Is the Universe its own Largest Computer?

missingmatterboy writes: "If the universe is simply a giant calculating machine, how big is it? Seth Lloyd, who two years ago worked out the theoretical maximum possible power a laptop computer could posess, has now "estimated how much information the Universe can contain, and how many calculations it has performed since the Big Bang." His conclusion: you'd need about 10^90 bits, with something like 10^120 manipulations of those bits, to express the universe since time began."

Comments

Bukaroo Bonsai Was On The Right Track...

[cybrpnk2]

The article implies there hasn't been enough time for each bit/particle in the universe to have been "flipped" more than once, which further implies that the universe is NOT a computer. However, the number of particles mentioned is that in out 3D/4D (space / spacetime) universe. With superstring theory postulating extra dimensions up to 10 or 11 all "curled up" out of our sight, maybe this is where extra particles/bits are located to support the universe as a computer?

Re:Change = Calculation?

[2nd Post!]

As far as I can recall, one of the basic premises of entropy and information theory is that *everything* can be expressed in bits.

If everything can be expressed in bits, then everything is computable.

A stupid question is whether the universe is a determinstic Turing machine or not, or whether it is by very nature indeterministic :P

It's not that something has to be made into a computer so much as redefining one's perspective of what a computer is to accomodate the realities of the universe; that DNA is a storage mechanism, with RNA and DNA replication and protein synthesis being complex computation processes. Or that the universe is really expressible as a bunch of states (read his article, and you'll see that), and as such the traversal from state to state is no more complex than following a state diagram in a really big state machine...

Which is just a computer, doncha know?

Moore or less...

[jolshefsky]

According to Moore's law, the typical desktop computer should be able to simulate the universe in less than 600 years.

(18 months per double; 10^120 =~= 2^399; 1.5 years * 399 = 598.5 years)

Clock rate 1x10-63second ... Plankt time.

[crovira]

According to some theories, the universe is an 11 dimensional finite state machine with a cycle time of 1x10-63second ... Plankt time.

It would seem to be guided by an irrational number calculation something very much like Mandlebrot's x=1/xi but in 11 dimensions.

A VERY simple calculation with chaotic consequences.

Submission Got Rejected, so I am posting anyway..

[cOdEgUru]

Tonight at 9:00 PM (Eastern Time) Discovery Channel (Channel 42) features a one hour program on the origins of the Universe.

In this feature, of which 21 minutes is devoted to NCSA produced visualizations, which includes the spectacular rendition of a flight from earth to the massive black hole on the center of our galaxy.

21 minutes of NCSA rendered graphics...yummm..

So dont miss it, even if you werent a space geek. Being a graphics fan would do fine.

It is, of course, even more complicated than that.

[RyanFenton]

For instance, gravity seems to have a universal effect. It diminishes over distance, but ultimately never stops having an effect. Thus, for every movement, you'd first need to look at all elements of the "gravity map" to determine your precise gravity vector, then you'd need to update the "gravity map" with your movement. This would seem to have at least an N^2 effect. The universe doesn't seem at least to kludge on things like this.

Many forces act like this, which would tend to make the exponent on the number of bit manipulations required blossom much faster than predicted. Take a look at raytracer graphic design to see how messy reality can be when you introduce more than a couple elements into a scene, much less of course a universe. If one is going for a true simulation of reality, at least force by force, particle by particle, I believe it's going to be more complex than this estimation.

:^)

Ryan Fenton

Analog computer; the map IS the territory...

[dpbsmith]

1) Yeah, but it's an ANALOG computer. How passe!

2) Except, it isn't even an analog computer, because there is no analogy involved; no abstractions, nothing representing anything else in a simpler, faster, cheaper or more convenient way.

Remember the map of England in Lewis Carroll's "Sylvie and Bruno?" Well, I'm not sure I remember it, but, IIRC it was at a scale of one inch to the inch, so it was extremely accurate, but very annoying when unfolded and spread out.

Hash functions

[XNormal]

10^90 is about 2^300 bits

10^120 is about 2^400 operations

Now, can anyone explain to me why anyone would need a cryptographic hash function with a 512 bit output?

compression (eg: Italy defeats Ecuador 2-0)

[ziegast]

There's a term used by many in the storage industry to get you investors excited about storage companies. It's called the "explosion of data". Because we are able to record so much data with so much detail, we do. Like the pack rats we are, we think it might be useful to us in the future. That's what the storage vendors are hoping for.

The following may be absurd, but (in a manner similar to Carl Sagan's Cosmos series) it may help enlighten us as to how much detail we don't see and don't collect about a particular event.

Instead of the entire universe, let's take a look at a World Cup soccer/football game.

• The best compressed description of the game might be, "Italy Defeats Equador, 2-0".
  
• Add a little more detail, and you might have an accounting of highlighted events from the game. For example, here's one article.
  
• They say a picture is worth a thousand words. Here's a picture. During the match, spectators probably took several thousand pictures.
  
• After the match, somoene probably went with a tape recorder and got quotes from each of the players. The audio is alot of information, but compressed, heres a text summary.
  
