(Roughly) Daily

Posts Tagged ‘nothingness

“I love to talk about nothing. It’s the only thing I know anything about.”*…

An empty cardboard box opened with flaps lifted.
No matter how hard you try to empty a box, zero-point energy remains (image source)

Try as they might, scientists can’t truly rid a space or an object of its energy. But as George Musser reports, what “zero-point energy” really means is up for interpretation…

Suppose you want to empty a box. Really, truly empty it. You remove all its visible contents, pump out any gases, and — applying some science-fiction technology — evacuate any unseeable material such as dark matter. According to quantum mechanics, what’s left inside?

It sounds like a trick question. And in quantum mechanics, you know to expect a trick answer. Not only is the box still filled with energy, but all your efforts to empty it have barely put a dent in the amount.

This unavoidable residue is known as ground-state energy, or zero-point energy. It comes in two basic forms: The one in the box is associated with fields, such as the electromagnetic field, and the other is associated with discrete objects, such as atoms and molecules. You may dampen a field’s vibrations, but you cannot eliminate every trace of its presence. And atoms and molecules retain energy even if they’re cooled arbitrarily close to absolute zero. In both cases, the underlying physics is the same.

Zero-point energy is characteristic of any material structure or object that is at least partly confined, such as an atom held by electric fields in a molecule. The situation is like that of a ball that has settled at the bottom of a valley. The total energy of the ball consists of its potential energy (related to position) plus its kinetic energy (related to motion). To zero out both components, you would have to give a precise value to both the object’s position and its velocity, something forbidden by the Heisenberg uncertainty principle.

What the existence of zero-point energy tells you at a deeper level depends ultimately on which interpretation of quantum mechanics you adopt. The only noncontentious thing you can say is that, if you situate a bunch of particles in their lowest energy state and measure their positions or velocities, you will observe a spread of values. Despite being drained of energy, the particles will look as if they’ve been jiggling. In some interpretations of quantum mechanics, they really have been. But in others, the appearance of motion is a misleading holdover from classical physics, and there is no intuitive way to picture what’s happening…

More on the development of our understanding of “zero-point energy” and on the questions that remain: “In Quantum Mechanics, Nothingness Is the Potential To Be Anything,” from @georgemusser.com in @quantamagazine.bsky.social.

For the most amusing of musings on nothing, see Percival Everett‘s Dr. No.

* Oscar Wilde

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As we noodle on nought, we might spare a thought for Kurt Gödel; he died on this date in 1978. A  mathematician, logician, and author of Gödel’s proof. He is best known for his proof of Gödel’s Incompleteness Theorems (in 1931). He proved fundamental that in any axiomatic mathematical system there are propositions that cannot be proved or disproved within the axioms of the system. In particular, the consistency of the axioms cannot be proved… thus ending a hundred years of attempts to establish axioms to put the whole of mathematics on an axiomatic basis. [See here for a consideration of what his finding might mean for moral philosophy…]

Black and white portrait of Kurt Gödel, a mathematician and logician, wearing round glasses and a suit.

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“Horror vacui”*…

A 1672 book about the vacuum by the German scientist Otto von Guericke depicts a demonstration he gave for Emperor Ferdinand III, in which teams of horses tried unsuccessfully to pull apart the halves of a vacuum-filled copper sphere.

Recently, (Roughly) Daily took a look at nothing– and the perplexing philosophical questions that it raises. Today, Charlie Wood examines nothing’s physical manifestation, the vacuum, and the similarly perplexing questions it raises for physicists…

Millennia ago, Aristotle asserted that nature abhors a vacuum, reasoning that objects would fly through truly empty space at impossible speeds. In 1277, the French bishop Etienne Tempier shot back, declaring that God could do anything, even create a vacuum.

Then a mere scientist pulled it off. Otto von Guericke invented a pump to suck the air from within a hollow copper sphere, establishing perhaps the first high-quality vacuum on Earth. In a theatrical demonstration in 1654, he showed that not even two teams of horses straining to rip apart the watermelon-size ball could overcome the suction of nothing. [See illustration above.]

Since then, the vacuum has become a bedrock concept in physics, the foundation of any theory of something. Von Guericke’s vacuum was an absence of air. The electromagnetic vacuum is the absence of a medium that can slow down light. And a gravitational vacuum lacks any matter or energy capable of bending space. In each case the specific variety of nothing depends on what sort of something physicists intend to describe. “Sometimes, it’s the way we define a theory,” said Patrick Draper, a theoretical physicist at the University of Illinois.

As modern physicists have grappled with more sophisticated candidates for the ultimate theory of nature, they have encountered a growing multitude of types of nothing. 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.

“We’re learning there’s a lot more to learn about nothing than we thought,” said Isabel Garcia Garcia, a particle physicist at the Kavli Institute for Theoretical Physics in California. “How much more are we missing?”

So far, such studies have led to a dramatic conclusion: 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.

Nothing started to seem like something in the 20th century, as physicists came to view reality as a collection of fields: objects that fill space with a value at each point (the electric field, for instance, tells you how much force an electron will feel in different places). In classical physics, a field’s value can be zero everywhere so that it has no influence and contains no energy. “Classically, the vacuum is boring,” said Daniel Harlow, a theoretical physicist at the Massachusetts Institute of Technology. “Nothing is happening.”

But physicists learned that the universe’s fields are quantum, not classical, which means they are inherently uncertain. You’ll never catch a quantum field with exactly zero energy…

For an explanation of how key to understanding the origin and fate of the universe may be a more complete understanding of the vacuum: “How the Physics of Nothing Underlies Everything,” from @walkingthedot in @QuantaMagazine.

* attributed to Aristitole, and usually “translated,” as above, “Nature abhors a vacuum”

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As we noodle on nought, we might spare a thought for Hugo Gernsback, a Luxemborgian-American inventor, broadcast pioneer, writer, and publisher; he died on this date in 1967 at the age of 83.

Gernsback held 80 patents at the time of his death; he founded radio station WRNY, was involved in the first television broadcasts and is considered a pioneer in amateur radio.  But it was a writer and publisher that he probably left his most lasting mark:  In 1926, as owner/publisher of the magazine Modern Electrics, he filled a blank spot in his publication by dashing off the first chapter of a series called “Ralph 124C 41+.” The twelve installments of “Ralph” were filled with inventions unknown in 1926, including “television” (Gernsback is credited with introducing the word), fluorescent lighting, juke boxes, solar energy, television, microfilm, vending machines, and the device we now call radar.

The “Ralph” series was an astounding success with readers; and later that year Gernsback founded the first magazine devoted to science fiction, Amazing Stories.  Believing that the perfect sci-fi story is “75 percent literature interwoven with 25 percent science,” he coined the term “science fiction.”

Gernsback was a “careful” businessman, who was tight with the fees that he paid his writers– so tight that H. P. Lovecraft and Clark Ashton Smith referred to him as “Hugo the Rat.”

Still, his contributions to the genre as publisher were so significant that, along with H.G. Wells and Jules Verne, he is sometimes called “The Father of Science Fiction”; in his honor, the annual Science Fiction Achievement awards are called the “Hugos.”

(Coincidentally, today is also the birthday– in 1906– of Philo T. Farnsworth, the man who actually did invent television…)

Gernsback, wearing his invention, TV Glasses

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