Fine tuning Multiverse Science

At Big Think: How the Multiverse could break the scientific method

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Theoretical physicist Marcelo Gleiser raises the issue that the multiverse hypothesis suffers from the unscientific property of non-falsifiability. Embedded in his article is a solid acknowledgement of the fine-tuning of physical parameters for life to exist in our universe.

Today let’s take a walk on the wild side and assume, for the sake of argument, that our Universe is not the only one that exists. Let’s consider that there are many other universes, possibly infinitely many. The totality of these universes, including our own, is what cosmologists call the Multiverse. It sounds more like a myth than a scientific hypothesis, and this conceptual troublemaker inspires some while it outrages others.

multiverse
Credit: rolffimages / Adobe Stock

How far can we push the theories of physics?

The controversy started in the 1980s. Two physicists, Andrei Linde at Stanford University and Alex Vilenkin at Tufts University, independently proposed that if the Universe underwent a very fast expansion early on in its existence — we call this an inflationary expansion — then our Universe would not be the only one. 

When a sufficiently large region of space is filled with the field of a certain energy, it will expand at a rate related to that energy. 

The result for cosmology is a plethora of madly inflating regions of space, each expanding at its own rate. Very quickly, the Universe would consist of myriad inflating regions that grow, unaware of their surroundings. The Universe morphs into a Multiverse. Even within each region, quantum fluctuations may drive a sub-region to inflate. The picture, then, is one of an eternally replicating cosmos, filled with bubbles within bubbles. Ours would be but one of them — a single bubble in a frothing Multiverse.

Is the multiverse testable?

This is wildly inspiring. But is it science? To be scientific, a hypothesis needs to be testable. Can you test the Multiverse? The answer, in a strict sense, is no. Each of these inflating regions — or contracting ones, as there could also be failed universes — is outside our cosmic horizon, the region that delimits how far light has traveled since the beginning of time. As such, we cannot see these cosmoids, nor receive any signals from them. The best that we can hope for is to find a sign that one of our neighboring universes bruised our own space in the past. If this had happened, we would see some specific patterns in the sky — more precisely, in the radiation left over after hydrogen atoms formed some 400,000 years after the Big Bang. So far, no such signal has been found. The chances of finding one are, quite frankly, remote. 

We are thus stuck with a plausible scientific idea that seems untestable. Even if we were to find evidence for inflation, that would not necessarily support the inflationary Multiverse. What are we to do?

Different kinds of different in the multiverse

The Multiverse suggests another ingredient — the possibility that physics is different in different universes. Things get pretty nebulous here, because there are two kinds of “different” to describe. The first is different values for the constants of nature (such as the electron charge or the strength of gravity), while the second raises the possibility that there are different laws of nature altogether. 

In order to harbor life as we know it, our Universe has to obey a series of very strict requirements. Small deviations are not tolerated in the values of nature’s constants. But the Multiverse brings forth the question of naturalness, or of how common our Universe and its laws are among the myriad universes belonging to the Multiverse. Are we the exception, or do we follow the rule? 

The problem is that we have no way to tell. To know whether we are common, we need to know something about the other universes and the kinds of physics they have. But we don’t. Nor do we know how many universes there are, and this makes it very hard to estimate how common we are. To make things worse, if there are infinitely many cosmoids, we cannot say anything at all. Inductive thinking is useless here. Infinity gets us tangled up in knots. When everything is possible, nothing stands out, and nothing is learned.

That is why some physicists worry about the Multiverse to the point of loathing it. There is nothing more important to science than its ability to prove ideas wrong. If we lose that, we undermine the very structure of the scientific method.

BigThink

If there is “nothing more important to science than its ability to prove ideas wrong,” is it fair to ask, “What is the means by which the theory of evolution could be proved wrong?”

11 Replies to “At Big Think: How the Multiverse could break the scientific method

  1. 1
    polistra says:

    It’s not even a hypothesis. Just a delusion.

  2. 2
    asauber says:

    It’s a fantasy- A story concocted so some can pretend there’s no design in the universe.

    Andrew

    PS “Nor do we know how many universes there are”

    We can’t even comprehend one universe.

    Andrew

  3. 3
    jerry says:

    The multiverse can be tested with logic.

    It refutes itself. Why?

    Ask what is not possible in a multiverse scenario. The answer nothing that’s physically possible. Each possibility must have happened and it must have happened an infinite number times.

    Ask what are the implications of that.

  4. 4
    PaV says:

    I posted a quick look at Jim Baggot’s Farewell to Reality almost eight years ago. Here it is.

    The problems were evident even then.

