Concepts explained
Light Falls Too — What Bends Is the Stage
Light has no weight, so it should not fall. Yet it bends beside something massive — not because it is pulled but because the road itself is curved.
Why? Light is not tugged toward the mass. The road itself is curved.
A bowling ball on a bedsheet
Stretch a sheet taut and set a bowling ball in the middle: the sheet dips. Roll a marble across it. The marble tries to go straight and still curves as it crosses the dip.
The analogy has limits. A sheet sags downward, while real space has no privileged down, and what curves is not only space but time along with it. The core survives anyway: what bends is not the light but the stage.
A photograph that had to wait for an eclipse
How do you check it? Look at a star behind the Sun. A star that ought to be hidden should appear slightly to one side, its light having been bent around.
The trouble is the Sun's glare, so they waited for a total eclipse. Photographs during the few minutes of totality, then the same stars photographed again months later in the night sky, and the two plates compared.
The stars sat a little off where they should have been.
The question that remainsIf it goes straight and still curves, what is bent — the road, or our idea of straight?