Happy 4th Birthday Weekend DNews!
To celebrate, let’s rewind to March 2014 when Trace and I captured the universe….
in a balloon.
Hi there space physics fans!
Ian here.
All this weekend we’re giving updates to our first DNews videos, and the first video
I ever worked on was about the big bang and gravitational waves.
A
balloon to simulate spacetime, brilliant!
See, in early 2014, the science world was going crazy over a discovery made by the BICEP2
telescope located at the South Pole.
To recap, the telescope is used to watch out for very slight changes in the polarization
of light from the Cosmic Microwave Background, or CMB.
The CMB is ancient radiation created by the birth of the universe -- the echo from the
Big Bang.
At the time of our first video, BICEP2 had announced the detection of a certain type
of polarization that we THOUGHT revealed observational evidence of primordial gravitational waves.
We’ve talked about this a lot on DNews, but gravitational waves are ripples in spacetime.
Imagine dropping a pebble into a pond and you’d see ripples going across the surface
of the water.
The pebble represents energy, and the ripples would be the gravitational waves.
Primordial gravitational waves were created from the energy of the big bang and should
be etched into the CMB, in theory.
So when BICEP2 found this polarization, it confirmed the existence of primordial gravitational
waves.
It also appeared to explain our entire universe, how it came to be AND provided strong evidence
of a quantum origin for gravity.
So.
Exciting.
Actually, not so much.
In the months following that video, the BICEP2 results started to fall apart and, long story
short, that primordial gravitational wave signal wasn’t a gravitational wave signal
at all.
Follow-up observations by the European Planck space telescope proved that it was actually
galactic dust that was fooling BICEP2 into thinking it was seeing these polarized wiggles
when, actually, there was nothing there.
This was a big lesson to the BICEP2 scientists not to make announcements so prematurely.
Sorry Trace, Planck popped our balloon universe.
Though these primordial gravitational waves have yet to be found, we DID find another
type of gravitational wave generated by black hole collisions happening RIGHT NOW in our
modern universe.
Unless you’ve been living under a space-time rock these last few months, you probably know
that 2016 has been an amazing year for physics.
In February, physicists of the Laser Interferometer Gravitational-wave Observatory (or “LIGO”)
confirmed the first detection of gravitational waves passing through the Earth.
Though it didn’t confirm a quantum origin for gravity or confirm certain models of the
Big Bang, the discovery of gravitational waves by LIGO proved Einstein was right ONCE AGAIN
and gave us a brand new way to actually “see” massive objects, like black holes, crashing
in the dark.
Just last week, LIGO turned its detectors back on to start a second run in the search
for gravitational waves.
And more gravitational wave observatories are going online and other existing instruments
are getting upgrades, including the European Virgo Interferometer and the planned LIGO-India.
The European Space Agency even has lofty plans to launch a gravitational wave observatory
in space called the Evolved Laser Interferometer Space Antenna (or “eLISA”) in 2034.
All of these efforts will culminate in an exciting future for gravitational wave astronomy.
Building more observatories on Earth AND in space helps us pinpoint the locations of some
of the most energetic events in our universe.
Many of these events, like black hole collisions and spinning neutron stars, are invisible
to classic astronomy as they don’t produce light.
But “seeing” the gravitational waves they produce, we can actually detect them.
This opens up a whole new field of astronomy that will reveal things that have, until now,
been a dark mystery.
Want to see how excited we were about the original BICEP2 results?
You can watch Trace and I geek out in my first ever DNews video:
Can you think of any other science “discoveries” that actually turned out to be wrong?
Let me know in the comments below and don’t forget to subscribe to DNews for new episodes
every day of the week.