Friday, February 4, 2011

The Quantum Observer

A direct link to the above video is at

When Hugh Everett III first came up with his Many Worlds interpretation in 1957, he made an important distinction: when we observe one outcome or another, we are not really collapsing the quantum wave function, we are merely observing it in a particular state. The other potential states continue to exist, just as real as the one we're observing. Whether we call it "observing" or "collapsing" doesn't change what we see, but it can change the implications of whether there are actually other equally real parallel universe versions of our reality, or whether those parallel universes are just an imaginary outcome of a thought experiment.

Everett's thesis, despite support from John Wheeler (one of the greatest physicists of the twentieth century) was met with indifference and in some cases derision from the physics community. So, instead of becoming a physicist upon his graduation, Everett took a job as a defense analyst with the Pentagon. Hugh Everett III has been credited with developing the infamous Cold War policy of Mutual Assured Destruction: the idea that if every nuclear power has enough atomic bombs to destroy the world, then no one should be tempted to start a war. Isn't it interesting to think about this policy, abbreviated appropriately enough as MAD, in the context of the Many Worlds Interpretation?

I've just come across a new book I'm going to order, pictured here, which is about this man's life: The Many Worlds of Hugh Everett III: Multiple Universes, Mutual Assured Destruction, and the Meltdown of a Nuclear Family.

So. If each of us is observing the wave function of the universe in a particular state, we are each a unique Quantum Observer. Should that make each of us feel isolated, or connected? Gevin Giorbran called this the Quantum Isolation Problem. With my 2011 entries I've been showing a way of thinking about how our quantum world is connected to the fourth dimension, and our "duration" is in the fifth, but how really both are interchangeable: this means that which label you assign to any particular spatial dimension depends upon your frame of reference established by the previous ones.

Last time, in Timelike Entanglement, I quoted a paragraph from my book and mentioned that the next paragraph was about The Quantum Observer, a topic that comes up a number of times with this project. Here's that paragraph now:

A particular meme-set, when it is attached to a physical body, is the quantum observer for that person, collapsing the wave of possibilities along the arrow of time and experiencing life as we know it. However, since that set of memes can also be thought of as existing completely separately from a physical body, there are many other ramifications to this.
Some of those ramifications get quite metaphysical, but this time let's look at some new articles that have come out recently to show how the quantum world connects to the fourth dimension, birds as quantum observers, and life as a subset of a quantum wave function.

Here's a link to a paper published at Cornell University Library's demonstrating the math behind Quantum Mechanics in Four Dimensions. Then, check out this new article at New Scientist magazine, "Quantum States Last Longer in Birds' Eyes". It reveals that birds are able to maintain electrons in an entangled state longer at the back of their eyes than any scientist working in a lab under carefully controlled conditions has been able to do so far. The birds, it appears are able to use the information gleaned from these entangled electrons to aid in their navigation abilities.

Finally, Micheal Brooks published a wonderful summation of the many interpretations of what it means to be a quantum observer last week in New Scientist: the article is called "Quantum Reality: The Many Meanings of Life". Here's some paragraphs from that article:
A CENTURY, it seems, is not enough. One hundred years ago this year, the first world physics conference took place in Brussels, Belgium. The topic under discussion was how to deal with the strange new quantum theory and whether it would ever be possible to marry it to our everyday experience, leaving us with one coherent description of the world.
It is a question physicists are still wrestling with today. Quantum particles such as atoms and molecules have an uncanny ability to appear in two places at once, spin clockwise and anticlockwise at the same time, or instantaneously influence each other when they are half a universe apart. The thing is, we are made of atoms and molecules, and we can't do any of that. Why? "At what point does quantum mechanics cease to apply?" asks Harvey Brown, a philosopher of science at the University of Oxford.
Although an answer has yet to emerge, the struggle to come up with one is proving to be its own reward. It has, for instance, given birth to the new field of quantum information that has gained the attention of high-tech industries and government spies. It is giving us a new angle of attack on the problem of finding the ultimate theory of physics, and it might even tell us where the universe came from. Not bad for a pursuit that a quantum cynic - one Albert Einstein - dismissed as a "gentle pillow" that lulls good physicists to sleep.
Unfortunately for Einstein quantum theory has turned out to be a masterpiece. No experiment has ever disagreed with its predictions, and we can be confident that it is a good way to describe how the universe works on the smallest scales. Which leaves us with only one problem: what does it mean?
Physicists try to answer this with "interpretations" - philosophical speculations, fully compliant with experiments, of what lies beneath quantum theory. "There is a zoo of interpretations," says Vlatko Vedral, who divides his time between the University of Oxford and the Centre for Quantum Technologies in Singapore.
No other theory in science has so many different ways of looking at it. How so? And will any one win out over the others?
Take what is now known as the Copenhagen interpretation, for example, introduced by the Danish physicist Niels Bohr. It says that any attempt to talk about an electron's location within an atom, for instance, is meaningless without making a measurement of it. Only when we interact with an electron by trying to observe it with a non-quantum, or "classical", device does it take on any attribute that we would call a physical property and therefore become part of reality.
Then there is the "many worlds" interpretation, where quantum strangeness is explained by everything having multiple existences in myriad parallel universes. Or you might prefer the de Broglie-Bohm interpretation, where quantum theory is considered incomplete: we are lacking some hidden properties that, if we knew them, would make sense of everything.
There are plenty more, such as the Ghirardi-Rimini-Weber interpretation, the transactional interpretation (which has particles travelling backwards in time), Roger Penrose's gravity-induced collapse interpretation, the modal interpretation... in the last 100 years, the quantum zoo has become a crowded and noisy place.
I liked this article because it points to a claim I've been making since my project began: that the Many Worlds Interpretation is seeing increasing acceptance from mainstream science. But as we've seen here, it's not the only game in town! Later on in the article, it offers further explanation for the rising popularity of Many Worlds.
Considering the nature of things on the scale of the universe has also provided Copenhagen's critics with ammunition. If the process of measurement by a classical observer is fundamental to creating the reality we observe, what performed the observations that brought the contents of the universe into existence? "You really need to have an observer outside the system to make sense - but there's nothing outside the universe by definition," says Brown.
That's why, Brown says, cosmologists now tend to be more sympathetic to an interpretation created in the late 1950s by Princeton University physicist Hugh Everett. His "many worlds" interpretation of quantum mechanics says that reality is not bound to a concept of measurement.
Instead, the myriad different possibilities inherent in a quantum system each manifest in their own universe. David Deutsch, a physicist at the University of Oxford and the person who drew up the blueprint for the first quantum computer, says he can now only think of the computer's operation in terms of these multiple universes. To him, no other interpretation makes sense.
He and Brown both claim that many worlds is already gaining traction among cosmologists. Arguments from string theory, cosmology and observational astronomy have led some cosmologists to suggest we live in one of many universes. Last year, Anthony Aguirre of the University of California, Santa Cruz, Max Tegmark of the Massachusetts Institute of Technology, and David Layzer of Harvard University laid out a scheme that ties together ideas from cosmology and many worlds (New Scientist, 28 August 2010, p 6).
I know it looks like I've quoted a lot here, but there's still much more to the full article and I invite you to follow the link and read the whole thing.

So, if we're each moving through a probability space of possible universes, are we causing reality to occur, or is reality simply happening to us as we helplessly observe one outcome after another? We'll return to this ongoing discussion of how much control do we really have as we navigate through the information that becomes reality, with an entry next week called Changing Your Brain. But right before that, let's look at this question: "What Is Reality?".

Enjoy the journey!

Rob Bryanton

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