Archives 26 February 2019

Slow-moving, hulking ships crisscross miles of ocean in a lawn mower pattern, wielding an array of 12 to 48 air guns blasting pressurized air repeatedly into the depths of the ocean.

The sound waves hit the sea floor, penetrating miles into it, and bounce back to the surface, where they are picked up by hydrophones. The acoustic patterns form a three-dimensional map of where oil and gas most likely lie.

The seismic air guns probably produce the loudest noise that humans use regularly underwater, and it is about to become far louder in the Atlantic. As part of the Trump administration’s plans to allow offshore drilling for gas and oil exploration, five companies are in the process of seeking permits to carry out seismic mapping with the air guns all along the Eastern Seaboard, from Central Florida to the Northeast, for the first time in three decades. The surveys haven’t started yet in the Atlantic, but now that the ban on offshore drilling has been lifted, companies can be granted access to explore regions along the Gulf of Mexico and the Pacific.

Twitter retains direct messages for years, including messages you and others have deleted, but also data sent to and from accounts that have been deactivated and suspended, according to security researcher Karan Saini. Saini found years-old messages in a file from an archive of his data obtained through the website from accounts that were no longer on Twitter. He also reported a similar bug, found a year earlier but not disclosed until now, that allowed him to use a since-deprecated API to retrieve direct messages even after a message was deleted from both the sender and the recipient — though, the bug wasn’t able to retrieve messages from suspended accounts.

Direct messages once let users “unsend” messages from someone else’s inbox, simply by deleting it from their own. Twitter changed this years ago, and now only allows a user to delete messages from their account. “Others in the conversation will still be able to see direct messages or conversations that you have deleted,” Twitter says in a help page. Twitter also says in its privacy policy that anyone wanting to leave the service can have their account “deactivated and then deleted.” After a 30-day grace period, the account disappears, along with its data. But, in our tests, we could recover direct messages from years ago — including old messages that had since been lost to suspended or deleted accounts. By downloading your account’s data, it’s possible to download all of the data Twitter stores on you.

Too little sleep. Not enough exercise. Far too much “screen time.” That is the unhealthy lifestyle of nearly all U.S. high school students, new research finds. The study, of almost 60,000 teenagers nationwide, found that only 5 percent were meeting experts’ recommendations on three critical health habits: sleep; exercise; and time spent gazing at digital media and television… “Five percent is a really low proportion,” said study leader Gregory Knell, a research fellow at University of Texas School of Public Health, in Dallas. “We were a bit surprised by that….”

“If kids are viewing a screen at night — staring at that blue light — that may affect their ability to sleep,” Knell said. “And if you’re not getting enough sleep at night, you’re going to be more tired during the day,” he added, “and you’re not going to be as physically active.”

Experts recommend a minimum of 8 hours of sleep at night for teenagers, plus at least one hour every day of “moderate to vigorous” exercise.

One professor of adolescent medicine points out that some high school homework now even requires using a computer — even though too much screen time can affect teenagers’ abiity to sleep.