Strange Glitch In LIGO Data Turns Out To Have An Incredibly Silly Explanation


Robin Andrews

Science & Policy Writer

Always with the birds. NAAN/Shutterstock

What is it about rogue animals and enormous physics experiments? It’s well known by this point that the Large Hadron Collider has been subjected to nefarious birds dropping baguettes into it and suicidal weasels chewing through its wiring, but it turns out that one of the LIGO facilities has also been under siege by another member of the animal kingdom.

As first spotted by ScienceNews, this glorious tale of cretinous critter mischief came courtesy of a presentation at the April meeting of the American Physical Society in Columbus.


First off, the talk pointed out that the LIGO instruments are almost unbelievably sensitive, which is how they’re able to distinguish gravitational waves emanating across the cosmos. Rather amazingly, we’re reminded that these instruments – based in Washington and Louisiana – can measure a length change “equivalent to the width of an atom in the distance from the Earth to the Sun.”

This sensitivity, however, means that the instruments can easily be disturbed by external sources of noise. Focusing on the LIGO Hanford facility, several examples of such troubling sonic shenanigans are given. One is airplanes, which is perfectly understandable and pretty much unavoidable. Propeller airplanes create considerable air pressure disturbances, and shielding from that is decidedly tricky.

The second example, rather delightfully, is “thirsty ravens”. Microphones at the facility had apparently picked up something of a staccato noise, which staff noticed sounded similar to ravens pecking on something – a phenomenon they’d seen before. Whatever it was, they certainly weren’t gravitational wave detection signals.

Going to check out the source of the noise themselves, they found peck marks all over a frozen section of piping, which strongly suggested that ravens were chipping away at the ice to satiate their thirst. In fact, having a bit of a look around, they caught one of the ravens in the act.


Birds seem to be a particularly persistent problem for astrophysics research.

Back in the 1960s, radio astronomers Wilson and Penzias, working out of Bell Labs’ Holmdel Horn Antenna in New Jersey, were trying to decipher cosmic signals their equipment was constantly picking up. They were thrown off the scent of this groundbreaking discovery, however, after finding two poop-prone pigeons had set up shop within their antenna.

Cleaning up their mess, they found that their mysterious signals continued to appear, which ultimately led to the detection of the cosmic microwave background radiation – the glowing embers of the Big Bang.


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