/sci/ - Science & Math

> observation/consciousness
>Does this mean that consciousness can affect anything else? Tantric shit.
No. Nonononononono. NO.

You're fucking retarded OP.

>>4715546
Please, do explain.

I remember telling my friend about the experiment in short note, back in the day trying to get him interested in physics. A week later he was watching psychic power videos from some self-help monk guy talking about how conscious beings are able to psychically change the things around them because of the experiment.

It's always blown my mind how quickly he was able to find that bullshit and actually start believing it.

"Observation" just means some physical interaction. It has nothing to do with consciousness.

>>4715558
This is all I really wanted to know. Thank you.

>>4715558
Guys I don't get what you saying. Please a link or explanation to this phenomena.

Light, it's just light.

>>4715572

In order to detect something, you need to interact with it.

This becomes problematic in the quantum realm. When dealing with very small quantum objects, what we call 'observation' is an interaction with that object that gives us some information about it.

When we observe a subatomic particles, the interactions we have with the particle in observing it are such that it affects the behaviour of the particle. In the instance of the double slit experiment, the interaction causes the photons to exhibit the properties or particles, whereas the unobserved photons behave like waves.

>>4715572
this was explained by Bohr, and to paraphrase, the mere act of observing something (i.e. measuring it [which requires some sort of interaction with what is being observed]), no matter how negligible or minimal, will affect the system. That is, even by just looking at the experiment (measuring it with whatever tool you choose) you are interacting with it and thus altering the result. It's like putting your hand inside a pond of water - all the fish will actively avoid your hand as opposed to swimming all over.

The particles are small. To 'observe' them we interact with them, since we cannot physically see them. This interaction obviously effects their behaviour.

Observe just get misunderstood and abused by morons bending data to their own purpose. If a blind person 'observes' a marbles movement alone the floor by touching it with his hands periodically yo gain information about it's trajectory, he effects the very behaviour he is trying to monitor. This does not mean he has magic powers. However, if you told a new age fag that a man altered a marbles course through observation, they don't give a shit about the finer details.

Sorry for shit explanation. Posting from phone.

>In the instance of the double slit experiment, the interaction causes the photons to exhibit the properties or particles, whereas the unobserved photons behave like wave

Could someone please elaborate upon this

>>4715610

With the copenhagen interpretation, if you were to try and observe photons moving through the double slit to see which one they go through, you'd see them going through one or the other.
If you weren't looking, you'd see them go through both. Even if you shot them one at a time, they'd behave like waves, and therefore interfere with themselves.

FUCK photons are weird.

>>4715610
Light should only be a wave and it acts like one when unobserved.
But, since light, massless energy, goes through the slit when it's observed, aka, energy that's added in one way or another to the system, it start behaving like a particle.
Duality is an archaic concept imo.

>>4715610
Mate didnt you know that light is both wave and particle?

>>4715610

Ok.

So we detect everything by interacting with it. Our eyes detect things by receiving information from photons that hit the retina, our ears detect things by monitoring the vibrations of hairs in our cochlea that are sensitive to the mechanical motion of atoms in sound waves. Dolphins detect objects in the dark by sending sonar signals out into the dark and seeing whether they bounce back, and get information from the time taken for a wave to reflect and it's intensity.

In the same way, we cannot simply know things about subatomic particles without interacting with it. This is a crude way of putting it, but we can't 'see' subatomic particles, they are too small. So we have instruments called detectors that work in a similar way to our senses, but are more sensitive, so they can detect individual subatomic particles.

The problem is, the interactions the particles from the detector have with subatomic particles is analogous to our ear hairs interacting with atoms in oscillating in sound waves, or photons reflecting off an object we can see, or sound waves reflecting off the target of a dolphin's sonar pulse.

In these instances, the methods of detection have a negligible effect on whatever they are detecting, but because subatomic particles are so small, any 'detector particle' that interacts with it is going to affect the particle. This changes the behaviour of the particle. The change is brought about by the physical interaction between two particles.

