On this blog, I have said repeatedly that I keep three examples of the fine-tuning in my back pocket, ready to go, because they are the ones that make the most sense to me, based on my memory of taking physics and chemistry courses. I thought it might make a good post to just write about them, and you can see if you want to memorize them, too. It’s a good argument, and non-theists respect it.

So, first, let me just explain what the argument is. Basically, if you remember in your high school physics textbook, there were lots of numbers for well-known constants and quantities, such as the speed of light and the gravitational constant. What they never told you was that if you change most of those quantities and constants, then the universe would not be able to support life. Not just life as we know it, but any conceivable kind of complex life.

It’s not as though you can change these constants, and you will just have Spock-ears, or green skin, or nose ridges. No. If you change these constants and quantities, terrible horrible things will happen to your universe. Maybe it recollapses into a hot fire ball. Maybe you have no galaxies. Maybe you have no stars. Maybe you have no elements heavier than hydrogen. Or maybe you have no hydrogen. All bad things! All the bad things that wreck the ability of your universe to support life.

So, without further ado, let me tell you THREE of the best evidences for fine-tuning that even a child can understand. Well, maybe not a child, but you can understand them, OK?

Here they are:

Amount of Matter in the Universe:

The universe’s total stuff—stars, galaxies, gas clouds, dark matter—sets its expansion path. Too much stuff, and gravity would’ve crushed the universe into a hot dense fireball after the Big Bang. Too little, and matter in the universe would scatter, never forming galaxies or stars. The universe has the perfect weight to create galaxies and stars. This balance lets stars and planets form stable homes for life.

Strong Nuclear Force:

This force binds protons and neutrons in atomic nuclei, forming elements like hydrogen, helium, and carbon, vital for human bodies. If 2% stronger, protons would stick too tightly, depleting hydrogen, so stars couldn’t burn properly, and water wouldn’t form. If 5% weaker, only hydrogen would exist, like a chemistry class with one element on the chalkboard. The precise setting that we have ensures the a diverse variety of different elements, allowing stars to shine and life’s chemistry to work.

Cosmic Expansion Rate:

The universe expands at a speed set by the cosmological constant’s dark energy, like a balloon being carefully inflated. If slightly faster, matter would scatter too thinly, preventing stars or galaxies. If slower, gravity would clump everything into black holes. The universe grows at the ideal speed to allow galaxies, stars, and planets to form a cosmic stage where life can thrive.

By the way, the first and the third are distinct constants that work together, like ingredients in a recipe.

Conclusion

So, there are the three I have memorized. If you have time for discuss one, use the strong force. And by the way, if you are dealing with an atheist, you can give him the book “Just Six Numbers” by the famous atheist astronomer Martin Rees. Rees talks about several instances of fine-tuning, including the strong force. To escape the evidence for a Designer, he has to invent a multiverse (for which there is NO PHYSICAL EVIDENCE). There’s actually evidence against the multiverse, and we talked about it in our podcast episode on the cosmic fine-tuning (transcript here).

If you want a good introductory book about this topic, I like Dr. Mike Strauss’ “The Creator Revealed”. And he’s a real experimental particle physicist, too. I’ve met him in person! Anyway, I hope you have fun with this list. According to the Bible, the Boss used evidence when appealing to skeptics, and so you must use evidence, too, if you want to follow the Leader.