Showing posts with label quantum mechanics. Show all posts
Showing posts with label quantum mechanics. Show all posts

November 11, 2009

Let’s get metaphysical: How our ongoing existence could appear increasingly absurd

So the Large Hadron Collider has been shut down yet again – this time on account of a bird dropping a piece of a bagel onto some sensitive outdoor machinery. The incident is not expected to keep the LHC out of commission for too much longer, but it represents yet another strange event that has kept the world’s most infamous particle accelerator out of service. In fact, the LHC has yet to function at full operational capacity since its completion over a year ago.

What makes this all the more interesting is that the Hadron Collider has been dubbed by some observers as a doomsday device on account of its unprecedented size and power. A minority of scientists and philosophers believe that the collider could produce a tiny black hole or a strangelet that would convert Earth to a shrunken mass of strange matter.

It's worth re-stating, however, that this is a fringe opinion. Several years ago, Max Tegmark and Nick Bostrom wrote a piece for Nature in which they concluded that a civilization destroys itself by a particle accelerator experiment once every billion years.

Okay, admittedly, one in a billion seems excruciatingly improbable. But not impossible. And it's this 'shadow of doubt' that has got so many people in a tizzy -- especially when considering that this so-called doomsday machine keeps breaking down. Seems awfully convenient, doesn't it? Are we to believe that this is mere co-incidence? Or is there something more to what's going on?

Now, I'm not talking about conspiracies or sabotage, here. Rather, a number of philosophers are making the case that something more metaphysical is going on.

Take, for example, the quantum immortality theory, which argues that you as an observer cannot observe your non-existence, so you will keep on observing your ongoing existence -- no matter how absurd. Aside from a large grain of salt, you also have to buy into the Everett Many Worlds interpretation of quantum mechanics for this to work. As the universe splinters into probability trees, there are new trajectories that are forced into existence by your ongoing presence; in an infinite universe all observations must be made, no matter how improbable.

Now, at any given time we have to assume that we are living in the most probable of all possible habitable worlds. But that doesn't mean it's true -- it's just an assumption given the absence of sampling data. As quantum probability trees diverge, those that tread into more improbable spaces will begin to splinter with less and less frequency and diversity; there will be a limited number of escape routes given absurd and highly complex (but survivable) existence spaces.

All this can lead to some rather bizarre conclusions -- including the thought experiment in which you attempt to obliterate yourself with an atom bomb, only to have some kind of force majeure get in the way that prevents you from acting on your suicide.

It's important to remember that this only works for your ongoing existence. The rest of the world can burn around you; what matters is that you continue to observe the universe.

Okay, back to Hadron. Let's assume for a moment that quantum immortality is in effect and that the LHC is in fact the apocalypt-o-matic. It can therefore be argued that, because we are all collectively put into peril by this thing, we will never get to observe it working properly. There will always be something that prevents the device from doing what it's supposed to be doing -- everything from mechanical failures through to birds dropping bagels on it.

What's even more disturbing, however, is that these interventions could get increasingly absurd and improbable. It may eventually get to the point where we have to sit back and question the rationality of our existence. The world may get progressively screwed up and surreal in order for our personal existence to continue into the future.

One could already make the case that our collective existence is already absurd on account of our possession of apocalyptic weapons, namely the nuclear bomb. We've already come alarmingly close to apocalypse, including the Cuban Missile Crisis and the infamous Stanislav Petrov incident. Would it be unfair of me to suggest that we should probably have destroyed ourselves by now? I would argue that the most probable of Everett Many World Earths have destroyed themselves through nuclear armageddon, but we happen to observe a version of Earth that has not.

This said, our ongoing existence does not seem ridiculously absurd. There are rational and believable reasons that account for our ongoing existence, namely self-preservation and a rigid safety-check system that has prevented a nuclear accident from happening.

But will the same thing be said a few years from now if the Hadron Collider keeps shutting down? What will happen to our sense of reality if stranger and stranger things start to intervene?

And what about the more distant future when we have even more apocalyptic devices, including molecular assembling nanotechnology and advanced biotechnologies (not to mention artificial superintelligence)? It's been said that we are unlikely to survive the 21st Century on account of these pending technologies. But given that there are some probability trees that require our ongoing existence, what kind of future modes will that entail? Will it make sense, or will the succession of improbably survivable events result in a completely surreal existence? Or will our ongoing presence seem rational in the face of a radically altered existence mode -- like totalitarian repression or the onset of an all-controlling artificial superintelligence?

