Our universe is merging with 'baby universes', causing it to expand, new theoretical study suggests

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By Andrey Feldman
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The universe is expanding faster and faster, but not all scientists agree that dark energy is the cause. Perhaps, instead, our universe keeps colliding with and absorbing smaller 'baby universes,' a new theoretical study suggests.

Ai Generated Multiverse Universe royalty-free stock illustration.
(Image credit: MrBeliever on Pixabay)

Our universe is expanding at an ever-accelerating rate — a phenomenon that all theories of cosmology agree upon but none can fully explain. Now, a new theoretical study offers an intriguing solution: Perhaps our universe is expanding because it keeps colliding with and absorbing "baby" parallel universes.

Studies of the cosmic microwave background, the afterglow of the Big Bang, have revealed that our universe is experiencing accelerated expansion. For this observation to fit with  the main theory of cosmic evolution — called the Standard Cosmological Model — physicists assume that the universe is filled with an enigmatic substance dubbed dark energy that drives the expansion.

But this elusive form of energy does not manifest itself in any other way, leading many astrophysicists to question its existence and explore the possibility of an alternative cause for the universe's expansion.

In a new study published Dec. 12, 2023 in the Journal of Cosmology and Astroparticle Physics, scientists proposed the idea that the expansion of the universe may be driven instead by constantly merging with other universes.

"The main finding of our work is that the accelerated expansion of our universe, caused by the mysterious dark energy, might have a simple intuitive explanation, the merging with so-called baby universes, and that a model for this might fit the data better than the standard cosmological model," lead study author Jan Ambjørn, a physicist at the Copenhagen University told LiveScience in an email.

Swallowing cosmic 'babies'

While the idea of multiple universes interacting with ours isn't new, this study develops a mathematical model to explore the hypothetical impact of this on the evolution of our universe. The researchers' calculations showed that merging with other universes should increase the volume of our universe, which could be perceived by our instruments as an expansion of the universe.

The scientists also computed the rate of expansion of the universe using their theory, and their calculations more closely fit with observations of the universe than the traditional Standard Cosmological Model, the researchers said.

Related: After 2 years in space, the James Webb telescope has broken cosmology. Can it be fixed?

An illustration of the Euclid spacecraft scanning the sky. Euclid's mission is to hunt for traces of dark matter and dark energy in the ancient universe, to help explain the mysteries of cosmic expansion. (Image credit: ESA)

The authors' theory also addresses  the problem of cosmological inflation — the mysterious super-rapid expansion that occurred in the early moments of the universe.

Physicists have previously proposed that this expansion was caused by "the inflaton" — a hypothetical field that drove ultra-rapid expansion in the first milliseconds after the Big Bang. But in the new study, the authors suggest this super-rapid early expansion could have been caused by our young universe being absorbed by a larger universe.

"The fact that the Universe has expanded … in a very short time, invites the suggestion that this expansion was caused by a collision with a larger universe, [that is] it was really our Universe which was absorbed in another 'parent' universe," the researchers wrote in their paper. "Since we have presently no detailed description of the absorption process, it is difficult to judge if such a scenario could take place in a way that would actually solve the problems inflation was designed to solve, but one interesting aspect of such a scenario is that there is no need for an inflaton field."

The scientists suggested that, after being absorbed, our newly enlarged universe then continued to collide with other “baby universes”  and incorporate them as well.

Although the authors' theory enables us to solve some important problems of modern cosmology, only observational data can validate their hypothesis. Many experiments are currently being carried out to study the properties of the microwave background, so scientists may be able to answer these fundamental questions in the near future.

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"Our late time expansion of the Universe is different from the standard cosmological predictions and we believe that observations from the Euclid telescope and the James Webb telescope will settle which model is best describing the present time expansion of our Universe," Yoshiyuki Watabiki, a physicist at the Tokyo Institute of Technology, told Live Science.

Andrey Feldman
Andrey Feldman
Live Science Contributor

Andrey got his B.Sc. and M.Sc. degrees in elementary particle physics from Novosibirsk State University in Russia, and a Ph.D. in string theory from the Weizmann Institute of Science in Israel. He works as a science writer, specializing in physics, space, and technology. His articles have been published in Elements, N+1, and AdvancedScienceNews.

5 Comments Comment from the forums
  • danr2222
    This article left me puzzled as to how we could be absorbing "baby universes" and not wind up with a (temporally and spatially) 'lumpy', inhomogeneous cosmos with blobs of big and small universes popping up all over the sky, not to mention adding their baby matter, and totally messing up the CMB profile.

    It left out a key description of what the authors mean by "baby universe", albeit it was buried in page 8, and this article's author perhaps didn't read that far:

    "...i.e. to the absorption of baby universes of infinitesimal size (which is one reason we introduced the word “baby universe” for the universes absorbed by our Universe). The absorption of such small baby universes can only result in a change of the spatial volume if infinitely many are absorbed per unit time and unit spatial volume."
    Possibly even "embryonic universe" wouldn't even begin to approach what they were driving at, and illustrates an objection I have regarding modern physics: adhering to Occam's razor, theoreticians are only too willing to ascribe a fecundity to the nature of reality that is a worse cure to a problem than that of the sin of a theory's unparsimony in moving parts, and why I'm inclined to throw out such enterprises as multiverses, and the many-worlds hypothesis.
    Reply
  • Andrey_Feldman
    1) Indeed, they didn't studied the effect of mergers with other universes on the CMB, so this remains a topic for future research.

