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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.
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.
This is the problem with the science blogosphere: they'll take any press release whatsoever and echo it around regardless of whether or not it makes any fucking sense at all.
Exactly. When they plug in an accuracy that makes more sense, all of a sudden they are 117 orders of magnitude off. In other words, they could have gotten any result they wanted by just picking some arbitrary value for the accuracy. "How much do we need the result to be? OK, then let's pick... 10 cubic kilometers. Because the universe really cares about round units based on the circumference of some arbitrary planet in some arbitrary milky way. See, only three orders of magnitude off, our theory is now better than quantum physics!"
Next month, they'l publish a new paper in which they have refined their theory by taking an accuracy of 0.71 cubic km. There, our refined theory now exactly predicts the correct density of the universe, from first principles! Throw away quantum mechanics, information theory is clearly superior!
Sounds like a bunch of philistine engineers to me. Armstrong's quote could easily be applied to Einstein or Maxwell. Heaviside probably would have condemned the Manhattan Project as a bunch of theorists.
It's telling that Tesla draws the line at Morse, who invented Tesla's chosen field of engineering. And Tesla was a brilliant engineer. But later, as an actual scientist and researcher, as someone that had to do experiments and develop new theory, Tesla was a failure. His work was a dead end.
Don't blame me, I voted for Baltar.
There is no reason or evidence to suggest that the universe operates in any way that correlates directly to our mathematics
Actually there is a lot of evidence that the universe operates in a way that correlates directly with mathematics. Using our mathematical models of fundamental physics we used them to predict the existence of a new particle, the Higgs boson, to solve the flaws in the model. Similarly the same principle applied to the discovery of quarks and the W and Z bosons before.
The fact that we can use mathematical models of the fundamental nature of the universe so incredibly successfully to predict new fundamental phenomena that we have never seen before is clear evidence that the universe does work in a manner that correlates with our mathematics. Indeed I would say that this is one of the truly remarkable things about the fundamental nature of the universe: we can construct mathematical models of it which agree perfectly within our, admittedly limited, ability to test them.