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'Zeno Effect' Verified: Atoms Won't Move While You Watch (cornell.edu)
An anonymous reader writes: One of the oddest predictions of quantum theory – that a system can't change while you're watching it – has been confirmed in an experiment by Cornell physicists. Graduate students Yogesh Patil and Srivatsan Chakram created and cooled a gas of about a billion Rubidium atoms inside a vacuum chamber and suspended the mass between laser beams (abstract).
In that state the atoms arrange in an orderly lattice just as they would in a crystalline solid. But at such low temperatures the atoms can "tunnel" from place to place in the lattice. The famous Heisenberg uncertainty principle says that position and velocity of a particle are related and cannot be simultaneously measured precisely.
The researchers observed the atoms under a microscope by illuminating them with a separate imaging laser. A light microscope can't see individual atoms, but the imaging laser causes them to fluoresce, and the microscope captured the flashes of light. When the imaging laser was off, or turned on only dimly, the atoms tunneled freely. But as the imaging beam was made brighter and measurements made more frequently, the tunneling reduced dramatically.
In that state the atoms arrange in an orderly lattice just as they would in a crystalline solid. But at such low temperatures the atoms can "tunnel" from place to place in the lattice. The famous Heisenberg uncertainty principle says that position and velocity of a particle are related and cannot be simultaneously measured precisely.
The researchers observed the atoms under a microscope by illuminating them with a separate imaging laser. A light microscope can't see individual atoms, but the imaging laser causes them to fluoresce, and the microscope captured the flashes of light. When the imaging laser was off, or turned on only dimly, the atoms tunneled freely. But as the imaging beam was made brighter and measurements made more frequently, the tunneling reduced dramatically.
I watched a pot once... it boiled anyways.
Weeping Atoms dept
Is it the laser or is it the looking? Sounds to me like you found an effect triggered by the laser over a certain intensity, as, the way I read it, under that intensity everything works just great, even if you enter a staring contest.
So, it's the "DOT Road Crew Effect."
Pretending this is my office full of bitter coworkers..
I know I'm a complete idiot, but shouldn't the conclusion be : Atoms won't move while illuminated by an imaging laser?
If you can hold them still, would they be easier to smash?
“He’s not deformed, he’s just drunk!”
The important thing about being 'observed' is if it has an effect on something else - such as the photons from the laser used to record it.
What is most certainly does NOT mean is that it does anything because a human consciousness is watching the process. A robot or mote of dust could have been 'observing' it (and in effect WAS), and the same effect would happen.
That's what I strongly dislike about the terminology around 'observer' effects. It makes people evoke touchy-feely human awareness stuff, when it's really just referencing microscale interaction events. What matters is that if events occur which COULD matter outside the system, like photons bouncing against the atom, then that's an 'ovservable' event in the context.
In the microscopic landscape of these experiments, we're a distant afterthought - a bacterium would be almost too big to sensibly consider - and trillions of bacteria would barely be observable to us. In other words, it's really not about US, to any sensible interpretation. Psuedoscience is all about us - keep that in mind when you see the sales pitches, as they'll be using the bad interpretation all the time they can.
Ryan Fenton
One of the oddest predictions of quantum theory – that a system can't change while you're watching it
Ah, stop right there.
Before the quantum kooks crawl out of the woodwork, the atoms don't stop moving because "you" (click-bait headline alert) are watching. They "stop moving" because they are being continuously "measured" (interacted with in ways that stop them going all quantum-y) by lasers.
A conscious observer is not required. And if you turn off the laser that's doing the measuring, peering through the window at the atoms with your actual peepers isn't going to stop them tunneling anywhere.
systemd is Roko's Basilisk.
I think it's the QM equivalent of confirming the light goes out when you close the fridge door.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
My wife can freeze thing just by looking..
Only outcome of this experiment was that they will publish a paper with huge list of authors and a minor finding. Now a days many particle physics papers have more authors than there are words in the paper.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
...pumping energy into a system makes it behave differently!
.: Semper Absurda
It's because you set your lasers to stun.
Well that's a good question. Should atoms with enough added energy to fluoresce still be tunneling?
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
The famous Heisenberg uncertainty principle says that position and velocity of a particle are related and cannot be simultaneously measured precisely.
What if 2 people watch? One for position and one for velocity.
Also, I'm not clear on how making the laser brighter causes the effect in the way the researchers state, if you can see them at lower levels of laser brightness then should behave the same then as they do when watched at brighter levels.
You can either watch them or not seems logical (to me anyway), this article seems to imply a gradient of the effect rather than an absolute.
"If any question why we died, Tell them because our fathers lied."
Or somebody is. Possibly some PR person at their university with zero clue. What they have is that shining the second laser seems to decrease tunneling. This could be a measurement error, it could be an unexpected, yet perfectly fine different effect, and it could, if all else is reliably being ruled out, indeed be the effect claimed. But making physical measurements is very tricky and misinterpreting the results is very easy.
Remember the guys that measured FTL particles and asked for help because they (sanely) did not believe their results? And remember all the nonsense the press wrote? Turned out to be a faulty connector, after all.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
So I the answer to "If a tree falls in a forest and no one is around to hear it, does it make a sound?" has been answered. Resounding NO! It doesn't, absolutely. Cuz 'speriments.
Hooray for reporters misunderstanding physics!
So, just reporters then?
Pretending this is my office full of bitter coworkers..
"Run the experiment under intense laser and observe the atoms with your eyeballs. Then run it again with same intensity laser, but do not observe it, don't even record it for future use. Compare the amount of tunneling for both."
Isn't that still 'observing' for the purposes of the meaning of observing? Really not sure - the whole thing is nuts...
systems behave differently when observed
==> (implies) humans control objective reality with their minds
==> as a human controller of reality you are responsible for what happens
==> if you're poor it's your own fault
==> Republican or Tory
> The word "watching" invokes just observing passively without doing anything to disturb the system.
UmNo... do you understand Schrodinger? The whole delta-p delta-x vs. h-bar of the Heisenberg Uncertainty principle? Because at subatomic particles isn't passive, by definition. The idea is that a photon is so energetic that it gives small particles a hefty kick. There is no such thing of 'just observing passively', there's just 'big things move imperceptibly when observed, small ones move more'.
Besides, this isn't about that. Quantum Zeno is about instability being 'stabilized' by measurement being constant. It's settlied science: quantumly weird, predicted, utilized in industry, and this is another example of it.
And your last sentence is trollery. Particle physics often involves teams that build and maintain the beam labs. What kind of know-nothing thinks that naming everyone changes the science? If a paper comes out that says "Here's a picture of the Higgs Boson", it's great science regardless of the entire CERN team getting a credit on the authors list.
(no pun intended).
If the system cannot change while I'm watching, how am I able to watch moving pictures on my TV?
linquendum tondere
I think the point is that if something is made detectable, it will have an effect on that thing. There is a bias to our Universe, such as being made of matter instead of anti-matter, things spin to the right, and not to the left, and those which spin to the left get annihilated. Except in the world of the very small where time has little effect on the energy, and the moment those quantum energies are made detectable, they enter our system of things and change properties to adjust. The observer in this instance matters because it's the observer "who", chooses to conduct this experiment to verify a hypothesis. Without the observer the quantum interactions are in possible states relative to the classical physics observing it. Basically it's "put" into a symmetry so "we" can say it is, otherwise it remains as is and isn't at that scale.
How does that comply with Eisenberg principle? The particle is stopped, hence we both know where it is and its velocity: zero