[Off Topic] Does time exist?

[JamesHunt]

Why is it, in the Youngs two slit experiment, each photon seems to co-operate to form the interference pattern? Can anybody answer this?

[TrueBeauty TS]

"Does time exist?"


Yes. You will find it on the nearest magazine stand.




.

[hondarobot]

Why is it, in the Youngs two slit experiment, each photon seems to co-operate to form the interference pattern? Can anybody answer this?

I have experienced this phenomenon. The cause is one too many cocktails.

:lol:

[DJ_Asia]

Why is it, in the Youngs two slit experiment, each photon seems to co-operate to form the interference pattern? Can anybody answer this?

I have listened to physicists debate this topic,and frankly I cannot begin to even wrap my mind around the theories....

BTW great topic for HA :roll:

[JamesHunt]

Why is it, in the Youngs two slit experiment, each photon seems to co-operate to form the interference pattern? Can anybody answer this?

I have experienced this phenomenon. The cause is one too many cocktails.

:lol:

No it's not, it's reality, believe me, ask Brenda, LOL

[hondarobot]

How could "time" not exist? I'd be up for throwing this idea around, it doesn't seem like something to argued. Time is the forth dimension in the regards to how we try to understand reality. How can that be debated? It's a rule.

It's a reference point. It's a dash mark on a four dimensional yard stick.

[JamesHunt]

BTW great topic for HA :roll:

As I said [Off Topic}

Interesting though to see who replies to this topic, everyone thinks I'm shallow, Baaahhhh!!!!

[DJ_Asia]

BTW great topic for HA :roll:

As I said [Off Topic}

Interesting though to see who replies to this topic, everyone thinks I'm shallow, Baaahhhh!!!!

Alien vs. Predator 2 is "Off Topic"

this thread is "Off Planet"

[trish]

Kurt Godel say time doesn't exist; at least not in the sense of a universally flowing progression of simultaneous events. See Pelle Yourgrau's "A World Without Time".
Frankly, I'm not so sure I agree.

The double-slit question may be unrelated to existence of time. Here's the way i like to think of it. take it with a large grain of salt:

It was once thought that to completely describe the state of a collection of particles all one needed to know was the position and momentum of each particle at one particular instant in time.
given the state of the collection, it was thought one could predict the future state at any given time using the laws of physics. it now seems to be the case that mechanical systems are not
collections of point particles and that the complete state of a mechanical system cannot be so simply described. Imagine a light source (of fixed frequency)
and a light detector with a double-slitted barrier between. Suppose the power of the source is turned down so that the state of the field between the source and the detector is non-zero but minimal.
The whole field is in a state of minimal energy non-zero energy. However, there are infinitely many different states the field could be in and still have that particular energy.
When the energy of the field is transfered to the detector, the detector changes states. But the detector is designed so that it's states fall into just two categories.
One category is classically interpreted as "the photon went through slit A" and the other category is "the photon went through slit B." In this way of looking at it, the field is everywhere between
the source and the detector and coalesces into a particle once the detector absorbs the field's energy.

[Quinn]

My very simple answer, which may be wrong (physics was never my specialty):

Time is tied to movement. All movement is driven by one of two forces: gravitational or electromagnetic. So long as either of those two forces exist, time must exist.

-Quinn

[hondarobot]

I don't accept that. There is an origin of energy and a return. I have not seen that theory proven wrong, within our framework of the laws of physics.

Then again, what do I know?

:P

[trish]

all i know is it's TIME for me to go to bed. goodnite moon, goodnite JamesHunt, goodnite TrueBeauty,
goodnight hondarobot, goodnite DJ_Asia, goodnite quinn, goodnite traumadoc.

[hondarobot]

all i know is it's TIME for me to go to bed. goodnite moon, goodnite JamesHunt, goodnite TrueBeauty,
goodnight hondarobot, goodnite DJ_Asia, goodnite quinn, goodnite traumadoc.

See, that's time.

[Quinn]

all i know is it's TIME for me to go to bed. goodnite moon, goodnite JamesHunt, goodnite TrueBeauty,
goodnight hondarobot, goodnite DJ_Asia, goodnite quinn, goodnite traumadoc.

Night, trish.

-Quinn

[loSTdoLLbaBY]

time doesn't really exist just like gravity doesn't exist- in as much as you can't hold gravity in your hand, just like you can't hold time in your hand....however you feel the pull of both of them and both have been determined to be relative- if i'm not mistaken.

but from where we all sit now time is affecting you just as gravity is affecting you- unless you're in space going at the speed of light, right?

(that's how santa does it all in one night- oh, and timezones help out too :D - yes, thank you... I'll have another brandy!)

[Quinn]

I don't accept that. There is an origin of energy and a return. I have not seen that theory proven wrong, within our framework of the laws of physics.

Then again, what do I know?

:P

I think this is a response to my post. If so, I'll be glad to discuss it tomorrow. I'm particuarly keen to hear Trish's response to either argument as this is definitely her type of topic. Until then, I'm going to try and get some sleep. Night, all.

-Quinn

[Don Ho]

Why is it, in the Youngs two slit experiment, each photon seems to co-operate to form the interference pattern? Can anybody answer this?yes time does exist but it is not consistant like humans belive(ie measure of time by earths rotation around the sun) Time is what created the universe(s).

[vegasboy]

Kurt Godel say time doesn't exist; at least not in the sense of a universally flowing progression of simultaneous events. See Pelle Yourgrau's "A World Without Time".
Frankly, I'm not so sure I agree.

