In a longitudinal wave, the parts where the coils are close together are called what.

The answer is compressions.

Explanation:

A compression is a region in a longitudinal wave where the particles are closest together. Hope this helped :)

the transfer of energy between two molecules spaced just nanometers apart plays a key role in many technologies, including photovoltaics, quantum information systems, lighting, and sensors, as well as in biophysics to measure nanometer distances and in photosynthesis. but an open question in this area is what effect, if any, the surrounding photonic environment has on this nanoscale energy transfer. by designing and performing a carefully controlled experiment to answer this question, scientists have settled the debate and found clues to improving the efficiency of many of the technologies that rely on this process.

explanation:

the sphincter muscles at the end of the digestive tract is the anus.