Simulations suggest other phenomenon besides black holes merging could produce gravity waves: A team of researchers with the University of Lisbon has created simulations that indicate that the gravitational waves detected by researchers with the LIGO project, and which are believed to have come about due to two black holes colliding, could just have easily come from another object such as a gravaster (objects which are believed to have their insides made of dark energy) or even a wormhole. In their paper published in Physical Review Letters, the team describes the simulations they created, what was seen and what they are hoping to find in the future. Read more at: http://phys.org/news/2016-05-simulations-phenomenon-black-holes-merging.html#jCp the paper: http://arxiv.org/abs/1602.07309 Abstract: It is commonly believed that the ringdown signal from a binary coalescence provides a conclusive proof for the formation of an event horizon after the merger. This expectation is based on the assumption that the ringdown waveform at intermediate times is dominated by the quasinormal modes of the final object. We point out that this assumption should be taken with great care, and that very compact objects with a light ring will display a similar ringdown stage, even when their quasinormal-mode spectrum is completely different from that of a black hole. In other words, universal ringdown waveforms indicate the presence of light rings, rather than of horizons. Only precision observations of the late-time ringdown signal, where the differences in the quasinormal-mode spectrum eventually show up, can be used to rule out exotic alternatives to black holes and to test quantum effects at the horizon scale.
I would say that a gravastar or wormhole would be a far more unusual discovery than a black hole. I'd also say that a wormhole would confirm GRT just as nicely as a black hole; a gravastar however would indicate new physics, where cosmological constant could appear without a metric, a very messy situation from a traditional GRT point of view.
Please Register or Log in to view the hidden image! Exactly the point of why I posted the article and paper! Please Register or Log in to view the hidden image! I was waiting for a particular anti mainstream poster to claim "yea yea I told you so!" I have said to our BH doubting friends even before the recent confirmation, that if BH's did not exist , then whatever was there would be far more weird and anti intuitive.
The earlier aLIGO results appeared too good...BH merging, Binary BH orbitting, Mass loss of 3M, GW etc etc and this was all based on template matching.....The obvious question was that could there be any other combination which could give similar results...and this papers says yes, and there will be more to come. Pattern matching with large number of variables, can not be so be deterministic.
BH's obviously are still way out ahead as the confirmed source, considering of course the exotic nature of the alternative. You yourself have poo pooed worm holes anyway. And of course when it does come back on line, further confirmation, along with other detectors are tipped to back the BH confirmation even further. PS: I certainly though would dearly love confirmation of worm holes, and even further solidarity for GR.
Solidarity is a non objective aspect....Science is brutal..Black and White...no grey. BH, WH, TT etc are presently at the highest level of Grey..no scope in their grey reduction.
No that is totally false. Not sure what your TT is but BH's are certainly as good as confirmed the last time I looked, and worm holes are still allowed by GR although no evidence of such at this time. So, as I previously said, if by any stretch of the imagination, the aLIGO gravitational waves confirmation could be attributed to worm holes, then this would have the cosmological world in raptures and further add the certainty value to the greatest theory of all time, GR. So, we'll settle for the more mundane BH's at this stage. Please Register or Log in to view the hidden image!
http://physicsworld.com/cws/article...g-gravitational-wave-signals-from-black-holes LIGO scientist Amber Stuver, who is based at the LIGO Livingston Observatory in Louisiana, US, is "thrilled" by the possibility that aLIGO may have detected an exotic object, but she confirms that "there is nothing in our observations that is inconsistent with this being a normal stellar mass black-hole system possessing an event horizon. Until we have evidence otherwise, we can't claim that this was anything but a stellar mass black hole binary merger." She tellsphysicsworld.com that "advanced detectors such as aLIGO, aVirgo, and KAGRA will need to increase their sensitivity" to pick up such signals. She also points out that the GW150914 event "was detected with aLIGO at about 30% of its design sensitivity. The potential is real that, if these exotic horizonless objects are out there mimicking black holes, we may very well find them in the near future". B S Sathyaprakash from Cardiff University in the UK, who is also a part of the LIGO team, agrees with the theorists' work, saying that "Our signal is consistent with both the formation of a black hole and a horizonless object – we just can't tell." He further explains that, although Einstein's equations predict how slightly deformed black holes vibrate, our understanding is incomplete when their deformation is large. "That's why we need a signal in which the post-merger oscillations of the merged object are large, and this can happen if we detect even more massive objects than GW150914, or if GW150914 is at least two to four times closer." Then, it would be possible to distinguish the signals, he says. Cardoso acknowledges that "black-hole mimickers are very exotic objects and by far black holes remain the most natural hypothesis". But he adds: "It is important to understand whether these exotic objects can be formed (for example in a stellar collapse) and if they are stable. Most importantly, we only focused on the ringdown part, but it is equally relevant to explain the entire gravitational-wave signal, including the inspiral and the merger phases. This would require performing numerical simulations with supercomputers to understand whether this picture is viable or not. We are currently working on this."
