What is Acoustics? The generation, propagation, and receiption of mechanical waves in fluid or solid media.
Where Can I learn more? Wikipedia is great, but ExploreSound.org is fantastic.
Are there prominent groups of Acousticians? The Acoustical Society of America is the most popular scientific group of Acousticians in North America.
Click here to learn about what a speedster hears when running at near or above the speed of sound.
What is Tribomechadynamics? A very niche, hybrid discipline of science and engineering that combines tribology, contact mechanics, and structural nonlinear dynamics: "Tribomechadynamics" (TMD).
Where Can I learn more? Outside of the scientific literature and conferences, there isn't much. Rice University's page or the tribomechadynamcis lab page is probably the best resource at the moment.
Are there prominent groups of Tribomechadynamicists? The de facto TMD leader in the Untied States is Dr. Matt Brake of Rice University. A Committee of Joint Dynamcis is currently being formed.
What is Friction? Friciton between solid materials is the force acting opposite to the direction of external forces on a system with touching surfaces. It is not a fundamental force itself, but a manifestation of electro-magnetic and gravity forces.
Where Can I learn more? The Wikipedia page on friciton has thorough notes about basic friction concepts.
Are there prominent groups of Friction Scientists? Most friction scholars can be classified as tribologists. Tribology is a very large field. A popular tribology resource is tribonet.org.