Is the universe a bubble? Let's check: Making the multiverse hypothesis testable

Is the universe a bubble? Let's check: Making the multiverse hypothesis testable

Perimeter Associate Faculty member Matthew Johnson and his colleagues are working to bring the multiverse hypothesis, which to some sounds like a fanciful tale, firmly into the realm of testable science.

Never mind the big bang; in the beginning was the vacuum. The vacuum simmered with energy (variously called dark energy, vacuum energy, the inflation field, or the Higgs field). Like water in a pot, this high energy began to evaporate -- bubbles formed.

Each bubble contained another vacuum, whose energy was lower, but still not nothing. This energy drove the bubbles to expand. Inevitably, some bubbles bumped into each other. It's possible some produced secondary bubbles. Maybe the bubbles were rare and far apart; maybe they were packed close as foam.

But here's the thing: each of these bubbles was a universe. In this picture, our universe is one bubble in a frothy sea of bubble universes.

That's the multiverse hypothesis in a bubbly nutshell.

It's not a bad story. It is, as scientists say, physically motivated -- not just made up, but rather arising from what we think we know about cosmic inflation.

Cosmic inflation isn't universally accepted -- most cyclical models of the universe reject the idea. Nevertheless, inflation is a leading theory of the universe's very early development, and there is some observational evidence to support it.

Inflation holds that in the instant after the big bang, the universe expanded rapidly -- so rapidly that an area of space once a nanometer square ended up more than a quarter-billion light years across in just a trillionth of a trillionth of a trillionth of a second. It's an amazing idea, but it would explain some otherwise puzzling astrophysical observations.

"That's what this research program is all about," he says. "We're trying to find out what the testable predictions of this picture would be, and then going out and looking for them."

Specifically, Johnson has been considering the rare cases in which our bubble universe might collide with another bubble universe. He lays out the steps: "We simulate the whole universe. We start with a multiverse that has two bubbles in it, we collide the bubbles on a computer to figure out what happens, and then we stick a virtual observer in various places and ask what that observer would see from there."

Simulating the whole universe -- or more than one -- seems like a tall order, but apparently that's not so.

"Simulating the universe is easy," says Johnson. Simulations, he explains, are not accounting for every atom, every star, or every galaxy -- in fact, they account for none of them.

"We're simulating things only on the largest scales," he says. "All I need is gravity and the stuff that makes these bubbles up. We're now at the point where if you have a favourite model of the multiverse, I can stick it on a computer and tell you what you should see."

This is interesting and could let us know if there is a multiverse or not once and for all.
If we can find evidence of a bubble collision, which this study shows is possible, then we'll know that we belong to a multiverse.

I personally believe in the multiverse theory. I can't quite explain it but it's just something that I believe is logical & possible.

What if there is only one universe that goes on forever and ever... and our universe is just a cluster of hundreds of billions of galaxies. And way out there in our universe, far far far way there exists another cluster of hundreds of billions of galaxies, and so on and so forth. Since we still can't see far enough away to the exact instant of the big bang, I don't see how we can prove the multi-verse, or disprove the single verse the way I "attempted" to describe by thought.

I'm not disagreeing with the theory of multi-verse, just merely adding a what-if?

Off topic: Kudos on the Puscifer Queen B avatar. Hail Maynard. MJK.

Hinduism tells that the universe is the exhaling breath of brahma which suggest that matter is still entering our universe even today. Sadly expansion was faster than light so we may never be able to prove anything because our observable universe is limited by the speed of light.

Another way to think of the bubbles of the multiverse is to consider the theory of Vacuum Instability.

With Vacuum Instability, a single Higgs particle is created with a slightly different energy state than the surrounding space.

"What happens is you get just a quantum fluctuation that makes a tiny bubble of the vacuum the Universe really wants to be in. And because it's a lower-energy state, this bubble will then expand, basically at the speed of light, and sweep everything before it," the Fermi National Accelerator Laboratory theoretician told BBC News

Link

The result would be a new universe would be born within a bubble inside of the existing universe; a bubble within a bubble. As the new bubble universe expands within the old bubble universe, the edges would collide destroying stars, galaxies, pretty much everything that comes in contact with the new universe as it expands.