• During the match, there were probably 10-30 professional video recorders sponsored by televsion stations in Italy and/or Ecuador that would provide a live satelite broadcast of the match for fans back in their home countries. The fans only saw one view of the data, the finished product. Each camera probably had its output recorded on tape. Out of the millions of viewers, a thousand of them may have recorded the match on video casssette. Inside the stadium, hundreds of fans probably used their own recorders. The amount of storage, accurately reproduced might total terabytes of data, yet this is only a fraction of the number of possible views that could have been recorded.
  
• The player of the game, Italy's Christian Vieri, must have been a crucial part of the win. What's his life's story? What events made him what he is today? Could we video his entire life (ala "The Truman Show"?). Can we understand all of his thoughts just during the game and why those thoughts occurred? What were his vital signs each minute of the match? How did his movements or actions affect each and every other player, physical object, and every fan who saw him play that day? What were the contents of his upper intestine? From which oil wells did the petroleum needed to make his shoes come from? How much energy did he expend? When he shot his goal(s), and all of those Italians in bars cheered, what was the effect of those cheers on the microclimates in each of the homes and bars where he was viewed? If one of the players he bumped into developed a bruise on his thigh, how many blood cells left circulation to stagnate in that area? What was the percentage of hemoglobin in those lood cells? What signals were sent to the brain and in which order were they recieved by which receptors to help trigger the player's lymph system clean out and heal that area? If we took one of the millions of hairs from his head and analyzed it, would we be able to find that he smoked marajuana a month ago? What is the data from all prior events over all time that was relevant to creating Mr. Vieri as he is today?
  
• What about the other thousands of people in the stadium? What are their stories? Where were their clothes manufactured and with which materials in which locations? Who developed the film on their cameras and what are their life stories? As they breathed, where did all of the carbon dioxide atoms that they expelled end up a few seconds later, a day later, a year later?
• What was the placement of each atom of the concrete and steel to create the stadium? What was the position of each blade of grass and molecular composition of each blade over each second of the game? Show me the path each electron took and its final position at the end of the match.
  

We cannot come close to understanding, though, the amount of data necessary to "record" that event. It is only through selective compression, what our senses tell us, that we develop our view of that event. For some, like Mr. Vieri, he may remember what he felt and experienced during and after that event. A fan in Italy might remember what they saw, and might even have a tape or picture that shows one view of the event. A sports writer in Equador might only remember that Italy beat Ecuador 2-0. The average person on planet Earth will have no knowledge or recollection of the event, and frankly, won't care because life is too short.

Good analysis of events is compression. Our memory is compression of our experiences. With good compression, we won't have to record everything, and therefore avoid the "explosion of data" as best we can. As we collect data, we need to consider its importance to us and discard anything not relevant.

For detail we do care about (eg: data needed to compute Earth's weather), we might try to build large data repositories and build expensive computers to process that data, but most of the Universe's data is best left unknown to us because it's not important to us (yet).

- ez

PS: You gotta hand it to the folks at Google for attempting to collect and store so much data from the Internet.

Re:...BUT...

[Luyseyal]

Yeah, I know a lot of people who think that way. While I'll grant that we invented math as an useful abstraction roughly approximating how one aspect of the universe works, the abstraction is still not the universe. As in any abstraction, detailed content is lost in the hopes of formalization. Unfortunately, such detail is algorithmically necessary for being the universe... it's not just a matter of setting a few constants and pressing "enter" in the math box.

Math is not a natural science.
-l

Re:...BUT...

[JordanH]

• • We didn't so much invent Mathematics as we discovered it.
  That's your belief.

Yes, and your view is a belief also. In fact, all positions are beliefs, so what? You label it a belief as if it's a withering criticism, when in fact, it's just a definition.

I don't want to get into a deep epistemological discussion on Slashdot, of all places. I will point out that you can't prove your position any more than I can prove mine. You, however, would deny that a proof is anything but an empty manipulation of symbols, devoid of any meaning.

• Mathematics is a developing language used to roughly model some aspects of observed behavior in the universe. Math isn't what the universe does --- math is a tool through which we understand a collection of observations about the universe.

We men "invent" math and logic. Right. Forget the observation that children are prewired for language and logic. Math and logic are at the base of our being. This is clear to me.

Yes, I'm a platonist. I see a theory in map theory is reminiscient of one in number theory. Is it because I invented it that way, or is there a mathematic truth that binds them together that I discovered through their similarity?

In the end, these are just appeals. I can't reason with someone who believes that reasoning is arbitrary.

Re:...BUT...

[JordanH]

They used to argue the same sort of things about negative numbers, but then their utility in showing direction proved too attractive to abandon them as "merely" abstract.

Similarly, irrational numbers are used to model multiple dimensions.

Various concepts of infinity come into play in Calculus and topology, which may seem very abstract now, may someday prove to help us understand reality.

Non-euclidean geometries were once considered the height of useless abstraction, but have come in very handy in Relativity and String Theory.

All Maths are grounded in the Universe as they are discovered by our minds which are part of the Universe. If we can recognize a logical mathematics, then it is a recognition of a logical formalism that our minds can comprehend.