There’s a cold spot at the edge of our observable universe and I’m HOPING that it’s evidence
for ANOTHER universe invading our personal space.
Hello!
I’m Ian O’Neill, space producer for Discovery News, and I wanted to chat about a cosmic
peculiarity that has fascinated me for years.
In an effort to understand the Big Bang, the scale of the universe and the very nature
of space-time, cosmologists look to the furthest reaches of our observable universe.
Waaaaaaay out there is a faint afterglow, basically what astronomers interpret as the
“echo” of the Big Bang that occurred over 14 billion years ago.
This signal is known as the Cosmic Microwave Background, or CMB.
It exhibits very slight temperature variations known as anisotropies (“an-isOtr’pees.”)
In recent years, increasingly advanced observatories have been able to measure these temperature
variations to extremely high precision.
Most recently, you may remember the big debate over whether or not the BICEP2 telescope at
the South Pole had detected gravitational waves etched in the CMB.
Unfortunately that result has been called into doubt by the European Planck Space Telescope,
but that doesn’t mean gravitational waves aren’t out there, we just need to look a
bit harder.
As you may have guessed, reading patterns in the CMB is a tricky affair.
When measuring tiny variations in CMB temperature, all kinds of complex statistical algorithms
are needed to help us understand whether or not the anomalies we see in the CMB are real
or just noisy data.
So that brings me to the infamous CMB “Cold Spot”, which could be one of the most mindblowing
features EVER discovered in the cosmos.
Or it could just be a glitch.
So it might be nothing...
but it could be EVERYTHING!
Cosmology certainly loves extremes!
The CMB cold spot was first uncovered by the NASA WMAP mission that mapped the entire sky
for CMB temperature variations.
And there it was, a conspicuous cold blob in the direction of the southern constellation
of Eridinus.
Then, in 2013, there was an “oh shit” moment when Planck ALSO detected the cold
spot, ruling out instrumental error as a possible cause of the WMAP anomaly.
This thing is huge -- covering 10 degrees of the sky -- and if it’s real, it would
be the biggest astronomical structure in the known universe.
So what is it?
In a nutshell, WE HAVE NO IDEA.
And this is why it’s so awesome.
But there are theories.
Probably the most down-to-earth theory is that the cold spot is being caused by a huge
void inside our universe between us and the CMB’s source.
We know that the universe is composed of a complex web of galaxies beaded along vast
dark matter structures.
But between these structures are voids of very little matter.
As the radiation from the CMB travels through these voids, its properties are tweaked by
the so-called Sachs-Wolfe effect indicating that a “supervoid” is creating a cold
spot that isn’t really there.
BUT, the most extreme and possibly most exciting explanation suggests the cold spot is actually
evidence of ANOTHER UNIVERSE pushing up against our own.
Naturally, cosmologists, physicists and astronomers are divided over this explanation, but it
would be cool.
If all other explanations are ruled out, and this one remains, it could support the “multiverse
hypothesis” -- where our universe is like one of countless bubbles floating in a multi-universe
soup.
But most recently, astronomers analyzing the new Planck data suggest the cold spot might
actually just be an artifact in how we correct for extraneous sources of microwaves, and
if we account for the motion of our galaxy, the cold spot fades away into the noisy background.
Boo.
So, for the sake of awesomeness, I’m hoping it’s being caused by a nosey parallel universe
neighbor.
Do you think there’s another universe out there?
Let us know in the comments below, and subscribe for more DNews every day of the week!
And if you're interested in learning more about space, find out how language can alter
our perception of the solar system
So make sure you check that video out, it’s the first link in the description, and subscribe
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