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First Observational Evidence Other Universes?

1 Jan , 2011

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The signatures of a bubble collision at various stages in our analysis pipeline. A collision (top left) induces a temperature modulation in the CMB temperature map (top right). The "blob" associated with the collision is identi ed by a large needlet response (bottom left), and the presence of an edge is determined by a large response from the edge detection algorithm (bottom right). (Feeny, et al.)

In the realm of far out ideas in science, the notion of a multiverse is one of the stranger ones. Astronomers and physicists have considered the possibility that our universe may be one of many. The implications of this are somewhat more fuzzy. Nothing in physics prevents the possibilities of outside universes, but neither has it helped to constrain them, leaving scientists free to talk of branes and bubbles. Many of these ideas have been considered untestable, but a paper uploaded to arXiv last month considers the effects of two universes colliding and searches for fingerprints of such a collision of our own universe. Surprisingly, the team reports that they may have detected not one, but four collisional imprints.

The team, led by Stephen Feeney at the University College London, considered a collision between bubble universes. They conducted a simulation based on a formulation of Einstein’s field equation, known as de Sitter space. This solution to Einstein’s equations is essentially a description of how space itself behaves. From interactions between such spaces, they determined a set of observable effects visible in the cosmic microwave background (CMB). Among them, they required that signals have azimuthal symmetry or are mirrored on both sides of the sky. Secondly, the signals should be circular in shape.

Searching the WMAP archives, the team found numerous possible signals, but eventually narrowed it town to four strong candidates.

The authors of the paper are quick to caution that these results are only consistent with the predictions of bubble universes but do not rule out other causes, or even simple blind luck from a large enough data set. To rule out other scenarios, astronomers will need to rely on instruments with higher sensitivity, such as the Planck satellite, launched in 2009, which working on completing a second scan of the entire sky with three times the sensitivity of WMAP.

If these results are confirmed, it would be support for a variation of cosmology known as “eternal inflation”. The title is somewhat misleading as the hypothesis doesn’t describe a single instance of inflation that continues eternally, but rather an eternal time period in which events of inflation, triggered by bubble collisions, can take place. Such collisions cause the rapid expansion of spaces forming universes like our own. Conversely, if a bubble is not found, “the conclusive non-detection of a bubble collision can be used to place constraints on theories giving rise to eternal inflation; however, if a bubble collision is verified by future data, then we will gain an insight not only into our own universe but a multiverse beyond.”

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iantresman
Member
January 1, 2011 2:59 PM

I found some dents in my car, clearly “fingerprints” indicating that “something” collided with my car. Something from another universe perhaps? Most of the dents are horizontally polarized, and tend to occur only on roads. All completely consistent with various multiverse theories.

albone
Guest
January 1, 2011 1:49 PM

I’m glad the multiverse possibility has gained some traction.
With our universe ever expanding and headed for the possibility
Of “The Big Rip” it’s nice to know ours Universe could be one of many.

Lawrence B. Crowell
Member
Lawrence B. Crowell
January 1, 2011 5:07 PM
The main question I have with this model is the extent to which the inflation is “eternal.” The dynamics of the space manifold (a’/a)^2 + 8?G/\/3 – k/a^2 = 0 is driven by the cosmological constant term /\ that has an energy density ~ 10^{110}GeV^4. For k = 0 the solution to this DE is exponential and the spacetime is de Sitter-like. The cosmological constant /\ ~ vacuum energy density, and this drops in a bubble nucleation which initiates reheating, a concept advanced by Coleman back around 1983. The vacuum energy level is determined by the scalar inflaton field, which in local regions exhibits a quadratic potential that corresponds to a bubble of nucleation. The vacuum energy drops… Read more »
jcamjr
Member
jcamjr
January 1, 2011 6:18 PM

Unless I’m missing something obvious there would seem to be no reason to assume that after phase transition any two spacial manifolds will have the same residual vacuum energy. My question in a nutshell is … At the time of contact between nucleation zones of differing vacuum energy states should we not expect an event much like a false vacuum decay to spread through both zones and essentially act as a vacuum energy leveling mechanism ? I don’t have the math skills to express this any clearer and apologize if I’m making no sense but on the off chance that I am would appreciate your thoughts on the subject.

Lawrence B. Crowell
Member
Lawrence B. Crowell
January 1, 2011 7:53 PM
jcamjr, Your question is relevant to this discussion.Coleman in his original paper wrote a little bit about how this could lead to the ultimate catastrophe, where the vacuum energy in one bubble transitions into that of another. However, this is not likely, for this potential function for the scalar dilaton or inflaton would be quartic and there are observable consequences for that. It appears the potential function for the post inflationary bubble is quadratic. A good comparison is between these bubbles and domains of magnetization in a ferromagnetic material below the Curie temperature point. Each has its own direction of magnetization and set direction. Yet they all sit within a metal and are adjacent to each other. There… Read more »
jcamjr
Member
jcamjr
January 2, 2011 11:34 AM

Thank you, I appreciate that you took the time to answer my rather vague musings in such a clear and helpful manner.

HOLOGRAMUNIVERSE@wordpress.com
Member

I believe the cmb rings are remenants of bruises and collisions from many smaller black holes all separately preexisting together moving in a stream that pretty much impacted at the same time. the largest collision of this stream triggered what we see as the big-bang. evidence data shows the cmb is not all-sky, and vast distances well beyond our visible telescopic horizon we surely know exist galaxies that are older then the age of thr big-bang baby universe supplied by standard model lovers.

The Eclectic Exterminator of Stupid Electricians
Member
The Eclectic Exterminator of Stupid Electricians
January 2, 2011 8:28 PM

Eh? This is just more gobbledegook from the master twit.
No evidence, just wild unimaginative clap trap that means nothing.
Just because you want the universe to be infinite to satisfy your own deranged version of plasma cosmology doesn’t make it so!
You are a total fool, sir.

