Month: October 2023

Enlarge / As paint drops dry, they can look like a “fried egg” (left) or develop a more even pigment distribution (right). (credit: S.M.M. Ramos et al., Langmuir 2023/ACS)

French scientists have been watching paint drops dry and monitoring the resulting patterns in hopes of finding ways to better control the drying process to reduce cracks and other imperfections. They found that some drops dried uniformly, while others wound up resembling fried eggs with pigmented "yolks" at the center surrounded by white, depending on pigment concentration and temperature, according to a recent paper published in the journal Langmuir.

The underlying mechanism is akin to the so-called "coffee ring effect," when a single liquid evaporates and the solids that had been dissolved in the liquid (like coffee grounds) form a telltale ring. It happens because the evaporation occurs faster at the edge than at the center. Any remaining liquid flows outward to the edge to fill in the gaps, dragging those solids with it. Mixing in solvents (water or alcohol) reduces the effect, as long as the drops are very small. Large drops produce more uniform stains.

"Whiskey webs" are another related example. As previously reported, Princeton University physicist Howard Stone has tracked the fluid motion in whiskey drops with fluorescent markers, concluding that surfactant molecules collect at the edge of the drop. This creates a tension gradient pulling the liquid inward (known as the Marangoni effect, which is also associated with "tears of wine"). There are also plant-based polymers that stick to the glass and channel particles in the whiskey.

Enlarge / Former FTX CEO Sam Bankman-Fried arrives for a bail revocation hearing at US District Court on August 11, 2023, in New York City. (credit: Getty Images | Michael Santiago)

Sam Bankman-Fried's criminal trial is beginning this week with jury selection on Tuesday morning. SBF, the 31-year-old man behind bankrupt cryptocurrency exchange FTX, is facing seven criminal charges with maximum sentences adding up to 110 years.

"Your client in the event of conviction could be looking at a very long sentence," US District Judge Lewis Kaplan told SBF's lawyers in a hearing on Thursday while rejecting the defense's request for a temporary release from jail. "If things begin to look bleak... maybe the time would come when he would seek to flee," Kaplan said, according to a Reuters article.

Bankman-Fried was previously under house arrest but was sent to jail in August after his bail was revoked. In their request for a temporary release, SBF's lawyers said the "case is highly technical and complex, and we need our client to help us understand the facts and explain many of the issues. He alone knows the facts which are also critical in preparing his defense."

Enlarge / Northrop Grumman proposed a free-flying space station based on Cygnus. (credit: Northrop Grumman)

Nearly two years ago, NASA placed its bets to develop commercial space stations on four companies—Blue Origin, Nanoracks, Northrop Grumman, and Axiom Space. Now, as the US space agency looks to find a successor to the International Space Station in low-Earth orbit, this landscape is shifting dramatically.

At the International Astronautical Congress meeting this week in Azerbaijan, sources report that there is widespread speculation that one of these four companies, Northrop Grumman, is dropping out of the competition. Northrop's plan had been to leverage its successful Cygnus spacecraft design to build a free-flying space station.

However, Northrop no longer plans to do so. Rather, it will join the venture backed by Voyager Space, which is partnering with Europe-based Airbus to develop a commercial space station. It's likely that Northrop would provide cargo transportation services, with Cygnus as part of the team. Officials from Voyager and Northrop Grumman declined to comment on the change in strategy, which could be announced soon.

Enlarge (credit: Aurich Lawson | Getty Images)

Tux the cat has been found, and Lyft has agreed to cover "all of her veterinary bills," after a Lyft driver zoomed away with the sick cat still in the car, a Lyft spokesperson told Ars.

"We’re so happy to report that Tux has been reunited with her owner, and we are focused on ensuring Tux has everything she needs right now, including covering all of her veterinary bills," Lyft's spokesperson told Ars.

Tux's story went viral online after the cat's owner, Palash Pandey, posted on X, detailing his attempts to recover his lost cat. The cat went missing on Saturday, and millions of concerned online onlookers worried she might not be recovered. But Pandey posted today that Lyft investigators helped retrieve the cat, which was found at a real estate agency in Austin, Texas.

Enlarge / Mark my words, if any of you jerks abandon the unit, there'll be hell to pay... (credit: Valve)

Anyone who has played a bit of Counter-Strike probably knows the frustration of having a teammate bail on a match early on, leaving your team at a 4-on-5 disadvantage. The recently launched Counter-Strike 2 is trying to limit this problem by imposing a harsh new penalty for players who leave a match before it's over. But that system is already drawing angry reactions from players who feel they've been punished unfairly for unintentional match departures.

In CS: GO, abandoning a competitive match early resulted in a "cooldown" period before you could join a new match. Those periods started at 30 minutes for the first offense and rose to a full week for a fourth offense (one offense was also expunged from the count every seven days).

That punishment system carried forward to the closed CS2 beta in recent months but was reportedly ineffective at slowing down extremely high match abandonment rates. A series of popular posts on the CS:GO subreddit last month asked for stronger punishments, complaining that "almost every single match now has one leaver... I get it, you haven't played CS in years and you're butthurt that you're losing but you're just wasting everyone else's time if you leave."