>>4715603
Even physically seeing things is interacting with it, since the sun bounces photons of of it for you

lol i dunno OP
lets ask my tulpa

If anyone is interested:

THE PROBLEM OF CONSCIOUS OBSERVATION
IN QUANTUM MECHANICAL DESCRIPTION
http://arxiv.org/pdf/quant-ph/9908084.pdf

What If you could do the double slit experiment with marbles without observing them. Would they behave like a wave?

>>4715638

>implying the photons would not still hit the thing if you weren't looking

The wavefunction collapses whenever it comes into contact with a "non-quantum" object. This would be a detector. Conscious observation is irrelevant. Look up decoherence.

http://www.youtube.com/watch?v=_OWQildwjKQ&feature=related
This guy says that if you observe the particles by detectors but dont disconnect them from actually collecting the information the wave function doesnt collapse. Is he right or wrong? Because to me that almost looks like a proof that the consciousness of the observer is important

>>4715819
What time does he say that, not sure what you're getting at

>>4715800

First,
> Fuck all your aquivocation fallacies, "observing" in the physicalist sense particle physics talk of isn't "observing" in the psychological sense where information from sensory organs becomes represented in a brain's working memory, go communicate with aliens through jugs of water and ask them for a trip to the 7th dimension or something.

Second - not to tread the point, but there's still an explanatory gap here (not in the scientific explanation, I mean in regards to this thread):

Saying that "observation affects behavior" (in any of the forms used above) is simply rephrasing "when detected, a photon suddenly acts like a particle"; that's like, when asked "why did the water suddenly came out of the tap when you pulled the handle", answering "because whenever you interact with the handle the tap allows water to pass through", which is of course true but not fully explanatory.

If we have a theory that explains WHY interaction with a photon that acts like a wave makes it act like a particle, I'd really like to hear it.

>>4715895

>If we have a theory that explains WHY interaction with a photon that acts like a wave makes it act like a particle, I'd really like to hear it.

And here's where you enter into the interpretations of Quantum Mechanics.

Copenhagen interpretation says it is both, it always is both simultaneously, and simply collapses immediately into one or the other upon observation. (See: Schrodinger's Cat) Many Worlds asserts that it is both, and the information of one or the other splits off into two realities whenever the wave function collapses.


http://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics

Short answer: we don't rightly know.
Long answer: there's a lot of ideas, and photons are fucking weird.

>>4715895

Why are you telling me the first point? That's exactly what I said in my post, hence "conscious observation is irrelevant".

And as for your question on actual theory, I gave you a suggestion to look up decoherence. That's exactly the phenomena you're asking about.

>>4715554
observation in physics does not mean observation as in you looking at stuff.

If something is "observed" in physics all that means is that some wave/particle/field has interacted with it. Like if you fire a photon through one of the slits, it is observed when it hits the thing you're projecting the interference pattern on to.

>>4716000
many worlds theory just strikes me as absurd. I mean, a photon takes all possible paths and where it lands is a matter of probability, not certainty. That means for every photon, there are an infinite number of new worlds surely.

Consciousness doesn't. The universe was here before us.

>In b4, how do we know?

We know

>In b4 But that's the thing, if herp derp consciousness then we're just causing history to collapse the way we want it to hence why it looks like the universe was always here

Well if that's your stance then we can't really prove or disprove anything as it could just be explained away by a possible wave function collapsing in a favorable way. It's not falsifiable and therefore is not science.


It doesn't work that way. When a photon interacts with anything else, the wave function collapses. You have to understand that when we try to observe such small objects, we bombard them with other tiny things. When that happens, photons behave like particles. Electrons move within probability clouds. When these things are not interacting with the universe, they act funny.

So it's not really consciousness, it's interaction in general.

http://en.wikipedia.org/wiki/Quantum_mysticism

>>4715616
>Light should only be a wave and it acts like one when unobserved.
no.
describing light as only a wave does not explain the quantization of its energy
when unobserved, you don't know anything about it, neither the wave-like properties nor particle-like properties.
>Duality is an archaic concept imo.
perhaps. but more importantly it is easy to misunderstand as in your case.
see http://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality#Treatment_in_modern_quantum_mechanics

>>4715895
>If we have a theory that explains WHY interaction with a photon that acts like a wave makes it act like a particle
acts like a wave means exhibits wave-like properties. that only occurs upon interaction.

as for why some type of interaction makes a photon act like a X, that's related to the details of that interaction.

