Category Archives: General

Nearly there, Idoru

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Could someone ever be able to mess up the Big Bang through observing it ?

I’ve had the chance to watch the episode “What Is Reality?” from BBC series, Horizon, yesterday. Very cool stuff ! I think it’s still possible to catch up with that on the BBC iPlayer.

The episode goes through open questions concerning quantum reality, its bizarre properties – to say the least – and recent years developments. The famous two-slits experiment, elegantly described by Prof. Anton Zeilinger, opened the episode and my attention stayed glued to it throughout. Although, I’d already known about such experiment (Young, 1801), I think I grasped more profoundly what it entails, this time. Apparently, Feynman once said that “if you wish to confront all of the mysteries of quantum mechanics, you have only to study quantum interference in the two-slit experiment”. I couldn’t help going after more details on the Internet about it straight at the end of the episode. …’cause of the appealing inquisitive way it had been presented, I suppose – a detective-like sort of way. It somehow allowed the idea that there were still room for improvement in unfolding the mystery.

The experiment is conceptually simple. A laser is put in front of a wall with two vertical slits on it, right opposite the laser. There’s another wall (screen) behind the one with the slits on and when the laser shoots the photons, one by one, the pattern taking shape on the screen in the back, because of the photons passing through the slits, unexpectedly differs from what we would expect. Moreover, once the scientists tried to detect what slit each photon was passing through before landing on the back screen, the pattern switched to a ballistic one, which is the one we would’ve expected in the first place, before attempting the photon route detection. Check out Wikipedia (double slit experiment) to get the nitty-gritty.

Quite incredibly, the scientists’ act of determining what route the photons had taken, played a role in the produced results. In other words, the attempt to find the route the photon (or proton or molecule) went before bashing against the rear wall, would alter the result of the experiment dramatically …to the point, that actually there were two experiments. One, with observation, giving the ballistic pattern as result, and the second one, without observation, that returns a diffraction pattern on the back screen as if the particle’s doubled itself while passing through the two slits at once behaving like a wave.

The following scientist in the programme picked up on that, explaining that the photon doubled the reality it was in instead of doubling itself. Explanation even harder to digest which implies another frame of knowledge/beliefs wrapping up the one we commonly use and feel at ease with. Coming back to the experiment, it’s like the particle was spread over the entire distance Laser -Back Screen (covering more routes, also) throughout the experiment. Property that is called “nonlocality”.

My little research didn’t take much to end up on something even more interesting (Wikipedia). Wheeler’s “delayed choice”s conceptual experiment, built on top of the 2 slits one and verified in 2007(!) asks, what if we detected the particle after coming out of one of the slits to see which slits it has just taken? No way, the experiment would once again collapse in the ballistic situation even though the decision to detect its route was decided after it had left the laser. It’s like the photon acted retroactively. It’s baffling, I know, but that also means the particle was “spread” in time also, during the experiment. That thing felt ahead of time, so to speak, that the scientist would try to catch it and consequently opted for the ballistic fashion before the decision was taken! That means that the there’s also a property of nontemporality, and I think that that is what teleporting entangled particles is about – another recent quantum gift. Anyway, these nonlocality/nontemporality properties actually quantum-lock the experiment.

Anyway, this observation thing …it’s quite difficult to swallow. At the end of the wiki-page there’s also a mention to an article written by physicists that claim that by observing the stars we could collapse them to a certain state. The next logical, although imaginative, step is ask What if we were able to take a clear look at the Early three minutes’s big bang?
Would there be the possibility to collapse it to a certain state only through the sole observation of it? Are we already “observing” the result of someone else’s previous observation?

I now look at the anthropic principle in a new light and it makes some sort of sense. I can’t believe what I’ve just written.

Love and kisses, Zaphod ;)