Conquer Club

I must be way behind the times because I only came across this today, but apparently since 1980-odd there's been a "famous" theorem by a Belfast fellow named Bell (known as... thats' right... the Bell theorem) which was designed to decide who had the correct view on quantum mechanics; Einstein or Bohr.

The theorem was only based on 2 assumptions;
1) That sub-atomic particles exist regardless of observation/measurement
2) That locality is preserved (here locality means that no information or anything is mysteriously transmitted at greater than the speed of light)

With this in mind the theorem then had an inequality as it's final test (of reality/quantum-stuff) where the experimental result, X, had to lie within the limits -2>X>2.

Most results ever since in various workings of the experiment (involving measurements of quantum-entanglement of particle pairs such as photons) VIOLATE this inequality...

Meaning 1 of the 2 assumptions is false. This wrecks my head! Am I to understand it has been a well-known principle that either the sub-atomic realm only pops into existence when we observe/measure bits of it OR lightspeed is not in fact the absolute speed limit I always thought?!

It seems Bohr reckoned the former, which is mind-blowingly unpalatable to say the least, not to mention seemingly ridiculous!
Yet it's either that or relativity is flawed...

Help?

Lord+Master wrote:With this in mind the theorem then had an inequality as it's final test (of reality/quantum-stuff) where the experimental result, X, had to lie within the limits [/b]-2<X<2[/b].

fixed. you had the x being less than -2 and greater than +2, a contradiction or an infinite possibility.
But no, I don't know anything about this really. But I agree, his conclusion was weird. i would have assumed light speed was not the limit (Star Trek was speeds way faster than light).

Well, no.
For many decades, sf writers have assumed that FTL travel involves some new principle - "space warps", "wormholes", "white holes", "jump points", "stargates", or some such. Some are better thought out than others, but all assume that light speed is a limit for "normal" travel.

jonesthecurl wrote:Well, no.
For many decades, sf writers have assumed that FTL travel involves some new principle - "space warps", "wormholes", "white holes", "jump points", "stargates", or some such. Some are better thought out than others, but all assume that light speed is a limit for "normal" travel.

Those things all rely on the same principle of travelling through a tear or tunnel through space-time (y'know, the folding a piece of paper so opposite corners touch and claiming to pop across rather than laboriously crawl all the way across the paper); none of them actually invoke ftl travel per se...
Anyway, this is a science fact, not the cunning machinations of a drugged-up author!

shieldgenerator7 wrote:

Lord+Master wrote:With this in mind the theorem then had an inequality as it's final test (of reality/quantum-stuff) where the experimental result, X, had to lie within the limits [/b]-2<X<2[/b].

fixed. you had the x being less than -2 and greater than +2, a contradiction or an infinite possibility.
But no, I don't know anything about this really. But I agree, his conclusion was weird. i would have assumed light speed was not the limit (Star Trek was speeds way faster than light).

Oh right, cheers for the correction! Are you a teacher by any chance?!
Why would you assume lightspeed to not be a limit? Surely that was pretty much the cornerstone of relativity...

Lord+Master wrote:

shieldgenerator7 wrote:

Lord+Master wrote:With this in mind the theorem then had an inequality as it's final test (of reality/quantum-stuff) where the experimental result, X, had to lie within the limits [/b]-2<X<2[/b].

fixed. you had the x being less than -2 and greater than +2, a contradiction or an infinite possibility.
But no, I don't know anything about this really. But I agree, his conclusion was weird. i would have assumed light speed was not the limit (Star Trek was speeds way faster than light).

Oh right, cheers for the correction! Are you a teacher by any chance?!
Why would you assume lightspeed to not be a limit? Surely that was pretty much the cornerstone of relativity...

I am not a teacher, just a humble computer programmer.
And that is one reason why I know nothing about this subject other than inequalities.

I heard a crazy theory a while back that suggested that Light speed isn't the limit but a significant point, in which other speeds must slow down to reach. Or was it that other speed on the other side of Light speed also had to speed up to reach light speed... wait that wouldn't make sense... well I did hear a crazy theory.

I can't really say much about Bell's theorem because I haven't learned about it yet (just took Quantum I this semester), but honestly from the way you're making it sound, this is just more reason for me to believe that science is fallible.

I wouldn't be surprised if either of those premises ended up being false. It wouldn't be the first time.

Oh, and some things do move faster than the speed of light.

