After the Orion capsule of the Artemis I lunar mission returned to Earth, it was found that massive chunks of its heatshield had been ripped off, posing a serious risk to any future missions. In a recent video in which [polymatt] takes a break from repairing old laptop shells and the like, he tries to recreate the Orion’s heatshield using a variety of methods and materials.

For this test a number of samples were created, each using the same kind of segmented structure as the larger Orion heatshield. The filler was created from the published materials for the heat shield by NASA, requiring just serious mixing.

The resulting samples were then cured with thermocouples inserted, before they got blasted with the heat from a propane torch, trying to simulate the various re-entry patterns.

Perhaps unsurprisingly, the results matched the findings by NASA for why the Orion’s heat shield had failed, being the build-up of gases due to the sustained pyrolysis processes that eventually fractured the material. Despite some experimental flaws that injected residual heat from the copper structure, this still seems to be a pretty good setup to test ablative heat shields in DIY lab conditions.

Silicon Valley is shifting away from chatbot queries toward a future filled with resource-intensive agentic AI—and it's driving the data center buildout.

“There’s no reason we can’t think that, at some point in the future, we can have volcano forecasts that are like weather forecasts.”

Longtime Slashdot reader fahrbot-bot shares a report from ScienceAlert: Scientists have now demonstrated one of the weirdest forms of ice yet -- under preposterous pressures up to 2.3 million atmospheres, and tremendous temperatures up to 2,630 kelvins (2,357 degrees Celsius, or 4,274 degrees Fahrenheit). [...] In their new experiments, a team led by physicist Alexis Forestier of the French Alternative Energies and Atomic Energy Commission subjected tiny samples of water to the sorts of extreme conditions expected in the interiors of ice giant planets. They squeezed the samples between the tips of diamonds to pressures as high as 230 gigapascals, while using lasers to heat them to thousands of degrees. That's 2.3 million times Earth's atmospheric pressure at sea level â" the pressure at the center of Earth, for context, is around 360 gigapascals. Then, using an extremely narrow beam of synchrotron X-rays, they probed for changes in the crystal structure of the ice. What emerged was a configuration predicted theoretically but never unambiguously observed in experiments: hexagonal close-packed, or hcp, ice. As the hcp crystal was heated, its expansion also showed a signature of superionic behavior, suggesting it entered the superionic state at around 1,700 kelvins. [Superionic ice is thought to exist deep inside Uranus and Neptune, where its unusual properties may play a role in generating the planets' equally unusual magnetic fields.] The findings have been published in Physical Review Letters.

Read more of this story at Slashdot.

Launched in 1976, LAGEOS-1 (LAser GEOdynamic Satellite) is unusual in that it contains no instrumentation, no electronics, no power supply, and no means of propulsion. It’s spherical, weighs just under 407 kg, and looks a bit like a disco ball. It may not be accurate to say it does nothing, but unlike most satellites its role is entirely passive. It’s also one of the oldest scientific satellites still in service.

The lens-like objects covering the surface of LAGEOS-1 are corner cube retroreflectors, which have the nifty effect of always reflecting incident light right back towards its source.

Ground stations fire short laser pulses at it and measure the time it takes for the light to return, a form of time-of-flight ranging. Since LAGEOS-1’s orbit is highly stable, it provides a reliable reference point for measuring even tiny changes in the Earth itself. The size, shape, rotation, and more of our planet can be measured as a result. LAGEOS data (LAGEOS-2 was launched in 1992) has also been used in tests of general relativity.

Its orbit and construction were deliberately chosen so that atmospheric drag and other disturbances would be minimal. The simple, maintenance-free design combined with an extraordinarily stable orbit means LAGEOS is expected to circle our world for millions of years to come.

LAGEOS-1 also contains a message to the future in the form of two identical plaques prepared by Dr. Carl Sagan just in case there’s anyone around to find it some day. Check out the short 1975 video from NASA, embedded just below.

Steven Strogatz coauthored a book about how math is moving beyond human understanding. He spoke with WIRED about the seismic impact artificial intelligence has had on his life’s work.

And if your tap water is undrinkable, you have no “constitutional right to truthful information” about it.

If you ask most satellite companies aside from SpaceX, they will tell you the world doesn't have enough capacity for launching payloads into orbit. This is despite the blistering launch cadence we've seen around the world in recent years, led by SpaceX's Falcon 9 rocket.

Customers in any sector will, of course, usually welcome competition. Theoretically, competition will lead to lower prices and allow the best to rise to the top. It seems like the customers buying launch services were right. SpaceX is dialing back its Falcon 9 launch program, and there is no certainty about when SpaceX's reusable next-generation super-heavy-lift rocket, Starship, will carry anything to orbit besides the company's own Starlink satellites.

