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The PlaguesEvery spring, Jewish people the world over celebrate Passover, a holiday that recounts the Exodus, when, according to the Torah (the Old Testament of the Bible), the Jews left Egypt for Israel.
However, before Moses could lead the 40-year journey through the desert, he needed the Pharaoh's permission to free the Jews, who were slaves in the land of Egypt, according to the Torah. But the Pharaoh had a hard heart, prompting the Lord to send down 10 plagues until the Pharaoh changed his mind, the Torah reports.
Could any of these plagues have occurred through natural phenomena? Live Science looks at possible scientific explanations behind each of the 10 plagues.
BloodSlide 2 of 21
To unleash the first plague upon the Egyptians, Moses struck the river Nile with his staff, turning its waters to blood. At the same time, his brother Aaron performed an identical transformation in the canals, tributaries, ponds and pools throughout Egypt.
After the water turned to blood, "thefish in the Nile died, and the Nile stank, so that the Egyptians could not drink water," according to the Bible, Exodus chapter 7, verse 21, English Standard version.
The sudden appearance of red-hued waters in the Nile could have been caused by a red algae bloom, which appears when certain conditions enable a type of microscopic algae to reproduce in such great numbers that the waters they live in appear to be stained a bloody red.
This phenomenon is known as "red tide" when it happens in oceans, but red algae are also well-represented in freshwater ecosystems. And these algae blooms can certainly be harmful to wildlife, as the algae contain a toxin that can accumulate in shellfish and poison the animals that feed on them. Fumes from densely-concentrated algae blooms can also disperse toxins in the air, causing breathing problems in people that live nearby.Slide 3 of 21
FrogsSlide 4 of 21
What do you do next, after turning a nation's water supply into blood? If you're following Moses' playbook, you inundate them with frogs.
For the second plague, Moses allegedly conjured vast quantities of frogs that swarmed into people's homes — even finding their way into the Egyptians' beds, ovens and cookware.
As it happens, the phenomenon of "raining frogs" has been reported multiple times throughout history and in a range of locations around the world. A report published July 12, 1873 in Scientific American described "a shower of frogs which darkened the air and covered the ground for a long distance," following a recent rainstorm. The account was one of dozens of similar anecdotes collected in "The Book of the Damned" (1919), though its somewhat skeptical author suggested that the frogs may have simply dropped from trees.
And in May 2010 in Greece, thousands of frogs emerged from a lake in the northern part of the country, likely in search of food, and disrupted traffic for days, CBS News reported.Slide 5 of 21
LiceSlide 6 of 21
The third plague, lice, could mean either lice, fleas or gnats based on the Hebrew word (Keenim). If a toxic algal bloom led to the first plague, and a pile of dead frogs followed, it's not surprising that a swarm of insects of some sort would have followed. That's because frogs typically eat insects; without them, the fly population could have exploded, Stephan Pflugmacher, a climatologist Leibniz Institute for Water Ecology and Inland Fisheries in Berlin, said in a television special about the plagues that aired on the National Geographic Channel in 2010. Interestingly, both body lice and fleas can theoretically transmit the bacteria Yersinia pestis, which causes bubonic plague, according to a 2010 study published in the journal Emerging Infectious Diseases. If so, then an infestation with lice could have set the stage for the later plagues, such as boils, a 2008 review of plague science found. Scientists have also argued that the sickness that killed the beasts of the field for Egyptians in later plagues might have been Bluetongue or African horse sickness, both of which can be spread by insects from this plague, according to a 2008 Yale Journal of Biology and Medicine.Slide 7 of 21
Wild beastsSlide 8 of 21