The Concept for the LISA Space Based Interferometer

The Concept for the LISA Space Based Interferometer


Is Einstein's Theory of Gravity Right?

  • Einstein's Theory of General Relativity represents the best understanding of gravity so far. A major prediction of his theory is the emission of gravity waves by massive dynamic systems. Examples of these systems are some of the most exotic objects known - binary neutron stars, coalescing black holes, and stellar explosions known as supernovae.
  • Gravity waves are analogous to light waves - but very weak! They cause minute but predictable changes in size in large scale systems. Examples of practical gravity wave detectors are space-based or ground-based long baseline laser interferometers.
  • Because of seismic and gravity gradient noise on Earth, the space-based platforms are best for exploring the gravity wave sky. A specific mission selected for this by ESA (European Space Agency) as a cornerstone mission for the 2015 time frame is LISA - Laser Interferometer Space Antenna. Participation by NASA in this mission should provide critical technologies and advance the schedule by a decade.
  • While testing Einstein's General Relativity Theory, gravity wave detections could also provide answers to questions like:
  • X-ray spectral line emission serves as a probe of matter close to the event horizon of a black hole, thereby providing key characteristics of the object and information about strong gravity effects needed to test general relativity.

    • Missions: Astro-E, HTXS, LISA

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