>>4716000
schrodinger's cat pertains to superpositions of two states randomly collapsing into one upon observation.

wave-particle duality is concerned with how a particle exhibits wave or particle properties depending on the type of observation.

>>4716030
i think the same.

>>4715543
>Do we know HOW observation/consciousness actually affects whether an object is a particle or a wave?

I don't think you underestand the double slit-experiment

The particle goes through both slits when you don't measure it because the which-way information is erased. The particle goes through one slit when you measure it because the which-way information is going to be amplified, making such an enormous number of copies that the information never quite goes away. It's the future fucking with the past, not mind fucking with matter.

>>4715543
>2012

>not understanding the double slit experiment

>still talking about wave/particle duality

Sure is 1920's in here

What do you actually do to "observe" in the double slit experiment? I realize they aren't looking at it with a spy glass, but I have no idea of anything beyond that.
Like how the fuck do you tell if an electron is at point X at time Y?

>>4715556
LOL my friends did this too.

I talk a lot about science, mostly cosmology. They ended up getting interested and all they do is watch videos on how to manipulate stupid ass body energy and inspirational speeches from that black dude, neil whats his face.

>>4715543
1) The double slit experiment has nothing to do with "consciousness"

2) The "observation" part of the double slit experiment comes form the "interaction" due to the "observation". All forms of "observation" actually require some "interaction" with the system being "observed". This "interaction" is insidtingusiheable from all other forms of "interaction". Ie, a rock, or a toaster, or anything, provides the same "interaction" as a human. Hence, again, it has nothing to do with humans or childish notions of consicoussness.

3) Particle/wave duality is a outdated concept. It is only taught to highschoolers and freshman for its novelity. In reality we know that all fundmental things exist as a "quantum filed". A quantum field is the fundamenl building block of nature, not particles, and not waves.

4) The quantum field has tons of different properties. Sometimes, it produces what we see as a particle, sometime it produces what we see as a wave. These are just an "after-effect" though, different expressions of the quantum field.

Questions?

\thread

>>4716096
http://en.wikipedia.org/wiki/Quantum_field_theory

>>4716098
>>4716096

Why do you atheists believe in quantum field theory when it is only a theory (a guess)?

>>4716117
why do you guess about anything when it's only a belief, a theory?
your move smart guy

>>4716096
It's not enough that something interacts with the particle. It has to stay interacted. Measurements can be reversed, and if they are, you get interference back.

>>4716124
>It's not enough that something interacts with the particle.

I don't think you understand interaction. Interaction will be a "wave function collapse". Once it is collapsed, it is fucking collapsed.

>Measurements can be reversed, and if they are, you get interference back.

I don't think you know what you are talking about. While technically true, what you are saying has no relevance to this discussion.

As far as interaction goes, the system observed cannot distinguish from a photon produced from a rock, or that of a human observation system. At no time does the silly notion of "human" or "consciousness" enter into physics any fucking where.

A rock continuously sending photons to a system is indistinguishable from humans doing that shit for "observation".

Humans and consciousness have no special place in physics, and any level what so ever.

Questions?

>While technically true, what you are saying has no relevance to this discussion.

It's relevant because it refutes the claim that any interaction collapses the wavefunction.

>>4716194
Nope.

I don't think you understand what a wavefunction is or what wavefunction collapse is. Maybe I can help you.

Interaction by defintion collapses a wavefucntion. That is very very very very very very very basic physics. For any system, you can always find a wavefunction that is collpased upon introduction of an outside object. I mean it is the fucking definition of interaction! This is how we "define shit".

The wavefunction collapse (or greatly) changes the original system in a way, and forms what we can consider as a new system.

Through more interaction, the new system could in fact revert to the form of the old system. Again, this is a wavefucntion collapse.

