What's the Total Energy In the Universe?
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The question, then, is why the ball started falling in the first place. How did something – composed of equal positive and negative parts, mind you – come from nothing?
Physicists aren't exactly sure, but their best guess is that the extreme positive and negative quantities of energy randomly fluctuated into existence. "Quantum theory, and specifically Heisenberg’s uncertainty principle, provide a natural explanation for how that energy may have come out of nothing," wrote Filippenko and Pasachoff.
They continued, "Throughout the universe, particles and
antiparticlesspontaneously form and quickly annihilate each other without violating the law of energy conservation. These spontaneous births and deaths of so-called 'virtual particle' pairs are known as 'quantum fluctuations.' Indeed, laboratory experiments have proven that quantum fluctuations occur everywhere, all the time."
Cosmologists have constructed a theory called inflation that accounts for the way in which a small volume of space occupied by a virtual particle pair could have ballooned to become the vast universe we see today. Alan Guth, one of the main brains behind inflationary cosmology, thus described the universe as "the ultimate free lunch."
In a lecture, Caltech cosmologist Sean Carroll put it this way: "You can create a compact, self-contained universe without needing any energy at all.""
What's the Total Energy In the Universe?
Quantum Foam, Virtual Particles and Other Curiosities
"Quantum physicists regularly ask you with a straight face to accept what seems to be complete nonsense. Particles are also waves; cats are alive and dead at the same time. But some of the most incredible creatures of the quantum realm get far less attention than Schrödinger’s famous cat. They’re called virtual particles, and they might be the reason the universe exists in the first place. In the pencast below, I’ll explain the basics of virtual particles. Then read on to learn more.
While the Big Bang theory explains how the universe has expanded and cooled since it began, it is quite silent on what “pulled the trigger,” so to speak. We simply don’t know what started the process. How there could be nothing at one moment and an entire baby universe the next?
It turns out that getting something from nothing is just business as usual for virtual particles.
Quantum Foam, Virtual Particles and Other Curiosities - The Nature of Reality — The Nature of Reality | PBS