/sci/ - Science & Math

means that the net energy = 0

Not 2D flat, but more like flat in every direction as three dimensions allow.

>>1795680
So what you are saying is... if flat the universe is infinitely large.

>>1795691
The area the universe is in is infinitely large, yes.

Imagine a flat 2d plane that is in a 3d space. Now imagine the 3d equivalent of that flat 2d plane is in a 4d space.

>>1795702
>area the universe is in
>implying the universe is in something
What the fuck are you smoking?

1. Get popcorn
2. Watch this: http://www.youtube.com/watch?v=7ImvlS8PLIo

It goes for about an hour. Answers that question and explains how the universe doesn't need a creator.

>>1795713
You obviously have no idea what a universe is then, nor can discern the difference between a material verse and endless emptiness around one.

>>1795727
Take your chakras and healing stones and gtfo.

>>1795727

>>1795713
Oh boy, you have a lot of reading to do kid:
>http://www.astronomy.pomona.edu/projects/moderncosmo/sean's%20mutliverse.html
>http://en.wikipedia.org/wiki/M-theory
>http://critical-path.itgo.com/Articlesanscover.html
>http://en.wikipedia.org/wiki/Many-worlds_interpretation
>http://en.wikipedia.org/wiki/Quantum_mechanics
>http://www.grandunifiedtheory.org.il/Third%20Book/quantum_universe.htm
>http://en.wikipedia.org/wiki/Quantum_field_theory

>>1795754
The universe is everything.

You also think the expansion of the universe consists of galaxies moving through space don't you?

>>1795759
No. Universe expanding is uniform. I bet you're just smarter than every person on the planet aren't you?

>>1795759
I lol'd

>>1795762
You said there is space outside of the universe. That means you think the universe is expanding into it, but it isn't.

Well, in differential geometry, flat space means a manifold with everywhere-vanishing Riemann curvature tensor. Not sure how to translate that into layspeak.

>>1795765
Do YOU even know what that means? What mathematics is that?

>>1795713
one of the basic principles of quantum physics is that there are multiple universes outside our own that move and collide with each other all the time, another theory going farther to say that when one or more collide with each other not only do they obliterate each other completely but also give birth to a new one in their place (as particle collision tests in CERN have been backing up), string theory goes even farther and says that each universe is not really certain places but rather vibrating frequencies depending on what they exhibit and what dimensions they allow.

you can also throw in the cycle model and oscillating universe theory in the middle one.

>>1795770
youre confusing people with each other again, young'n. they're saying that there's space/vast emptiness around our universe (as in every particle/mass/energy that currently exists in it), and that our universe is simply expanding into it. simply put: there's an endless emptiness or blackness in which no light, energy, mass, particle, photons, or materials have reached yet; there's not an unlimited number of anything in existence other than that consistent emptiness we expand into.

>>1795744
>>1795733
>>1795713
>>1795770
>>1795759
>still in high school

>>1795795
>young'n
>ad hominem
Ironic.

>>1795795
>one of the basic principles of quantum physics is that there are multiple universes outside our own
You have never taken quantum mechanics.

>>1795709
So flatness is basically anything that cannot or doesn't go beyond a certain dimension? Like 2D is flat because it doesn't move into the third dimension, and we're flat because we can't move into the fourth dimension?

>>1795811
You obviously haven't yourself. Also
>Ironic
>could only point out an alleged ad hominem as a counter argument

>>1795820
I know you haven't taken quantum mechanics.

OP asks a simple, unbiased question, and gets this thread in return
>mfw

>>1795765

That's what I thought it meant, that the curvature tensor vanishes. Is this wrong, /sci/?

>>1795811
If you've taken QM yourself, you'd know that quantum physics deals with the possibility of parallel universes. Examples being that at point QM states that once a particle is in motion, it breaks off into separate parallel universes with the particles' causatum varies differently in each one (you can see why quantum physics is an iffy subject to some).
>http://www.daviddarling.info/encyclopedia/M/multiverse.html

Those parallel universes just deal with endless universes that are just different results from another, while multiverses are just simply that: multiple universes on their own.

