Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Quantum Measurements Leave Schrödinger's Cat Alive

samzenpus posted about 2 years ago | from the looking-in-the-box dept.

Science 210

First time accepted submitter Walking The Walk writes "Your co-workers who keep using Schrödinger's cat metaphor may need to find a new one. New Scientist reports that 'by making constant but weak measurements of a quantum system, physicists have managed to probe a delicate quantum state without destroying it – the equivalent of taking a peek at Schrodinger's metaphorical cat without killing it. The result should make it easier to handle systems such as quantum computers that exploit the exotic properties of the quantum world.'"

cancel ×

210 comments

Sorry! There are no comments related to the filter you selected.

first post ! (-1)

Anonymous Coward | about 2 years ago | (#41545771)

???

Re:first post ! (1)

User8201 (573530) | about 2 years ago | (#41545807)

Does anyone here RTFA?

Re:first post ! (-1)

Anonymous Coward | about 2 years ago | (#41546177)

Does anyone here RTFA?

too busy watching the niggers vote for obama

Re:first post ! (4, Funny)

Cryacin (657549) | about 2 years ago | (#41546265)

Does anyone here RTFA?

Of course! It's about scientists no longer using sledgehammers to check for the existence of cats in a box. Instead they shine a torch inside. Quite obvious really!

Re:first post ! (5, Informative)

Anonymous Coward | about 2 years ago | (#41546369)

Does anyone here RTFA?

Yes, I did. The summary quotes this part line by line: "physicists have managed to probe a delicate quantum state without destroying it – the equivalent of taking a peek at Schrodinger's metaphorical cat without killing it."

This shows a fundamental misunderstanding of the cat experiment, in that the author is assuming that by opening the box the cat gets killed. When in fact the cat can be considered both alive AND dead while the box is unopened, and if you open it it might very well be alive and not dead. Thus it would be equally accurate (or inaccurate, rather) to say "the equivalent of taking a peek at Schrodinger's metaphorical cat without making it LIVE."

And to be even more nitpicky, it does alter the quantum state- it changes the oscillation but does not destroy the superposition. They also have (simply put) found a way to return the oscillation to the pre-observation state within a relatively small timeframe.
So yes, the parent's "???" was justified as the use of the analogy was horrible incorrect.

Re:first post ! (4, Interesting)

Savage-Rabbit (308260) | about 2 years ago | (#41546653)

This shows a fundamental misunderstanding of the cat experiment, in that the author is assuming that by opening the box the cat gets killed. When in fact the cat can be considered both alive AND dead while the box is unopened, and if you open it it might very well be alive and not dead. Thus it would be equally accurate (or inaccurate, rather) to say "the equivalent of taking a peek at Schrodinger's metaphorical cat without making it LIVE.

I'm not a quantum physicist but If I understand Schrödinger's experiment correctly (feel free to reeducate me), the cat is both alive and dead until you open the box and 'fix' it's state. Until you observe the cat all you can say is that the closer you get to an hour (the radioctive matierial decays one atom per hour) the more likely it is that the cat is dead. So have these scientists managed to observe Schrödinger's cat in it's dual live/dead 'flux' state?

Re:first post ! (2, Funny)

TheDarAve (513675) | about 2 years ago | (#41546979)

So have these scientists managed to observe Schrödinger's cat in it's dual live/dead 'flux' state?

They must work for the Umbrella Corporation.

I want a refund, Slashdot (4, Funny)

Anonymous Coward | about 2 years ago | (#41545773)

The SchrÃdinger's Cat [thinkgeek.com] I bought from Think Geek keeps dying half the time.

Equivalent of peeking without killing it ?! (0)

Anonymous Coward | about 2 years ago | (#41545777)

Why is it equivalent of peeking without killing it ?!

The cat might already be dead when you peek. Now, apparantly you simply can peek at the cat's state.

Re:Equivalent of peeking without killing it ?! (4, Insightful)

Sun (104778) | about 2 years ago | (#41545801)

Why is it equivalent of peeking without killing it ?!

The cat might already be dead when you peek. Now, apparantly you simply can peek at the cat's state.

I think you missed the whole point of the thought experiment. No, the cat is decidedly not already dead when you peeked. It is the moment of your peeking that picks a state for the cat.

Which, of course, means that the summary is meaningless. I'll go read TFA, and, more likely, then consult with a Physics Phd I know to try and make (relative) sense of this discovery.

Shachar

Re:Equivalent of peeking without killing it ?! (3, Insightful)

Intropy (2009018) | about 2 years ago | (#41545843)

I think perhaps you may be the one confused. The point of the thought experiment is that you cannot know whether the cat is alive or dead before opening the box. It's 50/50. In one interpretation of quantum mechanics that means that the cat exists in a combination of both states prior to observing it. Observing it causes one or the other of the states to prevail.

Re:Equivalent of peeking without killing it ?! (4, Interesting)

Sun (104778) | about 2 years ago | (#41546025)

The point of the thought experiment is that you cannot know whether the cat is alive or dead before opening the box.

No, that is not the experiment's point. That is its premise.

It's 50/50. In one interpretation of quantum mechanics that means that the cat exists in a combination of both states prior to observing it. Observing it causes one or the other of the states to prevail.

It is the only interpretation that I am aware of (though its precise phrasing varies). In fact, it is the only reason that anyone hopes qbits will work. Hence me not being confused.

Unlike what the original poster said, the cat is not already dead when you open the box. That is the whole point of the experiment. The cat is neither alive nor dead until the point in time in which you look, at which point it has already been alive/dead all along.

