Author: easyfilo

Enlarge (credit: Wikipedia)

It’s a question I’m sure was keeping you up at night: can you make an object spin with a sound wave? The answer, generally speaking, used to be no. Now, though, mechanical engineers have taken a look at what their colleagues who play with lasers can do, and having seen the light, they copied it. And with that, spinning objects with sound waves has been achieved… but only in simulations.

Is it really that hard to make things spin?

To get an idea of why making things spin with sound waves is difficult, picture a tube that holds a turbine. Normally, to make the turbine spin, a fluid would flow past the blades of the turbine. The force of the fluid on the blades imparts a torque, which sets the turbine spinning. If we replace that flow with a pressure wave (like a sound wave), the fluid moves back and forth. So the local motion will first impart a torque that is clockwise and then one that is counterclockwise. The result is a rocking motion.

More fundamentally, the wave carries linear momentum but not angular momentum (specifically, it’s orbital angular momentum, but we’ll drop the “orbital”). Something that spins has angular momentum. In the turbine example, the total angular momentum cannot change. If the wave has no angular momentum and the turbine has no angular momentum, nothing will change.

Enlarge / KYIV, UKRAINE – FEBRUARY 28: A mother tends to her baby under medical treatment in the bomb shelter of the pediatric ward of Okhmatdyt Children’s Hospital on February 28, 2022 in Kyiv, Ukraine. (credit: Getty | Chris McGrath)

The World Health Organization on Wednesday said Russia is in violation of international humanitarian law based on several reported attacks on Ukrainian hospitals and health workers.

Several of the reports are unconfirmed, but in at least one confirmed case, a hospital came under a “heavy weapons attack” that killed four and injured 10 others, including six health workers. WHO Director-General Dr. Tedros Adhanom Ghebreyesus said the agency is working to confirm several other reports.

“The sanctity and neutrality of health care—including of health workers, patients, supplies, transport and facilities—and the right to safe access to care, must be respected and protected,” Tedros said in a press briefing Wednesday. “Attacks on health care are in violation of international humanitarian law.”

Enlarge / Asus PD5 with white light bars. (credit: Asus)

Asus’ ProArt Station PD5 desktop, announced Tuesday, aims to make it easier to multitask while you’re rendering, as lights on the tower’s front panel notify you when the process is complete.

An embedded smart module controls a thin pair of LED light bars, which run up parallel channels on the front panel. When the computer is rendering, the lights can flash a color or LED effect of your choosing, selected via Asus’ ProArt Creator Hub software. You’ll know the job is done when the lights revert to their standard white (or a different color of your choosing).

You can set the color or effects of the lights. (credit: Asus)

You can also set up rendering notifications through Microsoft Teams.

Enlarge (credit: Apple)

Apple will stream its next hardware event to the masses on March 8 at 10 am Pacific (1 pm Eastern), the company announced today. Invitations have already been sent to the press—though the event will be yet another prerecorded, streaming-only presentation with no media in attendance. Apple marketing SVP Greg Joswiak tweeted the now-customary Apple-logo-centric teaser video that doesn’t actually tease anything.

We never know exactly what will be announced at any given Apple event, but Bloomberg’s Mark Gurman reports that the lineup will include a refresh of the budget-friendly iPhone SE and the first iPad Air update in a little over a year.

Rumors have also circulated about updated designs and new Apple Silicon chips for the MacBook Air and the 13-inch MacBook Pro, and the high-end Intel Mac Mini, the 27-inch iMac, and the Mac Pro are all still running Intel chips. The characteristically cryptic “peek performance” tagline does at least hint at new chips for one or more Macs, whether that’s a truly next-gen Apple M2 for thin-and-light laptops or an M1 Pro/Max-focused refresh for the more powerful desktops.

Enlarge / Arc watch face on the Ionic. (credit: Valentina Palladino)

Google’s Fitbit brand is recalling 1.7 million smartwatches after dozens of reports of burns from the wearable fitness device. Apparently, the battery in the watch can overheat and burn the user’s wrist. The US Consumer Product Safety Commission (CPSC) reports that Fitbit has received 174 reports of the battery overheating worldwide, with “78 reports of burn injuries in the United States, including two reports of third-degree burns and four reports of second-degree burns.”

The CPSC says consumers should stop using the watch and contact Fitbit to receive pre-paid packaging to return the device. Just fill out the Fitbit recall form here to get the return kit. There’s also an official FAQ that describes the process. Upon receipt of your Ionic, Fitbit says you’ll get a full refund for the $299 MSRP and a coupon for 40 percent off “select Fitbit devices.” Before sending in your device, it’s a good idea to erase your data; go to “Settings -> About -> Factory reset” in the watch software.

Fitbit was a pioneer in fitness devices, but the rise of smartwatches like the Apple Watch has threatened single-use fitness devices. Fitbit’s answer was to buy the smartwatch company Pebble in 2016. A year later, the first Fitbit smartwatch, the Ionic, arrived. The device was sold from September 2017 through December 2021, though production stopped in 2020. With Google’s acquisition of Fitbit in 2021, the lineage of the “Fitbit OS” devices like the Ionic, Versa, and Versa 2 is most likely dead.