If I had a one million kilometers long pencil I could write something down with it, and I'd only see it a little more than 3 seconds after I wrote it.

Question: How much would the police fine you if you violated the lightspeed limit?

Whenever I read about some stuff like that I just get the impression that the physicists are making this shit up for a laugh.

Hey, AoG, you should know more about this stuff than me. How much of the "current" research in physics is based on actual solid empirical results and how much is based on: "we've got this here measurement/inconsistency/redundancy, we have no idea what it is, hey let's write a complex mathematical model that tries to explain it away". To my relatively uninformed self it seems that string theory is definitely part of the latter category.

If there's any physicists lurking about feel free to blast what I said to pieces, i could use some reassurance that modern physics isn't actually turning into philosophy *shudder*.

Oh, and some things do move faster than the speed of light.

A tachyon (play /ˈtæki.ɒn/; Greek: ταχύς, takhus, "swift" + English: -on "elementary particle") is a hypothetical subatomic particle that moves faster than light.

Also of course Science is fallible, especially in the realm of theoretical physics. The whole point of science is that theories can be changed based on new evidence.

Tachyons do not move faster than light, they go backwards in time.

Haggis_McMutton wrote:Whenever I read about some stuff like that I just get the impression that the physicists are making this shit up for a laugh.

Hey, AoG, you should know more about this stuff than me. How much of the "current" research in physics is based on actual solid empirical results and how much is based on: "we've got this here measurement/inconsistency/redundancy, we have no idea what it is, hey let's write a complex mathematical model that tries to explain it away". To my relatively uninformed self it seems that string theory is definitely part of the latter category.

If there's any physicists lurking about feel free to blast what I said to pieces, i could use some reassurance that modern physics isn't actually turning into philosophy *shudder*.

I'd guess it's a little bit of both. I mean, I'm only a second year physics student. Other than basic kinetics and E&M (electricity and magnetism for those who aren't in the know), I've only done some Modern Physics and Quantum I, so it's not like I'm a genius in the field. I'm just pretty good at the related mathematics. I remember Einstein did his general relativity theoretically first and then was able to prove it during the solar eclipse during the first World War (I think, someone correct me if I'm wrong).

But all of it is confusing as f*ck anyway. I guess modern physics is too young for us to wrap our heads around it, probably in the same way things like gravity and electromagnetism didn't make sense a few hundred years ago (or maybe they did make sense, Idk, I'm just guessing).

And jones, I think going faster than light and going backwards in time are one in the same. Granted, the only reason I know about tachyons are from the Universe series on the History Channel (favorite series ever) where they talked about how it may possibly be used to propel spacecraft so they can go faster and farther.

MeDeFe wrote:If I had a one million kilometers long pencil I could write something down with it, and I'd only see it a little more than 3 seconds after I wrote it.

Question: How much would the police fine you if you violated the lightspeed limit?

The boys in blue shift would never catch you.

Army of GOD wrote: But all of it is confusing as f*ck anyway. I guess modern physics is too young for us to wrap our heads around it, probably in the same way things like gravity and electromagnetism didn't make sense a few hundred years ago (or maybe they did make sense, Idk, I'm just guessing).

they still don't make sense ... fuckin magnets.


Anyway, soon enough we'll run simulations of possible universes on computers and all this faffing about will end.
You might lose your job though.
Sorry


Anyway, at least you physicists aren't as bad as those damn biologists.
Come on, how long does it take to figure out how that pound of flesh inside our heads functions? fuckin' slackers

Haggis_McMutton wrote:

Army of GOD wrote: But all of it is confusing as f*ck anyway. I guess modern physics is too young for us to wrap our heads around it, probably in the same way things like gravity and electromagnetism didn't make sense a few hundred years ago (or maybe they did make sense, Idk, I'm just guessing).

they still don't make sense ... fuckin magnets.


Anyway, soon enough we'll run simulations of possible universes on computers and all this faffing about will end.
You might lose your job though.
Sorry


Anyway, at least you physicists aren't as bad as those damn biologists.
Come on, how long does it take to figure out how that pound of flesh inside our heads functions? fuckin' slackers

My dad's trying to convince me to become an astronaut. I'm pretty sure I'm too short for that. =(

Wait, just checked, I think I'm tall enough by 3 inches. f*ck YEA MR. KOOL AID!