This principle is the one that drives the quantum computing research. The idea is that you create 512 qbits signifying a number. Since they are in their base form, they each can be either 1 or zero, which means that they are, potentially, all 2^512 possible numbers. You then pass them through a series of filters that, essentially, force them to multiply with another set of 512 qbits and form a known result. Only then do you check what each of the qbits is. You have just factored a 1024 bit integer in zero time by letting quantum mechanics test all possible combination concurrently.

Shachar

Re:Equivalent of peeking without killing it ?! (4, Insightful)

Intropy (2009018) | about 2 years ago | (#41546101)

It's 50/50. In one interpretation of quantum mechanics that means that the cat exists in a combination of both states prior to observing it. Observing it causes one or the other of the states to prevail.

It is the only interpretation that I am aware of (though its precise phrasing varies).

There are many other interpretations. The one where it exists in a combination of the possible states is the Copenhagen interpretation.
Another popular one is the many words interpretation. Instead of the cat being in a combination of the possible states, there are multiple universes with each universe containing a different possible history (dies at T=1, dies at T=2, still alive, etc.) and there is a different version of the observer in each universe coming to a conclusion based on which universe he's in.
In the relational interpretation observer 1 could take a peek, and know the cat is dead, while for observer 2, who hasn't peeked, the cat is still in both states.
In the ensemble interpretation the cat is definitely either alive or dead, you just don't know which before making the observation. The probability distribution does not apply to a single cat, but rather to an ensemble of cats. Repeat the experiment 1000 times and you'll get about 500 alive and 500 dead.

Unlike what the original poster said, the cat is not already dead when you open the box. That is the whole point of the experiment. The cat is neither alive nor dead until the point in time in which you look, at which point it has already been alive/dead all along.

That interpretation is different from "the only interpretation [you] are aware of." As I said above the interpretation Schrodinger was discussing has the cat in a combination of both states. Not that it's not in "neither" state. It's in a combination of them. The AC above was pointing out that you might not be keeping the cat alive while peeking. You might be peeking while keeping the cat dead. Or as the article rather than the headline actually says, you get to peek and keep it in the superposition without collapsing it.

Re:Equivalent of peeking without killing it ?! (0)

Anonymous Coward | about 2 years ago | (#41546399)

Or as the article rather than the headline actually says, you get to peek and keep it in the superposition without collapsing it.

As the article says, in order to continue to use the Cat-based thought experiment we must consider in the original experiment that the box was either completely open or completely closed, and they've found a way to only open it partway- you are only getting a limited view of the cat's state but that they have found a way to infer its state and then close the box again, allowing the cat to remain "both alive and dead".

Anyhow, it's just a thought experiment.

Re:Equivalent of peeking without killing it ?! (1)

hajus (990255) | about 2 years ago | (#41546701)

These interpretations all are similar in their measurable outcomes. That's why we have these interpretations instead of focusing in on one of them.

The many worlds postulate, for instance, doesn't split the universe into many until the observation is made. So the cat is in a multi-state until that point in time. In all the interpretations, there is a multi-state until the measurement is made and then something happens, depending on the interpretation.

Re:Equivalent of peeking without killing it ?! (1)

Nerdfest (867930) | about 2 years ago | (#41546985)

Does this method of observing really change anything? To me, it doesn't unless they can actually measure it, find it dead, measure again, the find it alive. If the observation is still fixing the state, in what way does this help? I will add here that I an not a quantum physicist,I did not RTFA, and it's 06:00. (That sounds like the SlashDot equivalent of that line towards the end of the "Blues Brothers").

Re:Equivalent of peeking without killing it ?! (4, Interesting)

sFurbo (1361249) | about 2 years ago | (#41546165)

It is the only interpretation that I am aware of (though its precise phrasing varies).

That is the Copenhagen interpretation. There are several others: In the many-world interpretation, there are universe in which the cat is alive, and universes in which the cat is dead. Until you open the peek, you can interact with both. Ones you have peeked, the versions of you in the universe where the cat is dead and the versions of you in the universe where the cat is alive diverges, and cannot interact anymore (roughly). Then there is the de Borglie-Bohm [wikipedia.org] interpretation, where the cat is either dead or alive (particles have a definite, deterministic position), but until you have observed it, you can only interact with the wavefunction, which is the same for dead and alive cats (I think, but I might have horribly misunderstood it). In fact, there a quite a lot different interpretations of quantum mechanics [wikipedia.org]

In fact, it is the only reason that anyone hopes qbits will work.

Qubits works because of quantum mechanics, that is, because the equations are as they are. That have nothing to do with the interpretation, which is how we understand the equations. Interpretations are not scientific, as they make exactly the same predictions as the underlying model, but are more complex. They are not really needed, but the human mind doesn't like thinking in equations, it prefers to have something that behave like something physical, so we like having them.

Re:Equivalent of peeking without killing it ?! (1)

Anonymous Coward | about 2 years ago | (#41547043)

They are not really needed, but the human mind doesn't like thinking in equations, it prefers to have something that behave like something physical, so we like having them.

Exactly. A workable interpretation would be that since the equations work that the world is in fact just those equations. Values are simply undefined until you plug in the values for the other variables.

But we're evolved to our experience of the real world, so want the real world to be 'real' and equations only to describe how the real world worlds, not be it. So we reject that idea instinctively.