The double-slit question may be unrelated to existence of time. Here's the way i like to think of it. take it with a large grain of salt:

It was once thought that to completely describe the state of a collection of particles all one needed to know was the position and momentum of each particle at one particular instant in time.
given the state of the collection, it was thought one could predict the future state at any given time using the laws of physics. it now seems to be the case that mechanical systems are not
collections of point particles and that the complete state of a mechanical system cannot be so simply described. Imagine a light source (of fixed frequency)
and a light detector with a double-slitted barrier between. Suppose the power of the source is turned down so that the state of the field between the source and the detector is non-zero but minimal.
The whole field is in a state of minimal energy non-zero energy. However, there are infinitely many different states the field could be in and still have that particular energy.
When the energy of the field is transfered to the detector, the detector changes states. But the detector is designed so that it's states fall into just two categories.
One category is classically interpreted as "the photon went through slit A" and the other category is "the photon went through slit B." In this way of looking at it, the field is everywhere between
the source and the detector and coalesces into a particle once the detector absorbs the field's energy.
I've heard it said that light acts as wavelike and particulate matter. This experiment seems to be defining that difference. Though continuous, it can be limited to two discrete states. So this says that time isn't continuous because it's directly related to energy which is best thought of theoretically as continuous, but sometimes behaves as discrete, particulate matter. So what does that mean? Time travel is possible? There is no such thing as time except as a reference point for people? *hits head*

[Quinn]

I don't accept that. There is an origin of energy and a return. I have not seen that theory proven wrong, within our framework of the laws of physics.

Then again, what do I know?

:P

I think this is a response to my post. If so, I'll be glad to discuss it tomorrow. I'm particuarly keen to hear Trish's response to either argument as this is definitely her type of topic. Until then, I'm going to try and get some sleep. Night, all.

-Quinn

Fuck it. Let me respond to this really quickly before going to bed (or try to). Anyway, as I understand it – and I could most certainly be wrong – in its simplest terms, motion/movement is energy and energy is motion/movement. Furthermore, if memory serves, energy can never, technically, be created or destroyed; it can only change forms.


What does all of that mean? Frankly, I’m not certain, but I’ll take a guess. Since all forms of movement are based upon two forces (gravitational and electromagnetic), then wouldn’t it stand to reason that energy, like time, is a result of – and dependent upon – the aforementioned forces existing? Wouldn't time and energy be related?

Now, I'm really going to try and go to bed.

-Quinn

[johnie]

Good idea, ask this on a tranny board....

[vegasboy]

Fuck it. Let me respond to this really quickly before going to bed (or try to). Anyway, as I understand it – and I could most certainly be wrong – in it's simplest terms, motion/movement is energy and energy is motion/movement. Furthermore, if memory serves, energy can never, technically, be created or destroyed; it can only change forms.


What does all of that mean? Frankly, I’m not certain, but I’ll take a guess. Since all forms of movement are based upon two forces (gravitational and electromagnetic), then wouldn’t it stand to reason that energy, like time, is a result of – and dependent upon – the aforementioned forces existing? Wouldn't time and energy be related?

Now, I'm really going to try and go to bed.

-Quinn
You brought back the law of conservation of energy for me when I thought it had disappeared in my head. :D

This is where I had ended up as well. Time is related to energy. Therefore, if energy is not continuous, or in other words can't be thought of as existing on a continuum (in certain circumstances), then time isn't necessarily continuous either. Of course, I haven't quite wrapped my head around why energy and time are related except in purely conceptual terms. It would sound kind of convoluted if I try to say.

[Jericho]

Time doesn't exist? :shock:
Shit...That's bad news for Switzerland!

[memyself]

time is an illusion, lunch time doubly so (hichhikers guide to the universe)

But in all seriousness (imhop).... time is a relative phenomena, if time is supposed to be a consistent division of measurement it must yeild to "the only constant in existence is change" and indeed fail.

Time only exists as a perception (that is created by the perceiver)
---a thought on this time---

[thx1138]

Yes, for us humans. We created time to measure the change in entropy we observe. For photons and electrons there is no time because they remain constant since their creation. Quarks (and heavy leptons) can experience change via the weak force.

[trish]

Kurt Godel say time doesn't exist; at least not in the sense of a universally flowing progression of simultaneous events. See Pelle Yourgrau's "A World Without Time".
Frankly, I'm not so sure I agree.

The double-slit question may be unrelated to existence of time. Here's the way i like to think of it. take it with a large grain of salt:

It was once thought that to completely describe the state of a collection of particles all one needed to know was the position and momentum of each particle at one particular instant in time.
given the state of the collection, it was thought one could predict the future state at any given time using the laws of physics. it now seems to be the case that mechanical systems are not
collections of point particles and that the complete state of a mechanical system cannot be so simply described. Imagine a light source (of fixed frequency)
and a light detector with a double-slitted barrier between. Suppose the power of the source is turned down so that the state of the field between the source and the detector is non-zero but minimal.
The whole field is in a state of minimal energy non-zero energy. However, there are infinitely many different states the field could be in and still have that particular energy.
When the energy of the field is transfered to the detector, the detector changes states. But the detector is designed so that it's states fall into just two categories.
One category is classically interpreted as "the photon went through slit A" and the other category is "the photon went through slit B." In this way of looking at it, the field is everywhere between
the source and the detector and coalesces into a particle once the detector absorbs the field's energy.
I've heard it said that light acts as wavelike and particulate matter. This experiment seems to be defining that difference. Though continuous, it can be limited to two discrete states. So this says that time isn't continuous because it's directly related to energy which is best thought of theoretically as continuous, but sometimes behaves as discrete, particulate matter. So what does that mean? Time travel is possible? There is no such thing as time except as a reference point for people? *hits head*

