MAY 2019. DISCOVER 49Einstein’s
Peculiar
Predictions
Relativity makes numerous
bizarre predictions, many of
them experimentally verified.
They only seem bizarre
because we don’t notice
them in our daily lives — we
live, for the most part, in
Newton’s reality. But beyond
that lies Einstein’s universe,
where gravity bends space
and time to its will. Here are
some of the theory’s strangest
side effects:* Gravity literally slows
down time. Waves of light
emitted by stars stretch
out because of this time
bending, and objects closer
to a massive object age more
slowly. Super-precise clocks,
which tick according to the
vibrations of atoms, have
verified that gravity alters
time’s flow.* Satellites have shown that
rotating celestial bodies
twirl the fabric of the
cosmos around themselves,
like honey twisted by a
spoon, affecting the motion
of gyroscopes.* One prediction solved a
long-standing dilemma, a
weird wobble in Mercury’s
orbit that Newton’s math
couldn’t account for.
(Astronomers had initially
blamed a hidden planet called
Vulcan.) Relativity explained
the wonky orbit in terms of
the warping of space by the
sun’s powerful gravity.* Tiny ripples in reality,
caused by colliding black
holes, have tripped sensors in
highly sensitive instruments
buried underground on Earth.
(See “Ripple Effect,” page 50.)why a clock on a satellite ticks a few dozen microseconds faster than a clock on Earth; without accounting for that discrepancy, GPS technologies wouldn’t work.
EinstEin’s
inspiration
for gEnEral
rElativity
struck whilE
hE was a
patent
clErk in
SwitzErland
in 1907.THE RELATIVE BASIcS
The main takeaways behind Einstein’s
general theory of relativity:1
Time and space are neither flat nor
fixed; they are curved and distorted
by mass and energy.2
Gravity is not a force, but rather a
distortion of time and space.3
The effects of gravity are
indistinguishable from
the effects of acceleration,
over a small space.HE
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