In 2019 there were some ripples in spacetime that were picked up by the LIGO and Virgo gravitational wave observatories.

At the time, the event was said to have been caused by two black holes colliding. The event was named GW190521, and while it was an unusual event, the explanation basically fit what was found, so it hadn’t been looked at closely by most astronomers.

A team of researchers at the Chinese Academy of Sciences, however, has taken the time to really dig into the data and think about what might have caused GW190521, and their proposed explanation is quite exotic.

In a yet-to-be-peer-reviewed paper, the team suggests that rather than two black holes combining in our universe, the gravitational waves may have been caused by a wormhole that was created when black holes in another universe merged. They explain:

“In this paper, we investigate the possibility of interpreting GW190521 as an echo produced by a postmerger wormhole, created from the inspiral and merger of [binary black holes] in another universe and connecting it to our own.”

One of the key points that is made in the paper is that the signal that was detected was very short in duration. Normally, when two black holes collide, the resulting signals are much more long lasting, and they grow in strength over time as the objects get close. The end result in a ‘chirp’ that was not detected in this event.

As part of their researchers, the team created a waveform model of what should happen in the event that a black hole collision occurs in another universe and creates an echo that travels through the wormhole that is created. The short signal that was observed fits within this model.

The team does acknowledge that this is just a theory at this time and says that much more research is needed to determine whether this is actually what happened in this instance.

Interestingly, a very similar signal was received at the LIGO Virgo observatory in 2023. Like the 2019 event, it is thought to have occurred due to merging black holes, but it too has a short signal with no ‘chirp,’ so that may not be the case.

At the very least, this new event will give researchers an additional set of data to review while trying to figure out what exactly is happening.

If you thought that was interesting, you might like to read about the mysterious “pyramids” discovered in Antarctica. What are they?