Re:Equivalent of peeking without killing it ?! (1)

Anonymous Coward | about 2 years ago | (#41546277)

Unlike what the original poster said, the cat is not already dead when you open the box. That is the whole point of the experiment. The cat is neither alive nor dead until the point in time in which you look, at which point it has already been alive/dead all along.

The Copenhagen interpretation of quantum mechanics is what made Schrödinger come up with that thought experiment to begin with. It is also what made Einstein say that God doesn't play dice with the world. (he was a firm believer of determinism.)
The cat thought experiment was Schrödingers way of being a bit of a sensationalist (I guess that is why the idea got so much publicity.) in that the claim is that if we follow the Copenhagen interpretation and say that the particles are in all possible states before measurement, even if we are just talking about a single particle, we can quickly get a situation where we can no longer differ between life and death. Obviously this is silly, the cat can't be both alive and dead, instead Schrödinger would have preferred an interpretation where the state just is unknown rather than all states at once.

Re:Equivalent of peeking without killing it ?! (4, Insightful)

Anonymous Coward | about 2 years ago | (#41546031)

Not exactly. A cat in such a situation would of course be dead or alive, regardless of whether you observe it or not. You may not know *whether* the cat is alive or dead, but you know *that* the cat is alive or dead. The measurement of the state to choose whether or not to kill the cat would in itself collapse the waveform.

Schroedinger developed the thought experiment to describe what he considered the absurdity of the Copenhagen interpretation of quantum mechanics. It's not meant to be taken as literally as it is tended to be.

Re:Equivalent of peeking without killing it ?! (2)

Sun (104778) | about 2 years ago | (#41546085)

Not exactly. A cat in such a situation would of course be dead or alive, regardless of whether you observe it or not. You may not know *whether* the cat is alive or dead, but you know *that* the cat is alive or dead.

The experiment doesn't work, so you are right. But had the experiment worked, then that claim would be incorrect. The point in time in which the universe decides whether the cat died or not is when we test it, not before. If we never test the cat, it is neither alive nor dead.

The measurement of the state to choose whether or not to kill the cat would in itself collapse the waveform.

Exactly. It is uncollapsed before the measurement.

Schroedinger developed the thought experiment to describe what he considered the absurdity of the Copenhagen interpretation of quantum mechanics. It's not meant to be taken as literally as it is tended to be.

But that interpretation prevailed. That is the whole point of ESR. It is not possible to extend a wavelength function, uncollapsed, to the size of a cat, but when actual atoms are involved it really is the point of testing that determines the result. The result is not there all along, just waiting to be measured.

Shachar

Re:Equivalent of peeking without killing it ?! (0)

Anonymous Coward | about 2 years ago | (#41546207)

The experiment doesn't work, so you are right. But had the experiment worked, then that claim would be incorrect. The point in time in which the universe decides whether the cat died or not is when we test it, not before. If we never test the cat, it is neither alive nor dead.

That... is an absolutely lovely bit of double think. Admit the experiment doesn't work, then spend the rest of the post arguing the point based on what it would mean if it DID work.

Re:Equivalent of peeking without killing it ?! (1)

daffy951 (546697) | about 2 years ago | (#41546227)

The point in time in which the universe decides whether the cat died or not is when we test it, not before. If we never test the cat, it is neither alive nor dead.

Uhm.. No? The point in time the cat died is exactly that point in time, whenever we test it? If we never test the cat, it's *either* alive or dead..

Re:Equivalent of peeking without killing it ?! (3, Informative)

Guignol (159087) | about 2 years ago | (#41546747)

If the cat was just either dead or alive (according to whether or not the gun, or poison or whatever was triggered by some beta decay) and we would just be unaware of it until opening the box
What would be wrong about it ?
You put a coin in a box, shake the box. surely, it is either head or tails, you just know what it is when you open the box
So why do you think there is such a buzz around the Schrödinger’s cat ?
Precisely because, the experiment is setup so that the cat is not either alive or dead, but in a special state
Schrödinger put together this thought experiment to show how silly the Copenhagen interpretation was (to his eyes)
The experiment is there to say "according to you, the cat is both dead and alive (which we can all agree on is ridiculous)"
Except it's not that simple, and then, there is entanglement and there indeed are "weird mixed states"

Actually it is right but also wrong (1)

aepervius (535155) | about 2 years ago | (#41546221)

The point of the cat thought experiment was to show the absurdity of taking QM at macro level.

Re:Equivalent of peeking without killing it ?! (-1)

Anonymous Coward | about 2 years ago | (#41546223)

I think perhaps you may be the one confused. The point of the thought experiment is that you cannot know whether the cat is alive or dead before opening the box. It's 50/50. In one interpretation of quantum mechanics that means that the cat exists in a combination of both states prior to observing it. Observing it causes one or the other of the states to prevail.

Will you fucking lemming-cunts stop modding everything up to +5 when it's wrong? Those who read the article know this is merely the PREMISE like Sun points out.

It's only seconds of thought. Try reading a few posts in a thread and then modding them.

While you're at it try eating an amount of calories that is equal to or less than what you burn. These two things are connected you see.

Re:Equivalent of peeking without killing it ?! (4, Insightful)

WaffleMonster (969671) | about 2 years ago | (#41546271)

In one interpretation of quantum mechanics that means that the cat exists in a combination of both states prior to observing it.

The only thing in any sort of superposition is the measuring device. The hammer which breaks the beaker of cat poison, the beaker breaking and the cat dieing are not part of the superposition. They are all separate events but whatever it all sounds much better if you make mystical claims.

Observing it causes one or the other of the states to prevail.

