Ray can not be seen but the effects of Ray can be seen and are often seen but not recognized. For many people, electricity is that which comes out of the two holes in the wall plug. For the scientifically inclined, electricity is a fundamental physical agency involving the presence and motion of electrons. For others, electricity is what causes electrical phenomena and electrical phenomena are caused by electricity. Let's take a quick look at these definitions.
Water is the flow of larger masses called molecules and there is only one outlet pipe for water.
The second definitions is circular and is of little help. This alternative view says that Ray is energy in one dimension and its common name is electricity. In space, it has the name neutrino , i.e., energy without mass. This one dimensional field is a strange concept for humans to accept especially for those who only believe in what they see. But consider this, one cannot see space.