Month: April 2021

Enlarge / A multi-wavelength image of the Cassiopeia A supernova remnant. (credit: Courtesy NASA/JPL-Caltech)

Supernovae happen. We've witnessed enough of them that we're pretty sure of that. Why they happen has been another issue entirely. As we've worked on understanding the physics that drives these immense explosions, we've occasionally gone through awkward periods when the stars in our models stop exploding. Adding in more realistic physics has generally gotten the models booming again, and right now we're in a period where the latest models appear to be happily self-destructing.

The challenge is trying to find evidence that the physics we're using in our successful models accurately reflects what's going on in a dying star—not an easy task with an event that instantly destroys much of the evidence.

Now, data from the Chandra X-ray Observatory provides a hint that a mechanism used in recent supernova models is probably right. The results are published in this week's issue of Nature.

Enlarge / Photographic reproduction of the Great Isaiah Scroll, the best preserved of the biblical scrolls found at Qumran. It contains the entire Book of Isaiah in Hebrew, apart from some small damaged parts. (credit: Public domain)

Most of the scribes who copied the text contained in the Dead Sea Scrolls were anonymous, as they neglected to sign their work. That has made it challenging for scholars to determine whether a given manuscript should be attributed to a single scribe or more than one, based on unique elements in their writing styles (a study called paleography). Now, a new handwriting analysis of the Great Isaiah Scroll, applying the tools of artificial intelligence, has revealed that the text was likely written by two scribes, mirroring one another's writing style, according to a new paper published in the journal PLOS ONE.

As we've reported previously, these ancient Hebrew texts—roughly 900 full and partial scrolls in all, stored in clay jars—were first discovered scattered in various caves near what was once the settlement of Qumran, just north of the Dead Sea, by Bedouin shepherds in 1946-1947. (Apparently, a shepherd threw a rock while searching for a lost member of his flock and accidentally shattered one of the clay jars, leading to the discovery.) Qumran was destroyed by the Romans, circa 73 CE, and historians believe the scrolls were hidden in the caves by a sect called the Essenes to protect them from being destroyed. The natural limestone and conditions within the caves helped preserve the scrolls for millennia; they date back to between the third century BCE and the first century CE.

Several of the parchments have been carbon dated, and synchrotron radiation—among other techniques—has been used to shed light on the properties of the ink used for the text. Most recently, in 2018, an Israeli scientist named Oren Ableman used an infrared microscope attached to a computer to identify and decipher Dead Sea Scroll fragments stored in a cigar box since the 1950s.

Enlarge / The lure of frozen deliciousness that led to uncovering insane techno craziness. (credit: NurPhoto | Getty Images)

Of all the mysteries and injustices of the McDonald’s ice cream machine, the one that Jeremy O’Sullivan insists you understand first is its secret passcode.

Press the cone icon on the screen of the Taylor C602 digital ice cream machine, he explains, then tap the buttons that show a snowflake and a milkshake to set the digits on the screen to 5, then 2, then 3, then 1. After that precise series of no fewer than 16 button presses, a menu magically unlocks. Only with this cheat code can you access the machine’s vital signs: everything from the viscosity setting for its milk and sugar ingredients to the temperature of the glycol flowing through its heating element to the meanings of its many sphinxlike error messages.

“No one at McDonald’s or Taylor will explain why there’s a secret, undisclosed menu," O’Sullivan wrote in one of the first, cryptic text messages I received from him earlier this year.

• 

  This is the 2023 Cadillac Lyriq, a new electric SUV. [credit: Cadillac ]

On Wednesday, Cadillac formally revealed the production version of its next SUV. Called the Lyriq, when it goes on sale next year starting at $59,990, it will join the Hummer EV as part of General Motors' third wave of electric vehicles (after Chevrolet's experiments with the EV1 and Bolt EV).

If you think this vehicle looks familiar, you're right—in August 2020, Cadillac presented a show-car version of the Lyriq, and the production version has changed very little. But, at the time, Cadillac wasn't ready to talk technical specs. Now it is.

Propulsion to the rear wheels is provided by one of GM's Ultium Drive motors that will appear in more than 20 new EVs in the coming few years. That electric motor endows the Lyriq with 225 kW (340 hp) and 440 Nm (325 lb-ft), which should mean the 2,545 kg (5,610 lb) SUV will be appropriately quick as opposed to face-meltingly fast.

Enlarge / A stack of 60 Starlink satellites launched in 2019. (credit: SpaceX / Flickr)

SpaceX has accused satellite-broadband rival OneWeb of spreading a false story claiming that the companies' satellites nearly crashed into each other.

In reality, "[t]he probability of collision never exceeded the threshold for a [collision-avoidance] maneuver, and the satellites would not have collided even if no maneuver had been conducted," SpaceX told the Federal Communications Commission in an ex parte filing. The filing describes a meeting that SpaceX and OneWeb representatives had with FCC staff yesterday in which SpaceX said it "corrected the record regarding recent press reports regarding physical coordination between SpaceX and OneWeb."

The meeting came one day after The Wall Street Journal published an article titled "Elon Musk's Satellite Internet Project Is Too Risky, Rivals Say." The Journal article described OneWeb's allegations as follows:

Enlarge / Bill Nelson, former Democratic senator from Florida, appears at his Senate confirmation hearing on Wednesday. (credit: Saul Loeb/AFP/Bloomberg via Getty Images)

The US Senate Commerce Committee held a hearing for former Democratic Senator Bill Nelson on Wednesday to consider his nomination as NASA administrator. Nelson was warmly welcomed by his former colleagues—both Republicans and Democrats—who praised his wealth of experience in making space policy and said he was the best person for the job.

In response to these comments, Nelson thanked the senators and offered fairly bland remarks. “If you ask me what is my vision for the future of NASA, it is to continue for us to explore the heavens with humans and with machines," he said. "There is a lot of excitement."

There was not a lot of excitement during the hearing, however, aside from a handful of questions about a recent NASA award for the Human Landing System as part of the space agency's Artemis Moon Program.

Enlarge / Don't cry for me, I'm already dead...

In the world of social media, new networks are constantly popping into existence and then fading away when they fail to become the next Facebook (or Twitter, or TikTok, etc.). Still, last week's shutdown of the PS4's Communities features (and the lack of a suitable replacement on the PS5) has left many PlayStation fans bitter about the death of a vibrant space they used to connect with fellow gamers.

For those who never had a chance to join a PS4 Community, the groups served as a kind of player-created and moderated message board system, accessible directly via the PS4's system menu (and through the PlayStation Mobile app, before that connection was shut off last year). Members could share text messages, screenshots, wallpapers, and more on a shared "Community Wall" or form parties to chat and play multiplayer titles together with other online members.

Specific PS4 Communities could form around a single game or series, a geographic area, a cultural grouping, or just shared general interests ("Smoke&Play" and "Vaping Gamers" were popular Communities at one point).