And what would the remnants of those collisions look like? I would think there would be some residual energy left, splotches of radiation on the edges of the expanding universe, just as we observe with cosmic background radiation.

Perhaps our universe is the bubble within another bubble. As our universe expands or space inflates, perhaps we are the bubble destroying a larger universe from within. And perhaps that universe is also expanding destroying an even larger bubble from within. Bubbles, within bubbles, within bubbles times infinity.

The Fibonacci sequence predicts a spiral, a shape we see at all scales from the orbit of electrons to the spiral of a galaxy. Perhaps this is the shape of the multiverse?

originally posted by: ThisIsMyRifle
What if there is only one universe that goes on forever and ever... and our universe is just a cluster of hundreds of billions of galaxies. And way out there in our universe, far far far way there exists another cluster of hundreds of billions of galaxies, and so on and so forth. Since we still can't see far enough away to the exact instant of the big bang, I don't see how we can prove the multi-verse, or disprove the single verse the way I "attempted" to describe by thought.

I'm not disagreeing with the theory of multi-verse, just merely adding a what-if?

Off topic: Kudos on the Puscifer Queen B avatar. Hail Maynard. MJK.

Hail Maynard.

The article talks about how it may be possible to prove the multiverse theory

That's a small step for a computer simulation program, but a giant leap for the field of multiverse cosmology. By producing testable predictions, the multiverse model has crossed the line between appealing story and real science.

In fact, Johnson says, the program has reached the point where it can rule out certain models of the multiverse: "We're now able to say that some models predict something that we should be able to see, and since we don't in fact see it, we can rule those models out."

For instance, collisions of one bubble universe with another would leave what Johnson calls "a disk on the sky" -- a circular bruise in the cosmic microwave background. That the search for such a disk has so far come up empty makes certain collision-filled models less likely.

There's a bit more than that but I decided not to quote it all.

originally posted by: Chronon
Another way to think of the bubbles of the multiverse is to consider the theory of Vacuum Instability.

With Vacuum Instability, a single Higgs particle is created with a slightly different energy state than the surrounding space.

"What happens is you get just a quantum fluctuation that makes a tiny bubble of the vacuum the Universe really wants to be in. And because it's a lower-energy state, this bubble will then expand, basically at the speed of light, and sweep everything before it," the Fermi National Accelerator Laboratory theoretician told BBC News

Link

The result would be a new universe would be born within a bubble inside of the existing universe; a bubble within a bubble. As the new bubble universe expands within the old bubble universe, the edges would collide destroying stars, galaxies, pretty much everything that comes in contact with the new universe as it expands.

And what would the remnants of those collisions look like? I would think there would be some residual energy left, splotches of radiation on the edges of the expanding universe, just as we observe with cosmic background radiation.

Perhaps our universe is the bubble within another bubble. As our universe expands or space inflates, perhaps we are the bubble destroying a larger universe from within. And perhaps that universe is also expanding destroying an even larger bubble from within. Bubbles, within bubbles, within bubbles times infinity.

The Fibonacci sequence predicts a spiral, a shape we see at all scales from the orbit of electrons to the spiral of a galaxy. Perhaps this is the shape of the multiverse?

From the article

Never mind the big bang; in the beginning was the vacuum. The vacuum simmered with energy (variously called dark energy, vacuum energy, the inflation field, or the Higgs field). Like water in a pot, this high energy began to evaporate -- bubbles formed.

Each bubble contained another vacuum, whose energy was lower, but still not nothing. This energy drove the bubbles to expand. Inevitably, some bubbles bumped into each other. It's possible some produced secondary bubbles. Maybe the bubbles were rare and far apart; maybe they were packed close as foam.

also

For instance, collisions of one bubble universe with another would leave what Johnson calls "a disk on the sky" -- a circular bruise in the cosmic microwave background. That the search for such a disk has so far come up empty makes certain collision-filled models less likely.