And at least read up on your subject and cite your claims before you make claims to other posters with such like:
>>1795826
Because we know you haven't either, nor have you been able to titillate a proper argument otherwise. And claim an ad hominem to mask your lack of scientific knowledge and experience if you life, it's still a cop-out and childish bickering to get out of explaining oneself.

>>1795838
>If you've taken QM yourself, you'd know that quantum physics deals with the possibility of parallel universes.
I have taking QM 1 and I'm going to be taking QM 2 next semester. The entire course is Schroedinger's equation. You said it was basic quantum mechanics, impying it is taught early on in QM, but it isn't.

Stop learning physics from philosophy professors.

>>1795838
>Examples being that at point QM states that once a particle is in motion, it breaks off into separate parallel universes with the particles' causatum varies differently in each one (you can see why quantum physics is an iffy subject to some).

Many-worlds crap
>implying Copenhagen is not right

>>1795852
Stop arguing, its boring.

>>1795855
Whats the Copenhagen explanation for what seems to be random probability in the quantum world?

>>1795852
It is basic QM because it's one of the major corner stones and juncture in which QM's take on the physics of reality as a whole. You're either taking slow courses trying get go into detail of every little bit of the field, or your classes are shit.

http://en.wikipedia.org/wiki/Many-worlds_interpretation
http://en.wikipedia.org/wiki/Interpretation_of_quantum_mechanics
http://www.pbs.org/wgbh/nova/manyworlds/pdf/dissertation.pdf
http://www.univer.omsk.su/omsk/Sci/Everett/paper1957.html
http://philsci-archive.pitt.edu/archive/00002717/01/OutcomeProbEverett.pdf

>>1795862
Wavefunction collapse.

>>1795834
What I said was right. Flat space is when Rabc^d = 0. This is actually more general than Euclidean space; a lot of people make this mistake.

>>1795786
Like I said, differential geometry. I know what it means in terms of the relevant tensor calculus (UGGH INDICES UP THE WAZOO) but I can't remember the goemetric import atm cause im tired

>>1795820
>So flatness is basically anything that cannot or doesn't go beyond a certain dimension? Like 2D is flat because it doesn't move into the third dimension, and we're flat because we can't move into the fourth dimension?
I know enough to say "No, not really." It has to do with parallel transport, torsion, that kind of shit on an infinitessimal level

>>1795838
Clealry you havent taken QM. (third party here btw). the mechanics arent the same as the modern ontological and metaphysical interpretations of them - don't force one schema down others throats and say its authoritative physics

>>1795858
What? You don't know the first thing about quantum mechanics and yet you are preaching about the multiverse, saying its basic QM. I called you out so other people wouldn't pick up your ignorant opinions... and you say this is boring?

I don't care that you think this is boring. I care that there is somebody that's WRONG on the internet.

>>1795869
> don't force one schema down others throats and say its authoritative physics
Like you're doing to us right now with that statement?

>>1795874
You're confusing like five other people in this thread with each other, obviously suggesting you're a single-minded person with little experience in physics.

(Third party here by the way).

>>1795874
>I called you out so other people wouldn't pick up your ignorant opinions
irony

>>1795869
1) What is your education?

2) What does the whole universe being a saddle thing mean? I understand what closed but unbounded means, but I can't wrap my head around this saddle stuff.

>>1795881
>implying you are a third party

>>1795891
IT is hard to visualize but just think of it as the mathematical equivalent of the opposite of a balloon

>>1795888
It would be ironic if I was expressing an ignorant opinion, but I'm not. I haven't argued anything beyond that the other poster didn't know what he was talking about.

>>1795900
So, if a closed but unbounded universe is a 4D ball, then a 4D saddle is curved but still goes off an infinite distance in every direction?

>>1795896
This is almost like Dunning–Kruger effect, except with the inability to draw multiple conclusions and suspects, and have to rely on single affirmations and dubitabilities.

>>1795903
>the other poster didn't know what he was talking about.
That is your arrogant opinion.

>>1795868
More specifically,
Many worlds: every possible particle position is a universe somewhere, and we happen to be in the universe where the particles are located such as we detect them to be

Copenhagen: A particle exists in all possible locations until it is observed, when its position is narrowed down to one possible position. Right?

