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Quotes on Fine Tuning by Physicists



The laws of science, as we know them at present, contain many fundamental numbers, like the size of electric charge of the electron and the ratio of the masses of the proton and the electron … The remarkable fact is that the values of these numbers seem to have been finely adjusted to make possible the development of life.

                  Stephen Hawking, Emeritus Lucasian Professor, Cambridge University
                 A Brief History of Time
, 1988


There are deep connections between the stars and atoms, between the cosmos and the microworld. Our emergence and survival depend on a very special “tuning” of the cosmos – a cosmos that may be even vaster than the universe we can see.

                   Sir Martin Rees, Astronomer Royal, Trinity College, Cambridge.
                  Just six Numbers, 2000


It is well known that the “strong” coupling constant is only marginally strong enough to bind nucleons into the nuclei. If it were rather weaker hydrogen would be the only element and this would presumably be incompatible with the existence of life.

                  Brandon Carter, Professor Physics, University of Cambridge
                 Large number coincidences and the anthropic principal in cosmology, 1974


The observed values of all physical and cosmological quantities are not equally probable… If the electromagnetic force where stronger or the strong nuclear force a little weaker, or both, then biologically essential [atoms] like carbon would not exist. The existence of [life] hinges upon this “coincidence.”

                  Professors John Barrow and Frank Tipler
                 The Anthropic Cosmological Principle, 1988


The Universe we live in is characterized by certain parameters that take specific values that appear to be remarkably fine-tuned to make life, including on Earth, possible. On more microscopic scales, certain fundamental parameters of the Standard Model of the strong and electroweak interactions like the light quark masses or the electromagnetic fine structure constant must take values that allow for the formation of neutrons, protons and atomic nuclei.

                  Ulf-G Meissner, Professor of Physics, University of Bonn (2015)    
                 Anthropic considerations in nuclear physics

If this were a purely scientific question and not one that touched on the religious problem, I do not believe that any scientist who examined the evidence would fail to draw the inference that the laws of nuclear physics have been deliberately designed with regard to the consequences they produce inside the stars. If this is so, then my apparently random quirks become part of a deep-laid scheme. If not, then we are back again to a monstrous sequence of accidents.

                  Fred Hoyle, Professor of Astronomy, Cambridge University
                 Lecture at Great St Mary’s Church, Cambridge, 1959


The really amazing thing is not that life on Earth is balanced on a knife-edge, but that the entire universe is balanced on a knife-edge, and would be total chaos if any of the natural ‘constants’ were off even slightly. Even if you dismiss man as a chance happening, the fact remains that the universe seems unreasonably suited to the existence of life—almost contrived—you might say a ‘put-up job’.

                   Paul Davies, Professor of Theoretical Physics, Adelaide University


If we nudge one of these (physical) constants just a few percent in one direction, stars burn out within a million years of their formation, and there is no time for evolution. If we nudge it a few percent in the other direction, then no elements heavier than helium form. No carbon, no life. Not even any chemistry. No complexity at all.

                   David D. Deutsch, Professor, Institute of Mathematics, Oxford


(speaking on some of the constants of nature)
The precision is as if one could throw a dart across the entire universe and hit a bull’s eye one millimeter in diameter on the other side.

                   Michael Turner, Professor, University of Chicago and Fermilab


The likelihood of the universe having usable energy (low entropy) at its creation is "one part out of ten to the power of ten to the power of 123." That is a “million billion billion billion billion billion billion billion billion billion billion billion billion billion zeros."

                   Roger Penrose, the Rouse Ball Professor of Mathematics, Oxford


The great mystery is not why there is dark energy. The great mystery is why there is so little of it [10^−122, nearly zero]. The fact that we are just on the knife edge of existence, [that] if dark energy were very much bigger we wouldn’t be here, that's the mystery. A slightly larger quantity of dark energy, or a slightly larger value of the cosmological constant would have caused space to expand rapidly enough that galaxies would not form.

                   Leonard Susskind, Professor of Physics, Stanford University


If you change a little bit the laws of nature, or you change a little bit the constants of nature -- like the charge on the electron -- then the way the universe develops is so changed, it is very likely that intelligent life would not have been able to develop.

                   Dennis Scania, Distinguished head of Cambridge University Observatories


How surprising it is that the laws of nature and the initial conditions of the universe should allow for the existence of beings who could observe it. Life as we know it would be impossible if any one of several physical quantities had slightly different values.

                   Steven Weinberg, Life in the Quantum Universe,
                  Scientific American, April 1995
                  Professor of Physics at Harvard University and Nobel laureate


 Suppose you are facing a firing squad. Fifty marksmen take aim, but they all miss. If they hadn’t all missed, you wouldn’t have survived to ponder the matter. But you wouldn’t just leave it at that—you’d still be baffled and would seek some further reason for your good fortune.

