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The largest lake the world has ever known
The megalake Paratethys once covered more than 2.8 million square kilometres, from the eastern Alps to what is now Kazakhstan. During its 5-million-year lifetime, the lake was home to many species found nowhere else, including miniature versions of whales, dolphins, and seals. As the Paratethys ebbed and grew saltier, the changes might have driven the ancestors of today’s giraffes and elephants to migrate towards the present-day African savannah. Eventually, erosion took its toll, and the megalake probably formed a spectacular waterfall as it drained into the Mediterranean Sea between 6.7 million and 6.9 million years ago.
Reference: Scientific Reports paper & Communications Earth & Environment paper
Features & opinion
Mathematicians answer: will it crush?
Mathematicians have revealed the threshold at which certain shapes can be crushed without becoming creased or distorted. The work helps to explain a pioneering idea from Nobel-laureate John Nash: you can crumple a sphere down to a ball of any size, without tearing it or using crisp folds. (The key is to add infinitely many smooth twists to its surface and put it in a higher-dimensional space.) The new findings are an important step to understanding sharp transition points in a variety of systems, such as when a flow becomes turbulent.
Reference: Advances in Mathematics paper & arXiv preprint