Now, astronomers of the Harvard-Smithsonian Center for Astrophysics (CfA) think the lensed galactic light may also contain information about the presence of supermassive black holes lurking in the cores of the foreground galaxies.
The amount of gravitational lensing is directly related to the foreground galaxy's mass. The greater its mass, the greater its collective gravity, the greater the lensing effect. If a supermassive black hole is present in the core of that galaxy, this additional compact mass could add some further warping to the structure of the lensed light.
Although the CfA astronomers don't think such a fine structure could be detected by the technology currently available to us, very large arrays of interconnected radio telescopes may detect it.
If you thought detecting black holes through gravitational lensing was weird, it's about to get even weirder.
In a Discovery News guest article published this week, Pat Galea of Icarus Interstellar Inc. describes a potential mechanism by which gravitational lensing could be used to "amplify" interstellar communications.
If a starship were to ever embark on a journey through the light-years of interstellar space - to Alpha Centauri, say, 4.4 light-years from Earth - a signal transmitted by the starship would take years to be received. Not only would there be the inconvenience of having to wait for very long periods of time, the power of the radio transmission may be too weak to detect after traveling such an extreme distance.
A novel way around this issue could see a relay spacecraft sitting at a distance of around 500 Astronomical Units (AU - where 1 AU is the distance the Earth orbits the sun) from the sun, in the opposite direction to where the starship is traveling.
Using the space-time distortion caused by the sun‘s mass, the solar gravitational lensing effect may be enough to focus the interstellar transmission at the 500 AU mark, allowing interstellar communications to occur.
This may sound like science fiction, but as Hubble is proving, gravitational lensing is potentially a powerful tool with applications from black hole hunting to communicating with interstellar spacecraft.
Image (top): The distant light of a galaxy forms a ring due to the warping of the gravitational field of a galaxy in the foreground. Image (middle): The reconstruction of a magnified galaxy through gravitational lensing. Credits: NASA, ESA, J. Rigby (NASA Goddard Space Flight Center), K. Sharon (Kavli Institute for Cosmological Physics, University of Chicago), and M. Gladders and E. Wuyts (University of Chicago)