No it is "disturbing" not "observing" ... just more unecessary mysticism to make understanding basic ideas seem more difficult than they actually are.

Re:Equivalent of peeking without killing it ?! (0)

someone1234 (830754) | about 2 years ago | (#41546451)

You know the cat is alive. But opening the box has 50% of killing it.

If the cat can "measure" the quantum state by its death, then it counts as "opening the box" too.

Re:Equivalent of peeking without killing it ?! (5, Interesting)

petes_PoV (912422) | about 2 years ago | (#41546469)

Meh, it's already been done experimentally

Have a look at the Quantum Zeno Effect which is both one of the scariest and most awesome pieces of experimental quantum physics around. Just in case your Google is broken, the experiment stops the random decay of unstable particles by continually measuring their state. Since the cat is just an allegory for these sorts of particles, the experiment has already been done - yes you can prevent a random (quantum) event by taking continuous measurements.

You don't need this thought experiment any more - as *real* physics cruised past these mind games decades ago.

Re:Equivalent of peeking without killing it ?! (2)

Stuarticus (1205322) | about 2 years ago | (#41546703)

"It's a bit like watching your kettle, to make sure it never boils"

Geordi La Forge

Re:Equivalent of peeking without killing it ?! (1)

WaffleMonster (969671) | about 2 years ago | (#41546215)

I think you missed the whole point of the thought experiment. No, the cat is decidedly not already dead when you peeked. It is the moment of your peeking that picks a state for the cat.

The worst ever "thought experiment" by far is Schrodinger's cat. To say a living cat was ever in a superposition of alive or dead is wrong and stupid. These words only confuse people unecessarily.

No cat was never a participant in any coherent quantum system only the measuring device which **triggers** death of the cat had anything to do with the quantum system.

Asking if a tree still falls in the forest if nobody sees it is about as instructive as the cat in the box analogy.

Which, of course, means that the summary is meaningless. I'll go read TFA, and, more likely, then consult with a Physics Phd I know to try and make (relative) sense of this discovery.

Nothing at all has been "discovered". All they did was physically implement something for which the properties have been calculated and well understood for many many decades.

Re:Equivalent of peeking without killing it ?! (1)

expatriot (903070) | about 2 years ago | (#41546841)

The cat is alive or dead and not ever in a state of superposition.

The example was (I hope intentionally) chosen to illustrate how poorly our macro world and macro thinking fail at the quantum level.

If you have any doubt of this and are romantically tied to the "alive and dead" cat, consider this: The cat is capable of making an observation. It is a complex collection of moving parts. If the parts stop moving, that is an observation.

It may be the case that quantum states on small particles do not have any internal world. That is a large area of discussion in physics. Is quantum mechanics the result of a hidden (to us) world that follows reasonable laws, or is it just very weird all the way down.

Re:Equivalent of peeking without killing it ?! (5, Informative)

Anonymous Coward | about 2 years ago | (#41545837)

This is the equivalent of weighing the box. By not opening the box you don't collapse the wave function. Instead you measure some other property that is independent of the wave function. It is nothing like peeking in the box, nor does it gain any information from the wave function.

Re:Equivalent of peeking without killing it ?! (1)

Nostromo21 (1947840) | about 2 years ago | (#41546009)

So it's like deducing if the cat is alive by listening very closely if any sound is coming from the box; or measuring minute vibrations from it, or perhaps even using IR to measure the body heat through the cardboard...? Ok, we're stretching metaphors a bit far now, BUT, is it possible with QM that the cat is actually *dead* to begin with (if that even makes sense for any solution of the wave function) AND you then bring it back to life by observing/interacting with it...?

Re:Equivalent of peeking without killing it ?! (2)

Sun (104778) | about 2 years ago | (#41546057)

No. You cannot measure whether the cat is alive without causing a determination of that very question. You can measure other things, though.

I should point out that the cat analogy is not a very good one, and TFA chose it only to make the article more appealing.

Shachar

Re:Equivalent of peeking without killing it ?! (0)

Anonymous Coward | about 2 years ago | (#41546313)

Ok, we're stretching metaphors a bit far now, BUT, is it possible with QM that the cat is actually *dead* to begin with (if that even makes sense for any solution of the wave function) AND you then bring it back to life by observing/interacting with it...?

No, the thing that makes the Copenhagen interpretation so controversial is that with it the cat is both alive and dead at the same time, the cat thought experiment was made by Schrödinger to highlight the absurdity of the Copenhagen interpretation, something can't be both dead and alive at the same time but if we assume that something can have several quantum states at once that is the natural extension of it.
The full thought experiment includes a living cat, a vial of poison and a radioactive particle what can trigger the poisoning of the cat. If the particle is in all states then it will both poison the cat and not poison it and the outcome is determined by opening the box. In determinable physics the cat is already dead or alive before opening the box and we only find out about the result upon opening.

Re:Equivalent of peeking without killing it ?! (1)

Dahamma (304068) | about 2 years ago | (#41546059)

But weighing the box won't tell you anything (no, a cat's soul does NOT weigh 21 grams). I think it's more the equivalent of smelling the box.

Re:Equivalent of peeking without killing it ?! (0)

Anonymous Coward | about 2 years ago | (#41546665)

nor does it gain any information from the wave function

Apart from measuring its frequency. It's nothing like weighing the box; they interact with the wave function. RTFA, and that goes for the modders who gave this +5 Informative (I guess wrong information is still information, though).

