Mark Megahan
There’s a lot more to nothing than most people imagine. Physicists who study quantum mechanics have really vivid imaginations. They put those daydreaming skills to use pondering ancient mysteries of the magical “zero” like modern Zen masters. For starters, in order to have a vacuum one must first consider what medium the hole is empty of.
A whole bunch of nothing
The key to understanding the whole universe, quantum physicists say, is intimate knowledge of nothing. Specifically, the region inside complete and total vacuum. When most people think of total vacuum they think of outer space. There isn’t any air out there but the vacuum isn’t nearly good enough for quantum researchers. Most people think of the kind of vacuum created by Otto von Guericke as the only one there is.
He “invented a pump to suck the air from within a hollow copper sphere, establishing perhaps the first high-quality vacuum on Earth.” The same equipment works really good at getting dirt out of carpets. The vacuum he created is an “absence of air.”
To create a vacuum useful to any modern physicist, they have to get rid of the air, then suck away any “medium that can slow down light.” That’s still not perfect. To get the ultimate in nothing, one must eliminate “any matter or energy capable of bending space.”
That, the quantum Zen Masters proclaim, is a true vacuum. Something along the lines of the space inside the exact center point of a black hole. “In each case the specific variety of nothing depends on what sort of something physicists intend to describe.”
What they found out is that nothing as a something behaves in really strange ways. “Each has its own behavior, as if it’s a different phase of a substance. Increasingly, it seems that the key to understanding the origin and fate of the universe may be a careful accounting of these proliferating varieties of absence.”
Isabel Garcia Garcia is a particle physicist at the Kavli Institute for Theoretical Physics in California. (And is rumored to have a minor in recursion.)
What are we missing
“We’re learning there’s a lot more to learn about nothing than we thought. How much more are we missing?” As Isabel explains, “our universe may sit on a platform of shoddy construction, a ‘metastable‘ vacuum that is doomed — in the distant future — to transform into another sort of nothing, destroying everything in the process.”
She hopes that isn’t the final answer. Vacuum started getting serious study once researchers realized reality is a collection of fields. It’s normal in classical physics for a field’s value to “be zero everywhere so that it has no influence and contains no energy.” Those are boring. At least they used to be.
“Nothing is happening,” notes Daniel Harlow, a theoretical physicist at the Massachusetts Institute of Technology. That’s a good thing. If you think of a quantum field with zero energy, you can depict it as “an array of pendulums — one at each point in space.” At zero, they hang straight down. Left alone, a quantum field will stay that way. They call it the “ground state.”
Things get freaky when there are some quantum fields who’s ground state is non-zero. That’s like a collection of pendulums all hovering at a 10-degree angle. They like it that way and they are stable. Physicists call that a “scalar field.”
In 2012 the Large Hadron Collider proved that a scalar field known as the Higgs field permeates the universe. The “nonzero Higgs value is what gives many elementary particles the property known as mass.” That bothers the guys who study the something that happens in nothing.
“With scalar fields around, the stability of the vacuum is not necessarily absolute. A field’s pendulums might have multiple semi-stable angles and a proclivity for switching from one configuration to another. Theorists aren’t certain whether the Higgs field, for instance, has found its absolute favorite configuration — the true vacuum.” They say even if our bubble might suddenly pop, it won’t happen for “billions of years.”
