Delta_V

joined 2 years ago
[–] Delta_V@lemmy.world 5 points 12 hours ago

Locking in the gains and taking time to reload and refuel before round 2.

 

The Lebanese Armed Forces on Monday urged people displaced from the south of the country by Israeli military operations there not to return to their homes and await further instructions, following Sunday's announcement of a memorandum of understanding that could bring an end to the U.S.-Israeli war with Iran.

"In light of recent developments in the region and with news circulating about reaching a ceasefire, the Army Command emphasizes the need for residents to postpone their return to the southern border villages and towns, and to adhere to the instructions of the deployed military units, in order to protect their safety from the danger of Israeli violations and attacks,"...

Israeli Defense Minister Israel Katz on Monday said that the Israel Defense Forces will not withdraw from areas it has seized in southern Lebanon, Syria and the Gaza Strip regardless of a deal with Iran.

 

Qcells has begun manufacturing solar cells at its new facility in Cartersville, Georgia, bringing the company closer to operating what it says is the United States’ first and only fully vertically integrated solar manufacturing factory.

The company announced that the plant is now producing solar cells and expects all production lines to reach full capacity by the third quarter of 2026. Once fully operational, the facility will manufacture ingots, wafers, cells, and solar modules under one roof.

The start of cell production marks a significant milestone for domestic solar manufacturing, as most solar panels installed in the US still rely on imported components. Qcells said the Cartersville site will become the largest operating solar cell factory in US history...

[–] Delta_V@lemmy.world 1 points 2 days ago

It was also rotated 90 degrees for some reason? The river is on the south side of the community.

[–] Delta_V@lemmy.world 3 points 3 days ago

The writing and atmosphere is better in New Vegas, but the gunplay is better in 4.

 

Images from EarthCam showed numbers on the lawn since at least Wednesday afternoon, with the number eight appearing most clearly as browned grass. It's not clear what caused the grass to brown.

 

A little over a year ago, Sen. Tim Sheehy floated an audacious proposal to reshape the way the federal government fights wildfires. It called for expanding the use of private planes and helicopters to quickly attack blazes while also eliminating the U.S. Forest Service’s rigorous airworthiness inspections for those aircraft.

The idea stood to benefit Sheehy, a Montana Republican, personally. Before running for Congress, he founded and ran an aerial firefighting company called Bridger Aerospace, which is known for its scoopers, aircraft built to retrieve water from lakes or oceans and drop it onto fires. Since 2021, the Forest Service has paid Bridger more than $235 million for use of its scoopers, according to public records.

Sheehy’s ownership of Bridger is well known, but what hasn’t been reported is that the same month the proposal leaked, a Forest Service inspector had discovered a crack in a wing of an aircraft Bridger had presented as ready for service. The scooper had failed the very inspection Sheehy sought to eliminate...

“Very seldom do you find a crack in a major component,” said Paul Markowitz, a former national aviation maintenance manager for the Forest Service. Detecting such problems is the reason the Forest Service operates an airworthiness program, he added: “It’s to keep people alive.”...

...“Why can’t we be inspecting ourselves?”...

Since 2010, when the Forest Service implemented its current airworthiness program, the accident rate for aircraft it owns or contracts has plummeted. Between 1993 and 2010, it reported 85 accidents that killed 63 people — an average of nearly four deaths per year. Between 2011 and 2023, the last year for which data is available, the agency reported just 17 accidents and seven fatalities...

...In January 2024, Bridger presented its first scooper as ready for service, only to have a Forest Service inspector find issues with the engine and electronics...

In early April 2025, Bridger presented two scoopers for carding, saying they were ready for service. During one of these assessments, a Forest Service inspector found a crack in a wing...

[–] Delta_V@lemmy.world 13 points 5 days ago

Walked through the revolving door from professional bribe solicitor to pro-active agent of bipartisan capitalist corruption.

 

Former Biden administration official Shuwanza Goff is joining Paramount Skydance as VP of U.S. government affairs...

Goff will be tasked with helping shape the company’s public policy and government affairs strategy, including engagement with federal and state policymakers and industry partners. She was previously a partner and chief strategy officer at lobbying firm Empire Consulting Group.