Yeah, the state of the electromagnetic field is described using a complex valued function whose domain is a region of the spacetime manifold. This function can be decomposed into an infinite sum of simpler wave-like functions (propagating sines and cosines). On the other hand, the states of a CCD (charge-coupled device for detecting light) are more restrictive; i.e. a minimal energy exposure will only turn one pixel from a zero to a one. So when the energy of a minimal energy EM-field is transferred to the CCD only one pixel can light up. We interpret that pixel as being the place where a photon fell. However, the photon didn’t exist as a particle until the detector absorbed the energy of the field. All this seems to be consistent with the assumption that the spacetime manifold itself is continuous, however, there are some theoreticians (e.g. Lee Smolin) who do toy with the notion that it is not.

Is time travel possible? I think so. One interpretation of particle/anti-particle interaction invokes time travel over small ranges allowed by Heisenberg’s uncertainty principle. Larger scale time travel is certainly consistent with the general theory of relativity. Whether it’s consistent with the remainder of physics remains to be seen. I’m pretty close to inventing a time machine myself. I’m not really working on it per se. I’m just waiting for my future self to come back and tell me how I did it.

[Ecstatic]

I’m pretty close to inventing a time machine myself. I’m not really working on it per se. I’m just waiting for my future self to come back and tell me how I did it.

Brilliant!

[CORVETTEDUDE]

We have a saying in the deep south....

WHAT IS TIME TO A HOG?!?!

[Night Rider]

time doesn't really exist

Next time I'm late for work, I'll just say loSTdoLLbaBY told me there's no such thing as time. :D

[hombredetia]

I hope you don't mind me saying so,
but the most interesting evolution at the moment
is not the abstract thinking about time,
but surely the advancement of neural networks
and bioneurology.

H

[CORVETTEDUDE]

I hope you don't mind me saying so,
but the most interesting evolution at the moment
is not the abstract thinking about time,
but surely the advancement of neural networks
and bioneurology.

H

Not to mention, the ass in that picture....

[vegasboy]

Yeah, the state of the electromagnetic field is described using a complex valued function whose domain is a region of the spacetime manifold. This function can be decomposed into an infinite sum of simpler wave-like functions (propagating sines and cosines). On the other hand, the states of a CCD (charge-coupled device for detecting light) are more restrictive; i.e. a minimal energy exposure will only turn one pixel from a zero to a one. So when the energy of a minimal energy EM-field is transferred to the CCD only one pixel can light up. We interpret that pixel as being the place where a photon fell. However, the photon didn’t exist as a particle until the detector absorbed the energy of the field. All this seems to be consistent with the assumption that the spacetime manifold itself is continuous, however, there are some theoreticians (e.g. Lee Smolin) who do toy with the notion that it is not.

Is time travel possible? I think so. One interpretation of particle/anti-particle interaction invokes time travel over small ranges allowed by Heisenberg’s uncertainty principle. Larger scale time travel is certainly consistent with the general theory of relativity. Whether it’s consistent with the remainder of physics remains to be seen. I’m pretty close to inventing a time machine myself. I’m not really working on it per se. I’m just waiting for my future self to come back and tell me how I did it.
Very interesting. I read that carefully, and as I don't have a background in physics, I can only say I understood the gist (if I'm lucky). Ironic that I read your first post, thought I understood it and came to the wrong conclusion about the spacetime manifold. It's up to me if I want to really understand it like you do and figure out how to calculate the state of an electromagnetic field or how the charge coupled device actually works. I probably won't end up doing that, though it's undoubtedly interesting.

That said, great last line :D .

[trish]

thanks, vegasboy...but like i said...it's just one way of looking at it and it should be taken with a grain or three of salt...preferably on the rim of a margarita.

[Ecstatic]

My niece is a physicist, and she and I have had some great conversations about stuff that makes my head spin. She actually understands the math, while I can only think about these things in abstract, philosophical terms.

Like over Xmas, we talked about Rees' Just Six Numbers which make ours the Goldilocks universe (not too hot, not too cold). For instance, (if I get this more or less right, lol), the strong nuclear force has a value of 0.007. If it were a little weaker--say 0.006--then all the hydrogen in the universe would have fused into much heavier elements, preventing life from developing (for one thing, there's be no H2O). And if it were a little stronger--say 0.008--then fusion would not have taken place sufficiently to develop the heavier elements needed.

Anyway, it's fun to talk about these things. What we enjoy most are what she calls "bad physics moments" in TV and movies, like her favorite, extinguishing a runaway nuclear reaction by dunking it in the East River (Spider-Man II). :)

[trish]

or catching a beautiful but falling girl just feet above the hard pavement.

[Ecstatic]

Ah, like Spidey snagging Gwen Stacy with his web as she plummeted from the top of --was it the Brooklyn Bridge? The shock and force of the web killed her instantly.

Superman on the other hand seems to somehow completely overcome inertia, so he can catch Lois without killing her as she plummets 40 stories.

[trish]

exactly. or when the six billion dollar man lifts a car totally off the ground with his right hand and doesn't topple over.

