1) Some scientists are arguing that Mars has an entire ocean’s worth of water… but trapped within the crust. Generally, everyone agrees that water once existed in great supply on the surface, due to telltale geographical features of Mars that indicate ancient shorelines, as well as networks of gullies that merge into larger channels implying erosion by water. The obvious question, though, is where did all this water go? The long-standing theory posits that, due to Mars’ lower gravity, all the Martian water evaporated and escaped through the atmosphere into outer space. The new theory, however, posits that as much as 99% of the ancient water was absorbed and bound into the rocky crust. As we know already happens on Earth, when water interacts with rock, chemical weathering forms clays and other hydrous minerals that contain water as part of their mineral structure. Both the old and new theories would equally expect to find hydrous minerals on the surface; however, they would disagree in expectations over the traces of water still in the Martian atmosphere. While water is made up of hydrogen and oxygen (H2O), the hydrogen part of water comes in two types: protium (light) and deuterium (heavy). The deuterium water makes up just a tiny fraction (0.02 percent) of water molecules, and because it is heavier, it is far less likely to escape the Martian atmosphere. Thus, if the old theory is correct that nearly all the water on Mars evaporated into space, it would predict the ratio of deuterium water molecules to protium water molecules still remaining in the atmosphere to show far more deuterium. However, if the new theory is correct that most of the ancient water was absorbed into the crust, then it would predict a much lower amount of deuterium in the atmosphere. Data collected by the ExoMars satellite reveals that the amount of deuterium in the atmosphere is indeed much lower than the old theory predicted.

2. Although noted thousands of years earlier by Aristotle, the peculiar “waggle dance” of the honeybee upon returning to the hive had remained mostly a mystery, or passing curiosity, until Karl von Frisch’s work in the 20th Century. In the 1920s, von Frisch’s first theory about the waggle dance was just that the dancing bee was merely imparting the scent of the flower in which it had just foraged, exciting its fellow bees to go off in search of more of the same. However, some 20 years later, von Frisch challenged his old theory with a new one. The new theory posited that the waggle dance was communicating much more information than just the scent of the flower; the waggle dance was also communicating specific flight directions. In 1943, von Frisch set up an experiment and installed one feeding place close to the hive (within 12 meters), and another much further away (300 meters). For this new experiment, the old theory predicts no change in the waggle dance between bees foraging the nearby food versus bees foraging the far away food, while the new theory predicted differences in the dances of the two sets of bees. In his observations, von Frisch noticed very different dancing patterns from foragers returning from the nearby feeding source as opposed to those returning from the distant feeder. All foragers from nearby performed short and round dances, whereas all foragers from the long-distance food source performed longer figure-8 tail-wagging dances. Karl von Frisch also noted the fact that the honeybee tail-wagging dance was different between the two groups in their dancing at different angles relative to vertical, which corresponded to the different angles relative to the sun that would direct the bees to the nearby or distant feeders.

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