This article is accompanied by the complete interview with Dr. Alejandro Jenkins.
Quantum physics is probably the most bizarre part of our description of the universe that is collectively known as "the standard model." The field is concerned with the physics of the incredibly small, like atoms and the subatomic particles of which they are composed.
The science describing the behavior of these particles is so different from our daily experience, so counter-intuitive, that the entire field of physics is divided into "classical physics"--the normal-sized physics of Newton and Galileo, and "modern physics"--the massive-and-tiny physics of Einstein, Heisenberg and Hawking.
Things this small are right at the edge of our powers of observation. As such, describing their seemingly very strange properties stretch science and scientists--and philosophers--to their absolute technical and theoretical limits. For instance, in the quantum world, things appear and disappear. Things can be in more than one place at the same time. Things can send information faster than the speed of light.
Observed things and observing things affect each other, rather than the one-way causation that we perceive. The causal determinism of our world, which allows us to predict when the sun will rise, has been replaced by probability and randomness. It's this last bit that might end up changing the way that we view our lives in the most radical way imaginable.
Young's experiment, or the "double-slit experiment" is a famous example of this strangeness. Like the peaks and troughs of the ocean surf, light is a wave. Even the smallest unit of light, called a photon, is still a wave... even though it is also a particle. It's a wave-particle. When photons enter a box through a pair of narrow slits, they create a reinforcement pattern of vertical bands, where the light peaks from one slit strengthen those from the other and where the light troughs from one weaken those from the other.
This happens even if only one photon enters at a time. This is only possible if the photon passes through both slits at the same time and reinforces/weakens itself. That's only possible because a photon appears to behave differently than a pachinko ball, or a runaway Toyota Prius. It is a particle and it can be described as such. But, like all light, it is also a wave with the fuzzy qualities of the ocean on a bad day at Diamond Head.
If that were the end of it, that would be strange enough. But as if the photon is making sure that no one is watching--like a tea party member about to throw a brick--it only does this trick when no one is observing it. If something or someone is monitoring the slits as it enters the box, the photon creates a spread pattern of dots, instead of the reinforcement bands. It's the kind of pattern that a bunch of individual particles would produce.
Alejandro Jenkins, of Florida State University describes this as the "problem of observation." The process where a photon changes from a wave to a particle is called the wave function collapse. It is such a strange part of nature, that when researchers refer to their explanations of what is happening, they call them "interpretations." Amongst the different interpretations of this phenomenon, is the many worlds interpretation, originally put forward by Professor Hugh Everett.
In 1957 he proposed that whenever an experiment is conducted, all possible outcomes occur, and each exist in their own discreet universe. In essence, there is one universe where the photon passes through slot one and one where it passes through slot two. He proposed the existence of parallel universes that are created to accommodate every possible outcome. The idea is that an experiment is a small, system where everyone involved--the photon, the device and the scientist--are all interacting and all outcomes are actually expressed. This process works the same way for the entire universe. Every possible universe that could exist does, hence the "many."
Dr. Jenkins supports the many world interpretation. His research, featured on the cover of January's Scientific American, explored the possibility of life in other universes. He and his colleagues "tweaked" the laws of physics in models that describe the properties of an elementary particle called a "Quark," to see if the building blocks of matter could still arise. They found that despite developing in very different ways, these parallel worlds could still develop organic life.
He describes a two-way interaction at work in the double-slit experiment. "Everett realized that an observation or a measurement is really a physical interaction between you and whatever you are looking at. The process of observation changes both." But that baits the question: Why isn't the box an observer? (Click here for a philosophic response to this question by Prof. Peter Lewis of the University of Miami)
The many-minds interpretation builds on Everett's ideas. It suggests that the conscious mind of the scientist is somehow capable of behaving (or making other things behave) in ways that other things are not. Our minds might function the same way as the entire universe--experiencing all possible outcomes every time we come to a fork in the quantum road. Since, from your point of view, the "possible" outcomes only include those where your mind is actually present, this brings up a strange--and alarming possibility:
You cannot commit suicide and you will never die.
Quantum immortality and quantum suicide are perhaps the most bizarre authentically-scientific ideas ever. Anytime some potential demise looms, each one of your "many minds" will experience one of the possible paths. Since your can't experience paths where it isn't present, that leaves only the "you survive" paths.
Max Tegmark, the MIT professor who has explored the topic extensively, has argued that one could only avoid death from an out-of-everyday-experience quantum cause, presumably involving some contrived device triggered by radioactive decay, like Shroedinger's Catbox(?). Ordinary deaths involving nursing homes, cancer or pork products are governed by classical physics. Quantum effects are only detected in systems with very little information. They quickly "decohere" when something else interacts with them because the information increases as the relationships increase.
That said, Dr. Jenkins is cautiously open to the idea, but sees no cause for alarm. "It seems logical enough if you buy the many worlds interpretation. Frankly though, it seems like idle speculation."
Let's face it, idle speculation can be fun.
In theory (speculative though it may be), no matter how unlikely you'll survive stepping out an airlock into space or being hit by a bus, out of the infinite outcomes, there will always be some where you do, in fact survive. Therefore you can never experience a universe where you're dead. Others can, and, as we all know, you will experience their deaths, but no matter what happens, you will always find yourself alive in your ever-more-unlikely existence.
The darkest imaginable scenario would mean that you and your mind would be a real-world Energizer Bunny. You would keep going, and going and going in an ever-more-empty, eternal "you-niverse," population 1
On the other hand, quantum immortality could mean that you can never start down a path where you end up in a situation with a 0% chance of survival. If throwing yourself into a vat of molten metal cannot be survived in any circumstance, then something, somehow will always prevent it from happening. And, if continued consciousness means awareness, no injury which resulted in brain death can befall you. It could also mean that by being close to one another, two people would be less likely to die in the other's world by eliminating any accident that could only claim you both together.
That could be extrapolated to the large scale. Nothing that wipes out everyone, everywhere can ever occur. If you cannot possibly survive the explosion of the sun, the sun won't explode. The "killer asteroid" will never arrive. Nuclear apocalypse is foregone.
At least some physicists believe that the Large Hadron Collider--the most powerful particle accelerator every built--is being prevented from reaching full power by the universe itself. Glitches, including police activity and birds dropping bread on equipment, have "conspired" to push its projected full speed to the end of 2012. Perhaps it's quantum immortality that's preventing "the death of us all" through a man-made black hole or an "abhorrent" particle that would travel backwards in time and tear the very fabric of the universe itself.
Unfounded, alarmist concerns about science are as old as science itself. Quantum suicide and immortality are ideas that cannot be ruled out by the evidence, but they are not even close to being well supported.
As Dr. Jenkins puts it: "I personally can't think of any important scientific consequence for this idea."
Except as a source of endless, idle speculation.