[vegasboy]

thanks, vegasboy...but like i said...it's just one way of looking at it and it should be taken with a grain or three of salt...preferably on the rim of a margarita.
Sounds good to me. Some of my best ideas come that way :D Cheers.

[JamesHunt]

Jeez, some of the shit I post, but take the polarization experiment, why can't scientists predict which photon will pass through the polorizer, when angled at 45 degrees

[bettervedder]

The existence of time and the nature of time are two separate questions. What it really comes down to is whether you live by Protogoras (sorry about the spelling I am getting ready to go to bed) with his convo with Socrates with man is the measure of all things. Conceptually and metaphysically, I argue that time is merely a measure between consequence (ie before and after) how it is divided (what the definition is of sec, min, hour is completely arbitrary) and consequence are also up the air as well. But, then again what isn't defined by human convention and agreement of definition. But, enough of semantics, lets talk semantics :).
As far as the nature of time, there are two views on the nature of time, and they are divided up in two theories. One is A-Theory and the other is B-Theory (you would think philosophy could be more creative than that, but sadly no). A theory has the idea that time flows through us. The very essence of time (whether the existence is purely by human birth or of natural process, is dependent upon your perspective for this topic). So an A theorist would say that Yesterday, Today, and Tomorrow are all defined by the present and can never actually say that yesterday and tomorrow exist since they can only empirically experience the now or today (that is the weakness/or correction to the vernacular misconception of time). As far as B-Theorist are concerned, the view time as something that we flow through, which would make it possible for us to identify yesterday and tomorrow and see time as a fourth dimension, which more often than not is coupled with Four Dimensionalism (quite creative again huh). I seem to favor the B-Theorist simply because it agrees with me concerning Leibnez's Law of Indiscernabilities of Identicals and his other law Identicals of Indiscernabilities is more consistent if you understand this whole blurb. Sorry about how lengthy this is.

[bettervedder]

nonexistentialists already have their answer to this (that was the other side that I forgot)

[trish]

Do I detect a philosopher in our presence? I believe it was John Ellis McTaggart who invented the A-series and the B-series in his 1908 paper “The Unreality of Time” (http://www.ditext.com/mctaggart/time.html). The A-series conceives of time as ordered accordingly: …2 seconds past, 1 second past, now, 1 second in the future, 2 seconds in the future…
Under this conception a given time has the property of being either in the past, present or future. McTaggart argues any given moment has all three properties (it starts in the future, rushes through the present and into the past). He also argues that since a moment cannot be both future and past that the A-series is misconceived and unreal.

The B-series is really a binary relation between the moments of time. In fact it is just the relation “before.” The B-series can be constructed from the A-series, but not vice-versa. The B-series is kinda like the A-series except the “now” is left out. McTaggart also argued the B-series is unreal, though I not sure I understand his train of thought there.

The theory of relativity has no need for the A-series conception of time. Each observer, in the theory of relativity, has a world-line parameterized by their own proper time which they can use to order events into a B-series. Though it’s not part of the formal theory of relativity, our actual experience indicates there is a “now” flowing along each one of those world lines as well. But in relativity, simultaneity of events is relative. And so the shouts of two observers exclaiming “NOW” may be heard by a third observer at different times.

It always seems somewhat dangerously self-referential to describe time as flowing, since the notion of flowing seems to require notion of time. If time flows, then at what rate does it flow? One hour per hour? Does that make sense? (You can’t see me, but I’m shrugging my shoulders here. Kinda cute actually, letting my bra strap drop over my left arm as I type).

[Ecstatic]

"Hurry up please, it's Time." - Overheard in any pub near closing time. ;)

[bettervedder]

I didn't know I could be more precise with my thoughts. I am not a big fan metaphysics, since my encounters with Nietzsche. As far as flowing concerned, yes it does require of time. However, you have mentioned a very good question towards the "consequence" of time. The before and after affect. Some define time as the acquisition of a new property or the loss of. The notion of time is as fleeting for human reason.
Now to clarify what my problems were with A theorist, is that you have the 2 seconds to the past, 1 second the past, now, 1 second to the future, two seconds the future. Each of these times relative, even relative to the person possess different properties, to where the properties associated with the context of that time are not the same when using the same title as, 1 second past. For example, it is 1:58:59 and I am typing about a subject, and then proceeds to the Now of 1:59:00, the Now of 1:59 adopts new properties changing what Now has properties of. Well, Alex what is wrong with that? In order for a time to exist, it must contain property (unless like I said before you are a nonexistentialist (sorry have to include that everytime). The A-theorist Now cannot contain one property and disappear, since Now constantly exists (unless of course you are a huge Doomsday advocate). Lets put this aside, there are other perspectives on that issue. Lets go the the past and the future of now. With these changing constantly, how can one accurate identify past and future when it constantly changing in the now. What I mean is, what I did 304 seconds a go is, now 305 seconds ago from the now, thus the notion of time, is at best, very hard to identify with consequence of our environment (perhaps we are all identifying time wrong). Linguistically, when referring to future or past, we would have to say 10 minutes ago, 10 minutes and one second ago, (of course you could say about 10 minutes ago), but you could not identify the time it happened, if time is not going to be identified that way. But, beyond linguistics, let us suppose that, we embrace whole heartedly, for example, we have the phrase, "Thank god that's over". We are referring to the past. And I ask, "Thank god what's over?". They then reply, I drooling over that girls picture that responded to that guys post to the existence of time. Well, I guess that past could have a property of that. But, in the same note, couldn't the past contain a property of not drooling over that girl? So, we have a concept containing a person drooling over a girl, and a person not drooling over a girl. Where one could say, nobody drooled over that girl, and somebody drooled over that girl means that something possess properties that conflict and cannot exist logically. Sort of like the idea of a squircle, if I need to explain that let me know.
As far the claims against B Theorist, I unfortunately of a bias towards it. Whether some yells Now, and hears it at different times, does not mean that the standard of time is based upon human faculties. Our perception of hearing the now, to the hearing of the now and or reacting to the now, does not mean that now has two separate places in time. Just means that the person reacting to the now, is reacting as soon as he reacts to someone saying now. Which means that it is impossible for a human to experience the same now as someone else, due to perspectival difference (two physical objects cannot occupy the exact same space). But, it isn't to say that, now is a loose concept that is mere vernacular. I can still use the now appropriately in B-Theorist Language. The Now of 1:58:59 I was writing about A-Theory of Time. I have given a property of a certain time. I still can still identify with times along the time line.
Now, I can go on with this forever, but to make things more interesting, lets ask, is time travel possible?
I say no.
Thoughts?

