Does the Universe Exist if We’re Not Looking? According to the rules of quantum mechanics, our observations influence the universe at the most fundamental levels.
To Wheeler [John Wheeler, scientist and dreamer, colleague of Albert Einstein and Niels Bohr, mentor to many of today's leading physicists, and the man who chose the name "black hole"] we are not simply bystanders on a cosmic stage; we are shapers and creators living in a participatory universe.
Wheeler’s hunch is that the universe is built like an enormous feedback loop, a loop in which we contribute to the ongoing creation of not just the present and the future but the past as well.
I seriously do not want this getting into the hands of The Secret brigade. This is science, ladies. This will not bring you true love. Read elsewhere.
By the time the astronomers decide which measurement to make— whether to pin down the photon to one definite route or to have it follow both paths simultaneously— the photon could have already journeyed for billions of years, long before life appeared on Earth. The measurements made now, says Wheeler, determine the photon’s past.
Far out. Why doesn’t anybody say Far Out anymore? I mean, these things are.
In one case the create a past in which a photon took both possible routes from the quasar to Earth. Alternatively, they retroactively force the photon onto one straight trail toward their detector, even though the photon began its jaunt long before any detectors existed.
Does this mean humans are necessary to the existence of the universe?
I certainly hope not. We are already stuffed to the gills with entitlement.
While conscious observers certainly partake in the creation of the participatory universe envisioned by Wheeler, they are not the only, or even primary, way by which quantum potentials become real.
Thank god.
At every moment, in Wheeler’s view, the entire universe is filled with such events, where the possible outcomes of countless interactions become real, where the infinite variety inherent in quantum mechanics manifests as a physical cosmos. And we see only a tiny portion of that cosmos. Wheeler suspects that most of the universe consists of huge clouds of uncertainty that have not yet interacted either with a conscious observer or even with some lump of inanimate matter. He sees the universe as a vast arena containing realms where the past is not yet fixed.
Ah. Interacted with a conscious observer or a lump of inanimate matter.
I knew it. We are but a moment’s sunlight, fading on the grass. —Jesse Colin Young
![Reblog this post [with Zemanta]](http://img.zemanta.com/reblog_c.png?x-id=0889fec3-5816-40b7-b660-c789dc081b89)
Well, I always thought the hip bone was connected to the thigh bone; now I know it.
If we can shape the past, does that mean we can go back and deal with Mozart’s one lone mistake: he wrote ten million notes and got one of them wrong. Can I go back and fix it, you know switch a few protons around so that that damned G-sharp becomes a G-natural? I surely hope so. And maybe I could shave Hitler’s moustache while I’m at it.
What fun….
Well, to pick a nit, observations are caused by interactions on its most fundamental level. So, that photon would exist as a probability wave until it hits good ‘ol planet Earth, things around to see it or not — the planet is a perfectly good detector, and is too big to be tucked away under the blanket of probability or interference problems. The fact that a group of probabilistically treated particles collapsing due to interactions with the environment is known as quantum decoherence.
Wheeler’s interpretation is problematic in some ways; in particular, his notion of affecting the past doesn’t jive with particle self-interference. It will self interfere, and we can record said interference, until we plop a detector in beam path and suddenly, we just get two lines.
On the other hand, even if it did retroactively “fix” the path of the photon, since we didn’t observe it then, what does it matter? The physics all works out at the end, and though it hurts the brain, causality isn’t violated. Oh quantum mechanics.