Harry
Member
Harry
January 3, 2011 4:31 AM

Nice choice of words there crumb. I do not understand how dark energy and dark matter can be part of so called mainstream science, and the hypothesis/theory presented in the article above can not be.

neoguru
Member
neoguru
January 2, 2011 6:54 AM

If we keep it up, soon science will be investigating Santa Claus, the Easter Bunny, and other stupidities. Hopefully we’ll return to the days where science actually uses EVIDENCE for their theories and not fantasy.

Torbjorn Larsson OM
Member
Torbjorn Larsson OM
January 2, 2011 9:01 AM
I thank Jon and Lawrence for neat summaries. Another neat summary is a guest blog from one horse’s mouth: While we didn’t make any clear detections of bubble collisions, we did find four features in the WMAP data that are better explained by the bubble collision hypothesis than by the standard hypothesis of fluctuations in a nearly Gaussian field. We assess which of the two models better explain the data by evaluating the Bayesian evidence for each. The evidence correctly accounts for the fact that a more complex model (the bubble collisions, in this case) will generally fit the data better simply because it has more free parameters. This is the self-consistent statistical equivalent of applying Ockham’s Razor.… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
January 2, 2011 12:19 PM
There may be another level of multiverse. The flat space which our bubble is contained in is defined by strings on a D3-brane, where type IIB strings can connect up a whole foliation of these. The Dp-branes are a bit like extended quarks, and the strings gluons. So our observable universe could be just one bubble on a space which contains a vast number (about a mole) of other bubbles, and where this whole space is induced by the string modes on oneD3-brane in a huge foliated stack of such D3-branes. So there is then another level of multiverse altogether which may exist as well. These multiverses may be tied to each other through black hole singularities, and… Read more »
Torbjorn Larsson OM
Member
Torbjorn Larsson OM
January 2, 2011 9:20 AM
To iantresman and neoguru I lift out the part of the guest blog intro where Carroll replies to dogmatic thinking of the religious a priori type: A lot of other people are aghast that this is considered science. Personally I think science talks about unobservable things all the time, and this question is going to be resolved by people doing hard work to make sense of multiverse scenarios rather than by pronouncements about what is or is not science. Note that what Carroll describes are unobservable things like Lucretius atoms, not their observable effects (such as our own biochemical machines). We can never observe anything directly (or in real time), but need photons to reach our eyes et… Read more »
Editor57
Member
Editor57
January 2, 2011 10:13 AM

It would seem this article is a little late. Response to the Penrose paper was swift and generaly negative; see this http://www.scientificamerican.com/article.cfm?id=no-evidence-of-time-before-big
http://arxiv.org/abs/1012.1268
http://arxiv.org/abs/1012.1305
http://arxiv.org/abs/1012.1656
Finally Penrose etal respond http://arxiv.org/abs/1012.1486

Underlings
Member
January 2, 2011 10:47 AM

Before an idea becomes a theory, it has to be an hypothesis, right? And if we constrained hypothesizing, we’d eliminate a lot of scientific discoveries. So what’s wrong with posting multiverse hypotheses on a science news website? Especially when there’s at least some predictive evidence to support it?

William928
Member
William928
January 2, 2011 7:11 PM

As a layman, I contend that any subject that fosters inquiry can only be positive. Perhaps discussing the unknown or unexplored idea or theory will lead to further groundbreaking discoveries. Isn’t that one of the principle functions of Science?

astrohrishi
Member
astrohrishi
January 2, 2011 8:55 PM

Hi,

Why is bubble universe a possible option while Penrose’s cyclic universe theory sounds more appealing…

Thanks,
Hrishi

kurzastar
Member
kurzastar
January 3, 2011 3:16 AM
Strange to read this article today. I’ve been thinking many hours today about how I’d get a thought I have had into a short story for a creative writing website. The gist of it is that, even after a flat earth in the center of the universe around which all things revolved, we humans are still so impressed with our ability to think that we create hypotheses to explain things which may just be unexplainable or at very least completely outside of our ability to understand them. My current favorite is a yet undetected energy which is accelerating the expansion of the universe. An energy that is cold and doesn´t produce anything visible on the electromagnetic spectrum. So… Read more »
Lawrence B. Crowell
Member
Lawrence B. Crowell
January 3, 2011 10:51 AM
The soda idea is not completely half baked. Pouring the soda water into a glass is analogous to the generation or quantum tunneling of the space out of the vacuum or from an instanton associated with a black hole in some other space (universe). The process generates lots of fizz, and the bubble are generated by the myriads, and our observable universe is one of these bubbles. Of course unlike the drink the bubbles persist as the “drink” medium is “infinite.” Yet as I indicate above there is a “friction” associated with the inflaton scalar field and the “soda” will go “flat.” The huge inflation process will then wind down. Of course the bubbles do remain and are… Read more »
Aqua4U
Member
January 3, 2011 12:51 PM

“…this age of social confusion.”

Be Thee Reborn,
with the Renewal of Thy Mind.

Buck up MATE! A prediction…. our science will soon create an energy replacement for fossil fuels. Expect incredible resistance to this from the ‘status quo’ factions…. but economic turnover will become inevitable and the accompanying opportunity for social evolution most welcome!

Lawrence B. Crowell
Member
Lawrence B. Crowell
January 3, 2011 6:34 PM

The issue is not about some future energy source, or techno-magic. It is that the American people have magnificently transformed themselves into a population of idiots.

The rest of the world’s political powers are looking upon this situation eagerly, for they may … .

It sucks being in a declining civilization.

LC

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