Cosmic 'Cold Spot' Challenges Inflation Model Of The Early Universe
This past spring, the most detailed mapping of the early universe was released to the public. Certain anomalous features of this map have attracted the intense scrutiny of astrophysicist and cosmologists. In particular, there appears to be a massive “cold spot” in the data distribution whereas the current Inflationary Model of the universe says there should be none. And there are other puzzling observations as well.
The cosmic map referred to here was compiled from data collected by the European Space Agency’s Planck spacecraft. Specifically, the data concerned fluctuations in the cosmic radiation temperature known as the Cosmic Microwave Background (CMB) — the energy “footprint” or remnant of the mighty explosion — the Big Bang — that began our universe.
At some point within the first 10-36 seconds following this massively energetic explosion, the universe underwent an “inflationary epoch” in which the size of the universe expanded a great many orders of magnitude — eventually dispersing the initial energy of the Bang throughout space-time.
But here’s the problem: according to the Inflationary Theory (first posited by Alan Guth in the 1980’s) , since all parts of space expanded equally, this cosmic microwave energy should be distributed uniformly throughout the universe (at its largest scales). So, if the data collected by Planck is good (and there’s no reason to question its quality), then scientists who study the origin and evolution of our cosmos have a major problem or puzzle to work out: the data shows a “cold spot” — an area of unusually high density (possibly from highly compacted matter) that does not fit neatly with the inflation model of the early universe.
This anomalous feature was discussed in a recent roundtable comprised of three key members of the Planck observatory team and held at the Kavli Foundation (Oxnard, CA), a research foundation dedicated to the study of cosmology. And the central question that arose from this roundtable was loud and clear: Will our present model of the early universe have to be altered and/or fundamentally changed?
At the roundtable discussion (as reported by World Science), astrophysicist George Efstathiou at the University of Cambridge (and director of the Kavli Institute for Cosmology at Cambridge), commented:
[The inflationary model] “predicts that today’s universe should appear uniform at the largest scales in all directions. That uniformity should also characterize the distribution of fluctuations at the largest scales. But these anomalies, which Planck confirmed, such as the cold spot, suggest that this isn’t the case…This is very strange. And I think that if there really is anything to this, you have to question how that fits in with inflation…. It’s really puzzling.”
Efstathiou, who has been involved with the Planck mission since its inception in 1993, added:
“Perhaps our theory of inflation is not correct, despite its beauty and simplicity.”
And there are other anomalous features, such as the recently discovered “super cluster” of quasars (a large quasar group, LQG) which seems to defy the Einstein principle governing the maximum achievable size of cosmic structures. This structure — found amongst millions of galactic images from the Sloan Digital Sky Survey (SDSS) — would represent another non-uniformity (or anisotropy) in the background energy distribution.
(Note: The third member of the roundtable discussion was Anthony Lasenby, professor of Astrophysics and Cosmology at the University of Cambridge)
Alternative Explanations of Cosmic Inflation
To explain the so-called cold spot, some astrophysicists are beginning to modify their view of the current inflation model, allowing that the initial cosmic inflation may have been much more limited in scope than originally thought.
Other scientists assert that anomalous features like the cold spot are indications that one or more “other universes” — at some distant point in the cosmic past — bumped into our universe. This view lends support to the bouncing branes theory of cosmogenesis (that’s ‘branes’ as in membranes as in cosmic boundaries) proposed by Paul Steinhardt and Neil Turok in 2007.
In the bouncing brane theory, two cosmic membranes make contact for a short period (aided by a “springy” 5th dimension and drawing upon the gravitational field for energy) causing a tremendous volume of energy to spill from one into the other; the recipient (cosmos) of this sudden energy influx experiences a Big Bang and rapid expansion. An interesting component of this theory is that this membrane contact and energy transfer is not localized, but spread out over the entire (recipient) cosmos — non-uniformly.
One other thing: the theory does not limit the number of time such bounces, or bumps, can happen. So, in theory, there may have been any number of previous big Bangs (and inflationary epochs) prior to this current one. Here, the universe does not at some point in the future begin contracting irreversibly (the “Gnab Gib”) back to a singularity. Rather, it receives long-time scale infusions of energy from a neighboring (but invisible to us) cosmos, starting the whole operation over, in a kind of cosmic renewable energy system. And, there may have been an infinity of previous brane bounce cycles.
An Earlier CMB Map With a ‘Ring’ of Truth
An earlier mapping and analysis of the CMB drawn from the Wilkinson Microwave Anisotropy Probe (WMAP) data revealed another curious feature of the CMB: the appearance of a “concentric ring” structure in the CMB temperature flux. It has been posited (Penrose and Gurzadyan, 2010) that these rings (i.e., circular bands of temperature variations, or anisotropies) represent pulses of energy transfers due to collisions from earlier Big Bangs; these “echos” have been preserved in the microwave background (a form of cosmic memory, if you will). Interestingly, in this theory — known as Conformal Cyclic Cosmology (CCC) — the ring structure represents both non-uniformity and pattern in the CMB.
But if these rings are indeed echos of past Big Bangs, then that would imply that our universe has had several previous “creations”, perhaps an infinite number of them.
One of the Planck Collaboration team scientists, Krzysztof Gorski, speaking at the roundtable, observed:
“Perhaps we may still eliminate these anomalies with more precise analysis; on the other hand, they may open the door to something much more grand—a reinvestigation of how the whole structure of the universe should be.”
One thing seems ironically clear: the universe that we inhabit is a far more mysterious and strange place (and time) than we know.
Some source material (and quotes) for this post came from the July, 2013 World Science article: “Inflation” theory of infant cosmos may need revision by the World Science staff (and courtesy of the Kavli Foundation)
Top image: The anisotropies of the Cosmic Microwave Background (CMB) as observed by Planck. The CMB is a snapshot of the oldest light in our Universe, imprinted on the sky when the Universe was just 380,000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today. (Credits: ESA and the Planck Collaboration)