I think that part that is confusing you is you assume there is only once wave function, and once it is collapsed is signifys some "unchangeable state". This is usually not the case.

The wavefunction is just a way we use to represent the system. We can always write wavefunctions. We can always collapse them (as all interactions can), and we can always write new wavefunctions for the new systems.

Questions?

>>4716194

>>4715789
anyone?

>>4716205
>Interaction by defintion collapses a wavefunction.
No. If I have two two-state system, and one interacts with the other, I can describe the interaction with unitary evolution.

Collapse and unitary evolution are very different things. The big difference is that collapse introduces randomness. Unitary evolution is deterministic.

Why isnt the interaction of the photons with the slits not collapsing the wave function?

>>4716213
>collapse introduces randomness

Randomness is not the same thing as propabalistic

>>4715789
In principle, there's no limit to the size of the objects you can do a double-slit experiment with. But in practice, if you tried it with marbles, the interference bands would be way too small to see, you don't have good control over the initial momentum of the marble to get an interference pattern, and even if you did have that control over the initial momentum, they're large enough that even the light shining on them disturbs their momentum enough to screw up the interference pattern.

>>4715789
In principle, there's no limit to the size of the objects you can do a double-slit experiment with. But in practice, if you tried it with marbles, the interference bands would be way too small to see, you don't have good control over the initial momentum of the marble to get an interference pattern, and even if you did have that control over the initial momentum, they're large enough that even the light shining on them disturbs their momentum enough to screw up the interference pattern.

>>4716216
Those words mean the same thing. Whatever weird meaning you've assigned to them is not one scientists use.

did someone just watch through the wormhole?

>>4716233
Nope.
Randomness is without any sort of sustained pattern, and any such patters are produced independently of any supporting physical mechanics present.
Probability implicitly states chances, the odds of patterns occurring or concurring in specific ways.
The reason why the two are so similar is because of the sheer number of factors to take into account when considering Probability are mathematically 'infinite', restricing us from placing any definitive numbers on the odds of anything.

That's why we study Chaos Theory, which is a mathematical trick to model patterns of probability in reality by creating a virtual space of pure randomness and then subjecting it to various formulae and watching the the result.

>>4716241
Look, your notion of something without pattern which can't be characterized by probabilities is pure philosophy. It's not something that's ever studied by science.

Chaos just means that very small changes in the initial conditions of a system get amplified. Because of chaos, you can get apparently non-deterministic behavior from a deterministic system. But the system isn't random in any objective sense; the appearance of randomness comes from our lack of knowledge of the initial state. But we can still characterize our lack of knowledge with a probability distribution, and calculate the probability of the system being in various states in the future.

>>4716255
So I got chaos theory backwards?

Here's a nice way of seeing whether two alternative paths (like the two holes the electron can go through) can interfere with each other:

Imagine a movie in which things go along one path. Then when you get to the end of the movie, rewind it back to the starting configuration, except on the way back, take the alternate path. If it's possible to do this, you have interference.

It's easy to imagine taking the opposite path as you rewind for the undisturbed double-slit experiment. But if there's a device that measures which hole the particle went through, then at the end of the movie you've got not just a spot on the screen, you have a detector that was triggered. As you rewind the movie, the particle has to use the same hole because there's a detector at the hole it has to untrigger.

Consciousness does not have anything to do with it.

>this thread
The word "observe" in this context means to take measurement
Of course physically interacting with it will affect it.
How you inferred observation = consciousness is beuond me.

>>4716261
It sounds like you might have. Chaos happens in deterministic systems. Here's a common introductory example of a chaotic system:

<span class="math">x_{n+1} = 4 x_n (1 - x_n)[/spoiler]

Start with some value of x, and plug it into the formula repeatedly. Then try a slightly different value of x, and do the same thing. You'll notice that even though you start very close, the sequences drift apart and eventually don't look related to each other at all.

Another interesting thing about this system is the transition from periodicity to chaos that happens when you adjust the coefficient.

