What IS Wave?

Waves must have wave carriers. All waves carriers are matters, gas, liquid, and solid matters.

It is impossible to find waves in the vacuum space.

When a mass is accelerating, its gravity affects the line of sight masses at any distance simultaneously. 

When a mass's surface atoms are oscillating, its levity affects the line of sight matters' surfaces at any distance simultaneously. 

Sound is a gravity wave, light is a levity (universal repulsion force) wave. Both waves are coexisting with the carriers/mediums/matters.

If you jump on the floor, it vibrates, produces gravity waves in the building and air. If you knock on the door, it vibrates, produces gravity waves in the door and air. If you wave your big hand, it produces low-frequency gravity waves.  

A gravity wave is a matter-wave. Due to gravity is coexisting with the matters.

Antennas or power lines have current flow back and forth? What is an EM wave? How to produce an EM wave? What mechanism? What is a photon? What carries EM waves? space or air?

Is photon particle existing? What is an EM wave? Is the photon an EM wave?