How Black Holes Smashing Together Could Settle an Astronomical Dispute - CNET

Violent ripples reverberating across spacetime might finally reveal how quickly our universe is expanding.

David Gross, a particle physicist and former director of the KITP was talking about the rate at which our universe is expanding.

Basically, astronomers from the University of Chicago believe when black holes lurking in deep space smash into one another – which they do sometimes – the gravitational leviathans reverberate ripples across the fabric of space and time that might leave traces of information crucial to decoding the Hubble constant. .

In the end, if scientists can figure out the true Hubble constant, they can also derive answers to some really big questions about our universe like: How did it evolve to the stunning realm we see today.

When this happens, the merger sends ripples across the fabric of space and time -- as coined by Albert Einstein's general relativity -- just like dropping a rock in a pond would send ripples across the water. .

Just four years before Gross and fellow physicists hosted their stressful debate over the Hubble constant conundrum, two powerful observatories managed to capture those black hole-induced ripples from down here on Earth.

Over the past few years, both LIGO and Virgo have detected the ripples from almost 100 pairs of black hole collisions, and those readings might help us calculate the rate at which the universe is expanding, according to Daniel Holz, an astrophysicist at the University of Chicago and co-author of the new study.

What this means is that if a black hole collision happened way (way) out in space, and the signal has been traveling for a long (long) time, the gravitational ripples emanating from the event would've been affected by the universe expanding since the incident

Therefore, if we can somehow measure the changes in black hole collision ripples, perhaps we can understand the rate at which some of those changes occur