  5. 5
    Lieutenant Commander Data says:

    :))A multiverse doesn’t solve the problem of coded functional information. It’s just impossible for matter and energy to produce a code /language .

    Matter can’t do the job that is done only by a MIND(to make projects and then to implement them) but AFTER matter is domesticated(with functional codes) will serve to certain purposes programmed by a mind via injected informations .

  6. 6
  7. 7
    ET says:

    “What is the means by which the theory of evolution could be proved wrong?”

    There isn’t any scientific theory of evolution, but Darwin said:

    “If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.” [Darwin 1859, pg. 175].

    That is the whole point of irreducible complexity. IC meets that criteria. So, IC is ignored or handwaved away.

  8. 8
    William J Murray says:

    The debate about whether or not there is a “multiverse,” or whether or not it is “testable,” and “how” such a concept could be tested, is being argued on both sides in a disproved conceptual framework: ontological realism.

    Neither side if these arguments (as currently debated) make any sense under the last ontology standing: idealism.

  9. 9
    jerry says:

    From comments on YouTube video that BA77 posted above. It’s very long.

    This is similar in my argument for falsification of multiverse. If you accept the multiverse proposition, you accept an infinite number of gods of infinite power/knowledge.

    Where are these infinite number of gods?

    If a multiverse did exist and if intelligent life could appear within such a universe without any need for a creator God then we should at least consider this: Some time ago I came to hear that an atheist mathematician had announced a theory of natural repetition that went something like this: When everything that can happen, i.e., every single permutation of every movement in all matter (matter being something as opposed to nothing) has happened, the only logical thing to happen next would be for everything to start repeating itself, and ultimately, to continually keep repeating itself over and over again ad infinitum. This then would include the natural process that started our universe, our solar system and the following naturally formed evolutionary cycle that produced the intelligent life on our planet. Even the present intelligent life on earth that we now perceive as our own would, sometime in the very far distant future be repeated, and not just once, but over and over again. So the theory goes.

    What is more, so I was told: Even though the time span between the cycle that produced us now and the repeated cycle that would eventually produce us again in that far distant future might look like bordering on the infinite, it would still only seem like an instant between our loss of consciousness at death, and our regained consciousness through the rebirth of our naturally repeated evolved lives in the future. This is because only the time registered in our consciousness would be recorded and therefore known… so the theory goes.

    Now the point I am coming to is this: When we apply this theory of natural repetition to our universe, (which is believed by many scientists to be a rapidly expanding ‘bubble’ billions of light years across and which started from an incredibly small point some 10-20 billion years ago) then we can also very easily arrive at a completely different and infinitely more interesting conclusion that goes way beyond the original idea of a naturally repeating eternity of endless births, deaths and rebirths, but first we must consider the following…

    If our universe, as some would have us believe, could be the first one or one of a finite number capable of starting and supporting evolved intelligent life, then it would mean that as time has advanced so the variation in the movement of matter would have increased. In which case, if we were to trace time back we would have to witness a decrease in that variation. Eventually, if we were to trace time back far enough we would have to reach a point of absolute zero movement in all matter, and that would result in a physical impossibility for any movement to begin. The only logical way out of this would be that our universe cannot be the first one or one of a finite number but instead must be one in an infinite number (from an atheistic point of view). Some atheist scientists though have also argued that our universe could have started from nothing by way of a “quantum fluctuation”, but even if this was true it would still logically follow that if nothing was responsible for starting this rapidly expanding ‘bubble’ we call our universe, then wherever there was nothing there would be countless universes about to be formed, being formed and already formed. In other words, it would have been impossible for nothing to have existed without already producing a mass of countless expanding (and possibly contracting) ‘bubbles’, similar to the one we presently call our universe. In which case, we would still be in the realms of “natural repetition”. (from an atheistic point of view)

    This in turn then would mean that evolved intelligent life in one form or another would not only have already strived an infinite number of times to understand, create and control whatever it so willed but would already have had an infinite period of time in which to do it in. Whatever kind or form of evolutionary cycle that would have produced this almighty free thinking God of reason then could also be seen to be the origins of God and therefore also a part of God. So even from an atheistic point of view I was able to see what could be described as a reasonable concept of an eternal infinite all knowing all powerful God who came into existence but with no conceivable beginning to the finite mind of man… if you see what I mean.

  10. 10
    Dick says:

    Whether other universes have different physical laws or not, there are two questions I’d like to see proponents of the theory address: 1) Why should a universe, any universe, be governed by laws at all, and 2) how does a mindless physical process like cosmic inflation create physical laws in the first place?

  11. 11
    jerry says:

    there are two questions

    Excellent questions.

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