Army of GOD wrote:I can't really say much about Bell's theorem because I haven't learned about it yet (just took Quantum I this semester), but honestly from the way you're making it sound, this is just more reason for me to believe that science is fallible.

science is supposed to be fallible though, lol

john9blue wrote:

Army of GOD wrote:I can't really say much about Bell's theorem because I haven't learned about it yet (just took Quantum I this semester), but honestly from the way you're making it sound, this is just more reason for me to believe that science is fallible.

science is supposed to be fallible though, lol

Not according to atheists.



inb4

Haggis_McMutton wrote:

Army of GOD wrote: But all of it is confusing as f*ck anyway. I guess modern physics is too young for us to wrap our heads around it, probably in the same way things like gravity and electromagnetism didn't make sense a few hundred years ago (or maybe they did make sense, Idk, I'm just guessing).

they still don't make sense ... fuckin magnets.


Anyway, soon enough we'll run simulations of possible universes on computers and all this faffing about will end.
You might lose your job though.
Sorry


Anyway, at least you physicists aren't as bad as those damn biologists.
Come on, how long does it take to figure out how that pound of flesh inside our heads functions? fuckin' slackers

Hey! The brain is a difficult thing to experiment with. Obviously ethics prevent us from just poking around in there with probes and cameras. And the ability of neurons to form bridges is still extremely difficult to answer. It governs memory and learned abilities and skills.

Say I bumped into you on the street today. The brain would form a neural bridge that says "this person is Haggis, he looks like this". Over time, if I didn't meet you again, the bridge will degenerate from disuse. 10 years later when I meet you again, the brain is able to instantly rebuild the bridge that says "hey, it's Haggis" without me having to relearn who you are.

That's also partly why humans are better at recognition and logical reasoning than AI's.

yes, good point safariguy.
Whoa! I never thought I'd find myself agreeing with you, but what you just said makes sense.
And also, whoever said that physicists would lose their jobs because of computer models is just plain ignorant. Computer programs just don't come up by themselves, you know, us programmers have to program them, and how do we know how to program them? From the info from the physicists. So it starts with the physicists, and the programs will be used as a tool for the physicists to use rather than a replacement for the physicists.

shieldgenerator7 wrote:yes, good point safariguy.
Whoa! I never thought I'd find myself agreeing with you, but what you just said makes sense.
And also, whoever said that physicists would lose their jobs because of computer models is just plain ignorant. Computer programs just don't come up by themselves, you know, us programmers have to program them, and how do we know how to program them? From the info from the physicists. So it starts with the physicists, and the programs will be used as a tool for the physicists to use rather than a replacement for the physicists.

Are you familiar with the concept of a joke?
And if we do actually reach the point where we can simulate universes, then all of the physicists will likely have to be computer scientists to some degree as well.

Any simulation we ever do will be considered a joke compared to the actual event. I expect our current ways of thinking are probably so simplistic as to be considered wrong to a future grouping of ourselves.

Well, back to the OP, I am only studying chemistry, so the atomic physics isn't something I've studied to much, but my understanding was that the electron was not entirely a particle, but not entirely a wave, and so it could reach light speed, as it is partially just an energy wave around the nucleus. Again, this is based off of chem books, not quantum mechanics.

Bell's theorem in the 1960s, and the related experiment by Aspect in the 1980s, have proven convincingly that quantum mechanics is nonlocal. That is, a quantum state is maintained by an instantaneous connection (or at least one that moves so fast we can't put an upper bound on it). This is not just the stuff of theoretical physics papers -- numerous experiments in the last three decades have substantiated this finding.

This does not conflict with special relativity. The speed limit c is a limit on the speed of a causal connection (or, as it's commonly said, it is the speed of information exchange). It says, basically, that an event at point X could not have been influenced by an event at point Y in the past, if a light signal released at the time of event at Y would not have reached point X by the time of the event at that point. The nonlocality of quantum mechanics avoid this problem in a subtle way - it says that a quantum state connecting two "particles" exists over the entirety of space, and changing the quantum state changes it everywhere; those two connected particles are still parts of that quantum state and are necessarily changed together, so it makes no sense to say that a change in one particle "causes" a change in the other. The only meaningful interpretation is that a change in the state occurs, which influences all the particles tied to that state. It's tricky, but experiments tell us that this must be the case. As an example, we have done experiments where we "link" two particles together and have them fly off in opposite directions over macroscopic scales (kilometers, say), and change the state of one particle while simultaneously measuring the other. We find the other particle changes before it possibly could have learned about the first particle's change by a light signal.