Sunday, August 27, 2017

Gravitational Waves II - Gossip Over Colliding Neutron Stars

Rumors Swell Over New Kind of Gravitational-Wave Sighting

Gossip over colliding neutron stars has astronomers in a tizzy

Astrophysicists may have detected gravitational waves last week from the collision of two neutron stars in a distant galaxy—and telescopes trained on the same region might also have spotted the event.
Rumours to that effect are spreading fast online, much to researchers’ excitement. Such a detection could mark a new era of astronomy: one in which phenomena are both seen by traditional telescopes and ‘heard’ as vibrations in the fabric of space-time. 
Astronomers who do not want to be identified say that NASA’s Fermi Gamma-ray Space Telescope is rumoured to have spotted γ-rays emerging from the same region of sky as the potential gravitational-wave source—gossip which a senior Fermi member declined to comment on.
When the scientists at LIGO made their claims about having detected gravitational waves as result from the merging of two black holes, one of my criticism was that there was no additional evidence for such an explanation and that I would have expected to see a gamma-ray-burst at the same time, which was not the case. This time however there are rumors that a GRB was indeed detected at the same time as the event at LIGO. Does this change my assessment of the observation and the capability of LIGO? 
- Yes, it does. If the rumors are true and a GRB is confirmed by the Fermi telescope, then LIGO was able to make a correct prediction strengthening the theory that what they measured were indeed gravitational waves. As a scientist I need to be willing to change my initial theory as soon as new evidence becomes available.
- A simultaneous detection of an event at LIGO and a GRB would indicate that LIGO was able to measure gravitational waves. However it does not tell us what event exactly caused these gravitational waves. The merging of two neutron stars is a plausible explanation, but the observation is not a sufficient proof for it.
- Anyway the oscillations that have been detected in this event were significantly different from the earlier ones, which is why the LIGO scientist explain it with the merging of lower mass neutron stars instead of black holes. Since black holes do not exist in the way how most of today's astrophysicists imagine, while there is ample proof for the existence of neutron stars (pulsars), this explanation is far less questionable than the one of earlier events. And the lower frequency of the oscillation indicates that it was a completely different event this time. Therefore there is no reason to change my assessment of the earlier ambitious announcements of having detected merging black holes. These claims were not supported by sufficient evidence and therefore based on sloppy scientific methods. 
- If the Fermi telescope confirms a GRB, then we know how real gravitational waves look like and that they have to coincide with gamma ray burst, as I have apparently correctly predicted in my first post about this subject. It also shows that the first two observations were wrongly interpreted by the scientists at LIGO. It would have coincided with a far stronger GRB, if it had been caused by two black holes. The last event was farther away and is supposed to be caused by two neutron stars, which have a lower mass. How much stronger would have been the GRB of merging black holes.
Some astrophysicists may claim that merging black holes have no GRB because the radiation gets swallowed by the gravity of the black holes. But someone who makes such an argument only shows that he does not understand what black holes are. As even Stephen Hawking, the main proponent of "black holes", has confirmed, nothing ever gets swallowed by a "black hole", because nothing can ever pass through its horizon, which should always have been obvious for anybody who understood Einstein's General Relativity. What is called a "black hole" is neither black nor a hole. If anything at all it is dark red (extremely red-shifted), and nothing can ever completely disappear in it.
Therefore merging "black holes" would cause an extremely strong gamma ray burst, much stronger than that of merging neutron stars. Even if half of the energy gets red-shifted and ends up as undetectable long-wave radiation, there would still half of the energy be emitted as gamma rays. We did not detect anything like that the last two times, so the explanation as merging black holes was wrong.
- It remains to be seen, whether or not whatever the Fermi telescope has seen coincides with the observation at LIGO. It could be the first evidence for gravitational waves, but we need to be careful not to over-interpret the observation with far-fetched explanations.

Another question that we need to ask is: Why do we need to know all this? Does a phenomenon that does not affect us in any way justify the immense expenses or would the money not be better invested in the colonization of Mars? Science should not be about the collection of useless knowledge; science should advance our civilization. What does not affect us, does not require our attention.

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