>>4716285
>How you inferred observation = consciousness is beyond me.
Correction: it is BEHIND you, as you have already learned the denotative definitions for each word.
This other guy has not yet learned this information.

>>4716285
Depends on the context. In the Copenhagen interpretation, collapse has everything to do with an observer, but that's because collapse is just something he does to a density matrix when he learns new information. With this approach, you don't have to worry about the philosophical issues because the density matrices hide the issues behind a veil of ignorance. If the questions about where you get interference and where you instead get two possible outcomes don't change the density matrix, you can shut up and calculate without having to address them.

Now there are objective collapse models where collapse is a real process somewhat modeled after what Copenhagen people do mathematically when they update their information, but originally and most commonly "collapse" is the game Copenhagen people play with their density matrices.

Although I should point out that even though Copenhagen DOES talk about observers, it really has nothing to do with consciousness. It's about "How can Alice do useful calculations about that block if she doesn't know the motion of every atom?" not "Does Mary the color scientist know what red looks like?"

>>4716285
I keep trying to tell you fuckers that you are totally stupid to be using the word "observer" for this very reason.
All these idiots think that conscious perception by an organism is causing something simply because you use the word "observer" and not "measuring equipment".
Duh.

So what happens if you measure/observe the photons but delete the information gained by the measuring devices immediately after it? Does collapse or not?

>>4716395 delete the information gained.
You can't do that. Once you've bounced a photon off of an electron you can't just make the photon disappear. The trajectory of that photon is now determined partially by that electron it ran into; even if it spends a thousand years bouncing around mirrors and gravity wells.

So what if for every possible path every single photon takes a seperate world exists and while being unobserved they dont physically /causally interfer with the rest of the world so while being unobserved all photons lead to exactly the same result for the rest of the world(so the rest of the world exists in superposition not the cat in box) but when being observed only lead to one definite world(or maybe just less worlds)( collapse of the wavefunction).
So the wavefunction is actually the sum of all worlds where the photons take different ways when unobserved that all lead to the same results when interfering with the rest of the world.

>>4716508
>So the wavefunction is actually the sum of all worlds where the photons take different ways when unobserved that all lead to the same results when interfering with the rest of the world.
That's precisely what it is, bro.

http://www.lookas.net/ftp/_Asmeninis_/Universitetas/EDA/EDA-Mental-dmils.pdf

Explain this faggots !

thinking about someone changes their galvanic resistance of skin and other shit.

I win!

>>4716395
Depends on how you try to do it.

If you go back and reinteract with the system you measured and reverse the measurement process, then it will be as if the measurement was never performed.

If you have it on a hard drive and you just format the drive, that doesn't actually kill the information. The information counts as entropy, and the only way to wipe the drive is to transfer the information somewhere else. It might be unreadable wherever you move it to, but it won't be gone.

The third option is to delete the information by storing it in only a quantum-mechanical system and then measuring a complementary variable on your storage device. This can cause some interesting effects. Let's say in your experiment you measure the position of particle A as it goes through the slits and encode it in the position of particle B. Then you measure the momentum of particle B. You've still disturbed the momentum of particle A, and if you're only looking at particle A, you won't see an interference pattern because the fringes will be shifted by a random amount. But by looking at particle B, you can figure out how much momentum was transferred, and then you can reconstruct the interference pattern (with a number of runs of the experiment to build up the pattern, of course).

The third option is the idea behind the "quantum eraser" experiment:
http://en.wikipedia.org/wiki/Quantum_eraser_experiment
http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser

>>4715543
> Do we know HOW observation/consciousness actually affects whether an object is a particle or a wave?
It doesn't. Consciousness is not a feature of QM, which you might expect since there isn't a mathematical framework for consciousness. Instead, it is any interaction which would reveal quantum information. These happen all over the universe all the time.

Objective reality is a fairy tale. If you believe in things that aren't qualia, you believe in a hidden-variable theory.

I always giggle when my Optics professor says "Young's slits"

>>4716033
>when unobserved, you don't know anything about it, neither the wave-like properties nor particle-like properties.
[citation needed]