Hopefully I don't need to remind my readers that this is pure philosophical speculation. Metaphysics is often fun (or disturbing as in this case), but it is no substitute for science. I think we should think about these possibilities, but not to the point where it impacts on our daily life and sense of reality.

But I'm sure we'll all want to keep a close eye on that rather interesting particle accelerator in Switzerland.

June 12, 2009

But I Have Promises to Keep...

I promised George a longer reply than just "no" on my objections to the video link on science and Buddhism that he posted earlier today. The reply is now up at my site: Keeping an Open Mind is a Virtue, but not so Open that Your Brains Fall Out. Here is the first paragraph, to whet your appetites, your knives, or both:

Alan Sokal was a teaching assistant in my quantum mechanics (QM) course. I still recall vividly the day he came with a graph showing the spike of the first-ever observed strange particle. I remember, too, the playful twinkle in his eye. Thirteen years ago, Alan (at this point a physics professor at NYU) submitted a paper to the prominent cultural studies journal Social Text, titled “Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity”.

Athena
Starship Reckless
On Being Bitten to Death by Ducks

January 2, 2009

Seth Lloyd: Quantum computers will 'undo the present and recall the past'

One of my favorite answers to this year's Edge.org question was given by quantum mechanical engineer Seth Lloyd. Like so many other respondents, he chose an answer directly related to his field. But in Lloyd's case, the suggestion that quantum computers will 'change everything' may actually be right on the mark.

His astounding contention is that quantum computers, because they operate at the level of individual atoms, will enable us to undo the present and recall the past. "This ability," argues Lloyd, "is built into quantum computers at the level of fundamental physical law." What goes forward, he says, can also go backward.

While quantum computers afford their users protection and anonymity that classical computers cannot, even classical computers can be programmed to share this ability to erase regret, although they currently are not. Although classical computers dissipate heat and operate in and a physically irreversible way, they can still function in a logically reversible fashion: properly programmed, they can un-perform any computation that they can perform. We already see a hint of this digital nostalgia in hard-disk 'time machines,' which restore a disk to its state in an earlier, pre-crash era.

Suppose that we were to put this ability of computers to run the clock backward to the service of undoing not merely our accidental erasures and unfortunate viral infections, but to undoing financial transactions that were conducted under fraudulent conditions? Credit card companies already supply us with protection against theft conducted in our name. Why should not more important financial transactions be similarly guaranteed? Contracts for home sales, stock deals, and credit default swaps are already recorded and executed digitally. What would happen if combined digital finance with reversible computation?

Lloyd offers an example where, if a logically reversible computer were used to record a financial contract and to execute its terms, and if the parties were not satisfied with the way those terms were executed, then those terms could be 'un-executed,' any money disbursed, reimbursed, and the contract deleted, as if it had never happened. He calls it a 'digital time machine.'

Lloyd argues that he has the law of physics and computation on his side and that the only inhibitor may prove to be human nature.

World changing, indeed; we'll be keeping our eye on this one.

April 24, 2007

No observer, no reality

Found this on PhysicsWeb: Quantum physics says goodbye to reality.

Description:
Some physicists are uncomfortable with the idea that all individual quantum events are innately random. This is why many have proposed more complete theories, which suggest that events are at least partially governed by extra "hidden variables". Now physicists from Austria claim to have performed an experiment that rules out a broad class of hidden-variables theories that focus on realism -- giving the uneasy consequence that reality does not exist when we are not observing it (Nature 446 871).
Entire article.

March 21, 2007

The rise of 'biocentrism'

There's a provocative article over at Astroroach: "A Biocentric and Holographic Universe." The general idea behind biocentrism is that our cosmology and metaphysics cannot ignore the important interplay between conscious observers and quantum effects. As Robert Lanza notes,
"The trees and snow evaporate when we’re sleeping. The kitchen disappears when we’re in the bathroom. When you turn from one room to the next, when your animal senses no longer perceive the sounds of the dishwasher, the ticking clock, the smell of a chicken roasting—the kitchen and all its seemingly discrete bits dissolve into nothingness—or into waves of probability. The universe bursts into existence from life, not the other way around as we have been taught. For each life there is a universe, its own universe. We generate spheres of reality, individual bubbles of existence."
This fits in very nicely with not just the revealing sciences, but with the foundations of consciousness-centric Buddhist metaphysics as well.