In recent discussions with atheists on Twitter, I’ve encountered objections to the term “fine-tuning.” This term refers to the fact that, according to physics and cosmology, the fundamental physical constants and forces of the universe (the strength of gravity, the strength of electromagnetism, the cosmological constant, the number of spatial dimensions, and so forth) all appear to be precisely “tuned” within an extremely narrow range—an incredibly delicate balance that permits the existence of life in the universe. There are dozens of these constants and forces, and if just one of them had a slightly different value—if it were altered by as little as one part in billions or even trillions—life could not exist.

I find that most of the atheists I encounter have never heard of fine-tuning or the anthropic principle. When I explain it to them, they are aghast and refuse to believe what I’m saying. They frequently accuse me of lying or ignorance.

Those who are more astute and well-read will frequently object to the term “fine-tuning” because they think that even using that term is stacking the deck. “‘Fine-tuning’ requires a Fine-Tuner,” wrote one. “The term ‘fine tuning’ is a conclusion disguised as a premise: the argument is truly, technically circular.”

To his thinking, the term “fine-tuning” implies intentional tinkering with the laws of physics by a deity. That’s not how the term is commonly used and understood within the scientific community. “Fine-tuning” is actually a values-neutral, secular, scientific term that describes the nature of the constants and forces of the universe. Physicists, cosmologists, and astronomers actually do observe the universe to be “fine-tuned” without regard to how it got that way. It’s a description of the state of the universe, and does not presuppose how the universe got that way.

Whether or not there was a “Fine-Tuner” (i.e., God), the universe is fine-tuned. It is certainly conceivable that the universe could have come into existence by random-chance processes—with all of its physical constants and forces balanced within that incredibly narrow range, and without the intentional intervention of a “Fine-Tuner.”

Let me say that again for emphasis: Even if there was no intelligent “Fine-Tuner,” the universe is undeniably fine-tuned.

Atheists who wrongly accuse me of trying to bias the discussion with the term “fine-tuning” are themselves guilty of trying to force the discussion toward their conclusion by taking a perfectly common, descriptive, and neutral term, and trying to rule it out of bounds. If you read the literature on cosmic fine-tuning and the anthropic principle, it becomes clear that the term is used by scientists as the best way to describe the condition of the universe, and without any hint or suggestion of theistic propaganda. Some examples:

In The Anthropic Cosmological Principle, physicists John D. Barrow and Frank J. Tipler write:

Hoyle realized that this remarkable chain of coincidences—the unusual longevity of beryllium, the existence of an advantageous resonance level in C¹² and the nonexistence of a disadvantageous level in O¹⁶— were necessary, and remarkably fine-tuned, conditions for our own existence and indeed the existence of any carbon-based life in the universe.

These coincidences could, in principle, be traced back to their roots where they would reveal a meticulous fine-tuning between the strengths of the nuclear and electromagnetic interactions along with the relative masses of electrons and nucleons.

—John D. Barrow and Frank J. Tipler, The Anthropic Cosmological Principle (New York: Oxford, 1988) 253.

Barrow and Tipler aren’t using “fine-tuning” to promote theism. They are simply describing some of the fine-tuned conditions in the cosmos that make life possible. Similarly, cosmologist Martin Rees, Britain’s Astronomer Royal (and definitely not a theist), also uses “fine-tuning” in a purely objective, scientific fashion:

These six numbers constitute a “recipe” for a universe. Moreover, the outcome is sensitive to their values: if any one of them were to be “untuned,” there would be no stars and no life. Is this tuning just a brute fact, a coincidence? Or is it the providence of a benign Creator? I take the view that it is neither. An infinity of other universes may well exist where the numbers are different. Most would be stillborn or sterile. We could only have emerged (and therefore we naturally now find ourselves) in a universe with the “right” combination. This realization offers a radically new perspective on our universe, on our place in it, and on the nature of physical laws. . . . If you imagine setting up a universe by adjusting six dials, then the tuning must be precise in order to yield a universe that could harbour life.

—Martin Rees, Just Six Numbers: The Deep Forces That Shape the Universe (New York: Basic Books, 2001), 4 and 22.

In The First Three Minutes, Nobel-winning physicist (and atheist) Steven Weinberg writes about the fine-tuned nature of the cosmological constant:

There may be a cosmological constant in the field equations whose value just cancels the effects of the vacuum mass density produced by quantum fluctuations. But to avoid conflict with astronomical observation, this cancellation would have to be accurate to at least 120 decimal places. Why in the world should the cosmological constant be so precisely fine-tuned?

—Steven Weinberg, The First Three Minutes: A Modern View of the Origin of the Universe (New York: Basic Books, 1993), 186-187.

In The Grand Design, physicists Stephen Hawking and Leonard Mlodinow also write about the fine-tuning of the cosmological constant in Einstein’s general relativity equations, calling it “the most impressive fine-tuning coincidence” in cosmology. They go on to describe other fine-tuning problems in cosmology:

Most of the fundamental constants in our theories appear fine-tuned in the sense that if they were altered by only modest amounts, the universe would be qualitatively different, and in many cases unsuitable for the development of life. . . . The emergence of the complex structures capable of supporting intelligent observers seems to be very fragile. The laws of nature form a system that is extremely fine-tuned, and very little in physical law can be altered without destroying the possibility of the development of life as we know it. Were it not for a series of startling coincidences in the precise details of physical law, it seems, humans and similar life-forms would never have come into being.

—Stephen Hawking and Leonard Mlodinow, The Grand Design (New York: Bantam, 2012), 160-161.

So, to answer the question “Am I being dishonest about fine-tuning?,” the answer is no. I’m using the term “fine-tuning” in exactly the same way physicists and cosmologists Barrow, Tipler, Rees, Weinberg, Hawking and Mlodinow use it. I’m not playing word games to force a preordained conclusion. I lay out the evidence, I tell you what I think it means, and you are free to draw a different conclusion.

One of the most annoying experiences I have on Twitter is when atheists who don’t understand my views accuse me of lying. Why would I lie? For one thing, I’m morally and ethically committed to the truth. For another thing, I’m convinced that the evidence stacks up on my side. I believe that if I honestly present the evidence, including the sources and footnotes, the evidence will speak for itself.

I hope you’ll examine the evidence rationally and skeptically. If you are intellectually honest, you’ll at least see that I have valid reasons for my views. You may not be persuaded. You may not agree with me. You may have some counter-arguments to toss my way. Please do. All I ask is that you think critically, challenge everything, demand evidence—then be willing to follow that evidence wherever it leads.