Rumours about the detection of gravitational waves

These days, the web is full of rumours about a possible discovery of gravitational waves by the LIGO detectors (see for example here). LIGO is a set of several ground interferometers in the US. They recently started operations in their advanced version and have reached a sensitivity that makes a detection in the coming years probable. Has it already happened? Well, the rumour says that a detection occurred simultaneously in two detectors during an engineering run (used to test the apparatus).

This would be an exciting piece of news and a new window opened onto the Universe.

But before rejoicing, this rumour has to be confirmed. And to be frank, most rumours of this type never lead to a confirmation, because many other effects may lead to something that looks like a signal. Remember some years ago the neutrinos that travelled faster than the speed of light. Moreover, in the case of LIGO, there might be an even more devious reason: false signals injected into the detectors. Indeed, because gravitational waves are very difficult to isolate from the background, physicists have invented a “stress-guaranteed” method: a small group of physicists from the collaboration injects a false signal of gravitational waves into the detector without warning the rest of their colleagues, just to make sure that the false signal is identified and interpreted correctly. I was told (but did not check my information) that, on the last time this mischievous deed was performed, the rest of the collaboration had started writing the publication announcing the discovery before being told about the false input. So maybe once again, the LIGO physicists are playing with their own nerves (doing this in a engineering run, and not a scientific one, would be another degree in mischief).

In any case, if this rumour turns out to be real, it will probably take several months before the news is confirmed. There is no competition to the LIGO/Virgo detectors (which operate jointly, the Advanced Virgo detector in Europe being ready next year) and so one can imagine that the physicists will take their time to check and recheck the data before announcing such a ground-breaking discovery.

 

Pierre Binétruy

3 Comments

  • Peter Gehrke

    After all scientists are human and the ease of publishing in the internet and spreading spectacular news via the social networks creates a huge temptation to be the first to harvest fame and research budgets. I guess many scientists crave for the times when well edited and reviewed journals were the main platform for publication of discoveries.

    • Gravity!

      Dear Peter,
      You are right. But one should be fair to the LIGO/Virgo collaboration whose members have been mute about this rumor, neither confirming nor invalidating it. If they found anything, they should take their time to make sure that this is a discovery, all the more because this would be a major one. There is, at this point, no competitor, which helps in making a sound analysis of the situation. This is different when there is a strong competition between different experiments, which sometimes leads to a rushed publication of results which can be more damaging than simple rumors.
      Pierre Binétruy.

    • Neil McLellan

      Background here http://www.nature.com/news/physics-wave-of-the-future-1.15561 including “Mornings are a lost cause, thanks to the sonic chaos from traffic rumbling along the nearby interstate highway, trains roaring past and loggers occasionally unleashing their chainsaws on plantations of pine trees!”

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