There were many kinds of glasses, but generally speaking, young people mostly wore nearsighted glasses, which used concave lenses, while the elderly were more often farsighted and used convex lenses.
In Grosseteste's time, people had already discovered that convex lenses could magnify objects. Given his age, the glasses he used were reading glasses. The earliest nearsighted glasses did not appear in Florence until 1289, thirty years after his death.
The old monk had no children or relatives to inherit his "property." Though what he left behind was mainly documents, those manuscripts were divided up. Some were taken by universities, some by the Church, and others fell into the hands of private collectors.
Among them was a baron named Roger Bacon. He had studied the arts at the University of Oxford in 1247 before later transferring to cosmological science. In papers he published, he mentioned the polarization of light, which was generally believed to have been quoted from materials left behind by Grosseteste. If light was a substance, then no matter how "simple" its composition was, it had to multiply as its path lengthened.
Newton supported the corpuscular theory of light. He believed light was a stream of particles that left its source and moved in straight lines at a constant speed through a uniform medium according to the laws of mechanics. Newton's law of gravitation held that gravity propagated at infinite speed. No matter how far apart two objects were, or what kind of medium lay between them, once it formed, they could immediately sense its gravitational pull. Special relativity, meanwhile, held that the fastest speed at which information could travel through the universe was the speed of light...
Simply put, Newton defined time as absolute. Special relativity believed spacetime was variable and flat, while general relativity believed spacetime was