Meanwhile, the team is at work figuring out what other kinds of evidence a bubble collision might leave behind. It's the first time, the team writes in their paper, that anyone has produced a direct quantitative set of predictions for the observable signatures of bubble collisions. And though none of those signatures has so far been found, some of them are possible to look for.

If there were a multitude of separate universes, it seems likely that they would jostle each other, and that our universe would have some of these circular 'bruises' in the cosmic microwave background radiation that were spoken about. It is said that none have been observed. Any likely version of the multiverse hypothesis therefore seems unlikely.

originally posted by: Ross 54
If there were a multitude of separate universes, it seems likely that they would jostle each other, and that our universe would have some of these circular 'bruises' in the cosmic microwave background radiation that were spoken about. It is said that none have been observed. Any likely version of the multiverse hypothesis therefore seems unlikely.

if i remember correctly there are a couple of voids in the large scale filament structure of the universe that were considered candidates for bubble collisions. i remember an article form a while back to that effect.

I think all universes exist at the same time in the same place.

The thing that separates each zone of universe's is scale, its infinitely large and infinity small at the same time. Everything exists somewhere, where on the scale it comes and ones ability to perceive it is what really divides it all.

Remember the scene at the end of men in black with the alien playing with marbles that were actually galaxies. Thats what i believe in.

Parallel universes? How and where could they exist? How could anything or anyone transverse into another universe? Impossible. But perceive a macro universe, could be possible. And i like that idea.

You see photons as they strike your retina and your brain turns that into an image, imagine particles that where so massive you simply cant register it. Same can be said for particles so small that you need fancy science equipment to even detect them let alone perceive a universe that small on the scale it exists you cant really 'live in it'. Time is also a factor here, the smaller you go the faster things go, the bigger you go the slower it goes. Our existence might be barely a blink of an eye for a being on a scale so massive it dwarfs literally everything we can see.

This might be in part to chemicals i cant discuss here and my experiences with fractals due to them. But i prefer a limitless fractalverse over parallel or otherwise other-dimensional universes. Everything exists somewhere.

Strange rant i know, i hope that it might add a new view to this discussion.

B

originally posted by: Biigs
I think all universes exist at the same time in the same place.

The thing that separates each zone of universe's is scale, its infinitely large and infinity small at the same time. Everything exists somewhere, where on the scale it comes and ones ability to perceive it is what really divides it all.

Remember the scene at the end of men in black with the alien playing with marbles that were actually galaxies. Thats what i believe in.

Parallel universes? How and where could they exist? How could anything or anyone transverse into another universe? Impossible. But perceive a macro universe, could be possible. And i like that idea.

You see photons as they strike your retina and your brain turns that into an image, imagine particles that where so massive you simply cant register it. Same can be said for particles so small that you need fancy science equipment to even detect them let alone perceive a universe that small on the scale it exists you cant really 'live in it'. Time is also a factor here, the smaller you go the faster things go, the bigger you go the slower it goes. Our existence might be barely a blink of an eye for a being on a scale so massive it dwarfs literally everything we can see.

This might be in part to chemicals i cant discuss here and my experiences with fractals due to them. But i prefer a limitless fractalverse over parallel or otherwise other-dimensional universes. Everything exists somewhere.

Strange rant i know, i hope that it might add a new view to this discussion.

B

i do not think it's impossible. check this out:

phys.org...

synopsis: Neutrons disappear faster than thier natural decay rate predicts. a widely known hypothesis involves a mirror domain of the universe. one of many articles on mirror particles. mirror particles are not antimatter. regular neutrons in the effect of a mirror magnetic field transform into mirror neutrons and sometimes back into regular neutrons. this is not the type of universe that the OP was about but the tangent you brought up.

originally posted by: Biigs
I think all universes exist at the same time in the same place.