Goff served as the director of the White House Office of Legislative Affairs from 2023 to 2025 in the Biden administration. In that role, she drove the White House’s policy agenda and was the steward of key bipartisan relationships on Capitol Hill...

[–] Delta_V@lemmy.world 21 points 1 week ago

The cease fire was broken on day one when USA blockaded the ports, Iran demanded ships pay tolls for passing through the strait, and Israel and Hezbollah never got the memo to stop shooting at each other.

'Negotiating' in those conditions is performative at best.

[–] Delta_V@lemmy.world 5 points 1 week ago* (last edited 1 week ago)

PBH with mass <10^6g would have evaporated before the universe had cooled enough for atoms to form. Its possible they didn't fully evaporate, but instead became "Plank relics", which are a dark matter candidate.

PBH with mass 10^7g to 10^16g would have evaporated already, producing a background of gamma rays and gravity waves that we don't see.

PBH with mass 10^17g to 10^22g would still exist today, and the gravity waves they generate are too small to be detected by current detectors. These are also a dark matter candidate.

PBH with mass >10^23, in sufficient numbers to explain the existence of dark matter, would cause gravity lensing that we don't observe.

So according to observations, if the early universe produced PBH, they didn't have an even distribution of masses from giant to tiny. Either they were all tiny (<1 ton), or they were all medium size (asteroid mass).

My favorite explanation of dark matter is the formation of asteroid mass PBHs when the early universe went through the phase change that separated the electroweak force into the electromagnetic force & nuclear weak force. Just a bit before electroweak symmetry breaking, the universe was in a state of supercooled false vacuum, and then bubbles of today's vacuum energy started expanding. The pockets of false vacuum between the expanding bubbles of true vacuum would be slower to inflate, causing their density to grow relative to the rest of the universe, until they collapse into PBH. Because they're all formed at the same time, from similar size pockets of similar density plasma, the resulting population of PBH are uniformly asteroid mass rather than having a Gaussian mass distribution.

Further reading:

Gaussian Planck Relics are Ruled-Out as Dark Matter by LIGO

Constraints on primordial black holes from the Galactic gamma-ray background

 

...New research examines the issue. It's titled "The Life and Death of Stars That Capture Primordial Black Holes," and it's available at arxiv.org...

...When a star captures a PBH, the PBH finds its way to the stellar core. Once there, it accretes material from the star's interior, having a dramatic effect on the star's evolution. "The resulting object, a “Hawking star”...

There are two diverging paths post engulfment, and both are terminal...

It's all about disk formation, which is governed largely by angular momentum. Above a certain threshold, accretion is rapid, and powerful feedback destroys the star. If accretion is slow and steady, the Hawking star can survive...

The quiet terminal branch potentially produces gravitational waves (GWs). While the explosive branch leaves behind a low-mass, rapidly spinning BH..."Any future GW detection of a compact binary containing a subsolar or otherwise anomalous low-mass BH would be a striking signature of nonstandard compact-object formation."

The remnants from both branches are valuable probes of PBH. "Their rates, environments, and electromagnetic signatures could constrain the PBH contribution to dark matter," write the authors...

 

Commonwealth Fusion Systems (CFS) has verified the core plasma physics assumptions for its upcoming ARC fusion power plant following a peer-reviewed study published in the Journal of Plasma Physics.

The research confirms the ARC reactor design aligns with known physics, allowing the company to shift its focus toward detailed hardware engineering...

According to the validated models, the ARC plant will produce approximately 1.1 gigawatts (GW) of fusion power to generate 400 megawatts (MW) of net electricity for the grid...

CFS engineers are using this simulation framework to optimize upcoming design iterations, adjusting dimensions like tokamak width and divertor length to refine reactor performance before manufacturing begins.

[–] Delta_V@lemmy.world 2 points 1 week ago (1 children)
[–] Delta_V@lemmy.world 20 points 1 week ago (5 children)

H A U L I N G A S S ! ! !

Each is moving at ~6% of the speed of light!

 

...the two black holes orbit one another every 121 days. Their separation is roughly 250 to 540 times the Earth-Sun distance...