Re:Equivalent of peeking without killing it ?! (3, Interesting)

Black Parrot (19622) | about 2 years ago | (#41545927)

I always wondered why the cat didn't qualify as an observer to begin with.

Re:Equivalent of peeking without killing it ?! (1)

Anonymous Coward | about 2 years ago | (#41546029)

AFAIK it does, which is why this experiment wouldn't *actually* work. From what I have gathered about the topic, an "observer" is any VERY-many-particle system (read: billions of billions of degrees of freedom) that interacts with the quantum system. Introdouce that many degrees of freedom and the superposition is gone.

Re:Equivalent of peeking without killing it ?! (-1)

Anonymous Coward | about 2 years ago | (#41546097)

From what I have gathered about the topic, an "observer" is any VERY-many-particle system

There is no such objective ontology. Only a retard who doesn't understand even the very basics of QM would say such an absurd thing.

The closest thing you find among actual physicists is something like Penrose's objective reduction -- there, collapse happens once a system grows to a certain size. Of course, no one takes Penrose seriously. It's retarded and requires his idiotic ideas about quantum gravity.

We don't live in a billiard-ball universe. That idea was outdated in Newton's time. Get with the program and learn about the topic before you repeat bullshit, or shut the fuck up.

Re:Equivalent of peeking without killing it ?! (-1)

Anonymous Coward | about 2 years ago | (#41546695)

There is absolutely no need to be so horribly rude and swearing. Please read your post back before you submit it and imagine you would be speaking it to someone live. You *may* know something about QM (though you seem a bit too sure of *the truth* to be an actual expert), but please read up on human-human interaction, which is different from atomic particles ;-)

Re:Equivalent of peeking without killing it ?! (-1, Offtopic)

Anonymous Coward | about 2 years ago | (#41546705)

For the first time in my life I've observed the superposition of a flapping cunt and a huge dick.

Only a retard who doesn't understand even the very basics of QM would say such an absurd thing.

I think I can safely say that nobody understands quantum mechanics.
Richard Feynman

No one knows what defines an observer, but "a sufficiently complex system" is a leading contender. And your belief that QM doesn't have particles is, um, incorrect. Perhaps you should retake the QM 101 course at whatever sport college you attend. Oh, and lay off the steroids.

Re:Equivalent of peeking without killing it ?! (0)

Anonymous Coward | about 2 years ago | (#41546195)

Combining quantum mechanics and relativity ... maybe from the cat's point of view, it is alive, but it isn't sure whether you are alive or dead until it escapes from the box.

Re:Equivalent of peeking without killing it ?! (1)

Anonymous Coward | about 2 years ago | (#41546063)

There are a lot of replies that seem to be missing it. If you measure quick enough after closing the box with the cat in it, the chances of it being dead versus alive are not 50-50. Since it was alive when you closed the box, there would be a really high chance it is still alive when you peak if you peak much quicker than the halflife of the decay process that is supposed to trigger the death (for the version that uses a decay particle as the source of chance). Since this peeking collapses the wave function back from a 99-1% split back to 100% alive state, you can keep doing this to keep collapsing it to the alive site with very high probability. In the right conditions, you can go from what was a 50% chance of it being dead after a certain amount of time, to a vanishingly small chance if you can keep measuring quick enough. The actual states of a cat are much more complex, but there are two state quantum systems that take a certain amount of time to evolve into a superposition of both states.

The cat is alive... (4, Funny)

geoffrobinson (109879) | about 2 years ago | (#41545787)

and extremely pissed off about your experiment.

http://afternoonsnoozebutton.com/post/9395842065/breaking-news-schrodingers-cat-is-alive-and [afternoons...button.com]

Re:The cat is alive... (-1, Offtopic)

zbobet2012 (1025836) | about 2 years ago | (#41545803)

Where are mod points when you need them.

Scrodingpost (0, Offtopic)

Anonymous Coward | about 2 years ago | (#41545795)

Slightly look at me, and I will post and no post at the same time

The suspense is killing me. (0)

Anonymous Coward | about 2 years ago | (#41545797)

--In a large crowded stadium -- "Ladies and gentlemen, the results are finally in; the cat is in fact, ALIVE!" --- crowd erupts in applause with cheering--

The BEST related animation (4, Interesting)

Jonah Hex (651948) | about 2 years ago | (#41545811)

This one is as mind bending as the metaphor itself: http://www.youtube.com/watch?v=JNalMWLnt0o [youtube.com] From the youTube description:

This animation was created for an animation show in London by the very talented Chavdar Yordanov https://vimeo.com/chavdaryordanov [vimeo.com]

Not my Work! - HEX

Next up Photons Smotons (-1)

Anonymous Coward | about 2 years ago | (#41545813)

We can only create photons from promoting or demoting electrons in atoms.
We can only detect photos by watching it promote electrons in atoms.

So we can detect all those half photons that are out there and assume they don't exist because we can't create them... yet.

Re:Next up Photons Smotons (0)

globaljustin (574257) | about 2 years ago | (#41546245)

Interesting...IMHO what we call a 'photon' is essentially a different flavor of Higgs-Boson, not any sort of 'light packet' or somesuch...same for the 'graviton'...they are all just variations on the same thing...a thing that is **not** gravity

Essentially I'm saying maybe this means there are only two forces, strong/weak/electro/mag and gravity...

The real representative line from TFA (3, Informative)

Sun (104778) | about 2 years ago | (#41545815)

This wouldn't allow you to gain a "strong" piece of information – whether the cat was alive or dead – but you might be able to detect other properties.

