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RIPPLES
THROUGH
SPACETIME
GRAVITATIONAL WAVES
I
n 1916, as he worked on his
theory of relativity, Albert
Einstein predicted that, as
a mass moved, its gravity would
cause ripples in the fabric of
spacetime. Every mass would
do this, although larger masses
would make bigger waves, in
the same way that a pebble
dropped in a pond makes an ever-
increasing circle of ripples, while
a meteor impacting the ocean
creates tsunami-sized waves.
In 2016, 100 years after Einstein’s
predictions, a collaboration
between scientists working under
the name LIGO announced that
they had discovered these ripples,
or gravitational waves. TheirIN CONTEXT
KEY ORGANISATION
LIGO (2016)BEFORE
1687 Isaac Newton formulates
the universal law of gravitation,
which sees gravity as a force
between masses.1915 Albert Einstein presents
the general theory of relativity,
which explains gravity as the
distortion of spacetime by
mass, predicting the existence
of gravitational waves.1960 American physicist
Joseph Weber attempts to
measure gravitational waves.1984 Rai Weiss and Kip
Thorne found LIGO.AFTER
2034 eLISA is scheduled to
search for gravitational waves
using three spacecraft in
heliocentric orbits, between
which lasers will be fired.