Is the Universe Actually a Giant Quantum Computer?
According to professor Seth Lloyd, the answer is yes: "Everything in the universe is made of chunks of information called bits."
A researcher in Mechanical Engineering at MIT, Lloyd is one of the leaders in the field of quantum information. Decades ago, the feasibility of developing quantum computing devices was challenged. Now, as quantum computation is producing actual technologies, we are only left to wonder—what kind of applications will it provide us with next?
To begin understanding if the universe is a giant quantum computer—that is, a computer that operates using the principles of quantum mechanics—we must first understand the building blocks. What is information? According to Lloyd, everything in the universe is made of chunks of information called bits. These are the zeroes and ones that an engineer uses as the building blocks of computer software.
Atoms themselves are also bits of information. Tiny particles such as electrons, whose positions and velocities we cannot know for certain, are described by quantum mechanics. We can only give an estimate as to where an electron might be, and how fast it is moving. Before we make the measurement, the electron could be in any position, at the same time.
In a regular computer, information is encoded as bits interpreted as either 0 or 1. In a quantum computer, this information comes in slightly different variety – quantum bits, or “qubits”. These qubits can be in one state, in another, or somewhere in between.
A classical computer can read only one bit at a time, while a quantum computer will read all possible combinations. This means that quantum computers can give us a completely new and incredibly fast means of computing, such as factoring large numbers or evaluating extremely complex algorithms used for data analysis in finance, science, or cryptography.
Just like a quantum computer, physical processes involve the exchange and processing of information. Ed Fredkin first proposed that the Universe could be a computer in the 1960’s, as well as Konrad Zuse who came up with the idea independently. In their view, the Universe could be a type of computer called a cellular automaton, which describes a dynamic system that is broken apart into black and white grids, in which cells gather information from the surrounding cells on whether or not to change color. This is similar to the way a line or moving colony of ants might share information between each other about their surroundings, signaling to each other whether or not to follow a food trail.
However, this initial analogy to such sharing of information turned out to be not quite accurate. Regular computers are not so good at simulating quantum systems that do not follow the “yes” or “no” kind of signals, since quantum systems can have mixed signals! These are called the superposition of states, and can only be simulated by a quantum rather than classical computer. Since the universe itself is best described by quantum mechanics, Lloyd suggests that “quantum computing allows us to understand the universe in its own language.”
Physicists are not the only ones keen to reap the benefits of quantum computing; companies like IBM and Canadian D-wave as well as agencies like the CIA and NSA are also investing heavily in quantum computation research. The universe, however, might have already invested in a quantum computer. After all, information is processed in a very quantum mechanical way both on a tiny and large scale. The efficiency of these processes in our universe may very well suggest its true nature—of a quantum kind.