So, in essence, the main thing they found out is how to do more stuff with qbits without triggering a collapse of the wavelength function.

Real summary:
Obscure need which is somehow quantum computing, but not in any way feline, related gets obscure advance.

Shachar

Re:The real representative line from TFA (0)

Anonymous Coward | about 2 years ago | (#41545931)

"Next, the team measured the frequency of this oscillation. This is inherently a weaker measurement than determining whether the bit took on the value of 1 or 0 at any point, so the thought was that it might be possible to do this without forcing the qubit to choose between a 1 or a 0. However, it also introduced a complication."

So to extend the cat metaphor they measured how fast the cyclical Jesus-cat cycled between death and resurrection.... ?

Re:The real representative line from TFA (1)

Anonymous Coward | about 2 years ago | (#41545953)

"Next, the team measured the frequency of this oscillation. This is inherently a weaker measurement than determining whether the bit took on the value of 1 or 0 at any point, so the thought was that it might be possible to do this without forcing the qubit to choose between a 1 or a 0. However, it also introduced a complication."

So to extend the cat metaphor they measured how fast the cyclical Jesus-cat cycled between death and resurrection.... ?

No, more like what colour the cat's fur is.

Re:The real representative line from TFA (1)

hughbar (579555) | about 2 years ago | (#41546975)

If the cat is really, really dead, there will be mould on the fur [I'm assuming that the box isn't very airtight], so analysis of the reflected spectrum from the weak quantumy torch [to use the precise technical term] should pick that up.

Can I have my Nobel prize now please?

Quantum cryptography? (4, Interesting)

timeOday (582209) | about 2 years ago | (#41545817)

What? Isn't the proven destructiveness of measuring a quantum system the bedrock of quantum key distribution [wikipedia.org] ?

Re:Quantum cryptography? (1)

mcrbids (148650) | about 2 years ago | (#41545853)

Came here to see this point made, was not disappoint.

Re:Quantum cryptography? (0)

Anonymous Coward | about 2 years ago | (#41545873)

I didn't read TFA, but schrodinger's cat was about large objects being able to go in superposition. So maybe they were able to peek at a large object which is and stays in super position.

The bits (single photons) being send in quantum key distribution are not in superposition, since the sender knows which random bits are send.

Of course I could be very wrong, I am not a quantum scientist.

Re:Quantum cryptography? (1)

Artifakt (700173) | about 2 years ago | (#41546479)

If an object the mass of a cat and composed of normal matter can exist as a quantum superposition, then mass and particle complexity are not fundamental limits. If the cat is possible, the Planet Jupiter can also exist in a Schrodinger's Cat like state.
          Then there's the question of what constitutes an observer. Mystical models assume something that is itself aware. The extreme antropomrphic end of observer definitions is "a being capable of understanding the implcations of Quantum Mechanics with regard to the given wave function". That interpretation means lots of humans don't qualify as observers. From there, the definitions tend to stay mystical, with debate over whether a being that can notice a light change from off to on, but has no idea what it implies, counts as an observer. One potential definition goes into whether the cat itself is aware, and whether that includes the cat having a related but possibly different thing we call "self awareness", and so on. The less mystical models treat any instrumentation capable of providing data as an observer, or even anything that can be toggled to a different logic state by interacting with the collapse of a particular state vector. By that sort of definition, an 'observer' is therefore any 'material' thing that is outside the array of matter that is part of your initial state vector, but only at the moment that outside object recieves data on the state vector.
            So, if the initial superposed object is the planet Jupiter as it exists at time T, then a liberal definition of observer means that state vector collapses a tiny fraction of a jiffy later when it reacts with the first particle we are not defining as part of Jupiter. On the other hand, limiting observers to beings with human-like awareness means that we can say only that Jupiter was a planet an hour or so ago, when the light we just recieved left it, but Jupiter is an 1 hour duration (approximately) state vector. That's one of the things that tends to make a mystical interpretation of "Observer" seem nonsensical when it's baldly stated like that.
            However, consider General Relativity. Relativity tells us using "is" and "was" to describe something at the other end of a beam of light isn't really meaningful, particularly across increasing distances. Simultanity is what the word 'is' implies, and that concept's really breaking down even if we don't go into Jupiter as a quantum state vector but stick with good old Einstein and say Jupiter is a planet at the other end of a one hour light cone from us but it becomes absurd to say "That was an hour ago, what is Jupiter doing simultaniously with now here on Earth?".
            Should we reject the mystical definition of an observer then? Even if it sounds weird or like some sort of religious philosophy contaminating the purely scientific explanation, in some ways it's really just forcing us to a similar position as Relativity does anyway.

Re:Quantum cryptography? (1)

Black Parrot (19622) | about 2 years ago | (#41545939)

What? Isn't the proven destructiveness of measuring a quantum system the bedrock of quantum key distribution [wikipedia.org] ?

I thought I remembered a recent story saying that researchers had found a method to "peek" at an quantum-encoded message without tipping Bob and Alice off to the fact that they had an eavesdropper. I wonder if this story is related to that.

Re:Quantum cryptography? (0)

Anonymous Coward | about 2 years ago | (#41546231)

IIRC there have been 2 methods that 'break' quantum encryption so far.
1: The data is fully intercepted, determined and a copy is sent further along. Of course this requires access to the system, which is rather difficult.
2: Data is read, but only up to a certain %. Quantum computing is inherently unstable and a certain % of the data can be wrong (i think 5-10% depending on the system). This method won't give you all the data, but you could make an educated guess.

