So if I understand the logical ramifications of your position correctly Penguin: since Professor Carroll accepts the existence of the unfalsifiable (multiverse and string theory), he has "
basically given up on reason", such that you could not even start a discussion with him because you "
can't examine the logic of a conclusion that has no logic behind it"? Have I got that right?
I personally believe, contrary to Professor Carroll, that rigorous science
should involve falsifiable hypotheses—ones that can be confirmed or disproved by data. That is the reason why Professor George Ellis, a greatly respected cosmologist and mathematician, has long been a strident opponent of the multiverse and string theory being touted as 'science', for instance in this peer-reviewed article from 2008:
Opposing the multiverse | Astronomy & Geophysics | Oxford Academic
Opposing the multiverse
George Ellis
Astronomy & Geophysics, Volume 49, Issue 2, 1 April 2008
The very nature of the scientific enterprise is at stake in the multiverse debate. Its advocates propose weakening the nature of scientific proof in order to claim that the multiverse hypothesis provides a scientific explanation. This is a dangerous tactic. Two central scientific virtues are testability and explanatory power. In the cosmological context, these are often in conflict with each other and there has been an increasing tendency in theoretical physics and cosmology to say it does not matter whether a proposal is testable: if it fits into our other theories in a convincing way, with great explanatory power, then testing is superfluous. The extreme case is the multiverse proposal, where no direct observational test of the hypothesis is possible...
In this context one must re-evaluate what the core of science is: can one maintain one has a genuine scientific theory when direct and indeed indirect tests of the theory are impossible? If one claims this, one is altering the meaning of science.
The key observational point is that the domains considered are beyond the visual horizon and are therefore unobservable. You cannot receive signals of any kind from beyond the horizon, as there has not been time for messages to reach us from there since the universe began. Hence no object out there is detectable by any kind of astronomical observation...
The multiverse idea is provable neither by observation, nor as an implication of well established physics. It may be true, but it cannot be shown to be true. It does have great explanatory power — it provides an empirically based rationalization for fine tuning, developed from known physical principles — but one must distinguish between explanation and prediction. Successful scientific theories make predictions that can be tested. The multiverse theory cannot make any testable predictions because it can explain anything at all.
Even though multiverse proposals are good empirically based philosophical proposals for the nature of what exists, they are not strictly within the domain of science. There is nothing wrong with empirically based philosophical explanation — indeed it is of great value provided it is labelled for what it is — but I suggest that cosmologists should be very careful not to make methodological proposals that erode the essential nature of science in their enthusiasm to support specific theories
However Carroll is right in what he says above, in some key respects: its just that he's taken the wrong conclusion. Its not that the scientific method should 'dump' falsifiability because the only way to explain the most vexing cosmological problems like "fine tuning" and account for the data is to speculate with concepts beyond the observable reality that we can never falsify; rather its that science has its "limits" and that these hypotheses - multiverse, string theory, God - have real value and promise in giving us satisfying explanations by
deducing these "hypothesis" from science but without actually touting them as scientific theories, since science itself is limited and always should be limited to what is observable, testable and falsifiable. As even Professor Ellis notes in his above critique:
The multiverse idea (like the Deist God) is provable neither by observation, nor as an implication of well established physics and does not make testable predictions, so it cannot be considered strictly within the domain of science but It does have great explanatory power — by providing an empirically based rationalization for fine tuning, developed from known physical principles — such that it can be labelled as an "empirically based philosophical explanation" derived from science and still be seen to possess "great value".
I believe the same about God.
God is put forward by theists and deists as the reason
for nature, the explanation of why things are the way they are (
why we have something rather than nothing, to reference Leibniz); as such God is outside what the realm of science can viably investigate and test - because science has physical and principal limits contingent upon what we are physically able to observe, whether directly or indirectly. But that doesn't make the notion of such a God utterly irrational and implausible IMHO, anymore than is the case for string theory or the multiverse.
As Professor Ellis has himself noted elsewhere:
Well, science does have its limitations...
Cosmology deals with all that was, is and ever will be, but as a science, he says, it has limitations.
"The universe has only been existing for 14bn years. Light can only travel a certain distance in that time and we can't see anything further out. So there is a whole mass of stuff ... in the universe we know nothing about and we never will know anything about, because the light will never get to us in time for us to know anything about it."
https://blogs.scientificamerican.co...-knocking-philosophy-falsification-free-will/
Ellis: Many of the possible high-energy physics experiments and astronomy observations relevant to cosmology are now in essence nearly complete. Physics experiments are approaching the highest energies it will ever be possible to test by any collider experiment, both for financial and technical reasons. We can’t build a collider bigger than the surface of the Earth. Thus our ability to test high energy physics – and hence structures on the smallest physical scales – is approaching its limits...
The belief that all of reality can be fully comprehended in terms of physics and the equations of physics is a fantasy...I make strenuous efforts to consider what aspects of reality can be comprehended by a strict scientific approach, and what lie outside the limits of mathematically based efforts to encapsulate aspects of the nature of what exists.
Many key aspects of life (such as ethics: what is good and what is bad, and aesthetics: what is beautiful and what is ugly) lie outside the domain of scientific inquiry
Yet this lack of testable predictions does present a dilemma for a good number of contemporary cosmologists. During a recent Ted Talk, Harry Cliff, a particle physicist at the European Organization for Nuclear Research (CERN), warned: “
The next few years may tell us whether we'll be able to continue to increase our understanding of nature or whether maybe, for the first time in the history of science, we could be facing questions that we cannot answer.” He added that scientists are approaching this limit as “
the laws of physics forbid” further understanding of the Universe. Mr Cliff says that his theory is based on two numbers - the finely tuned strength of the Higgs Boson Field and the cosmological constant that I've already referred to in the above - which account for everything that the Universe is made up of, and if these numbers are slightly off, then “
there would be no physical structure in the Universe.” Mr Cliff concluded his Ted Talk by saying: “
We may be entering a new era in physics. An era where there are weird features in the universe that we cannot explain. An era where we have hints that we live in a multiverse that lies frustratingly beyond our [scientific] reach. An era where we will never be able to answer the question why is there something rather than nothing.”
As the American theoretical physicist Lee Smolin writes in
Life of the Cosmos, p. 78 with reference to predictions that our observable universe is part of a larger multiverse:
"A fantastic consequence of general relativity theory [is] that the part of the universe that we will ever be able to see does not include the whole of it. The part of reality we can in principle ever see has boundaries. And there are necessarily regions of space and time beyond those boundaries."
Unlike what I can gauge of your standpoint, I think it is perfectly valid and rational to
deduce such a "hypothesis" from science (i.e. a multiverse beyond the observable boundaries of our universe, or a Deist God), that does not itself pass the bar (i.e. for 'falsifiability') to qualify as a scientific theory but which still has genuine merit: something that shouldn't be tartly dismissed, IMHO, like the tooth fairy or leprechauns as a stringent application of your falsifiabality principle might entail. The multiverse and string theory are both examples of such hypotheses (to me they are both compelling, fit and elucidate the data, fill in the 'gaps' and are at least worthy of serious intellectual consideration even if they can't technically be falsified). I would add the non-revelatory 'Deistic' God, or at least the Intelligent Fine-Tuner hypothesis most Deists believe in, as another viable candidate. I don't view either of these three options as comparable to the
Flying Spaghetti Monster or Dawkins'
Magic Teapot floating around Venus. These have zero explanatory power, fit no conceivable data and lack intellectual elegance.
