/sci/ - Science & Math

it's never really makes sense until you understand the math behind it

I can give you another example:
Most people are straight. But if you see one starting a thread on 4chan, he becomes OP and OP is a faggot. So the observation of an event (a post on 4chan) can change your sexual orientation

It's the whole concept of quantum physics, it doesn't make any sense to classical logic.

Essentially by observing it, the outcome changes.

>>3011555

I don't even.

Wat?

How can it not make sense? It HAS to be one or the other, doesn't it?

Its simply an effort to save resources. Complex physics events that potentially have more than one outcome that aren't being directly observed are not ran until they are observed.

and its not the argument of alve and dead. Its exists or doesnt

>>3011563

It would if the world was as simple as the classical world once thought.

But the universe is far complex to what we first comprehended, we now accept today that it is even possible that maybe we cannot comprehend the universe.

Have you not seen/heard of the double split experiment? By observing the photons, the outcome changes.

>>3011563

No. It is in a superposition wherein "both are true", it is simultaneously in two states.

The wavefunction collapses into one or the other when it is observed or when the circumstances for the superposition end (when the chance of the particle's decay exceeds 50%).

>>3011563
>It HAS to be one or the other, doesn't it?

Nope.

>>3011576

I have not. I will look into it.

>>3011563

It is both outcomes, until you check.
The double slit experiment, the single photon goes through both slits (which means it's in two places at once). But once we try to observe how it does this, it behaves normally, and goes through one slit at a time.

There is no denying it is confusing, but it's our bias not poor logic which limits us from comprehending.

>>3011579

Oh. This makes more sense.

So before the vial breaks, it is still seen as both because it has not happened yet. But if it WERE to happen (or not) it would cease to be both?

Or if you were to confirm one way or the other.

>The double slit experiment, the single photon goes through both slits (which means it's in two places at once). But once we try to observe how it does this, it behaves normally, and goes through one slit at a time.

You sly, tricky, mother fucking photon.

Reading that made me excited.

>>3011563
I hate people like you, for some reason you refuse to come to terms with something as simple as this just because it defies your personal observations

>>3011539
>How can it be alive and dead?

IT IS NOT FUCKING DEAD AND ALIVE DUMBSHIT!

THE THOUGHT EXPERIMENT IS TO SHOW THAT IT IS LAUGHABLE TO THINK IT IS DEAD AND ALIVE! NOT TO SHOW THAT IT IS DEAD AND ALIVE! JESUS FUCKIN CHRIST!

GTFO FAGGOT!

>>3011598
Cut the guy some slack, quantum physics is insanely different to classical and if you've only come across classical it can be a hard concept to digest.

>>3011539

>Am I missing something?

Yes, the point

>>3011602

This is a popular myth, but not what Schroedinger was actually going for.

The problem shows just the same as in this example:
If you take a cannon that can fire just one photon at a time, and keep it in front of a piece of paper with two holes in it, you measure the single photon going through both holes. If you check through which hole the photon will go, it will only go through one hole. This would indicate our observation has influence on what happens, get it?
too long, didn't read: When not knowing what will happen or what happened, both things did actually happen.

>>3011539
>Implying the schrodinger experiment says the cat is dead and alive

>Implying you didn't get everything ass fucking backwards

>>3011539

Chill brah, the idea of something not true or false is pretty old, Aristotles himself came up with it.

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

>>3011539
>>3011539
>>3011539
>Am I looking at it too literally

Yes.

Its to point out what Schrodinger thought was the absurdity of the implications of Quantum Physics.

Basically, from a Physics standpoint we can't tell which state something is in then we assume its in both states simultaneously in Quantum Mechanics. But the werid thing about Quantum Mechanics is that sometimes the particle itself seems it doesnt' know what state its in either, it doesn't choose one until we take a look at it (ie measure a property). If you don't measure a particles spin it seems it doesn't know either, until you try and measure its spin suddenly it chooses one.

Schrodinger basically conceived that thought experiment to point out how ludicrous that is, if it were a cat in a box, rigged with a 50% chance of the cat dieing for example, Quantum mechanically the cat itself wouldn't know if it was alive or dead until we peered inside the box which is clearly nonsense.

I think it only seems confusing because you can't really directly compare the Quantum Mechanical world to ours, it seems ludicrous to us but in the Quantum Mechanical world its fine. Also a particle isn't conscious like a cat (although it acts it sometimes!)

Thats my limited interpretation, I just thought of another I'll give in a sec maybe I'm wrong I don't know

>>3011610
>>3011610
Please stop reading shitty pop-science. Cut that shit out, it is only confusing you.

read about he double slit experiment
http://www.youtube.com/watch?v=DfPeprQ7oGc

>>3011635
>>3011610
exactly my point!

>>3011610
>>3011539

>>3011627
>>3011627
>>3011627

Second quicker interpretation. If the killing of the cat is decided on the decay of a particle, if its in a superposition of states where its both decayed and not decayed is the cat alive or dead?

>>3011627

[Spoiler]. The cat itself is an observer so it knows when it is alive or dead. [/spoiler]

>>3011539

>>3011539
Wow Op. Just Wow.

Confused?! The Physicists from the University of Nottingham are here to help!

(And one has pretty cool hair)

http://www.youtube.com/watch?v=CrxqTtiWxs4

>>3011653
What counts as an observer?
If we video tape it, will the camera itself be an observer, or will we actually have to view the tape in order to make the object choose what state it is in?

>>3011539
GTFO of /sci/ underage faggot

>>3011669
Isn't that guy a chemist? Was watching The Periodic Table of Videos the other day.

