Gravitational Waves: a new window to observe the Universe

Limits of detections
• All detectors are limited at high frequencies by shot noise,
which occurs because the laser beams are made up of
photons. If there are not enough photons arriving in a given
time interval it will be impossible to tell whether a
measurement is due to real data, or just random
fluctuations in the number of photons.
• All ground-based
detectors are also limited at low
frequencies by seismic noise, and must be very well
isolated from seismic disturbances. Passing cars and trains,
falling trees, earthquakes are significant sources of noise in
real interferometers.