Gravity waves finally discovered

Astronomers say they have finally found elusive gravitational waves, the mysterious ripples in the fabric of space. As these ripples pass the Earth, local space is alternately stretched and compressed

Gravitational waves:

Concentric

ripples that squeeze and stretch

fabric of space-time, caused by

movement of mass. Predicted

by Albert Einstein in his 1916

General Theory of Relativity

U.S.

Livingston,

Louisiana

Hanford,

Washington

LIGO sites

Two detectors

help sift out terrestrial rumblings,

such as traffic and earthquakes,

from other faint vibrations within space

Effect of gravitational ripples,

hugely exaggerated

LIGO – Laser Interferometer Gravitational Wave Observatory

1

Laser beam fed into machine

2

Laser’s light split in two and sent down

identical, perpendicular 4km tunnels

3

Beams bounce back

and forth between

mirrors

3

Mirror

Light

storage

arm

Light

storage

arm

Beam

splitter

2

Laser

4

Photodetector

4

Two light

paths recombined

and sent to detector

1

By analysing light reflected

off mirrors it is possible to detect

tiny changes – fractions of width of

an atom – in distance between mirrors

Source: LIGO Caltech

Pictures: Associated Press, NASA

Gravity waves finally

discovered

Astronomers say they have finally found elusive gravitational waves, the mysterious ripples in the fabric of space. As these ripples pass the Earth, local space is alternately stretched and compressed

Gravitational waves:

Concentric ripples

that squeeze and

stretch fabric of

space-time, caused

by movement of mass.

Predicted by Albert

Einstein in his 1916

General Theory

of Relativity

Effect of

gravitational

ripples, hugely

exaggerated

LIGO sites

Two detectors help

sift out terrestrial

rumblings, such

as traffic and

earthquakes,

from other faint

vibrations within space

U.S.

Livingston,

Louisiana

Hanford,

Washington

LIGO – Laser Interferometer

Gravitational Wave Observatory

1

Laser beam fed into machine

2

Laser’s light split in two and sent down identical,

perpendicular 4km tunnels

3

Beams bounce back and forth between mirrors

4

Two light paths recombined and sent to detector

By analysing light reflected off mirrors it is

possible to detect tiny changes – fractions of

width of an atom – in distance between mirrors

Light

storage

arm

Light

storage

arm

3

Mirror

Beam

splitter

2

Laser

1

4

Photodetector

Source: LIGO Caltech

Pictures: AP, NASA

Gravity waves

finally

discovered

Astronomers say they have finally found elusive gravitational waves, the mysterious ripples in the fabric of space. As these ripples pass the Earth, local space is alternately stretched and compressed

Gravitational waves:

Concentric

ripples that squeeze and stretch

fabric of space-time, caused

by movement of mass.

Predicted by

Albert Einstein in

his 1916 General

Theory of Relativity

Effect of gravitational ripples,

hugely exaggerated

LIGO sites:

Two detectors

help sift out terrestrial rumblings,

such as traffic and earthquakes,

from other faint vibrations

within space

U.S.

Livingston,

Louisiana

Hanford,

Washington

LIGO – Laser Interferometer

Gravitational Wave Observatory

1

Laser beam fed into machine

2

Laser’s light split in two and

sent down identical,

perpendicular 4km tunnels

3

Beams bounce back and forth

between mirrors

4

Two light paths recombined

and sent to detector

By analysing light reflected off

mirrors it is possible to detect

tiny changes – fractions of

width of an atom – in distance

between mirrors

Light storage

arms

3

Mirror

4

Laser

2

1

Beam

splitter

Photodetector

Pictures: AP, NASA

Source: LIGO Caltech