After 11 years of searching for the ripples of gravitational waves created by the collision of two massive black holes in space, it appears the waves are more mysterious than previously thought, according to a report on mashable.com.

Scientists thought they would have detected the waves by now, and that non-detection is causing some to rethink the mechanics of such a collision.

Gravitational waves are created when merging black holes disrupt the fabric of space-time surrounding them.  Researchers use powerful radio telescopes to search for them.

Vikram Ravi, a co-author of the study, told Mashable in an email, “The main reason we were surprised by our result is that we didn’t see the gravitational wave signals predicted by many teams of theorists.  “That is, we’ve achieved our design sensitivity that should have yielded a detection of gravitational waves, but didn’t. Our result means that theorists need to come up with new models for gravitational waves from binary super-massive black holes.”

Although they have never been observed, scientists expect the ripples in space-time to occur when massive black holes merge.  Understanding gravitational waves is last prediction of Albert Einstein’s theory of relativity that has yet to be confirmed.

The researchers aren’t sure why they haven’t found any evidence of the waves.  One theory is that surrounding gasses are creating friction and carrying the energy away faster than previously thought.

It is also possible that other factors may be masking the detection of the waves, and the scientists need to look at other parts of the data to see if they are hidden there.  Ravi added the result of the study means once they have removed the sources of measurement error, they still did not find any evidence of the waves.

But the scientists do not plan to discontinue the search.  The plan to sift through pulsar timing for many more years to come.