>>3011670
>What counts as an observer?

Anything that interacts to collapse the wave function. The observer could be a fucking rock.

>>3011653

But if you say the cats an observer wouldn't that imply that the photon in the double slit experiment is an observer?

I thought it was just scaling up a quantum effect to the macroscopic level so we can see how absurd it is, surely the whole point of the thought experiment was that quantum mechanics say it wouldn't know if it was alive or dead whereas clearly we know it would?

>>3011669

>mfw I'm going to Nottingham next year

>>3011675
Chemistry is just applied physics

>>3011680
Chemistry is just playing with goo

>>3011671
no offence bro, but there's no under-age on /sci/. however there is a certain expectation of maturity, an expectation which you have failed to meet. perhaps you should gtfo. :)

>>3011635

Wat. How the fuck can just observing it change what it does?!

To everyone else: Haters gonna hate. I didn't take an interest in school, so I am doing it now.

>>3011686

>>3011680
which is just philosophical math.

>>3011678
>>3011678
>Mfw so am I and thats how I found these videos
>Mfw I look at my coursemates and I'll know one of you goes on /sci/

>>3011675
>>3011675
Yeah the CHemistry videos were popular so the Physics department started making some too, that was one of their earliest ones so he appeared in it too as a sorta cross over thing and because it was one of the earliest ones.

>>3011699
haha yeah man, he's pissed, so pissed in fact that he was polite. Oh man he mad. he so mad he's stated his point thoroughly and asked you to leave without being rude once.

>>3011670
>>3011653
The detector that's recording the decay and triggering whatever is there to kill the cat is the observer.
The wavefunction collapses before any person pondering the situation would matter.

>>3011681
Which is just the thing. It doesn't work when scaled up to the macroscopic level. It isn't supposed to.

>>3011699
hesad.jpg

>>3011683
So basically, a particle needs to be in a vacuum or in some other environment where it's impossible for the environment itself to get any info on the particle?

Meh, I wish I had been able to pick more physics classes in my major

>>3011681

The photon isn't an observer because it is a particle. Particles have no eyes nor are they conscious.
The cat is conscious at all times during the experiment and as soon as it dies it ceases to be conscious. Therefore, this whole thought experiment is completely retarded.

>>3011701

Believe me, I won't be on your course. Not a science student, just deeply personally interested in it.

but schrodingers cat is inherently flawed. the cat is an observer of itself, therefore, if deadly neurotoxin turns up, the cat can observe itself dying.
anyway, its an airtight fuckint box, its not a matter of whether the cats dead or not, its a matter of how long it will take for it to die.

>>3011720
>>3011720
OMFG GTFO GTFO GTFO GTFO GTFO GTFO GTFO GTFO AND GO FUCKING KILL YOURSELF NOW!

A PHOTON CAN BE A "OBSERVER". AN OBSERVER IS ANYTHING THAT CAN COLLAPSE A WAVE FUCNTION.

IT COULD BE A PHOTON, A ROCK, OR YOUR FAT MOM.

\thread

>>3011720
I don't think you know what "an observer" is.

>>3011720

>>3011720
HA HA HA HA HA HA

>>3011720
No

>>3011725

You should be, I already made that mistake.

The reason I'm doing Physics there is I chose Engineering at first (which turned out to be a bit of a mistake when What I'm interested in is this) so I'm transferring subject and university starting next year.

>>3011738
>>3011737
>>3011733

Not that guy you guys are raging at but could you explain what an observer is?

Something that can collapse a wave function? What exactly does that mean, say, in layman's terms?

>>3011720
successfultroll.jpg

>>3011720
Nope
http://en.wikipedia.org/wiki/Wigner%27s_friend

>>3011720

fucking faggot, please an hero and sticky cam it for /b/

>>3011765

You mad

>>3011750
>laymens terms

It has no real good analogy in laymens terms. Not everything can be dumbed down for you son. You cant really explain calculus to someone who doesn't know what addition means.

Just think of it as anything that "interacts with", if that helps you. Anything that "interacts with" a system is an "observer" of the system.

How of are you 12? 14?

>>3011789

So there is no way of observing without interfering?

What makes that so impossible?

>>3011612
^Nicely explained anon.

It helps to think about how we observe things.
Any things.

All observation is colliding particles with the object intended to be observed.

Our vision relies solely on photons bouncing off things, and the results when they hit a detector (like our eyes).
To resolve details on smaller things, you need to hit them with smaller particles (trying to observe something smaller then a proton by using proton collisions would give you what amounts to a resolution of one pixel).
Hence, electron microscopes.

And that interaction, or any interaction which could give us information on the position of a wavefunction, is what collapses that wavefunction.

It's not supposed to make intuitive sense. It's a thought experiment designed to show how counter-intuitive quantum mechanics can be.

>>3011834
We can observe stuff using EM waves too, though. It's not just particles colliding with other particles, often it's EM waves being affected by (and effecting) a particle, then those EM waves interact with another particle that we use to observe.

>>3011824
What you ask is kinda nonsensical.

How would the information be transferred from the "system under observation" to "us", without something interacting with the system?

>>3011842
>>3011842
EM waves are photons dumbshit.

>>3011842
Wave-particle duality bro.

All matter and energy propogates like a wave, but transfers momentum like a particle.

>>3011539
It's easiest to ask: When exactly is a single unstable atom going to decay when it's decay is based on a half-life ?

>>3011539


You are all missing the point. The cat in this picture is eating a hamburger!

>>3011847
This pic is fucking mesmerizing.