Concrete is the most common artificial composite material of all and typically consists of loose stones (aggregate) held with a matrix of cement. Concrete is a very robust material, much more robust than cement, and will not compress or shatter even under quite a large compressive force.
2) Y-axis contains absolute brightness Why do astronomers use the H-R Diagram? Astronomers use H-R Diagrams to classify stars and to understand how stars change over time.
US recorded by the USArray. Magnitude 8.0 SOLOMON ISLANDS Wednesday, February 6, 2013 at 01:12:23 UTC. The circles in the movie represent earthquake recording stations and the color of each circle represents the amplitude, or hei\àµ§ht, of the earthquake wave detected by the stationâs seismometer.