The purpose of the evolved Laser Interferometer Space Antenna (eLISA) project is to detect gravitational waves. Gravitational waves are ripples in the fabric of spacetime that are caused by the acceleration of massive objects. They were first predicted by Albert Einstein in his theory of general relativity.

The eLISA project is an evolved version of the Laser Interferometer Space Antenna (LISA) project, which was initially proposed in the 1990s. The main goal of eLISA is to detect and study gravitational waves with much higher sensitivity and accuracy than ground-based detectors such as LIGO (Laser Interferometer Gravitational-Wave Observatory).

Here is a detailed explanation of the purpose of the eLISA project:

1. Gravitational Waves: Gravitational waves provide a unique way of studying the universe. They carry information about the most violent and energetic events in the cosmos, such as the mergers of black holes and neutron stars, supernova explosions, and the early moments of the universe. By detecting and studying gravitational waves, scientists can gain insights into the nature of gravity, the formation and evolution of galaxies, and the origin of the universe itself.

2. Space-based Observatories: Ground-based detectors like LIGO have already made groundbreaking discoveries in the field of gravitational wave astronomy. However, space-based observatories like eLISA have several advantages. They are not affected by the same noise sources as ground-based detectors, such as seismic activity and environmental disturbances. This allows for much higher precision measurements and the detection of lower frequency gravitational waves.

3. Laser Interferometry: eLISA uses a technique called laser interferometry to detect gravitational waves. It consists of three spacecraft flying in a triangular formation, with laser beams sent between them. Gravitational waves passing through the spacecraft cause tiny changes in the distances between them, which can be measured by the interference of the laser beams. This allows for the detection and characterization of gravitational waves.

4. Evolved Technology: The eLISA project aims to improve upon the technology and design of the original LISA concept. It includes advancements in laser and interferometer technology, as well as improvements in spacecraft formation flying and drag-free control systems. These advancements will significantly enhance the sensitivity and accuracy of gravitational wave measurements.

In conclusion, the purpose of the evolved Laser Interferometer Space Antenna (eLISA) project is to detect gravitational waves and study their sources and properties. By doing so, scientists hope to gain a deeper understanding of the universe and its fundamental forces.

To detect gravitational waves