Suppose you and a friend are skydiving and want to toss a ball back and forth while freefalling, what type of ball would you use? The answer, of course, is a ball with the same terminal velocity as a skydiver. In “The right ball for playing catch while skydiving” physicist Rhett Allain calculates the terminal velocities of popular sporting balls and finds them all lacking. Read his article to discover how it can be done.
Allain seems a bit obsessed with flying this week as he has also written an article about the physics of flying in an Iron Man suit – complete with free body diagrams.
Jean-François Bonnefon is a researcher who studies the interactions between humans and artificial intelligence (AI) systems. He became his own case study this week when a paper he had cowritten and submitted to a journal was thoroughly rejected by an AI system.
Some of the reasons for the rejection are hilarious. Bonnefon was accused of plagiarism, for example, because his paper contained journal references that had also appeared in other papers.
In a tweet he says “It would have taken 2 min for a human to realize the bot was acting up. But there is obviously no human in the loop here. We’re letting bots make autonomous decisions to reject scientific papers. I’m so excited to be at the forefront of this new era!”
Scientists using the HiRISE camera on NASA’s Mars Reconnaissance Orbiter have spotted structures on the surface of the Red Planet that bear more than a passing resemblance to the Starfleet insignia from Star Trek. According to the researchers, the structures were made when lava flowed around crescent-shaped sand dunes on the surface of Mars. You can read all about it in the Independent.
