Monday, March 03, 2014

Why The Universe Is What It Is : A Conjecture

The interwebs is full of krayzeee...  

This post was inspired by yet another crazy website/book I found : Galileo was Wrong, Church was Right. I am not really in the mood to discuss this website. It claims that Earth is the center of the universe, even relativity is false propaganda... etc etc. Read it till you are bored, or don't... whatever... I am not going to. Rather, I will talk about the science of what we know about the universe and our place in it and go on to make some pseudo-philosophical conjectures.

The Geocentric model or the Ptolemaic principle advocates that the earth is the center of the universe. It was the dominant world-view since probably the dawn of man at least up until the 15th century. Even though it was completely wrong, it is hard to be too harsh on this model even from a scientific standpoint. The best observations people could make pre-15th century were naked eye observations of the sun, moon and the stars, and yeah... it does kind of look like the earth is static and the sky resembles a back-lit canopy with holes punched in it that is revolving around the earth. But the philosophical/social/moral/cultural implications of this idea are profound and conversation-worthy. In particular, it is easy to extend this empirical observation to imply a general idea, that humanity, or life, or mankind is the central premise of the universe, its purpose even. That leads to the obvious question... why? If we are indeed special, we must have been created for a reason, for some purpose. But whose purpose, whose reason... a line of reasoning the undoubtedly led our ancestors to create the oldest Gods. 

This methodology of philosophy (love of wisdom) where thinkers and ponderers would sit in great halls and muse over the great questions is, after all is said and done, not much more than fantastic imagination. To understand or even contemplate the nature of the universe we must first study it. Thus began science, initially to supplement, but eventually entirely replacing philosophy. Philosophy as is understood by most people today, as it is taught now in schools and universities is actually just the history of classical philosophy. Ideas of a time before knowledge was rigorous, before the invention of logic. 

Philosophy of the modern world is through science, for there can be no wisdom without knowledge, no comprehension without information. Science is the ultimate quest of understanding who we are and our place in the universe, and it took many millennia before humans could develop a consistent method of elevating ideas and observation to undeniable truths that could then be used as the basis for further understanding . 
Proper Scientific discourse in the time of Copernicus and Galileo
And 19th century science could not find any evidence about the universe that suggests that humanity or life has any special place in it. 
The sun is an average star, the Milky way an average galaxy. Earth is not the center of the Milky way, or even the solar system let alone the universe. The Copernican principle, one that says that the earth, and by extension, humans, are not special, we are just another dot in the cosmos. In general, rigorous physics in the form of the general relativity confirms the idea that no reference frame is preferred even if its from our precious perspective. 

But if we are not special, if our existence is inconsequential, then why exist at all? Well, why anything exists is too meta a question, but as far as why we exist, Copernican philosophy could be extended to a general claim that the universe and everything in it is but an accident, including life. It was pure luck, or sheer probability, that we sit here... contemplating our existence... one molecule here and there and you and I might just as well have been barren rocks sitting on a bigger more barren rock. However, that Earth itself and all its inhabitants are seemingly alone in the universe is troublesome. Why are we alone? How can we be unique and ordinary at the same time? If we are not special, then why is the vast space not filled with constant traffic of misshapen gargoyle aliens and we just another inconsequential slumdog eking out our existence? The vast dark emptiness of space is puzzling... and depressing or inspiring depending on your point of view. The Copernican principle would explain the scarcity of life by its vast improbability. We are alone, not because we are special, but because we are an accident, more improbable than a monkey writing the Hamlet, although not quite impossible.
It is hard to not quote Carl Sagan. NP-Hard.
This has been, and still is, the dominant worldview of the industrial age. Yet as physics advances, revealing profound answers and secrets of the universe, perspectives change. The 20th century has provided us with more information that ever before about how the universe, the Earth and we came into existence. The obvious follow up question, why? Why was the universe created the way it was? Why this way and not any other? Our cycle of knowledge comes a full circle when we realize that the same science that disproves our privileged position in the universe, shows that if the fundamental constants of the universe had been but slightly off kilter, nothing that we recognize as being the building blocks of life would have even existed. Water, carbon, oxygen, earth, none of it would have existed if say, the fine structure constant, was just a few percent bigger. It made sense to claim that the creation of life is just a chance occurrence given a universe with well defined rules, but when the rules themselves seem to rigged to favor our existence, doubt is inevitable. Is not the fine tuning of the universe to these seemingly artificial constraints evidence of our uniqueness? 

