantastic desktop? Easy — chip away at the rough bits, polish the good stuff, and add awesomeness. After 29 years of development, KDE’s got the foundation nailed down. Plasma 6.5 is all about fine-tuning, fresh features, and a making everything smooth and sleek for everyone.

Ready to see what’s new? Let’s dive into Plasma 6.5!

Highlights:
- Automatic Theme Transitions: Configure when your theme will transition from light to dark and back.
- Caret Text Navigation: Zoom now swoops in to where you type
- KRunner Fuzzy Search: Even if you type it wrong, KRunner will find it!

Plasma 6.5

KDE is on the verge of making it big for the general public

^{Plasma 6.5}

How do you make a great desktop into a fantastic desktop? Easy — chip away at the rough bits, polish the good stuff, and add awesomeness. After 29 years of development, KDE’s got the foundation nailed down. Plasma 6.5 is all about fine-tuning, fresh features, and a making everything smooth and sleek for everyone.

Ready to see what’s new? Let’s dive into Plasma 6.5!

Highlights:
- Automatic Theme Transitions: Configure when your theme will transition from light to dark and back.
- Caret Text Navigation: Zoom now swoops in to where you type
- KRunner Fuzzy Search: Even if you type it wrong, KRunner will find it!

Plasma 6.5

KDE is on the verge of making it big for the general public

^{Plasma 6.5}