A decimal point, followed by 44 zeros, followed by 67
One of the (rather many) unsolved problems of physics is that there are certain constants that cannot be derived from something else; they can only be measured. They just ARE (Barrow and Tipler, 1988). One of these is the fine structure constant, the coupling constant for the electromagnetic interaction between a photon and an electron. Other constants include the speed of light c, vacuum permittivity ɛ, Planck’s constant h, and the gravitational constant G. Depending on who you listen to, there are up to 26 known fundamental (many of them dimensionless) physical constants. Many of these are critical to the current approximation of a Theory of Everything (“ToE”), called the standard model of particle physics.
It’s not a real TOE, of course, because for nearly a century no one has been able to figure out how to meld gravity with quantum mechanics. The theory du jour (for the past nearly 40 years) for this is actually a mélange called string theory, which requires us to believe that there are 10 (or in some flavors 11) dimensions in our universe, six or seven of them invisible and not measurable. The main problem with this is not the multiple dimensions (which can’t be tested or sensed), but the fact that string theory has over 10 to the 500th power possible solutions. In other words, you can use it to predict anything you want. On several levels it is thus fundamentally untestable, so by definition is not even science.
One must exercise a lot of faith to be a theoretical physicist these days.
Here’s the interesting thing about these otherwise unexplainable constants: if any one of them were just slightly different, no life as we know it could exist in the universe. If you threw a coin and it came up heads 26 times in a row, that would be unusual, right? In fact, the likelihood that all these constants line up perfectly is quite a bit less than 1/2^26.
I.e., a decimal point, followed by 44 zeros, followed by 67. THAT unlikely.
The only secular explanation for this is the so-called multiverse; we will say more about this later.
One example may be helpful here: the fine-structure constant, which measures the strength of the electromagnetic force that in turn controls how charged elementary particles (such as electrons and photons) interact. This (dimensionless) constant is nearly equal to 1/137. There are several ways to obtain it, but a simple one is this: The constant is equal to the ratio of the velocity of the electron in the hydrogen atom divided by the speed of light. Its value is precisely tuned to allow the formation of commonly observable (baryonic) matter, and thus the emergence of life. Another precisely-tuned number is the strong nuclear force coupling constant. Its value is about 1. A fraction of a percent increase in this value and the strong nuclear force would bind the dineutron and the diproton, and nuclear fusion would have long ago converted all hydrogen in the early universe to helium. Water, organic compounds, and stars, essential for the emergence of life, would never exist. No stars → no supernova → no heavy elements like oxygen, carbon, silica, and iron… → no life.
The amazing, beyond incredible multiple coincidences of precise tuning with all these variables is called the Anthropic Principle. Another way to say this: these finely-tuned physical parameters are a necessity, because living observers wouldn’t be able to exist and thus observe the Universe, if these constants were not just precisely what they are.
Physicists have no idea why this is the case. It just is.
Even the current age of the universe is critical: if it were a fraction of the current age, there would not have been sufficient time to build the heavier elements (especially carbon, silica, iron, and oxygen) from earlier stellar deaths – novas and supernovas. There would be no rocky worlds with salty seas to harbor life.
Attempts to explain the Anthropic Principle – this precise tuning that permits life to exist – invoke either of two ideas: the existence of multiple universes (the “multiverse”), or an intelligent creator or designer. “Intelligent design” or “ID” is treated with scorn by most scientists because it is un-testable and un-provable, and repeatedly invokes against-physical-laws action by a Designer God, and therefore is even not remotely scientific. In our view, it is also placing very narrow human perceptions and limits on Who and What God is.
But what about the idea of a multiverse? The idea here is that there are an infinite number of universes with different physical parameters – including the ONE that harbors life as we know it – so we exist by a sort of cosmic natural selection.
There is also the very non-trivial problem of where all the energy/mass for all these multiple universes would come from in the first place. The devil is in the details, as they say.
But the multiverse, like intelligent design, is completely untestable. Some critics conclude that the Anthropic Principle is more of a philosophical concept, or basic assumption like physical laws, since it thus cannot be a scientific principle. One way some scientists have tried to bypass the controversy is to emphasize the so-called Weak Anthropic Principle, i.e., the conditions that we observe in the universe must permit the observer to exist. In mathematics as well as philosophy, the weak form of an argument is one which is easier to support because it makes fewer claims.
It certainly is weak. In fact, if you find all of these arguments either non-explanations or circular reasoning, then put a gold star on your forehead. We personally find it amazing that some scientists are so desperate to avoid acknowledging the existence of a Creator presiding over this universe that they will flail around trying to promote something as non-scientific, as untestable (Karl Popper used the word “unfalsifiable”) as string theory, or a multiverse.
So, who is the believer in something they can’t see here?
We agree that there’s a lot that science can tell us – we are, after all, both professional scientists. However, we don’t think science knows everything by a very long shot. The evolving history of science alone makes this abundantly clear. And that’s good, because one of the pleasures of doing science is solving problems and looking forward to new answers. As we show here and elsewhere in this book, there are a lot of ways that scientists must operate on faith, including accepting a lot of untestable assumptions.
Just like believers.
So, the moral of the story here is you can believe in science and religion at the same time – as long as you don’t assume that either of them can currently tell us everything about the universe.