Gravitational Waves:

Some of the scientists think gravitational waves exist and which the fabric of space is swarming with them, just as the ocean is filled with chop and swells. There is a theory to the consequence that the evolution of the identified universe is a single cycle in an oscillating system, a wave with a period unbelievably long.

How many people walk about thinking that they are sub-microscopic specks on a particle in a collapsing and expanding bubble in the laboratory of the heavens? Not many, though even to them, gravitational waves, supposing that they exist, are not possible to see with our eyes and hard to envision even with the keenest mind's eye since gravitational waves are 4-dimensional.