Re:Quantum cryptography? (3, Informative)

Yvanhoe (564877) | about 2 years ago | (#41546003)

I thought at this point is had become obvious that quantum cryptography was just a nice scam to fund fundamental physics research?

Re:Quantum cryptography? (1)

L4t3r4lu5 (1216702) | about 2 years ago | (#41546511)

I thought at this point is had become obvious that quantum cryptography was just a nice scam to fund fundamental physics research?

We shouldn't need to scam anyone to fund fundamental physics research.

Re:Quantum cryptography? (1)

DontLickJesus (1141027) | about 2 years ago | (#41546431)

No information is gathered, rather the lifetime / distance of the qubit is extended. Since this caused the frequency of detection to change, I'm going to make an educated guess that the correction signal causes interference and/or destruction of a third channel which could be monitored for manipulation.

Bazinga (1, Funny)

selectiontimeout (1443281) | about 2 years ago | (#41545819)

You're welcome.

Entanglement? (0)

Anonymous Coward | about 2 years ago | (#41545855)

Could this be used to make communication via entanglement viable?

'quantum' as a marketing buzzword_and 'no' (1)

globaljustin (574257) | about 2 years ago | (#41546229)

Excellent question...I have thought much about it, as it used to be my job. Two electrons entangled in a true quantum state would be a perfect communication device...any change to the state of one would instantly change the other in the same way regardless of distance

In that **truly quantum** scenario, we would indeed have quantum signal transmission at a rate of 1/1...faster than the speed of light...instant over any distance...

That's **kind of** a big deal...Einstein called it "Spooky Action at a Distance"...it's definitely theoretically possible...and it definitely would turn particle physics on its head...and it most likely won't happen b/c the energy required to do it is probably equal to all the energy in the universe according to known science. (if you balance out the equations)

That's why I cringe every time I see 'quantum' used in reference to computing...its just marketing terms for a faster processor at this point

Re:'quantum' as a marketing buzzword_and 'no' (2)

RightSaidFred99 (874576) | about 2 years ago | (#41546513)

Two electrons entangled in a true quantum state would be a perfect communication device...any change to the state of one would instantly change the other in the same way regardless of distance

That's mumbo jumbo and simply untrue. Both have a state, peeking at one just tells you what the other is it doesn't change any state.

Quantum "instant" communication is impossible and will therefore never happen.

Look it up & get back w/ me (2)

globaljustin (574257) | about 2 years ago | (#41546681)

No, you're just wrong...and you actually agreed with me when you said, "...will never happen."

See, you really need to read up on 'Action at a Distance' because it is *exactly* the phenomenon you, I, and particle physics thinks will not and cannot happen...

Yet, Einstein himself identified it as predicted in his models....seriously look it up

The cat is dead (1)

mveloso (325617) | about 2 years ago | (#41545863)

If the cat isn't dead now, it will be eventually. So you might as well assume it's dead and move on.

We have to name it... (5, Funny)

irving47 (73147) | about 2 years ago | (#41545897)

Can we PLEASE call it a Heisenberg Compensator?

Re:We have to name it... (0)

Anonymous Coward | about 2 years ago | (#41546035)

Second!

whodathunkit? (2)

Tumbleweed (3706) | about 2 years ago | (#41545899)

Stargate SG-1 finally got some science right!

every time ... (5, Funny)

SchroedingersCat (583063) | about 2 years ago | (#41545915)

Every time they take a peek, God kills a kitten.

Re:every time ... (2)

TheInternetGuy (2006682) | about 2 years ago | (#41546013)

Every time they take a peek, God kills a kitten.

Only if the kitten is entangled with the cat in the box.

Looks like Schrodingers Cat stayed alive (1, Offtopic)

toygeek (473120) | about 2 years ago | (#41545933)

just long enough to be eaten by Pavlov's Dog

Entangled Garments (3, Funny)

Penurious Penguin (2687307) | about 2 years ago | (#41545963)

Rather than using small fury creatures with no propensity for entangled behavior, why not use something of similar size, but a bit more gracious and flat? For this I propose the noble sock - an item exhibiting (when in certain steel chambers) extremely random tendencies of existence and non-existence. We all know damned well what to expect of a cat run through a permanent-press cycle. However, no one, not even Martha Stewart knows what to expect of the sock - that ambiguous textile for which any state even science cannot predict.

Re:Entangled Garments (1)

DMUTPeregrine (612791) | about 2 years ago | (#41546525)

Naw, it's actually easy. The spinning motion of the drier cycle forms a wormhole, and when the socks are transported through it they end up in closets, transformed into coat hangars.
Go, look in your closet. Did you buy all those hangars? No! Most of them used to be your socks.

Re:Entangled Garments (1)

hweimer (709734) | about 2 years ago | (#41546707)

Two words: Bertlmann's socks [cdsweb.cern.ch] .

Copenhagen Interpretation (2)

dryo (989455) | about 2 years ago | (#41545985)

More chinks in the armor of the abominable Copenhagen Interpretation. Bohr, Heisenberg and Schreodinger were very smart people, but they couldn't be right about consciousness affecting physics. That's just stupid.

Re:Copenhagen Interpretation (1)

Anonymous Coward | about 2 years ago | (#41546127)

they couldn't be right about consciousness affecting physics.

Why not? Seems like you'd need to provide pretty strong evidence for that claim. Before you waste everyone's time with more ridiculous bullshit, you can't.

Science doesn't exist to conform to your poorly-informed world view.

Now, stop fellating your play-pretend scientist buddies and go read a book. You know, learn something before you spew idiotic nonsense like this around the internet.

