UPDATED: August 3, 2021 12:32 IST A scuba diver observes the purple, white and green microbes covering rocks in Lake Huron’s Middle Island Sinkhole. (Photo: AP) Scientists have a new idea for how Earth got its oxygen: It’s because the planet slowed down and days got longer. A study published Monday proposes and puts to the test the theory that longer, continuous daylight kick-started weird bacteria into producing lots of oxygen, making most of life as we know it possible. They dredged up gooey purple bacteria from a deep sinkhole in Lake Huron and tinkered with how much light it got in la...