 

...In the new study, the researchers also found signs in the same set of samples of an extended fungal bloom tens of thousands of years before the asteroid impact. This coincides with intense volcanic activity in what is now India and supports the idea that volcanism was a factor in the mass extinctions in that period.

Fungal surges are presumably due to the availability of dead plants and animals as food sources following disasters and disruptions...

“If you ask most people what killed the dinosaurs, they’ll say it was that asteroid, but our fungal microfossil-based results suggest that the world already had been undergoing a cataclysm when the asteroid struck,”...

[–] Delta_V@lemmy.world 8 points 1 week ago* (last edited 1 week ago)

The paper linked to in the article says the thrusters have a specific impulse of 600s, and a thrust-to-power ratio of about 50 mN/kW.

Compared to the xenon ion thrusters used on the Dawn spacecraft, these new multi-mode thrusters produce more thrust, but are significantly less efficient. Dawn's thrusters have a specific impulse of 3,100s and a thrust-to-power ratio of about 36 mN/kW.

Even so, it means satellites can be built with one small fuel tank that can power high efficiency electrospray thrusters to make slow maneuvers, or use the same fuel as a monopropellant to quickly get out of (or into) the way of something. ASCENT monopropellant thrusters can have a specific impulse slightly better (240 Isp) than traditional hydrazine monopropellant thrusters (235 Isp).

 

...The key to the new system is a special propellant that can power both chemical and electrical thrusters...

...a type of “green monopropellant” originally developed by the U.S. Air Force for use in chemical propulsion in space can also effectively power tiny “electrospray” thrusters. Electrospray thrusters are dime-sized rockets that use electric fields to charge up a liquid propellant’s particles, which are then shot into space as a thrust-generating spray...

[–] Delta_V@lemmy.world 4 points 2 weeks ago

To be fair, primordial black holes are a candidate for explaining what dark matter is.

...There is a range of masses, , usually described as the ‘asteroid mass window’, where PBHs can make up all of the DM...

source: https://www.sciencedirect.com/science/article/pii/S0550321324000609

 

The Justice Department’s $1.776 billion “anti-weaponization” fund, which would pay out public money in compensation for alleged overreach in federal prosecutions, including for the insurrectionists who stormed the Capitol on January 6, 2021, has been accurately described as one of the most nakedly corrupt actions in American history. It would give a tacit endorsement from every American taxpayer to the notion that the Capitol Riot’s only transgression, for example, came from those who tried to punish its perpetrators for attempting to halt the outcome of an election...

...if a judge can be convinced that this fund, established with no transparency and no congressional or judicial oversight, which emerged from a lawsuit between a sitting president and his own government, and is arguably contrary to the purpose of the Judgment Fund from which it derives authority, is an unconstitutional scheme to defraud the government by its very structure, then anyone can sue to recoup the money, and then some, under the False Claims Act of 1863...

...Anyone found guilty of a false claim must not only pay back the ill-gotten funds, but three times the amount in damages. That means that anti-weaponization fund recipients would risk having to pay much more back in the future, while going through years of litigation. Debts incurred by FCA violations are not even dischargeable in bankruptcy...

 

...That something has been named Phoebe. And working out what it actually is turns out to be one of the most intriguing puzzles in modern astronomy. The phenomenon at the heart of the story is called gravitational microlensing and it’s one of the most elegant predictions of Einstein's general theory of relativity. When a massive compact object passes between us and a distant star, its gravity acts like a lens, briefly magnifying the star's light in a very characteristic way. The shape of the brightening is distinctive and entirely unlike anything produced by a variable star, a flare, or an asteroid...

The team calculated the probability of the lensing object belonging to each possible population — Milky Way stars, Large Magellanic Cloud stars, or the dark matter halo between and around them. The dark matter halo wins by a factor of 100,000. Phoebe is five orders of magnitude more likely to be a dark matter object than anything associated with normal stellar matter...

[–] Delta_V@lemmy.world 1 points 2 weeks ago (1 children)

It looks like an interesting concept, but I wonder if a 2 stage system would be more efficient?

The rocket motor would provide more speed if it were not weighed down by the electric propulsion system. If it was built in two detachable parts, you could recover and reuse the launcher.

[–] Delta_V@lemmy.world 26 points 3 weeks ago

Went to school as an elvish impersonator.

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