The first set of waves to be detected by seismographs are P waves, or primary waves, as they’re the fastest. They’re compressional or longitudinal waves that push and pull the ground in the direction ...

Longitudinal waves show areas of compression and rarefaction: compressions are regions of high pressure due to particles being close together. rarefactions are regions of low pressure due to ...

The ability to withstand shear is one of the properties that distinguishes a solid from a liquid. The proposal of an elastic metamaterial that in one direction only supports compressional waves ...