Slashdot Mirror
Theory of Information Could Resolve One of the Great Paradoxes of Cosmology
KentuckyFC writes: When physicists attempt to calculate the energy density of the universe from first principles, the number they come up using quantum mechanics is 10^94 g/cm^3 . And yet the observed energy density is about 10^-27 g/cm^3. In other words, our best theory of reality misses the mark by 120 orders of magnitude. Now one researcher says the paradox can be resolved by considering the information content of the universe. Specifying the location of the 10^25 stars in the visible universe to an accuracy of 10 cubic kilometers requires some 10^93 bits. And using Landauer's principle to calculate the energy associated with all these bits gives an energy density of about 10^-30 g/cm^3. That's not a bad first principles result. But if the location has to be specified to the Planck length, then the energy density is about 117 orders of magnitude larger. In other words, the nature of information should lie at the heart of our best theory of reality, not quantum mechanics.
The idea does actually work if the assumption is that we are living in a simulation, similar to ours. ;)
The idea does actually work if the assumption is that we are living in a simulation, similar to ours. ;)
That's actually what I thought too. I've actually pondered this before. If we are in a simulation then stuff at the microscopic
or macroscopic only has to exist when viewed and can be generalized to a much lower resolution the rest of the time which
would greatly reduce the processing power required. This might also help explain some of the observation effects of quantum
physics where it seems that things act differently when observed.
It makes a tiny bit of sense to me.
"If we use [unstated first principles] to estimate what energy density should be, it's about 10^94 g/cm^3.
If we use the information content at the Planck scale, it's pretty close -- about 10^90 g/cm^3.
But we actually observe an information density of about 10^-27 g/cm^3.
And if we decrease the resolution from Planck scale voxels to 10 km^3 voxels, we get an information density that equates to 10^-27 g/cm^3.
This is evidence that we are living in a simulation, and the programmers aren't running the universe at Planck scale voxels, but only star sized voxels."
A large mountain of salt needs to be taken with this argument, but it does make sense -- as an argument.
"Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality." - Nikola Tesla
"The scientists from Franklin to Morse were clear thinkers and did not produce erroneous theories. The scientists of today think deeply instead of clearly. One must be sane to think clearly, but one can think deeply and be quite insane" - Nikola Tesla
"There is not self containing theory possible aside from practical meaning, for a language is used in its annunciations, which miplys that developed ideas and complex porocesses of thoughts are alrealy in existance beside the general experience associated with there with. We define things in a phrase using words, these words hale to be explained by other words and so on forever in a complicated maze. There is no bottom to anything, we all upside down." - Oliver Heaviside
"They (Scientists) substitute words for realty, and after that talk about the words." - Edwin Armstrong
Why, for instance, 10 cubic-kilometer voxels? Why not 100, or 1, or 0.1? How about 10^{15} cubic kilometers, which is about the volume of the sun? Adjust this number correctly, and you can match any energy density you want.
Fundamentally, you can't model the universe as voxels in the first place. The Holographic principle, or at least the part about maximum information density, seems quite solid. There's a maximum entropy available in a volume (and thus a maximum amount of information needed to describe that volume) that's proportional to surface area, not volume. The number is absurdly high, well over 10^100 per square meter, but for extremely large volumes the cube/square effect starts making that limit meaningful. And that limit always prevents you from using voxels of the "natural" size of one cubic Planck length - the precision we know can model everything.
Perhaps the 10 cubic-kilometer voxels are reasoned from the limit for the visible universe? Still sounds high, even for that volume, and the visible universe seems like an arbitrary boundary.
Socialism: a lie told by totalitarians and believed by fools.