While your own weight may fluctuate, the fundamental constant
of gravity, which keeps your feet on the ground and the Earth
going around the sun, is the same everywhere at all times. Or so
Einstein’s theory of gravitation claims, at least. Alternative theories have
speculated that this constant might in fact vary as the universe expands, or
near objects of drastically different densities, fundamentally changing our
understanding of how the cosmos operates.
for changes in the
using 21 years of data
from a pulsar (the
core of a dead star
that spins like a crazed
of light a thousand
times per second).
as it is known, has
a tiny white dwarf
companion star, and
the two orbit each
accounting for every factor that perturbed their dance over 21 years,
astronomers ruled out any change in the underlying gravitational constant.