Watering your lawn in the summer can be both pragmatic and fun with so-called "silly sprinklers," designed to create amusing loops and spirals of water jets. And there's some fascinating physics at work to boot. Researchers at New York University's Courant Institute conducted a series of experiments with different silly sprinkler designs to find the answer to a longstanding problem in fluid dynamics, according to a new paper published in the Proceedings of the National Academy of Sciences.

As previously reported, the reverse sprinkler problem is associated with physicist Richard Feynman because he popularized the concept, but it actually dates back to a chapter in Ernst Mach’s 1883 textbook The Science of Mechanics (Die Mechanik in Ihrer Entwicklung Historisch-Kritisch Dargerstellt). Mach’s thought experiment languished in relative obscurity until a group of Princeton University physicists began debating the issue in the 1940s.

Feynman was a graduate student there at the time and threw himself into the debate with gusto, even devising an experiment in the cyclotron laboratory to test his hypothesis. One might intuit that a reverse sprinkler would work just like a regular sprinkler, merely played backward, so to speak. But the physics turns out to be more complicated. “The answer is perfectly clear at first sight,” Feynman wrote in Surely You’re Joking, Mr. Feynman (1985). “The trouble was, some guy would think it was perfectly clear [that the rotation would be] one way, and another guy would think it was perfectly clear the other way.”

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When Warner Bros. showed new footage of its forthcoming satirical black comedy, Digger, at Cinemacon in April, industry insiders considered it a highlight of the event. The general public hasn't seen anything other than a title announcement and a teaser in May that largely provided a retrospective of star Tom Cruise's career, with just 30 seconds of footage from Digger tacked on at the end. But now we have the official trailer, and it certainly lives up to that earlier enthusiastic word of mouth. We're getting powerful Dr. Strangelove vibes, updated for our 21st-century times.

Digger is four-time Oscar-winning director Alejandro G. Iñárritu's (Birdman) first English-language film since 2015's The Revenant. The official logline is short and sweet: "The most powerful man in the world races to prove he's humanity's savior before the disaster he unleashed destroys everything." That disaster appears to be ecological in nature and involves a rapidly melting iceberg, as well as some nuclear waste.

Cruise is often at his best when he takes big creative swings and plays against type—the rage-fueled motivational speaker in Magnolia, for instance, or the over-the-top movie mogul in Tropic Thunder. He's almost unrecognizable in this new trailer as eccentric billionaire oil baron Digger Rockwell—wispy hair, potbelly, and all.

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