My driving professional passion is general scientific literacy for all people. The American Association for the Advancement of Science justifies this task in stark terms: "Without a scientifically literate population, the outlook for a better world is not promising."
One scientific question that should interest everybody is: What is the world made of? For decades, the standard answer was everything is made of atoms -- tiny objects made of even tinier "particles" called protons, neutrons, and electrons. Although this is still a helpful description of the normal world around us, science's answer today is far broader and more interesting.
For one thing, we now know 95 percent of the universe's energy comes in the form of something called "dark matter" and something else called "dark energy." The evidence for both is strong, but we don't yet know in any detail what either one is. Neither one is made of anything much like the chemical atoms comprising our normal environment but both are all around us and they fill the universe.
I could go on and on about this "dark" (unseen) side of the universe, but let me broaden the story further to tell you what everything, including dark matter and energy, is made of as we now understand it.
You are probably familiar with the notion of the "magnetic field" surrounding every magnet and also surrounding Earth. Magnetic fields are quite physically real, even if we can't see them or feel them (unless we happen, like knights of old, to be wearing a suit made of iron). If you've ever noticed clothes sticking together when you remove them from a clothes dryer, you've also experienced "electric fields." Today we understand these two types of fields as different aspects of one and the same field, the "electromagnetic field." This field might seem abstract because you can't pick it up the way you can pick up a rock, but it's quite real and it extends throughout the universe. You frequently experience its effects: Light waves, radio waves, and many other familiar phenomena are waves in this electromagnetic field.
Strange as it may seem, the picture painted by modern science is that there are about 15 other kinds of physical fields, all somewhat similar to the electromagnetic field. Each one fills the entire universe, and together they are responsible for everything in the universe: cabbages, kings, Earth's atmosphere, light, sound, stars, dark energy, dark matter, and you. Albert Einstein, along with most scientists today including me, thought we will eventually find a theory that explains all these fields as different aspects of a single unifying field.
These fields fill the universe. There is no empty space. If even a cubic millimeter somewhere contained no physical fields, that region of space would simply cease to exist. So it's fair to say that the universe -- all space and all matter -- is not only "made of" fields, it "is" fields.
What about atoms, and the still-smaller "particles" of which atoms are made? How do these things arise from space-filling fields? The answer is all these fields are made of a huge number of small, identical, spatially-extended, highly unified bundles of energy called "quanta" (the plural of "quantum") and so-called "particles" such as electrons and protons are actually the quanta of various fields. These quanta are radically eccentric. They obey a peculiar set of rules known as -- you guessed it -- "quantum mechanics," although most of us physicists today prefer the term "quantum physics" because these things' behaviors are quite unlike any ordinary machine.
Each type of field has its own unique type of quantum. For example, the quantum of the electromagnetic field is called a "photon." Photons are bundles of electromagnetic energy traveling at light speed. When you see light, it's because a batch (it takes five to 10 of them for the eye to begin to detect light) of photons entered your eye. For another example, each electron is a quantum of another kind of field called the "electron-positron field." For another example, the high-energy machine in Geneva known as the "Large Hadron Collider" recently discovered an entirely new type of quantum called the "Higgs boson." It's the quantum of a previously-undiscovered, but widely predicted, universe-filling field called the "Higgs field."
Quantum physics, which actually manages to make rational sense of all of this, is the most weird, wonderful and unbelievably original collection of ideas you can imagine. Nature, it seems, is an incomparably inventive artist.
Commentary on 04/04/2017
Print Headline: Nature: An incomparable artist