Every thought we have, everything we see, the number of stars in the sky, and the different sizes of ants in the ground can all be considered information. Some scientists believe information is so important to the constitution of our physical reality that it should be regarded as a fundamental state of matter, alongside gas, liquid, plasma, and solids.
Seeing the universe as chock-full of information has another potential ramification – if everything in the universe is data, then is the universe essentially a giant computer running a program that includes me and you, the one having this thought right now?
From that standpoint, it might be possible to estimate the total amount of information in the universe, and some scientists have been attempting to come up with such a number.
In a recent paper published in AIP Advances from the American Institute of Physics, Melvin M. Vopson, a University of Portsmouth researcher, calculated exactly how much information is in the universe. As he writes in the paper, “We determined that each particle in the observable universe contains 1.509 bits of information and there are ∼6 × 10^80 bits of information stored in all the matter particles of the observable universe."
How the numbers were calculated
For the math that Vopson carried out to make sense, one needs to accept the principle formulated by the researcher in the paper that, “information is physical, the information is registered by physical systems, and all physical systems can register information.”
While the “information capacity” of the universe has been hotly debated for decades, Vopson’s approach is different in relying on Shannon’s Information Theory in coming up with the estimate. Vopson devised a formula that calculates the total number of protons in the observable universe, the so-called Eddington number. From that number, the researcher estimated the number of all elementary particles in the universe and the amount of information about itself that is contained in each particle.
The information theory employed by Vopson was proposed by mathematician Claude Shannon, known as the "Father of the Digital Age." Shannon’s work on information theory dates from 1948 and outlines a method for quantifying information. The theory relates entropy, the amount of uncertainty within a system, to information. By the logic of the theory, the informational content of a message is a measure of how much entropy (or uncertainty) the message reduces, with different messages having varying values.
Vopson applied such entropy calculations to figure out how much information about mass, spin, and charge could be held by protons, neutrons, and electrons, before extrapolating the results to the entire universe.
"It is the first time this approach has been taken in measuring the information content of the universe, and it provides a clear numerical prediction," explained Vopson. "Even if not entirely accurate, the numerical prediction offers a potential avenue toward experimental testing."
Vopson’s current study has some limitations, in that it doesn’t consider antiparticles and neutrinos. It also makes some assumptions about the transfer and storage of information in the universe. Still, it can serve as an estimating tool for further research and practical experiments that is consistent with recent work by other researchers in this field.
What is information?
While researchers have been increasingly focused on figuring out the exact nature of information, it has remained a relative mystery so far. Even though we can describe information in a variety of ways, as consisting of facts, descriptions of physical states, or mathematical formulas, the question remains — does it have a physical presence that can be measured as some propose?
Vopson previously suggested that information is a fifth state of matter and could even possibly be the mysterious dark matter, which is estimated to make up around 27 percent of the known universe. Yet, this hasn’t been experimentally confirmed. By comparison, normal matter, which includes you and me and everything we can observe in the universe, is only five percent of all matter.
The computational universe
Vopson is not the first to conjecture that information may be a key building block of reality. Physicist John Archibald Wheeler described this idea as "it from bit" — with “it" being everything in the universe and ”bit" referring to information.
Seth Lloyd, an MIT professor who focuses on quantum information, sees the universe as a giant computer, calling it "a physical system that breaks up information into bits, and flips those bits in a systematic fashion."
He points to the example of an electron, whose spin, according to quantum mechanics, takes on either of two values - up or down. Lloyd compares this to computer bits, the smallest units of digital information, which also take on two kinds of information – either a 0 or a 1. As every elementary particle contains information, so does the universe, which Lloyd proposes also processes this information in a way that makes it quite similar to a computer. In fact, Lloyd maintains, the universe is not simply like a computer but is a computer, in which all changes in the universe could be considered as “computations”.
In his paper on the “Computational Universe,” Lloyd actually came up with a total for these computations, estimating how many “elementary logical operations” the universe would have performed since it began – a number that's close to 10^120 (10 to the 120). He also previously came up with his own estimate for how many bits could be contained by the amount of matter currently in the universe – 10^90 (10 to the 90) bits.
Of course, proving that the universe is a computer would have major philosophical and practical implications. One big question – who programs the universe’s computer? For Lloyd, the explanation may lie in “little random quantum fluctuations.” He suggests that quantum fluctuations may be responsible for all manner of physical phenomena, programming the universe and even our DNA, albeit with a certain amount of randomness. “If you trace that randomness down, you find that that randomness is actually arising from little quantum fluctuations, which masquerade as thermal and chemical fluctuations,” explains Lloyd, adding “Your genes got programmed by quantum fluctuation.”
Suffice it say, further research in this field can have profound consequences for everything we know about ourselves and our universe.