                   Canadian philosopher John Leslie cited by Physicist

                   John Rees in his book Just Six Numbers


To my mind, there must be at the bottom of it all, not an utterly simple equation, but an utterly simple idea. And to me that idea, when we finally discover it, will be so compelling, and so inevitable, so beautiful, we will all say to each other, "How could it have ever been otherwise?”

                   John Wheeler: Professor of Physics, University of Texas at Austin


Cambridge physicist Brandon Carter states that if gravity were altered by a mere one part in 10^40 (1 followed by 40 zeros) stars like our sun would not exist, nor one might argue, would any form of life that depends on solar-type stars for its sustenance.

                   Comments by Professor Paul Davies, (University of Adelaide) referencing the paper by Carter; Large number coincidences and the anthropic principle in cosmology, 1973

What does it mean for something to exist [the multiverse] if you can't observe it? I think that's a discussion that belongs safely in the realm of philosophy. People can believe in the multiverse all they want — but it's not science.

                       Sabine Hossenfelder, Physicist,
                       Frankfurt Institute for Advanced Studies, Germany


“Any coincidence”, said Miss Marple to herself, “is always worth noting. You can throw it away later if it is only a coincidence.”

                    Agatha Christie   


With so many errors and misjudgments, and with such a gross lack of understanding of the basic science we have seen exhibited by the supporters of supernatural fine-tuning, we can safely say that their motivation is more wishful thinking than truthful scientific inference. A proper analysis finds there is no evidence that the universe is fine-tuned for us.

                    Victor J. Stenger, The Fallacy of Fine-Tuning: Why the Universe

                    is Not Designed for Us, 2011


It is logically possible that parameters determined uniquely by abstract theoretical principles just happen to exhibit all the apparent fine-tunings required to produce, by a lucky coincidence, a universe containing complex structures. But that, I think, really strains credulity.

                     Frank Wilczek, Professor of Physics, MIT, Nobel Laurete
  Physics Today


All things are one thing and that one thing is all things—plankton, a shimmering phosphorescence on the sea and the spinning planets and an expanding universe, all bound together by the elastic string of time. It is advisable to look from the tide pool to the stars and then back to the tide pool again.

                      John Steinbeck, The Log from the Sea of Cortez



In science there are often contrary opinions to what is considered a “fact” by many. Fine tuning has its critics too. Dr. Luke Barnes (Sydney Institute for Astronomy, University of Sydney, Australia) has cowritten a book with Dr.Geraint Lewis; A Fortunate Universe, 2016.  It considers alternative views to the fine-tuning miracle.  Below are extracts from this book considering the objection, “Fine Tuning Has Been Disproved By (Insert Name Here)”


Page 239 criticism statement: “A number of scientists have looked closely at these fine-tuning claims and concluded that they are at least dubious, if not false. Fine-tuning has been debunked.”


The response: “Luke Barnes has published a review of the scientific literature on fine-tuning, carefully summarizing the conclusions of over 200 published papers in the field. These papers have built on the original work of key physicists, Carter, Silk, Carr, Rees, Davies, Barrow and Tipler, who pioneered the field. Their calculations have been refined using cutting-edge models and methods. Sometimes, new options for life have opened, and sometimes life has turned out to be more fine-tuned than previously thought. On balance, the fine-tuning of the Universe for life has stood up well under the scrutiny of physicists. Only a handful of peer-reviewed papers have challenged fine-tuning.”


An illuminating paper examining fine tuning, and the itemized objections of Victor Stenger, is The Fine-Tuning of the Universe for Intelligent Life by Luke Barnes (2012). This is a well written and deep paper. A careful study of it will expand your appreciation for fine tuning.


A wonderful book on fine tuning is, Just Six Numbers: The Deep Forces That Shape the Universe (2000), Dr. Martin Rees, Astronomer Royal, Trinity College, Cambridge.

From the book: “The nature of our universe is remarkably sensitive to just six numbers, constant values that describe and define everything from the way atoms are held together to the amount of matter in our universe.”

Incidentally, Dr. Rees has reviewed the Tuning page of this website and provided an encouraging and positive response to the author. 


For more insights into modern cosmology and physics consider the book, Our Mathematical Universe: My Quest for the Ultimate Nature of Reality (2014), Max Tegmark, Professor of Physics, MIT. The focus of this book is not fine tuning, but it is referenced. It has informative graphics and simple explanations of deep topics. Tegmark argues that mathematics describes the universe so well because the universe ultimately “is mathematics.”


See References for more links to books and scientific papers.

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