The image is based on the initial 15.5 months of data from Planck and is the mission’s first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380 000 years old.
At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2700ºC. When the protons and electrons joined to form hydrogen atoms, the light was set free. As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero.
This ‘cosmic microwave background’ – CMB – shows tiny temperature fluctuations that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today.
According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before. By analysing the nature and distribution of the seeds in Planck’s CMB image, we can determine the composition and evolution of the Universe from its birth to the present day.
Scientific American's John Horgan wrote that he used to get fired up over the idea that our universe was just one of many making up a grander "multiverse." But not anymore:
"Now, multiverse theories strike me as not only unscientific but also immoral, for two basic reasons: First, at a time when we desperately need science to help us solve our problems, it's irresponsible for scientists as prominent as Greene to show such a blithe disregard for basic standards of evidence. Second, like religious visions of paradise, multiverses represent an escapist distraction from our world."
Over at the Not Even Wrong blog, a colleague of Greene's at Columbia, mathematician Peter Woit, has his own set of moral qualms:
"My own moral concerns about the multiverse have more to do with worry that pseudo-science is being heavily promoted to the public, leading to the danger that it will ultimately take over from science, first in the field of fundamental physics, then perhaps spreading to others."
Was there a beginning? Did time continue before the Big Bang? Where did the Universe come from?
NARRATOR: Above all, they were still trying to solve the biggest problem of all: what caused the very start of the Big Bang, the singularity?
NEIL TUROK: Nobody has a solution for the singularity problem other than essentially by hand starting the Universe at a certain time and saying let's go from there and let's not worry about what happened before and that's very unsatisfactory. This is the deepest problem in cosmology.
Big as it is, our universe may be just one of many, all floating in a nearly unfathomable "multiverse," scientists say. Problem is, there's been no way to test the idea.
Now, though, physicists say they've devised a way to detect "bruises" from our cosmos's purported collisions with other universes.
The multiverse, if it exists, may have sprung out of a chaotic fluctuation of empty space.
Several "bubble" universes similar to our own, but perhaps with slightly different physical laws, would have appeared at about the same time and bumped against each other before diffusing across the multiverse.
Falling into a black hole may not be as final as it seems. Apply a quantum theory of gravity to these bizarre objects and the all-crushing singularity at their core disappears.
In its place is something that looks a lot like an entry point to another universe. Most immediately, that could help resolve the nagging information loss paradox that dogs black holes.