Earth: a large rock filled with molten rock that revolves around an even larger ball of gas in an ever-growing expansion of space. It sounds bizarre when you say it like that, doesn't it? The earth is insanely particular. Too much of this element or too little of that, and the whole system falls apart. Life, plant or animal, can only arise and grow when there is a perfect balance of multiple elements. Roses do well in limestone soil with a high pH. On the other hand, fungi such as mushrooms prefer a lower pH. Balance keeps our floating ‘Pale Blue Dot’ going.