[KO47]

http://img2.freeimagehosting.net/uploads/2a10b6fb11.jpg

[EyeCumInPiece]

Time doesnt exist. We created the concept of time by recording every fuckin bullshit that we do. From the ancient world to the Internet....Philosophy gives me migraines so im gonna go now, Bye!!

[Dino Velvet]

Time does exist as Hung Angels time is approx. 20 minutes ahead of Earth Time.
http://www.hungangels.com/board/viewtopic.php?p=420745&highlight=#420745

[EyeCumInPiece]

Time does exist as Hung Angels time is approx. 20 minutes ahead of Earth Time.
http://www.hungangels.com/board/viewtopic.php?p=420745&highlight=#420745

That is true!!!

[bettervedder]

As far as time doesn't exist, that is an acceptable and logically consistent stance. However, by admitting that time doesn't exist being a human convention. Then, so does the abstraction of ideas not exist, of which would mean that the idea that you support would be contrary to what you say. Strange, but consistent. (IE I think that people using examples is stupid, but I am smart). I use an example, I assign a property of people using examples, but create an exception to provide understanding of where I come from. However, it then beckons the idea of why something should be an exception, which most of the time creates a slippery slope. (How this applies?)
It applies by saying that time doesn't exist because it is a human convention, then ideas do not exist, since it is a human convention. Someone is having an idea that because something possess the property of being formed of years of convention makes it not exist. You have to state why it doesn't exist then I will be satisfied with your nonexistenialist claim.
For example, I don't believe time exists because our perception of consequence cannot be proven to be truth. The keystrokes I make, the screen I see, the environment around me could be all a lie. So, why should I justify time when I can't justify that which I touch, taste, smell, hear, and see. That is a good claim.
By not trusting something due it being a human convention means that I could do the same thing with punching someone in the balls. Your sense of pain is not justified because your senses are telling you that you got punched in the balls, but you don't KNOW if it really happened. I would punch someone in the face that told me that regardless if it was them who punched me in the balls or not. Of course, they could say that and be correct.
Whether the nature persists regardless of our senses will never be a fully justified thought according to our senses, however, because cause and effect relationships occur to be perceivable we must recognize it somehow and someway. Yes, it is arbitrary we all know that with its measure, but whether something be arbitrary or not does not mean it doesn't exist.
As far as nonexistenialism is concerned, if I were to say that nothing exists. Then that would mean a few things, 1) that something has to exist in order for nothing to exist in many regard, if nothing weren't to exist that would mean that there is something. The mere fact that you are saying that something exists is acknowledging that something that is not that something does not exist.
This is getting way off topic and I am probably losing a few people to boredom. I apologize.

[JamesHunt]

Bahhh!!!!

I believe we are all the same person, but experiencing each other via parallel universes...

Excuse me while I go and shag myself :lol:

[KO47]

This thread sucks.

[JamesHunt]

This thread sucks.

Only cos you don't understand it :lol:

[Ecstatic]

"Time, time, time is on my side, yes it is...."

Jagger the Elder

[trish]

If I follow you, bettervedder, I think I’m inclined to concur with your assessment of A-time and B-time. I find no problem with the B-notion and I believe that in fact the theory of relativity presents a consistent version the notion of B-time. A-time, as your post shows, is extremely baffling, yet its seems to be embedded in our language and I the ways we attempt to think about time.

It’s very handy that HA time is 20 minutes ahead of Earth time. I can write a post, return to Earth and still have time to shag my parallel self.

Does time exist? Who even knows what that means? Time can be measured. That’s good enough for me. However, the measurements are not Lorentz invariant. That could be a problem for anyone maintaining the absolute existence of time.

i got i got i got i got no time.

[Bigguy]

Why is it, in the Youngs two slit experiment, each photon seems to co-operate to form the interference pattern? Can anybody answer this?
I don't think this has much to do with time, but rather quantum physics. My understanding of it is that the photons aren't cooperating with each other to create the interference pattern. The pattern is made by each individual photon going through both slits at the same time and making an interference pattern with itself. Each photon will do this with itself and just make small piece of the pattern. All of them combined they will naturally make the whole pattern.

It may seem impossible that one particle can go through both slits at the same time bit that's what happens in quantum physics, provided the probability is there for the particle to go through either one.

