Zero - Charles Seife [73]
To understand the big bang, physicists must marry quantum theory with relativity. In the past few years they have begun to succeed, creating a monster theory that explains the quantum-mechanical nature of gravity, allowing them to peer at the very creation of our universe. All they had to do was banish zero.
The Theory of Everything is, in truth, a theory of nothing.
Zero Banished: String Theory
The problem is, when we try to calculate all the way down to zero distance, the equation blows up in our face and gives us meaningless answers—things like infinity. This caused a lot of trouble when the theory of quantum electrodynamics first came out. People were getting infinity for every problem they tried to calculate!
—RICHARD FEYNMAN
General relativity and quantum mechanics were bound to be incompatible. The universe of general relativity is a smooth rubber sheet. It is continuous and flowing, never sharp, never pointy. Quantum mechanics, on the other hand, describes a jerky and discontinuous universe. What the two theories have in common—and what they clash over—is zero.
The infinite zero of a black hole—mass crammed into zero space, curving space infinitely—punches a hole in the smooth rubber sheet. The equations of general relativity cannot deal with the sharpness of zero. In a black hole, space and time are meaningless.
Quantum mechanics has a similar problem, a problem related to the zero-point energy. The laws of quantum mechanics treat particles such as the electron as points; that is, they take up no space at all. The electron is a zero-dimensional object, and its very zerolike nature ensures that scientists don’t even know the electron’s mass or charge.
This seems like a silly statement. It has been nearly a century since scientists measured the electron’s mass and charge. How could physicists not know something that has been measured? The answer lies with zero.
The electron that scientists see in the laboratory—the electron that physicists, chemists, and engineers have known and loved for decades—is an impostor. It is not the true electron. The true electron is hidden in a shroud of particles, made up of the zero-point fluctuations, those particles that constantly pop in and out of existence. As an electron sits in the vacuum, it occasionally absorbs or spits out one of these particles, such as a photon. The swarm of particles makes it difficult to get a measurement of the electron’s mass and charge, because the particles interfere with the measurement, masking the electron’s true properties. The “true” electron is a bit heavier and carries a greater charge than the electron that physicists observe.
Scientists might get a better idea of the true mass and charge of the electron if they could get a little closer; if they could invent a tiny device that could get a short distance inside the cloud of particles, they would be able to see more clearly. According to quantum theory, as the measuring device gets past the first few virtual particles on the rim of the cloud, scientists would see the mass and charge of the electron go up, and as the probe gets closer and closer to the electron, it would pass more and more virtual particles, so the observed mass and charge go up and up. As the probe approaches zero distance from the electron, the number of particles it passes goes up to infinity—so the probe’s measurements of the mass and charge of the electron also go to infinity. According to the rules of quantum mechanics, the zero-dimensional electron has infinite mass and infinite charge.
As with the zero-point energy, scientists learned to ignore the infinite mass and charge of the electron. They don’t go all the way to zero distance from the electron when they calculate the