Have you ever wondered how big your computer hard drive would have to be to store all the information in the cosmos? Well, a physicist has provided an interesting ballpark figure. Every particle in the visible Universe would add up to 6x1080 bits of information. That’s a 6 followed by 80 zeros. For comparison. One terabyte is 8,000,000,000,000 bits (that’s just 12 zeros).

As reported in the journal AIP Advances, physicist Dr Melvin Vopson took two simple approaches to work out the information content of the universe. First, he looked at the estimation of just how many particles of visible matter there are out there. And then he multiplied it for how much information each particle corresponds to.

The first number was estimated using the Eddington number, which is the number of protons in the visible universe. Obviously, the visible matter is not just made up of protons, so Vopson expanded on that. The second number, the information contained in each particle, is estimated using Claude Shannon’s Information theory. In this study, each elementary particle corresponds to 1.509 bits of information.

“The information capacity of the universe has been a topic of debate for over half a century,” Dr Vopson, from the University of Portsmouth, said in a statement. “There have been various attempts to estimate the information content of the universe, but in this paper, I describe a unique approach that additionally postulates how much information could be compressed into a single elementary particle.”

A previous estimate by Seth Lloyd from almost two decades ago had a value much over a billion times higher but also, it included a very different derivation and interpretation of the information out there. And even previous work by Vopson had different estimates using different assumptions.

Different methods to answer this question might lead to a better understanding of information as a whole. It is very difficult to define what information is, despite it popping up in physics equations and being a crucial player in objects at the limit of physics like black holes.

“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 calculation purposely ignores the small quantities of antimatter present in the Universe, and neutrinos – extremely light and non-electrically charged particles – that are extremely abundant in the universe. It also ignores dark matter, a mysterious substance that might outweigh regular matter 5-to-1.