[iloveshemales77]

"The distinction between the past, present and future is only a stubbornly persistent illusion."
Albert Einstein

[bettervedder]

I never really liked talking about time with my college professors since most of them besides 2 favored B-Theory. The teacher that taught me some of my metaphysics was a right wight conservative. It was sort of immature of him and I to talk as much as we did about it. In the end, I sort of had a liking to Nietzsche teachings because it was perspectival and I believe that Nietzsche acknowledged time with a different twist of zeitgeist that the Nationalist Germans in the 1860s and 70s, till his meeting with a horse and it driver pushed him into a 12 year comatose. The way he speaks, undermines recognized philosophy and to force people to take The Greatest Stress, and to become their own Madman or woman. So, whether one concurs I do appreciate the support, but Nietzschean in me, is glad to hear discourse. Nietzsche did not to anybody copy him, but to embrace the nature of our existence, whatever that may be.[/i]

[Odelay]

Time is the great leveler of mankind.

A man can have more wealth than you.
A man can have a sexier spouse than you do.
A man can have more and wiser children than you do.
A man can have a better job than you do.
A man can be more happy than you.

But... no man will ever have more time in a single day or a single year than you do.

Some people don't take much comfort in this fact. I do.

[francisfkudrow]

Time does exist as Hung Angels time is approx. 20 minutes ahead of Earth Time.
http://www.hungangels.com/board/viewtopic.php?p=420745&highlight=#420745

Wasn't that the premise of the short-lived TV series Max Headroom? That it took place in some dimension that was always 20 minutes ahead of us?

[iloveshemales77]

I never really liked talking about time with my college professors since most of them besides 2 favored B-Theory. The teacher that taught me some of my metaphysics was a right wight conservative. It was sort of immature of him and I to talk as much as we did about it. In the end, I sort of had a liking to Nietzsche teachings because it was perspectival and I believe that Nietzsche acknowledged time with a different twist of zeitgeist that the Nationalist Germans in the 1860s and 70s, till his meeting with a horse and it driver pushed him into a 12 year comatose. The way he speaks, undermines recognized philosophy and to force people to take The Greatest Stress, and to become their own Madman or woman. So, whether one concurs I do appreciate the support, but Nietzschean in me, is glad to hear discourse. Nietzsche did not to anybody copy him, but to embrace the nature of our existence, whatever that may be.[/i]

I don't understand a word of that! :?

[Ecstatic]

Never mind A-time and B-time, what about T-time? You know, where an hour = 20 minutes?

[BrendaQG]

Kurt Godel say time doesn't exist; at least not in the sense of a universally flowing progression of simultaneous events. See Pelle Yourgrau's "A World Without Time".
Frankly, I'm not so sure I agree.

The double-slit question may be unrelated to existence of time. Here's the way i like to think of it. take it with a large grain of salt:

It was once thought that to completely describe the state of a collection of particles all one needed to know was the position and momentum of each particle at one particular instant in time.
given the state of the collection, it was thought one could predict the future state at any given time using the laws of physics. it now seems to be the case that mechanical systems are not
collections of point particles and that the complete state of a mechanical system cannot be so simply described. Imagine a light source (of fixed frequency)
and a light detector with a double-slitted barrier between. Suppose the power of the source is turned down so that the state of the field between the source and the detector is non-zero but minimal.
The whole field is in a state of minimal energy non-zero energy. However, there are infinitely many different states the field could be in and still have that particular energy.
When the energy of the field is transfered to the detector, the detector changes states. But the detector is designed so that it's states fall into just two categories.
One category is classically interpreted as "the photon went through slit A" and the other category is "the photon went through slit B." In this way of looking at it, the field is everywhere between
the source and the detector and coalesces into a particle once the detector absorbs the field's energy.

I would give that explanation an A+ .

I can only add that in different interpretations there are slightly different interpretations of this experiment.

Trish has used the traditional Copenhagen interpretation. Here is an alternative one due to David Bohm. In the so called Bohamian interpretation in this experiment the photons are just particles, localize at all times. The field only exist where there are particles and no where else.

What happens is that all the particles in the experiment are "entangled" with one another. The particles that compose the detector, as well as the emitter of the photons and the photons themselves. What this "entanglement" does is it causes correlations between quantum states that cannot be explained or understood classically.

What this has to do with time I do not see.

[Ecstatic]

Perhaps time is a "correlation between quantum states that cannot be explained or understood classically"?

I give up; I need my neice the physicist to decode this thread, and I don't think she's into tgirls.

[BrendaQG]

In considering the title question the first thing that comes to my mind is something Trish already brushed on. The theory of relativity and "space-time". Which leads me to reformulate the question like so: Does space-Time exist? Or is that just a mathematical trick used to make our math work out?

I think the answer is yes. In the classical sense the best proof that the space-time Dr. Einstein envisioned exist is the existence of Black Holes. They are nothing but really twisted space-time. No non relativistic theory of gravity that has been tried, that I know of, has been able to reproduce that. So to most physicist satisfaction the answer is that yes time indeed exist. It is something real. As opposed to some artifact of our anthropocentric world view, or a mathematical trick.

[iloveshemales77]

Thanks trish and BrendaQG for that! Fantastic explanation! I think I now have a rudimentary idea of what the the two slit conundrum is about, which has eluded me since high school. Though like Ecstatic, I'm gonna have to ponder on it a bit more. Afraid my algebra is exhausted by the time I reach very basic diff. equations.

[BrendaQG]

Perhaps time is a "correlation between quantum states that cannot be explained or understood classically"?

