BICEP Detection Of Gravitational Waves Called Into Question As Researchers Discover Potential New Way To Observe Them

Chuck Bednar for redOrbit.com – Your Universe Online
As one team of experts has published a study claiming to have discovered hints of gravitational waves in stars, another has released a new galactic dust map that casts doubts on previous research claiming to have detected such waves earlier this year.
In the first study, the authors demonstrated how these invisible ripples in the fabric of space and time could be observed by looking at the stars. Their new model proposes that a star oscillating at the same frequency as a gravitational wave will absorb energy from the wave and become brighter – an overlooked prediction of Einstein’s 1916 theory of general relativity which contradicts previous assumptions about the behavior of the waves.
They explained that gravitational waves are similar in nature to the sound waves emitted after an earthquake, except that the source of the so-called space tremors are events like supernovae, binary neutron stars or the mergers of black holes and neutron stars. While scientists have long known about the existence of gravitational waves, the researchers said that they have never directly observed them (though they are currently attempting to).
One of the reasons that detecting these waves is so difficult is because they interact so weakly with matter, the research team explained. However, their new model suggests that these gravitational waves could actually have more of an impact on matter than previously realized, and that stars with oscillations (vibrations) matching their frequency can resonate and absorb a large amount of energy from the ripples.
“It’s like if you have a spring that’s vibrating at a particular frequency and you hit it at the same frequency, you’ll make the oscillation stronger. The same thing applies with gravitational waves,” Barry McKernan, a research associate in the Museum’s Department of Astrophysics and a professor at the Borough of Manhattan Community College, said in a statement.
If the stars absorb a tremendous pulse of energy, they can become temporarily energized and made brighter than usual while they slowly discharge the energy. McKernan and his colleagues report that this method could provide scientists with a new way to indirectly detect gravitational waves – using detectors to search for a drop in the intensity of gravitational waves measured when a star at the right frequency passes in front of an energetic source.
In related research, a galactic dust map released by the European Planck space telescope on Monday and submitted to the journal Astronomy & Astrophysics (A&A), found a significant amount of interstellar dust in the region of sky previously studied by the BICEP2 telescope when it reportedly detected gravitational waves earlier this year.
That dust, according to Ian O’Neill of Discovery News, may have obscured the primordial light in which the South Pole-based telescope purportedly detected the signal of gravitational waves. The discover means that it is possible that BICEP2’s potential detection of gravitational waves may have been nothing more than a false alarm.
“In a nutshell, last March, astrophysicists… announced the potentially historic discovery that their experiment had, for the first time, detected the signal of gravitational waves etched into the ancient ‘glow’ of the Big Bang – a ubiquitous radiation seen at the outermost reaches of the observable Universe known as the cosmic microwave background, or simply CMB,” explained O’Neill.
“The discovery of gravitational waves would be historic in itself, but the ramifications of seeing gravitational waves in the CMB would be far-ranging. These gravitational waves would have their origins just after the Big Bang during a rapid period of expansion known as ‘inflation,’” he added. “This would therefore provide captivating evidence for one of the leading theories of cosmic birth… In short, the discovery of ancient gravitational waves could tie up some of the most fundamental questions of the quantum and cosmological nature of our Universe.”
However, as BBC News science correspondent Jonathan Amos points out, the new Planck report describes properties of dust polarization across a large percentage of sky at intermediate and high galactic latitudes, including a portion of the field relevant to BICEP2.
In fact, Amos said the findings were “not encouraging” because there was “significantly more dust” in the so-called southern hole than the BICEP2 team had expected. In fact, most of the data – if not all of it – could have been attributed to dust. Planck scientist Dr. Cécile Renault admitted to Amos that it was “possible,” but that their measurements had already accounted for a high degree of error.
“Even if the American and European approaches turn out to be unsuccessful this time, these groups will have pointed the way for future observations that are planned with superior technology,” the BBC News writer added. “Planck has actually now identified parts of the sky that have less dust than the area probed by BICEP.”
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Traveling at the Speed of Thought: Einstein and the Quest for Gravitational Waves by Daniel Kennefick