If two black holes collide in space and nobody’s
around to hear it, did they make a sound.
It turns out, YES.
And we can hear them, with the help of a supercomputer.
That’s right, folks.
Every few minutes a pair of black holes smash
into each other, apparently, which is something
no one told me about until now, like it’s
not the coolest thing ever?
When black holes collide, also known as black
hole mergers, they cause ripples that travel
through spacetime--this is what we call gravitational
waves.
As you may have heard, 2015 marked the first
time we were able to detect gravitational
waves, arguably one of the biggest astronomical
discoveries of the 21st century and confirmation
of Einstein’s 1915 theory of general relativity.
No big deal.
And while there are some gravitational-wave
producing events that are distinctly measurable--that
we have observed and recorded--there’s also
what researchers call the gravitational-wave
background.
This is basically background noise resulting
from all the hundreds of thousands of gravitational-wave
producing events, like black hole collisions,
that we can’t distinguish individually because
our equipment isn’t sensitive enough to
discern them.
We haven’t even been able to detect the
background noise as a whole YET, but new research
is out from a team that’s developing sensitive
ways of listening to space that may allow
us to detect it faster than we’d previously
thought possible.
And of course, they’re using a supercomputer
to do it.
These researchers are using a particular kind
of computer simulation, called Monte Carlo
simulation, to produce a kind of ‘practice’
background noise that they can listen to.
With a new and unique search strategy, they’ve
shown they can identify gravitational-wave
producing events within the “practice”
noise.
Their new methods mean they can perform this
search with about a day’s worth of calculation,
whereas by the previously existing method
it would take up to 40 months to detect the
same thing.
Plus, the researchers say that their method
is a thousand times more sensitive than previous
attempts.
We’re talking some serious sensitivity,
here.
Gravitational waves that we can pick up produce
a disruption in space about 10,000 times smaller
than the radius of a proton.
And that’s the ones we can detect and distinguish.
So, this team is making improvements in detection,
but not with the actual measuring or listening
capabilities we’ve developed.
Instead they’re working by improving data
analysis and basically, number-crunching technique
and capacity.
Wizardry, it’s wizardry.
To speed things along even further, as of
March of this year the researchers have access
to a new 4 million dollar supercomputer, allowing
them to search for this background noise for
real, not just in simulation.
In the future, the researchers think that
extensions of their research could be used
to study gravitational waves that originated
very far away, in both space and in time...potentially
even letting us see and listen to gravitational
waves leftover from the Big bang, which are
currently hidden behind more recent events.
So, we don’t know what the background noise
sounds like yet.
That’s the goal.
But individual gravitational waves that are
relatively close to us in space time sound….Kind
of chirpy!
Have 
a listen.
I don’t know about you, but my takeaway
from this is that computers basically could
be our best bet at understanding where our
universe came from, and that understanding
how to work with them could help us look at
the fabric of spacetime (which will never
not be the coolest phrase ever).
Need more gravitational waves in your life?
Subscribe to Seeker and check out this video
on how they could help us understand dark
matter.
And, fun fact, gravitational waves vary based
on the properties of the objects that smashed
into each other, basically like a thumbprint
of a unique spacetime event.
Thanks for watching Seeker, I’m Maren.