I give up; I need my neice the physicist to decode this thread, and I don't think she's into tgirls.

he he your in good company it took me a long while and allot of trial and error to get it. This link is to a plain language explanation of "entanglement". (http://en.wikipedia.org/wiki/Quantum_entanglement)

The best example in the classical world I can think of would be a game of pool. Suppose you don't have a straight shot at the ball you want to put in the pocket, and you cannot bank it off of the rail. What do you have to do is bank one ball of the other. What direction each ball will travel in after that is within a certain cone of probability and that probability is 100% determined. However what each ball does after that is entangled with the state of the other.

For the mathematically inclined... To see where I am coming from with this consider the pool table as a 2D plane, and the spin of the balls as an internal degree of freedom of the system. Each and every ball has an associated Hilbert space. After constructing these hilbert spaces take the tensor product and construct the hilbert space of all the balls. You will then find that there are some states that cannot be written as pure product states. Those are the so called entangled states.

[iloveshemales77]

hmmm, you lost me again I'm afraid. Whats the connection between entangled states and time?

[Ecstatic]

In considering the title question the first thing that comes to my mind is something Trish already brushed on. The theory of relativity and "space-time". Which leads me to reformulate the question like so: Does space-Time exist? Or is that just a mathematical trick used to make our math work out?

I think the answer is yes. In the classical sense the best proof that the space-time Dr. Einstein envisioned exist is the existence of Black Holes. They are nothing but really twisted space-time. No non relativistic theory of gravity that has been tried, that I know of, has been able to reproduce that. So to most physicist satisfaction the answer is that yes time indeed exist. It is something real. As opposed to some artifact of our anthropocentric world view, or a mathematical trick.

I concur. It has always seemed to my mathematically-impoverished mind that space-time is "real" and that "time" in this sense is an aspect or 'dimension' (not quite sure of the technically accurate use of this term) which is inseparable from space-time and which therefore is co-existant with 'our' space-time universe. However, from this point of view it makes no sense to talk about what happened 'before' the Big Bang because space-time did not exist prior to the First Event; there was no 'where' and no 'when' prior to the Big Bang from within the context of space-time. Doublespeak am good.

Anyway, I don't think that the relativistic space-time sense of time is the only sort of time; I think it is also quite possible that our minds create time as a means of sorting the universe, and this anthropomorphic time is not the same kind of time as space-time.

Now I'm sounding like a bad Doctor Who episode so I'll quit while I'm behind.

(Any Doctor Who fans? Remember the Tom Baker "Stones of Blood" episode where the Welsh archeologist asks the Doctor if he's from outer space, and he replies, "No, I'm more from what you would call Inner Time.")

[Ecstatic]

Perhaps time is a "correlation between quantum states that cannot be explained or understood classically"?

I give up; I need my neice the physicist to decode this thread, and I don't think she's into tgirls.

he he your in good company it took me a long while and allot of trial and error to get it. This link is to a plain language explanation of "entanglement". (http://en.wikipedia.org/wiki/Quantum_entanglement)
Umm, yeah...plain Engrish...me no speaka de Engrish....

Actually, I've always been rather stumped by the apparent paradox of quantum entanglement. As the wiki you quoted states:


Observations on entangled states naively appear to conflict with the property of relativity that information cannot be transferred faster than the speed of light. Although two entangled systems appear to interact across large spatial separations, no useful information can be transmitted in this way, so causality cannot be violated through entanglement. This is the statement of no communication theorem.

Although no information can be transmitted through entanglement alone, it is possible to transmit information using a set of entangled states used in conjunction with a classical information channel. This process is known as quantum teleportation. Despite its name, quantum teleportation cannot be used to transmit information faster than light, because a classical information channel is required.

How can two quanta be entangled and appear to interact when separated by a spatial distance so great that only faster than light communication could account for the interaction? Saying that "no useful information can be transmitted this way" doesn't really explain it. I've always tripped up on this (and looking at the math in the wiki shows why: I just have no idea what all that chicken scratch means).

In any event, the description of quantum teleportation is fascinating because, IF a classical channel were available, then all that "subspace" radio contact on SF movies and shows would be accounted for. Star Gate SG1 does a half-decent job, with the wormhole providing the classical channel for the quantum teleportation (minus any gravitic distortion, of course).


For the mathematically inclined... To see where I am coming from with this consider the pool table as a 2D plane, and the spin of the balls as an internal degree of freedom of the system. Each and every ball has an associated Hilbert space. After constructing these hilbert spaces take the tensor product and construct the hilbert space of all the balls. You will then find that there are some states that cannot be written as pure product states. Those are the so called entangled states.

Hilbert Space: now there's a character for Scott Adams! He should add Hilbert to his cast alongside Dilbert, Dogbert, Carbert, Ratbert and the rest. Some math genius at Dilbert's workplace who manages to be in two places at once. Hmmm....."Chief, lower the cone of probability please."

[BrendaQG]

@iloveshemales77

I have no idea what it has to do with space-time. But in a few different interpretations of quantum theory it has much to do with the double slit experiment.


Saying that "no useful information can be transmitted this way" doesn't really explain it. I've always tripped up on this (and looking at the math in the wiki shows why: I just have no idea what all that chicken scratch means). ....
....
Hilbert Space: now there's a character for Scott Adams! He should add Hilbert to his cast alongside Dilbert, Dogbert, Carbert, Ratbert and the rest. Some math genius at Dilbert's workplace who manages to be in two places at once. Hmmm....."Chief, lower the cone of probability please."