The thing that separates each zone of universe's is scale, its infinitely large and infinity small at the same time. Everything exists somewhere, where on the scale it comes and ones ability to perceive it is what really divides it all.

Remember the scene at the end of men in black with the alien playing with marbles that were actually galaxies. Thats what i believe in.

Parallel universes? How and where could they exist? How could anything or anyone transverse into another universe? Impossible. But perceive a macro universe, could be possible. And i like that idea.

You see photons as they strike your retina and your brain turns that into an image, imagine particles that where so massive you simply cant register it. Same can be said for particles so small that you need fancy science equipment to even detect them let alone perceive a universe that small on the scale it exists you cant really 'live in it'. Time is also a factor here, the smaller you go the faster things go, the bigger you go the slower it goes. Our existence might be barely a blink of an eye for a being on a scale so massive it dwarfs literally everything we can see.

This might be in part to chemicals i cant discuss here and my experiences with fractals due to them. But i prefer a limitless fractalverse over parallel or otherwise other-dimensional universes. Everything exists somewhere.

Strange rant i know, i hope that it might add a new view to this discussion.

B

It reminded me how there could be more that we aren't seeing due to it being in the infrared or ultra violet range. I sometimes wonder what we would see if we could see in those ranges.

originally posted by: knoledgeispower
For instance, collisions of one bubble universe with another would leave what Johnson calls "a disk on the sky" -- a circular bruise in the cosmic microwave background. That the search for such a disk has so far come up empty makes certain collision-filled models less likely.

What about the CMB Cold Spot? It might be the "bruise" left from touching another universe, or even the location where a new bubble universe grew out of ours.

By the way, I support the multiverse hypothesis fully, and Alan Guth is my personal hero of theoretical physics.
Chaotic Inflation

originally posted by: wildespace

originally posted by: knoledgeispower
For instance, collisions of one bubble universe with another would leave what Johnson calls "a disk on the sky" -- a circular bruise in the cosmic microwave background. That the search for such a disk has so far come up empty makes certain collision-filled models less likely.

What about the CMB Cold Spot? It might be the "bruise" left from touching another universe, or even the location where a new bubble universe grew out of ours.

By the way, I support the multiverse hypothesis fully, and Alan Guth is my personal hero of theoretical physics.
Chaotic Inflation

I am unsure. I did a quick read of the wiki information on it. It does say how it could be a sign of a parallel universe so it would be interesting if the people doing the study I talked about, took a look at the CMB cold spot. I am unsure if they have done so already.

Things like the CMB cold spot, dark flow (a comparatively slow, but very large scale movement of deep space objects in one direction), and cosmic voids between galaxy-rich areas) could be evidence for the multiverse. Some dispute this. We simply don't know at this point.
As it turns out, the multiverse may exist and leave no traces of itself on our universe at all. If cosmic inflation really exists and is strong enough for long enough, it may carry universe-bubbles apart before they can interact with each other.
There is a certain motivation in many scientists to find that the multiverse exists. Without it, the existence of our universe, with a multitude of physical parameters seemingly 'fine-tuned' to allow the existence of life is very hard to explain.

a reply to: Ross 54
"Seemingly 'fine-tuned' to allow the existence of life" is backwards logic. Is gravity fine-tuned to allow a bridge or a building to stand?

There are a number of conditions required for a universe that can host life. This is scientifically conceded. The odds of all these conditions being fulfilled by chance, with only one opportunity, seem remote. The thinking is that with a great many tries at universe making, at least one, or a few should be expected to have the needed parameters.

a reply to: Ross 54

If we assume that all the universes are born out of the same endless, eternal vacuum, I'd think that all physical properties are the same in all of them (being essentially the properties of vacuum). Particles, forces, energy, everything is made of the same "fabric" of space-time.

The symmetry breaking in which physical forces emerge from the vacuum is a quantum process and inherently unpredictable. The manner in which these forces emerge means that they could have different strengths, and interrelate to each other differently
en.wikipedia.org...:_Universes_with_different_physical_constants