Is the total possible amount of computer memory finite?

I went to a lecture presented by Prof. Lawrence Krauss, in which he said that if Moore’s Law holds true for another 42 years (I think) then all the energy in the observable universe will have been used in the resultant computer. That refers to processing power more than memory, but it is a similar idea.

The Israeli physicist Jacob Bekenstein has discovered the Bekenstein Bound which limits the amount of information it is possible to have within a given volume, which also limits the amount of computing power or memory it is possible to have. So yes, it is certainly the case that computer memory capabilities are finite.

@FireMadeFlesh That is if you don’t count quantum computing. It’s been suggested that unbounded problems could be solved in a quantum computer. Though that’s not the same as data storage, I’m sure there could be ways of using the same principles to store unlimited data.

@Shuttle128 – Even a quantum computer would have a finite memory and processor speed. In fact, quantum mechanics implies that the universe is “digital” in nature with discrete (or quantum) energy states and discrete coordinates that all particles must occupy. Even if such a quantum computer could extend itself into “parallel” universes, there would still be a finite number of energy levels and coorinates in the sum.

@Shuttle128 Prof. Krauss’ assertion is based on conventional computing, I think, but the Bekenstein Bound is a result of QM. I don’t fully understand it, but if you extrapolate its principles across multiple universes I imagine it would account for quantum computing too.

Modern physics says that information is a more fundamental entity than matter, so the law of conservation of mass-energy is a variation on the law of conservation of information. Since information cannot be created or destroyed, there is no such thing as unlimited information and therefore it is impossible for infinite amounts of data to exist.

Potential is never finite we’ll just keep finding new ways to make more and more storage.

@FireMadeFlesh Interesting, never heard it said like that before.

@HungryGuy True, the finite speed of the processing would prevent us from getting or storing infinite data….you might be right, I guess even infinite universes have to eventually repeat the states.

@Shuttle128 – Even if there are multiple universes, it’s unlikely that there’s an infinite number of them. The number of universes would still have to be finite, though very large.

Also consider that in our universe, the cosmological constants have taken on values that allow matter condisive to human life to exist. Had any of the cosmological constants been even slightly off from what they are now, matter as we know it could not exist. Thus, in most of the parallel universes, even if there is a near infinity number of them, it it unlikely that matter as we know it exists.

@HungryGuy Could the constants have taken on a different value? As far as I know we are unaware of what determines their value, so we cannot know whether they can be any different to what they are, let alone the probability distribution of what they might have been. Its a bit of a leap to assume equal probability of all values.

You’re right. We don’t know the probabilities of the distributions of the possible values of the cosmological constants. But many cosmologists find it unlikely that they just happen to take on the exact values that make life as we know it possible.

@HungryGuy I think it is unlikely too, but that very apparent improbability is a reason to reject the idea that they are based on probability. My hunch is that they can be derived from a GUT, rather than taking on different values in different universes or relying on the anthropic principle. Just my idea.

Well, yes, if we hat a GUT (Grand Unified Theory of everything) then we could just “plug in” whatever values we wanted to try, and then calculate what the resulting universe would look like.

It doesn’t matter how improbable the possibility was that this universe exists as it is. It does exist. Because it exists in such a state that we developed as we have, we ask what the probability of our universe existing is. We can’t answer that question yet, but I don’t think it is weird in any way that we find ourselves in this universe.

only if the universe is finite

@talljasperman That is a well established fact.

@FireMadeFlesh We know the shape of the universe (omega = 1) but we can only observe a finite amount of the universe. We can’t say whether or not the stuff we can observe is all that exists.

@Shuttle128 True, but in knowing the shape we know the volume of the universe is finite even if we cannot see it all.

@FireMadeFlesh
Shape of the universe a known? what shape please? I’d heard the 4 dimensional donut hypothosis, is that now the current understanding?

(I love these tangents)

Also, had a thought, I was thinking about stereo speakers, and how we piggy-back multiple vibrations on the speaker cone to give multi channel sound (if that’s the right way to describe it?). So anyway what I was thinking was that if space is full of resonating energy (the so called zero point field), and that if I’m right in saying that there would be an infinite number of frequencies since amplitude and wavelength would be infinitely variable, that if you could encode information and trap it in some form of resonance chamber, that the amount of information storable would be infinite?

Apart from the obvious technical problems of storage, the only other problem I can see is that of information recovery, since any attempt to recover would interrupt all the other information.

Anyone any thoughts?

Waves can’t hold infinite information. They can hold continuous information rather than discreet information, but the bandwidth is not by any means infinite.

The universe is spatially flat according to the WMAP data.

I’m not really sure about the zero point field, but QM says that waves are separated into discrete quanta, and so their energy spectrum must be in Planck energy increments. Interesting idea though, it may be a superior method even if it doesn’t hold infinite data.