Thus new ideas, conjectures and philosophies, bearing our current level of understanding in mind are required. None of them yet have quite become as widely accepted, so I will address the most appealing ones.

Anthropic - "Of or pertaining to mankind or humans, or the period of humanity's existence."

According to Wikipedia, the phrase "anthropic principle" was first used by a theoretical astrophysicist Brandon Carter, even though he wasn't really the first person to articulate this idea. It is the consideration that observations of the physical universe must be compatible with the conscious life that observes it. This definition is purposefully vague and broad to accommodate the entire spectrum of this idea, some of which I find noteworthy.

tries to explain the seemingly overwhelming coincidence of our existence as simply selection bias. The universe seems to be fine tuned to allow life to exist, simply because if it were not so, we would not be able to ask this question. There is no mystery, the basic rules of Copernican principle still apply, we are not special, our existence is not special, just necessary for us to contemplate this question. 
This is fairly compelling and I cannot really find fault with the logic. That would have been enough in the classical age, but not today, not in the age of science. We must look for ways to test, to prove or to falsify this theory. Unfortunately, as it stands, it might be completely untestable. If a person wins the jackpot the very first time he plays the lottery, he will probably think the odds of winning were always 100%. It is highly unlikely, but entirely possible. Of course, another person who played 1 hand and lost, might deem it impossible to win the lottery, 0% odds. And just with one try, there is no way to prove or disprove either hypothesis. The only way to find the true odds would be to spend the entire jackpot in buying lottery tickets and see the percentage of wins. But how do we roll the dice of the universe again?

If the answer is that we cannot, then unfortunately the WAP must be resigned to hypothetical, an untestable fantasy, never to be attain the status of knowledge. This is certainly a very big flaw for any theory. But there might a way to know. If there are an uncountable number of galaxies and stars and planets in the universe, one could easily argue that Earth and life occurred by random chance through sheer probability. But if the physical laws of the universe are decided by random probability, perhaps our universe is also one of many, and we obviously happen to be in the one that suits us most. This is the so called Multiverse or Parallel Universes or Many Worlds hypothesis. I shall come back to this shortly.

is the other version which says that the universe is for some reason compelled to have such properties which allow life to develop at some point in its evolution. This seems almost suspiciously like an Intelligent Design, or the Ptolemaic principle. SAP itself offers no real answer as to why it should apply, and in this form is too mysterious to even consider seriously. 

More notable and acceptable contributions come from the famous John Archibald Wheeler. He developed the idea of "It from Bit", which is derived from the fundamental measurement problem in Quantum Mechanics. Quantum Mechanics postulates that the "real" is not quite as tangible 'in situ'. Instead all "things" in the universe are probability fields and effectively evolve in every possible trajectory possible weighted by the likelihood of said trajectory. However the act of observation, or 'measurement', collapses this wave-function into one of the possible trajectories. Therefore Physics, or more radically Reality, is not a description of what exists, rather just what we can observe; i.e from the observer's point of view. This framework of Quantum Mechanics seems to fly in the face of the Copernican principle, and even Relativity. Consciousness, seemingly is a 'special' frame of reference whose interaction with the world is decidedly different from the interaction of objects without 'consciousness'. Such an idea or postulate sounds ridiculous and would have never survived a day in the scientific world, but it works so damn well. I have been reading/working on Quantum Physics for more than 12 years now, and from the very start the philosophical implications of the bizarre and counter intuitive yet mathematically beautiful framework enraptured me. But in the end, it is not theory but physical, observable reality that differentiates physics from fiction. If nature did not agree, all the beauty is nothing but fiction, elegant fiction. But nature does agree, with Quantum Physics better than any scientific theory in human history. I have tested it in the lab myself... it works!! 