My question is still what Copenhagen says about why wavefunction collapses to position one rather than position two. Is it random? I know its based on probability, but why collapse to one likely position rather than the other likely position?

Oldschool believer here, I still think things are moving around too quickly or differently enough for us to detect, so it looks random.

Wait I read in a steven hawkings book that since the fabric of space time folds as a result of matter that there is not infinite space extending from the big bang but an arrow that finds its way back to itself. Does that make sense to anyone else.

>>1795924
Yeah we're aware of that old notion that the universe was curve until we figured out it's flat instead.

>>1795910
Speaking crudely, yes, that is the basic picture.

In a room of an unknown amount of people, all anonymous, its silly to try to attribute specific posts to specific people.

User:Sup
CB: Not much, you?
User: I'm recovering from an all-nighter.
CB: Oh, that's terrible. What is the illness?

Cleverbot sucks.

>>1795921
If by "arrogant opinion" you mean "fact" then yes. He admitted he had never taken a course in QM.

>>1795896
you argue with multiple anons and yet keep pointing to a specific member of those anons like he's the only one out to get you. this is one of the reasons why paranoia is considered "irrational"

>>1795922
>but why collapse to one likely position rather than the other likely position?

Because eigenvalues and eigenvectors.

>>1795941
If you have to attack his credentials, it means you can't attack his ideas, which means either he's right, or you don't know your own position very well

>>1795947
What are eigenvalues and eigenvectors and what do they do?

>>1795941
>confuses facts with opinions; cannot decipher between the two
Cool delusion bro.
>he had never taken a course in QM.
Like ты?

I've been considering switching my major to physics because I've always had an interest in this type of thing. What courses do I need to take to fully understand what is going on in this thread, aside from quantum mechanics?

>>1795852
You've only taken one course on Quantum Mechanics so far?

>>1795952
>he thinks he can become a physicist without getting a formal education

>>1795959
Now that's just making up allegations on the spot.

>>1795951
See, this is the problem.

You can't even begin to comprehend QM until you know enough math to understand the formalism behind it. Until then you are just going to believe whatever simplified crap people tell you.

Anyway, the state of a system can be expressed as a linear combination of eigenvectors of an observable quantity, the terms in the combinations are related to the probability of observing the eigenvalue associated to the eigenvector they are multiplied by. Of course this will mean nothing to you.

alrighty i dunno who the fuck is who in this thread
I am >>1795869

>>1795929
We're talking about net curvature of the universe. Or at least cosmologists are.

>>1795891
I did some vec calc / diff equ / lin alg in hs, but otherwise I'm self educated. Here's the difference between a balloon and a saddle: on a balloon, you curve inwards no matter which way you go. On a saddle, you could curve one way, the other way, or if you go in between you can be uncurved. This is an extremely crude portrait, but it basically is a way of saying that how the universe curves in on itself is different throughout space (still obeying laws and shit).

>>1795922
According to the mechanics, its probabilistic. Unfortunately your idea of "things just moving too fast and looks random" is mathematically impossible thanks to the bell theorem. Even if there is a nonprobabilistic underneath to it all, it must be a nonlocal theory (ie where matter/energy/ and or information travel greater than light speed, possibly even instantaneaously)

>>1795967
Thats not what I asked. You're just describing how to calculate the probability field, as jargonly as you can, but I asked why a particle will exist at one location versus another when its waveform collapses.

You must have a lot of friends IRL if when they ask you a question, you intentionally give them the most obfuscated wording you can, then mock them for not understanding you.

>>1795960
You said the poster wasn't ignorant despite having no formal education. I didn't make up anything. No education is pretty darn close to the definition of ignorant.

inb4 people can teach themselves
Like I said...
>implying one can become a physicist without getting a formal education

>>1795986
>why a particle will exist at one location versus another when its waveform collapses

Because the math says so, you moron.

>>1795983
>self educated

>>1795986
You can't understand what kinds of "shapes" electromagnetic fields can take until you know how a gradient works.

You can't know how QM works until you know when eigenvalues are.

Just learn the math.

>>1795990
There's a difference between being educated and being intelligent, we're having trouble believing you're either.

Also it is an opinion itself to assert lack of conventional education correlates into ignorance.