So it's no surprise satellite operators are cheering the success of a new launch provider. This was especially the case a few days ago, when Germany's Isar Aerospace reached orbit for the first time with its Spectrum rocket. The launcher delivered a batch of CubeSats to low-Earth orbit from a spaceport in northern Norway, and Isar tasted success after its first test flight ended in failure last year.

Read full article

Comments

© Isar Aerospace

Games may be life with all the hard bits removed, but they provide a way to study why people make the choices they make. Traditional games are usually played against a static background: the rewards per outcome are constant. That limits their relevance to behavior because, in real life, the rewards and consequences of strategic choices are ever changing. Now, researchers have used a mathematical model to study a series of games that include evolving strategies and randomly varying returns.

A bit of history

Perhaps the most famous game-theory contest is the prisoner’s dilemma. In the prisoner’s dilemma, a pair of thieves have been captured and are being separately interrogated by the police. If both clam up, they will be punished for a lesser crime. If one prisoner makes a deal (defects) then that prisoner gets to go free and the other gets a heavier sentence. If both make a deal, they both get an in-between punishment.

The person running the game can start it with different rewards for cooperating and defecting to explore how the optimum strategy varies with reward and risk, which the players can figure out by varying the strategies across multiple rounds. Depending on the balance between the reward for staying silent (cooperating) and betrayal, the game stabilizes with everyone betraying everyone. In this simple situation, everyone loses.

Read full article

Comments

© NurPhoto

The use of coal to generate electricity on the US grid has been plunging for nearly two decades, and the first Trump administration was unable to affect the trend. So his second administration has attempted more aggressive interventions to prop up coal use. One of its most direct means of doing so is to order coal plants that were scheduled to close to remain open, even if there is no need for them.

The administration's justification for these orders is a statute that allows the Department of Energy (DOE) to declare an emergency in the case of wartime or a sudden shortfall in generation. A number of parties, including states where coal plants have been slated to close, have challenged this declaration. And on Friday, in the first of these cases to make its way through the courts, the declaration was judged to be contrary to the statute. While this only affects a single coal plant in Michigan, the reasoning of the decision will apply to every coal plant closure that has been blocked by the DOE.

No emergency

The decision was issued by a unanimous three-judge panel from the DC Circuit's Court of Appeals. It focuses on the J.H. Campbell Generating Plant, which was scheduled to close last year but has been kept open by a total of five emergency declarations by the DOE, each limited to 90 days by the Federal Power Act. At issue was section 202(c) of that Act, which allows the DOE to declare emergencies when the US is at war or when “an emergency exists by reason of a sudden increase in the demand for electric energy, or a shortage of electric energy.”

Read full article

Comments

© UCG

The precise composition of ancient Egyptian paints, binders, adhesives, and similar materials used to make artifacts is largely unknown, in part because a full analysis would require taking samples that would damage those valuable artifacts. The development of cutting-edge, non-destructive techniques has been helping to unlock those secrets, aiding conservation efforts.

Most recently, researchers have used mass spectrometry-based proteomics to analyze the glues and adhesives in a broad set of Egyptian artifacts, according to a new paper published in the journal Science Advances. They found plenty of expected sources, such as animal collagens and egg proteins, but also plant proteins, specifically from sesame and drumstick tree (moringa) cereals.

As previously reported, the ancient Egyptians had a highly formalized (and easily recognizable) painting style, and there has been considerable interest in gaining insights into the specific pigments and painting techniques employed. Common pigments included hematite and realgar for red; goethite and orpiment for yellow; Egyptian blue; Egyptian green; carbon-based black; and calcite, gypsum, anhydrite, and huntite for white. (Just last year, Washington State University researchers were able to re-create Egyptian blue by mixing together silicon dioxide, copper, calcium, and sodium carbonate in varying proportions and heating them at very high temperatures akin to those of ancient kilns.)

Read full article

Comments

© Johan Jeppsson/Museum of Mediterranean and Near Eastern Antiquities, Stockholm

Almost a hundred years ago, physicists theorized out what free fall should do to a quantum wave. If the solution they came up with is wrong, quantum mechanics and Einstein's theory of gravity flatly contradict each other. But testing it has been impossible because nobody has managed to build an interferometer that could perform the necessary measurement.

Now, a team led by Ron Folman, a physicist at Ben-Gurion University of the Negev, with collaborators in Germany, the UK, and the US, including Nobel laureate Roger Penrose, has done it. They built a new interferometer that gives a single atom two possible paths at once: one that involves a free fall, and another where it is held perfectly still. Both paths end at the same place at the same moment, allowing the team to measure what the fall does to a wave-like property of the atom.

Long time coming

Ever since Galileo, physicists have known how to describe a falling object—where it is, how fast it goes, or how quickly it accelerates. Quantum mechanics, though, insists that every object is also a wave. “Every particle, doesn't matter if it's a car or a spaceship or an atom, is a wave,” Folman says. “Everything that is a wave, like sea waves or sound waves, goes up and down. And if you're up or down, this is measured by something called a phase. A phase just tells you if you are at the top of the wave or at the bottom.”