So I guess John Wheeler decided to take the premise and just run with it. Whereas inanimate objects merely interact and evolve, a conscious being extracts information from the system it observes, but in the process constraining the system to a state conforming to the information that was extracted. This view when extended to a cosmological scale implies the universe can be considered a giant quantum state starting from the singularity through the big bang. The evolution of the universe could be considered as a wave-function, following all possible trajectories. The emergence of consciousness, or life, would therefore be able to collapse the wave-function into one trajectory through the act of measurement. Thus the universe is brought into existence by the act of measurement by the very consciousness that exists within it. It would seem quite obvious that the constraints imposed by such a  measurement would at least be consistent with the existence of such an observer. This is the basis of the It from Bit principle, that particulate or definitive reality is not fundamental, rather reality is probabilistic and definitive reality arises as a consequence of conscious entities extracting information. Therefore, "It" arises from the "Bit". (By definitive reality I mean the kind of reality we experience everyday, where events are not probabilistic but strictly causal). 

This is a fairly attractive idea because it seemingly agrees intimately with QM, the most successful description of the world we have till date. However it still does distinguish consciousness from the rest of the universe, somehow we are a part of the universe and yet transcend it somehow, an idea that sounds more mystical than most scientists are comfortable with. That in itself is not a reason to reject it - truth can be uncomfortable - but until we can find some vital essence or soul which set consciousness apart, there is no reason to believe this hypothesis either and reject centuries of physics.

The universe is what you see it as...
That is if we accept my interpretation to the measurement problem. 
Relativity is a very powerful idea, almost as indefatigable a theory as QM, and yet the two stand at odds at the measurement problem. In my opinion, both are correct and can coexist. Relativity is true, there is no preferred reference, even if said reference is the mind of the sentient being. What then is the source of QM's predictive power, what is measurement? Think back to the Schrodinger's Cat idea. The cat is in a superposition of either dead and alive until a conscious (human) observer opens the box and collapses the cat into either dead or alive. This definition raises a lot of ambiguity about the definition of the observer. Is the cat not conscious enough to collapse the wave-function, why do we need a human observer? What makes the observer conscious? I find this problem and its implications fascinating and after much thought over the years I have my own hypothesis, a "solution" for the measurement problem. I propose to define measurement as the act of entangling the measurer with the measured. There is no reason to differentiate between a conscious and an unconscious observer. 

Let me illustrate this with an example. 

We have in our possession two quantum bits, Q1 and Q2, which can each be either |0> or |1> or any superposition thereof. Lets take Q1 which is in a superposition, |0>+|1>, (forget the normalization factors). If I now measure this object in the standard basis, the measurement result will be either 0 or 1, and the act of measurement will collapse the state into the corresponding state |0> or |1> respectively. Now I am claiming that the act of measurement is actually the act of entanglement, so first let us understand what entanglement really means. 

Entanglement : Say we want to entangle Q1 and Q2. If Q1 is in state|0>+|1> and Q2 in |0>, the CNOT entangling gate entangles the two Qbits and forms the final state |00>+|11>. This state is pretty awesome. If we (as an observer outside the system) measure Q1 and get 0(or 1), we know that Q2 must be 0(or 1) as well with 100% certainty. Yet if we tried to measure Q2, we would measure 0 or 1 with 50% chance. Therefore measuring Q2, tells us what Q1 is with certainty, even though measuring Q2 itself would be more uncertain. 