Re:Copenhagen Interpretation (0)

Anonymous Coward | about 2 years ago | (#41546523)

You stupid asshole, _you_ need to provide the evidence. Consciousness affecting physics is laughably improbable, and exceptional claims require exceptional proof.

Re:Copenhagen Interpretation (3, Insightful)

expatriot (903070) | about 2 years ago | (#41546881)

1. Stop being a jerk

2. Look up the work on collapse of interference in the double slit experiment.

3. If you can determine conclusively what constitutes an observation of a quantum system, you will be in line for a big prize.

4. Ignore any discussion of cats. It is a joke that everyone has fallen for.

Observing, Not Avoiding (4, Interesting)

jIyajbe (662197) | about 2 years ago | (#41546099)

From the abstract:

"The act of measurement bridges the quantum and classical worlds by projecting a superposition of possible states into a single (probabilistic) outcome. The timescale of this 'instantaneous'process can be stretched using weak measurements usuch that it takes the form of a gradual random walk towards a final state. Remarkably, the interim measurement record is sufficient to continuously track and steer the quantum state using feedback..."

The way I read this, they aren't claiming they prevented collapse, nor that they can predict which state it will collapse to; rather, they have (1) increased the time of the collapse of the wave function (via feedback) and (2) been able to "watch" the electron collapse to whichever state it goes to. [N.B.: I am totally open to correction. I haven't paid the $32 for a copy of the paper.]

So, no Heisenberg compensator here.

Unfortunately... (1)

srussia (884021) | about 2 years ago | (#41546113)

the p -value of their "weak measurements" was 0.5

Obligatory Portal reference (0)

Anonymous Coward | about 2 years ago | (#41546283)

The cat is alive.

Does this imply FTL comms? (1)

pipedwho (1174327) | about 2 years ago | (#41546325)

If the state of an entangled set of quantum bits can be known in advance and their states observed without collapsing them, then it stands to reason that a remote communications station with a pre-delivered set of pre-entangled bits could receive a message by observing the collapse the instant the 'transmitter' causes it to happen.

I wonder if this research provides this possibility, or if there is something inherent to the entanglement/observation process that prevents this.

I very gently opened the link (1)

niftymitch (1625721) | about 2 years ago | (#41546341)

I very gently opened the link and found that
it kept changing. At best it seems to be a
suggestion that perhaps maybe the cat has
whiskers that wiggle. As long as I look gently
on a windy day the whiskers could be wiggling because
it was alive or the wind was blowing.

Even the Google ads kept changing.
I think Google could be a cat killer if the
quantum bits was a Google search engine.

The Air in the box observes the Cat. (0)

Anonymous Coward | about 2 years ago | (#41546409)

The Air observes the Cat, the Box observes the Air, The human observes the Box -- Before the experiment the Universe is observing all the components: Before, during, and after the experiment the waveform is collapsed. The cat was only ever both alive and dead in some imaginary incomplete explanation of a property that our incomplete quantum theory has.

Headline? (2)

wonkey_monkey (2592601) | about 2 years ago | (#41546477)

Quantum Measurements Leave Schrödinger's Cat Alive

Shouldn't that be "Quantum Measurements Leave Schrödinger's Cat In A Superposition Of Alive And Dead"? If it's decidedly alive then the waveform has collapsed, and isn't that what they're avoiding? (did not read TFA)

But then curiosity killed the cat anyway? (0)

Anonymous Coward | about 2 years ago | (#41546597)

But then curiosity killed the cat anyway?

Who cares? (1)

sconest (188729) | about 2 years ago | (#41546599)

Schrödinger's cat has surely died of old age by now.

I saved Schrödinger's Cats life (0)

Anonymous Coward | about 2 years ago | (#41546687)

I managed to save Schrödinger's Cat. How so? This is what I did:
a. The cat is an observer - i.e., it can smell whether or not a toxic gas is being released.
b. The cat is a constant observer - cats are known for sleeping in brief periods of time called "cat naps".
c. The cat is a constant observer that triggers the Quantum Zeno effect [Wikipedia: https://en.wikipedia.org/wiki/Quantum_Zeno_effect] - thus postponing indefinitely the unstable particles decay.
Of course it is assumed (as it was on the original experiment) that the cat never starves or asphyxiates.-Ignacio Agulló

Point is moot (1)

BananaBender (958326) | about 2 years ago | (#41546759)

According to Quantum_decoherence [wikipedia.org] , there is no superposition of quantum states. As the radioactive element interacts with the cat and the box, its decoherence time becomes very short, so the wave function collapses almost instantly. The cat is either dead or alive, but there is no extended state of superposition.

Schrödinger's Cat is Lame anyway you look at (0)

Anonymous Coward | about 2 years ago | (#41546905)

For a real Schrödinger's Cat you need to superimpose a dead and a living cat. Furthermore the dead cat needs to be the deceased remains of the living cat. This would imply a violation of the principle of causality.

Knowledge itself does not lock the quantum state? (1)

adam.skinner (721432) | about 2 years ago | (#41546913)

Looks like knowledge of the quantum state does not lock it in place, then.

(5, Hilarious) (0)

Anonymous Coward | about 2 years ago | (#41546961)

So, in other words, instead of poking the cat to see if it's alive, we've been hitting it with a sledgehammer.

Quantum cryptography implications (1)

the cleaner (1641) | about 2 years ago | (#41546993)

Someone enlighten me: Have we just cracked quantum cryptography?

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>