Editing Multiverse (section)

== Arguments against multiverse hypotheses ==
In his 2003 ''New York Times'' opinion piece, "A Brief History of the Multiverse", author and cosmologist [[Paul Davies]] offered a variety of arguments that multiverse hypotheses are non-scientific:<ref>{{cite news |title=''A Brief History of the Multiverse'' |first=Paul |last=Davies |url=https://www.nytimes.com/2003/04/12/opinion/a-brief-history-of-the-multiverse.html?pagewanted=all |newspaper=New York Times |date=12 April 2003 |access-date=16 August 2011}}</ref> {{quotation|text=For a start, how is the existence of the other universes to be tested? To be sure, all cosmologists accept that there are some regions of the universe that lie beyond the reach of our telescopes, but somewhere on the slippery slope between that and the idea that there is an infinite number of universes, credibility reaches a limit. As one slips down that slope, more and more must be accepted on faith, and less and less is open to scientific verification. Extreme multiverse explanations are therefore reminiscent of theological discussions. Indeed, invoking an infinity of unseen universes to explain the unusual features of the one we do see is just as ad hoc as invoking an unseen Creator. The multiverse theory may be dressed up in scientific language, but in essence, it requires the same leap of faith.|author=Paul Davies|title="A Brief History of the Multiverse"|source=''[[The New York Times]]''}}

[[George F. R. Ellis|George Ellis]], writing in August 2011, provided a criticism of the multiverse, and pointed out that it is not a traditional scientific theory. He accepts that the multiverse is thought to exist far beyond the [[cosmological horizon]]. He emphasized that it is theorized to be so far away that it is unlikely any evidence will ever be found. Ellis also explained that some theorists do not believe the lack of [[Empiricism|empirical]] [[testability]] and [[falsifiability]] is a major concern, but he is opposed to that line of thinking: {{quotation|text=Many physicists who talk about the multiverse, especially advocates of the [[string landscape]], do not care much about parallel universes ''per se''. For them, objections to the multiverse as a concept are unimportant. Their theories live or die based on internal consistency and, one hopes, eventual laboratory testing.}}

Ellis says that scientists have proposed the idea of the multiverse as a way of explaining the nature of [[existence]]. He points out that it ultimately leaves those questions unresolved because it is a [[metaphysical]] issue that cannot be resolved by empirical science. He argues that observational testing is at the core of science and should not be abandoned:<ref name="SciAmer-9723382">{{cite magazine |first=George F. R. |last=Ellis |date=1 August 2011 |title=Does the Multiverse Really Exist? |magazine=[[Scientific American]] |volume=305 |issue=2 |pages=38–43 |url=http://www.scientificamerican.com/article/does-the-multiverse-really-exist/ |access-date=16 August 2011 |doi=10.1038/scientificamerican0811-38 |url-access=subscription |bibcode = 2011SciAm.305a..38E }}</ref> {{quotation|text=As skeptical as I am, I think the contemplation of the multiverse is an excellent opportunity to reflect on the nature of science and on the ultimate nature of existence: why we are here. {{omission}} In looking at this concept, we need an open mind, though not too open. It is a delicate path to tread. Parallel universes may or may not exist; the case is unproved. We are going to have to live with that uncertainty. Nothing is wrong with scientifically based philosophical speculation, which is what multiverse proposals are. But we should name it for what it is.|author=George Ellis|title="Does the Multiverse Really Exist?"|source=''[[Scientific American]]''}}

Philosopher [[Philip Goff (philosopher)|Philip Goff]] argues that the inference of a multiverse to explain the apparent fine-tuning of the universe is an example of [[Inverse Gambler's Fallacy]].<ref>{{Cite web|url=https://www.scientificamerican.com/article/our-improbable-existence-is-no-evidence-for-a-multiverse/|title=Our Improbable Existence Is No Evidence for a Multiverse|first=Philip|last=Goff|author-link=Philip Goff (philosopher)|website=Scientific American}}</ref>

Stoeger, Ellis, and Kircher<ref>{{cite arXiv |eprint=astro-ph/0407329 |first1=W. R. |last1=Stoeger |first2=G. F. R. |last2=Ellis |title=Multiverses and Cosmology: Philosophical Issues |date=2006-01-19 |last3=Kirchner |first3=U.}}</ref>{{Rp|at=sec. 7}} note that in a true multiverse theory, "the universes are then completely disjoint and nothing that happens in any one of them is causally linked to what happens in any other one. This lack of any causal connection in such multiverses really places them beyond any scientific support".

In May 2020, astrophysicist Ethan Siegel expressed criticism in a [[Forbes]] blog post that parallel universes would have to remain a science fiction dream for the time being, based on the scientific evidence available to us.<ref>{{cite web |author=Siegel |first=Ethan |date=22 May 2020 |title=Ask Ethan: Have We Finally Found Evidence For A Parallel Universe? |url=https://www.forbes.com/sites/startswithabang/2020/05/22/ask-ethan-have-we-finally-found-evidence-for-a-parallel-universe/ |access-date=18 September 2020 |website=[[Forbes]] |language=en-us}}<!-- auto-translated by Module:CS1 translator --></ref>

''[[Scientific American]]'' contributor [[John Horgan (journalist)|John Horgan]] also argues against the idea of a multiverse, claiming that they are "bad for science."<ref>{{cite web | url=https://www.scientificamerican.com/blog/cross-check/multiverse-theories-are-bad-for-science/ | title=Multiverse Theories Are Bad for Science | website=[[Scientific American]] }}</ref>