Awesome :). Now that we understand entanglement, let us make the final assumption. Say Q2 is not an inanimate Qbit, but an observer himself, you, or me, or our friend Albert. Or perhaps just an inanimate detector. Nothing should change, a sentient observer is, in principle, just another quantum system like any other. Albert made a measurement on Q1, and in the process got entangled to Q1. But instead of |0> and |1> being two states of a spin or an atom, they are the two unique states of existence of Albert. The |0> state of Albert corresponds to him having measured 0 on Qbit 1, and the |1> state corresponds to him having measured 1 on the Qbit. This is just like the cat, the cat gets entangled with the system, in one situation it dies and in one not, but there is no ad hoc collapse, the cat is now in a superposition of having experienced either state. There is no reason Albert cannot replace the cat and instead of dying, he just measures the system in a less fatal way. That would mean Albert the observer is now in a superposition of having measured 0 and having measured 1. Now this alternative framework must explain or be compatible with the collapse framework simply because the collapse frameworks works. And it is. The central idea of the collapse is that the observer cannot see the full wave-function but only one of the possible outcomes. When you measure |0>+|1>, you never get the superposition, you only get either |0> or |1> with 50% probability. More importantly, once you measure, say |0>, all further measurements yield the same value, 0 in this case, with 100% probability. So it seems that the measurement has changed, or collapsed, the initial state. But the same effect is achieved if the act of measurement entangles the measurer and the measured. A x (|0>+|1>) becomes |A0>|0>+|A1>|1>. But think from the perspective of A0, there is no superposition. A0 thinks the system is 0 with hundred percent probability. Similarly A1 thinks the state has collapsed into 1 after the measurement. A0 cannot access the 1 anymore, after the measurement/entanglement. Perfect!!
No relation to this discussion, but fellow radio listeners may empathize.
This is what we would expect the system to be if the observer was an inanimate observer, say a computer or a photon detector. Yet when the observer is a human being, we are afraid to claim superpositions and instead invoke a measurement postulate. Maybe I am wrong, surely there are many people, many of them smarter than me, many of whom have been working on this for many more years than me. But I don't know why this would be wrong. It is far more likely that I am not the first person to think of this. And I guess the reason this is not the mainstream way of teaching quantum physics, is because the simplicity of this idea and the (huge) benefit of keeping the relativistic principle is offset by the relatively scary (and as yet untested) claim that all of us intelligent observers exist in a superpositions of our existence of having experienced one thing or the other. 

The Multiverse interpretation, claiming the universe branches out at every measurement one for each outcome, can be easily shown to be a more sci-fi (and hence more attractive) way of saying the branches are simply probability superpositions of the universe going one way or the other at each measurement. It is not, however, as rigorous as I hoped it would be. For instance, the Everett version claims the separation of world lines occurs due to decoherence. Decoherence is not a fundamental process of QM, rather it is an outcome of our inability to isolate systems and prevent loss of information. Therefore the wording of MWI seems horribly misleading to me, even if ultimately consistent with my interpretation. 

But what I like even more about my explanation, is that the anthropic principle objections are also resolved in one fell swoop. The universe seems fine tuned precisely because of the selection bias, the universe is simultaneously in all its possible states and we obviously can observe only in the states that are conducive to life, by definition. In this case, A0 is us and 0 is our universe, while A1 is the situation where we are just a barren rock and 1 the universe where life does not originate. Moreover, its not that we got ridiculously lucky, instead it is inevitable since some possibilities of the universe will support life. Therefore in some sense, both the SAP and WAP are correct. "We must exist, because we can". But the single greatest aspect of this hypothesis is that it is not an untestable self defeating tautology like some variants of the anthropic principle. There are many tests of entanglement between two quantum states. Now all we have to do is construct such a test, except that now one part of the system is now a conscious observer, hopefully a human being, and there is a second observer outside this entangled system. A0 cannot experience the superposition, but an external observer certainly can. This experiment would prove(or disprove) this hypothesis and be a giant step towards answering the mechanism of the our existence in the universe. It would also provide, what I think is, a believable explanation of the puzzling coincidences and arbitrary fundamental constants of the universe. 

Needless to say, this experiment is practically impossible at the current state of technology. But it is not impossible in principle, so perhaps in the not too distant future, we might have some answers. So what do we need to do this experiment? And when we can answer where we came from and how, perhaps we can go on to the more important question, why are we here? I will leave those questions for a future post... :)  


  1. very high level one. tried, but i think a tete a tete talk will get something in my head.

    1. hehe, yeah, i wanted to make a simpler primer to these ideas, but got excited and carried away... sorry about that... I'm trying to be better at communicating high level physics ideas... not quite made it this time.