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iStock / VeraPetruk
iStock / VeraPetruk

Can You Solve the Pirate Riddle?

iStock / VeraPetruk
iStock / VeraPetruk

In the video riddle below, we explore the distribution of pirates' booty. It gets complicated.

The scenario is this: Amaro is the captain of a pirate ship. His mateys, Bart, Charlotte, Daniel, and Eliza, are the other members of the crew. The group has come upon a bounty of 100 gold coins, and now must divide it up among the group according to "the pirate's code."

The code stipulates that Amaro, as captain, gets to suggest the first plan for distributing the coins among the five pirates. After that proposal, each pirate (including Amaro) votes "yarr" or nay on whether to accept the proposal. If the proposal results in either a tied vote (equal numbers "yarr"/nay) or a majority of "yarrs," it passes and the coins are immediately distributed. If it fails to meet this threshold, Amaro must walk the plank, making Bart the next captain. (Amaro walking the plank removes him from future votes, as well as eligibility for coin disbursals, on account of his death. Yuck.)

This process now repeats with Bart as captain, and the captain's hat will be passed on, in order, to Charlotte, Daniel, and finally Eliza. (If it gets all the way to Eliza without a passing proposal, she gets the booty.)

To make the situation more complex, there are rules governing how the pirates act. First, they each want to stay alive (that's their highest priority), but their next priority is maximizing their personal gold horde. Second, they distrust each other—there are no alliances and they cannot collaborate on a strategy. Third, they are bloodthirsty, and would love to see a fellow pirate walk the plank if they think it won't affect their own gold distribution. Fourth, each pirate has excellent logical deduction skills, and they're aware that everyone has the same skills. For the purposes of the puzzle, we can assume everyone is logical and obeys all the rules.

So we arrive at the key problem for Amaro: What distribution should he propose to ensure he lives and maximizes his own gold return? In order to figure this out, we have to walk through the chain of events and sort it out. Get your scratch paper ready!

The video below explains this puzzle (and its solution); here are the "rules" as stated at the 1:48 freeze-frame:

1. The captain makes a proposal for splitting up the 100 gold coins, which everyone votes on. A proposal that gets a tie or a majority of yarrs passes. A proposal with a majority of nays fails, and the captain has to walk the plank. The new captain then makes a proposal. The order of succession is Amaro, Bart, Charlotte, Daniel, and Eliza.

2. Each pirate's primary objective is to stay alive.

3. Each pirate's secondary objective is to maximize his or her gold.

4. Each pirate will vote to make the others walk the plank, all other results being equal. There are no abstentions.

5. Each pirate knows that the others share the same set of preferences.

6. Pirates cannot collaborate, make promises to each other, or form alliances; there is no communication outside the proposal and the votes, and no other trickery like murder or bribery. Even though they're pirates.

7. Each pirate is a perfect logician and all of them know this about each other.

Think on this a bit, and for the answer, have a look:

For more on the puzzle, check out this TED-Ed page. For a solution (and longer/more complex versions), read this PDF of an article by Ian Stewart.

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Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

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WWF
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Animals
Watch an Antarctic Minke Whale Feed in a First-of-Its-Kind Video
WWF
WWF

New research from the World Wildlife Fund is giving us a rare glimpse into the world of the mysterious minke whale. The WWF worked with Australian Antarctic researchers to tag minke whales with cameras for the first time, watching where and how the animals feed.

The camera attaches to the whale's body with suction cups. In the case of the video below, the camera accidentally slid down the side of the minke whale's body, providing an unexpected look at the way its throat moves as it feeds.

Minke whales are one of the smallest baleen whales, but they're still pretty substantial animals, growing 30 to 35 feet long and weighing up to 20,000 pounds. Unlike other baleen whales, though, they're small enough to maneuver in tight spaces like within sea ice, a helpful adaptation for living in Antarctic waters. They feed by lunging through the sea, gulping huge amounts of water along with krill and small fish, and then filtering the mix through their baleen.

The WWF video shows just how quickly the minke can process this treat-laden water. The whale could lunge, process, and lunge again every 10 seconds. "He was like a Pac-Man continuously feeding," Ari Friedlaender, the lead scientist on the project, described in a press statement.

The video research, conducted under the International Whaling Commission's Southern Ocean Research Partnership, is part of WWF's efforts to protect critical feeding areas for whales in the region.

If that's not enough whale for you, you can also watch the full 13-minute research video below:

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