>>1795986
You can't understand what kinds of "shapes" electromagnetic fields can take until you know how a gradient works.

You can't know how QM works until you know what eigenvalues are.

Just learn the math.

why did the galaxy cross the mobius strip?


to get to the same side

>>1795983
Regarding probabilistic universe
What if I also believe that particles spawn with their properties decided, and measuring them only reveals their spin etc. No FTL violation for entanglement. .

>>1796007
ignorant != unintelligent

I didn't use the word "intelligent" or "unintelligent" once up until this point.

>>1795991
So theres no theory of how it works, just that it DOES work?

>>1796010

>>1796010
Why did the herp cross the derp?

To hurr to the durr.

>>1796013
Hidden variable theories. Bell's inequality proved them wrong.

>>1796016
No, you're still using the same argument for intelligence and ignorance otherwise.

>>1796007
>we're having trouble believing you're either.
>implying one poster is aware of another poster's thoughts
>THE MOST OBVIOUS SAMEFAG EVER!

>>1796021
There is no theory to WHY it works. Science doesn't answer why, science doesn't care about why. Science only cares about how crap works.

>>1796026
I'll say it again. I didn't use the words "intelligent" or
"unintelligent" once. Stop putting words in my mouth. I was talking about ignorance, not intelligence.

>>1796034
You don't have to mention either, you still were and still are making the same argument for intelligence and ignorance.

>>1796030
I was about to post that same thing.

>>1796026
Third party here. Do you know the difference between intelligence and ignorance?

>>1795983, >>1795869, >>1795765 here

>>1795990
People can teach themselves. The vast majority can't do it up to the levels you get with formal education, and most people are just kidding themselves, but there are people who do it and succeed. I've succeeded to a minuscule extent to satiate my appetite for math, but I'm still pretty young so I've no worries.

>>1796013
What you believe isn't really of significance. That you can construct certain scenarios in which FTL isn't achieved doesn't mean that quantum mechanics disallows it in general.

Einstein: God does not play dice with the universe.
Borh (I think): Einstein, stop telling God what to do.

>>1796037
>you still were and still are making the same argument for intelligence and ignorance.
Prove it. Where did I say anyone was unintelligent?

>>1796030
Oh boy! Semantics! Thats much more fun than talking about science.

>>1796042
No one ever said you used the word [un]intelligent, at all, you're just simply suspecting you did. We're just saying that you're using the same argument to bring out attention to the other person's ignorance as well as to bring attention to his intelligence.

>>1796050
So you are calling the distinction between how and why semantics? You are more moronic than I gave you credit for.

>>1796025
From wikipedia:
In quantum mechanics, a local hidden variable theory is one in which distant events are assumed to have no instantaneous (or at least faster-than-light) effect on local ones.

How does local variable theory apply to me thinking that a particles properties are decided before they're observed?

>>1796056
Me: Why does the moon orbit the earth?
You: Because 9.8 meters per second

What I'm asking is for things like mass bending spacetime and things falling towards lower gravitational potential. Everyone here seems to want to show off what words they've heard, but don't know how to explain what they know in normal terms (inb4 us intellectual peasants have to learn the terms before we can understand)

This thread is a rare example where namefagging could come in handy.

>>1796057
>How does local variable theory apply to me thinking that a particles properties are decided before they're observed?

The FTL transmission of information depends on there actually being information, which depends on indeterminacy up until collapse. If the position/momentum/etc were determined prior to collapse, then according to our mechanics the physical system would evolve differently from there forward than if it had been undetermined. Our mechanics hold up to experiment.

>>1796071
>You: Because 9.8 meters per second

No, because Newton's law of gravitation.

Why does matter attract other matter? Nobody knows, nobody cares.

>>1796071
>meters per second
>per second
>my face

>>1796077
In what way would a particle behave differently if its various properties were cemented in reality before it was observed? Wouldnt whatever rule you're talking about also prove the many worlds theory wrong, because they believe that the particles already exist in a specific state even before they're measured?

>>1796084
Oops, right. Meters per second per second. Whatever, you knew what I meant.

OP here. I'm deleting this awful awful thread.

>>1796111
Please do, there is no point in all this crap.