Science Says…

Scientists are the Priests of the world without God.

Carlo Rovelli, a theoretical physicist, has written a few books now revealing the secrets of the temple of Science to those outside its walls. And it is, as Rovelli is quick to point out, not a pretty picture for those who want to believe in the all-knowing Science. Rovelli repeatedly come back to: “This permanent doubt, the deep source of science.”

The book: Reality Is Not What It Seems. In this case, the title is a perfect summary of the book. If you want to understand the state of science today, if you want to go on a mind-bending journey into what we know and what we do not know about the physical world, then you will love this book. Beautifully written, engaging and lively. It’s a masterpiece. (Also, the mathematics are kept to a minimum for those not interested in wading through the equations. Rovelli is a story teller, a good one.)

But, before you start, just look at that title again. What you will discover in this book is that Reality is not at all what you think it is.

There are two pillars of our current conception of reality. General Relativity and Quantum Mechanics.

General Relativity warps the old Newtonian view of objects moving linearly though time and space. Instead, as Rovelli summarizes:

[We] are immersed in a gigantic, flexible mollusk (the metaphor is Einstein’s). The sun bends space around itself, and Earth does not circle around it drawn by a mysterious distant force but runs straight in a space that inclines, like a bead that rolls in a funnel: there are no mysterious forces generated by the center of the funnel; it is the curved nature of the funnel wall that guides the rotation of the bead. Planets circle around the sun, and things fall, because space around them is curved.

Einstein continued to draw out the implications of this in all sorts of ways. Time is not a fixed thing; it varies with the speed of the object moving through time. The universe is neither infinite nor does it have a boundary—it curves, so if you got in a spaceship and sailed straight out from the earth, you would eventually arrive at the earth.

General relativity is hard to describe in words. It works in Mathematics. Understand the math and you understand general relativity. But, is the math a correct description of the world in which we live? Absolutely. There have been very many tests of General Relativity. It passes them all.  

Set aside General Relativity for a moment. Think about Quantum Mechanics.

Think about an object. Any object. Where is that object? This seems like a really easy question to answer. Along come Heisenberg. Rovelli explains:

What if, effectively, electrons could vanish and reappear? What is these were the mysterious “quantum leaps” that appeared to underlie the structure of the atomic spectra? What if, between one interaction with something, and another with something else, the electron could literally be nowhere?

The conclusions of this line of thought are staggering. Matter and light are granular, like little pebbles which continually vanish and reappear. The future location of all these granular things is indeterminate; there is a probability distribution governing the world which makes the exact nature of the world unpredictable. Note this is not saying what you will do tomorrow is unpredictable (though it may be); it is saying the location of an atom in the future is unpredictable. And then, we cannot describe how things “are;” we can describe how things enter into relationships with other things instead, the relationships are what define the things.

Again, none of this really makes any sense translated into words. There are very many things wrong with the paragraph above. But the mathematics makes perfect sense. We just can’t translate the mathematics in anything less than a wobbly fashion. But, are the mathematics a correct way to describe the world? Absolutely. Quantum theory passes very single test it encounters.

You might think what has just been said is a bit weird and hard to understand. But, now we get to the really mind-blowing part.

1. General Relativity is a correct description of the world; it works mathematically and has been verified empirically.

2. Quantum Theory is a correct description of the world; it works mathematically and has been verified empirically.

3. General Relatively and Quantum Theory cannot both be true. They contradict each other.

A university student attending lectures on general relativity in the morning, and others on quantum mechanics in the afternoon, might be forgiven for concluding that his professors are fools, or they haven’t talked to each other for at least a century. In the morning, the world is a curved space-time where everything is continuous; in the afternoon, the world is a flat one where discrete quanta of energy leap and interact.

Remember that sentence that starts “Science says…”?

Theoretical physicists are still working to figure out how to reconcile theories which seemingly both cannot be true. Rovelli sketches out his preferred answer, and if you are ready for some even more mind-blowing description of what you used to call reality, well, enjoy.

Rovelli sets out to describe quantum gravity, a possible explanation of the world.

The first conclusion: Space does not exist. We think of space as a continuum in which particles move, but instead, maybe space doesn’t exist. There is a minimum quantum of volume. No space smaller than that unit exists. So there is no such thing as a space between these quantum units.

The second conclusion: Time does not exist. Time like space has minimum units and indeterminacy and, well, by the time your work out the mathematics, there is nothing recognizable as time anymore.

So if space doesn’t exist and time doesn’t exist, what does exist? Rovelli calls it the covariant quantum field, but he really doesn’t have a coherent description of this in words.

Indeed reality is not what it seems. We don’t really know what reality is. We don’t really have any ability to explain it. But, you can safely toss out all those ideas you have about what physical reality is. Science says it just ain’t so.