    2) The conclusion that merging only occurs with universes of infinitesimal size is an approximation, as discussed in the last paragraph of section 3. In general, a universe of any size can be absorbed, as is clearly stated after the equation (3.20).
    Reply
  • Bruzote
    danr2222 said:
    This article left me puzzled as to how we could be absorbing "baby universes" and not wind up with a (temporally and spatially) 'lumpy', inhomogeneous cosmos with blobs of big and small universes popping up all over the sky, not to mention adding their baby matter, and totally messing up the CMB profile.

    It left out a key description of what the authors mean by "baby universe", albeit it was buried in page 8, and this article's author perhaps didn't read that far:

    "...i.e. to the absorption of baby universes of infinitesimal size (which is one reason we introduced the word “baby universe” for the universes absorbed by our Universe). The absorption of such small baby universes can only result in a change of the spatial volume if infinitely many are absorbed per unit time and unit spatial volume."
    Possibly even "embryonic universe" wouldn't even begin to approach what they were driving at, and illustrates an objection I have regarding modern physics: adhering to Occam's razor, theoreticians are only too willing to ascribe a fecundity to the nature of reality that is a worse cure to a problem than that of the sin of a theory's unparsimony in moving parts, and why I'm inclined to throw out such enterprises as multiverses, and the many-worlds hypothesis.
    Parsimony would lead to less publishing, and we all know the creed of publish or perish. I sure hope nobody is teaching this stuff.
    I am still upset about the terms Dark Matter and Dark Energy.
    Reply
  • 7%solution
    A mind-boggling proposition. It challenges our theoretical thinking process beyond imaginary possibilities. It's already a stretch to picture our universe in its entirety, where its boundaries are, let alone what may exist beyond these boundaries. It makes it abundantly clear how much we don't know. The only way we'll ever get absolute proof of any theories what happens at the end of time is by getting there. That would require travel at many times the speed of light. This seems physically impossible. The mind twister in this context is time itself. The question becomes is time even real? In looking across the universe the question evolves, is there really a beginning and an end of time? If so, then it should be possible to find a place certain for each. The truth is, such places may not exist. The idea of time originates with the big bang. We measure the time via the expansion of the universe that presumably is the consequence of the big bang. What if there never was a big bang? According to an alternative theory, the big bang could've been the effect of a collision with another substantial universe that shook up everything we can see. This would indicate that time is infinite, no beginning, no end. Just a constant ongoing destruction and renewal process, where things get rearranged into new things, a constant metamorphosis of matter. Then the question arises, is what we can see all there is? I think that we can only see a fraction of all there is, like a slice of a pizza. The rest is invisible to us. In our intuitive thinking, if it's not visible, then it must not exist. Wrong. We already dubbed the invisible stuff as dark matter. What if we could see this dark matter with our own eyes? What would the universe look like then? And, what would it take to make such an expanded universe visible to us? It's possible that if we could see the dark universe, we could also see shortcuts how to get to other places within the entire creation in an instant. Perhaps the darkness is not really dark at all. It's just beyond the light spectrum our eyes can process. To clear that up we need to understand how human eyesight developed during its evolutionary history. It's conceivable that our eyesight was different 50k years ago. After all, eyesight is a reconstruction of reality by our brains based on information extracted from our vision process. Perhaps it just takes an adjustment in our brains to make the universe fully visible to us. Instead of looking outward for answers, perhaps the answers are already within us. Why not? After all, we're made of the same stuff we can see out there, even the currently invisible stuff. That would make it plausible that we already know everything about everything, we're just lacking the key to unlock it.
    Reply
  • E=MC²
    admin said:
    The universe is expanding faster and faster, but not all scientists agree that dark energy is the cause. Perhaps, instead, our universe keeps colliding with and absorbing smaller 'baby universes,' a new theoretical study suggests.

    Our universe is merging with 'baby universes', causing it to expand, new theoretical study suggests : Read more
    You say baby universes, I say baby black holes. It's rather obvious our universe is just one small link in an infinite chain of black holes nested inside of black holes like matryoshkas growing infinitely smaller yet each with the same level of detail for the observer within. Think of it like a 3-dimensional depiction of the Mandelbrot set where we get the opportunity to observe how what we see as planck's constant could very well be enormously large to an observer nested in a universe smaller than ours much like we are nested as a black hole in a universe much larger than ours. Not only does it explain the cosmological constant through universal expansion at an exponential rate consistent with that of a black hole like we observed in 2021, it also explains angular momentum, dark matter/energy, and the information paradox. When I died in 1955, I tried to mutter this to a nurse in German forgetting that she spoke English and THAT was my greatest blunder you nincompoops!
    Reply