Read full article

Comments

© ALIOUI Mohammed Elamine

The yeast used won’t brew beer, but it can help brew a building.

Anthropic produced an extensive collection of case studies covering the ways its current AI models have been misused.

While the strengthening El Niño helped boost temperatures, climate change is the main culprit for making August so hot.

The European Space Agency is moving "full steam ahead" with development of a robotic mission to Venus after NASA officials determined they were unlikely to fulfill a commitment to provide a US-built radar instrument for the spacecraft, the mission's project scientist said.

The European orbiter, named Envision, will map the Venusian surface at 10 times higher resolution than the last radar mission sent to Venus by NASA in the 1990s. The planet is enshrouded in a blanket of thick clouds of sulfuric acid, rendering its mysterious surface unseen by optical cameras in orbit. Radar is the most effective way to penetrate the clouds of Venus to reveal the terrain below, and scientists will use Envision to look for signs of active volcanism.

NASA and ESA signed a memorandum of understanding in 2024 outlining their partnership on Envision. NASA agreed to supply a US-made synthetic aperture radar instrument, Envision's primary means of mapping the surface of Venus, along with providing tracking and communications support through NASA's Deep Space Network. In exchange, ESA would include US researchers on Envision's science team. Europe would build the Envision spacecraft and the rest of its science instruments and provide the launch on an Ariane 6 rocket.

Read full article

Comments

© ESA/Paris Observatory/VR2Planets

It turns out Jean-Luc Picard was an even better starship helmsman than the writers knew. A physicist has gone through the details of a warp-speed trick from the first season of Star Trek: The Next Generation and found a subtlety the show missed. But instead of a plot hole, the detail he found actually makes the maneuver more impressive… as well as a great opportunity to teach about a lesser-known feature of the theory of relativity.

Níckolas de Aguiar Alves, a physicist at the Federal University of ABC in Brazil, first watched Next Generation as a master’s student. When he got to the episode "The Battle" in the show’s first season, the plot reminded him of his relativity coursework.

In "The Battle," a Ferengi leader reminds Picard of a battle he fought years ago as captain of a ship called the Stargazer. Under fire from a mysterious attacker, Picard’s ship’s shields were down. He had to get closer without taking a hit, so he made a gamble. Picard ordered the Stargazer to charge the enemy ship at warp speed (meaning faster than light), then stop abruptly and fire. By going faster than light, Picard anticipated that the other ship would see two images of the Stargazer: where it reached warp speed and where it stopped. If they fired on the wrong image, they would miss the Stargazer, and Picard could win the battle.

Read full article

Comments

© Paramount

Before reentering our atmosphere, the telescopes onboard NASA’s Neil Gehrels Swift Observatory have been restarted to take their last observations.

Scientists have an indisputable playful side, evidenced by frequent allusions to popular culture in their research publications. That includes popular song lyrics. And the most popular musical group, in terms of how frequently their songs and lyrics appear in the scientific literature, is The Beatles, according to a new paper published in the journal PLoS ONE.

“Some of these are genuinely brilliant," said co-author Gabriel Budel of Delft University of Technology in the Netherlands of the more than 3,000 references they found to The Beatles. "'The lung and winding road' is a paper on Long COVID that changes one vowel. 'Here comes the SU(N)' turns 'Here Comes the Sun' into a quantum computing paper about mathematical groups. Someone was having a very good day at their desk.”

Back in 2014, scientists at the Karolinska Institute in Sweden revealed that they had been deliberately inserting Bob Dylan lyrics into their papers as part of a long-running bet, starting with a 1997 Nature review entitled "Nitric Oxide and inflammation: The answer is blowing in the wind." That resulted in a 2015 study on whether Dylan lyrics appeared elsewhere in the biomedical literature; the most frequently referenced were "The Times They Are A'Changin'" and "Blowing in the Wind."

Read full article

Comments

© Ramon Dorenbos, CC-BY 4.0

On Tuesday, Google announced AlphaGenome Atlas, a resource that attempts to predict the consequences of every possible single-base variant in the human genome. The human genome is about 3 billion bases long, so trying the other three DNA bases that don't appear in our reference genome means sending a total of 9 billion bases through AlphaGenome software.

AlphaGenome is designed to identify potential functions of non-coding DNA, which does not encode proteins but makes up the vast majority of the human genome. Some of this non-coding DNA is essential for controlling the activity of the protein-coding portion—it tells the cell where and when to make messenger RNAs, how to process them into mature protein-coding forms, and so on. But much of it appears to be little more than the remains of viruses and other molecular parasites.

Being able to identify the functional portion is very useful, as is having all the analysis done by a single software package. But until biologists start to use it heavily (assuming they do), it won't be clear what AlphaGenome offers beyond what we could have gotten out of its training data.

Read full article

Comments

© Vertigo3D