Composting can be pursued at many different levels, from the gardener who likes to produce "black gold" to the operator of a multi-acre commercial composting facility. Some of the topics in the Science and Engineering section may be far too technical to be relevant to casual composters. On the other hand, some may be intriguing. You might, for example, wish to learn more about the invertebrates or the microorganisms that create compost. You might be curious about the temperature curve produced by compost as it goes through its cycle of heating and cooling. Or you might like to learn how to measure the pH or moisture content of your compost. You might even want to try calculating desirable proportions for the materials you wish to compost. We invite you to explore these pages to whatever level your curiosity takes you, realizing that compost is a rich topic for scientific research and discovery as well as a practical method of recycling organic matter and reducing solid waste.