Light is detected
No light is detected
How the Ligo system works
Mirror
Detector
building
Laser beam
4
Recombined, they cancel each other out
3
Back inside the detector, the laser beams arrive perfectly aligned
2
Mirrors reflect the twin beams back to a detector
1
A single laser beam is split and directed down two identical tubes, 4km long
Detecting gravity waves
3
The recombined waves no longer cancel each other out. Light reaches the detector and the gravity wave can be measured
2
As the distances fluctuate the peaks and troughs of the two returning laser beams move in and out of alignment
1
When spacetime is distorted by a gravity wave, the two tubes change length. One tube stretches as the other contracts over and over until the wave has passed
Spacetime
What is a gravity wave?
Rippling out from a supermassive collision, for example between two black holes, gravity waves could be detected through the stretching and contracting of space and time
Light is detected
No light is detected
Spacetime
Detecting gravity waves
3
The recombined waves no longer cancel each other out. Light reaches the detector and the gravity wave can be measured
2
As the distances fluctuate the peaks and troughs of the two returning laser beams move in and out of alignment
1
When spacetime is distorted by a gravity wave, the two tubes change length. One tube stretches as the other contracts over and over until the wave has passed
How the Ligo system works
Mirror
Detector
building
Laser beam
4
Recombined, they cancel each other out
3
Back inside the detector, the laser beams arrive perfectly aligned
2
Mirrors reflect the twin beams back to a detector
1
A single laser beam is split and directed down two identical tubes, 4km long
What is a gravity wave?
Rippling out from a super- massive collision, for example between two black holes, gravity waves could be detected through the stretching and contracting of space and time