Let me put it simple for ya. The whole "nothing can travel faster than the speed of light" part of special relativity also implies that nothing can transmit data faster than the speed of light. That data cannot be transfered by entangled particles ensures this. To communicate bits of data a signal has to be compared to reference at some kind. Entangled particles cannot perform that function.

[Bigguy]

How can two quanta be entangled and appear to interact when separated by a spatial distance so great that only faster than light communication could account for the interaction? Saying that "no useful information can be transmitted this way" doesn't really explain it. I've always tripped up on this (and looking at the math in the wiki shows why: I just have no idea what all that chicken scratch means).

I don't follow the math either but I always find this stuff interesting but at times difficult to grasp. I think I get the general idea on this one though. If you have two particles in an entangled quantum state, it means they would be in any sort of random state. You wouldn't know the state of either until they are measured, but when you measure it, it would set the other entangled particle's state no matter how far away it is, which could also be measured.

So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?

Brenda, is there anything wrong with this explanation? If this is good, how do we know that just entangling the particles does not set their state to begin with?

[BrendaQG]

How can two quanta be entangled and appear to interact when separated by a spatial distance so great that only faster than light communication could account for the interaction? Saying that "no useful information can be transmitted this way" doesn't really explain it. I've always tripped up on this (and looking at the math in the wiki shows why: I just have no idea what all that chicken scratch means).

I don't follow the math either but I always find this stuff interesting but at times difficult to grasp. I think I get the general idea on this one though. If you have two particles in an entangled quantum state, it means they would be in any sort of random state. You wouldn't know the state of either until they are measured, but when you measure it, it would set the other entangled particle's state no matter how far away it is, which could also be measured.

So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?

Brenda, is there anything wrong with this explanation? If this is good, how do we know that just entangling the particles does not set their state to begin with?

No you got it just right. I have tried to explain this concept to other educated people online. Some of whom claim to be physicist who cannot get it. You get a gold star on your paper. :-)

[JamesHunt]

OK, I'm slightly drunk, but hows about this one? Einstens thought experiment & length contractions. As the train paases us at varying speeds, its length contracts, and as it approaches the speed of light will disappear from our frame of referece. So a photon being emitted from a light bulb and strilikg a wall, from its frame of reference, if we could travel with it, the space between the light bulb & wall doesn't exist, does that make sense? I'm sure theres something in this. Didn't Feynman touch on this, saying there was only one photon in the whole universe, but it was everywhere and nowhere at the same time?

[OEMEnemyNum1]

Wow, we have some physicists here. But how many people here can do simple diff eq based dynamics problems?

[Ecstatic]

I don't follow the math either but I always find this stuff interesting but at times difficult to grasp. I think I get the general idea on this one though. If you have two particles in an entangled quantum state, it means they would be in any sort of random state. You wouldn't know the state of either until they are measured, but when you measure it, it would set the other entangled particle's state no matter how far away it is, which could also be measured.

So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?

Brenda, is there anything wrong with this explanation? If this is good, how do we know that just entangling the particles does not set their state to begin with?

No you got it just right. I have tried to explain this concept to other educated people online. Some of whom claim to be physicist who cannot get it. You get a gold star on your paper. :-)

Sorry, I still don't get it. You say "So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?" What difference does it make whether the information is useful or random? The point is the instantaneous transmission of [datum][some random value], and if it's instantaneous, regardless of distance, then it's faster than light.

There is some kind of connection which is outside space-time if the state of one particle is entangled with another and each changes in accord with the other regardless of distance.

I feel a little like Galileo trying to measure the speed of light by shuttering and unshuttering lamps on hilltops a few miles apart: sure seems instantaneous at that distance.

[JamesHunt]

There is some kind of connection which is outside space-time

As I said above, outside of our space/time, in a completely different frame of reference.

[BrendaQG]

I don't follow the math either but I always find this stuff interesting but at times difficult to grasp. I think I get the general idea on this one though. If you have two particles in an entangled quantum state, it means they would be in any sort of random state. You wouldn't know the state of either until they are measured, but when you measure it, it would set the other entangled particle's state no matter how far away it is, which could also be measured.

So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?

Brenda, is there anything wrong with this explanation? If this is good, how do we know that just entangling the particles does not set their state to begin with?

No you got it just right. I have tried to explain this concept to other educated people online. Some of whom claim to be physicist who cannot get it. You get a gold star on your paper. :-)

Sorry, I still don't get it. You say "So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?" What difference does it make whether the information is useful or random? The point is the instantaneous transmission of [datum][some random value], and if it's instantaneous, regardless of distance, then it's faster than light.

There is some kind of connection which is outside space-time if the state of one particle is entangled with another and each changes in accord with the other regardless of distance.

I feel a little like Galileo trying to measure the speed of light by shuttering and unshuttering lamps on hilltops a few miles apart: sure seems instantaneous at that distance.

Exactly. The value is random so there is no way to distinguish it from the background noise at that instant. Only once the two measurements on the quantum state can be compared can we say that any information can be transmitted. The only way we can do that is by transmitting a classical signal. (i.e. flashing a light down a optical fiber).

[Bigguy]

Sorry, I still don't get it. You say "So basically it is just instantly transmitting some random value. How could random information be useful in transmitting information?" What difference does it make whether the information is useful or random? The point is the instantaneous transmission of [datum][some random value], and if it's instantaneous, regardless of distance, then it's faster than light.
I think that is why Einstein called it spooky action at a distance. When you said faster than light communication, I was thinking you were wondering if it could be used for faster than light communication, which it can't.

I don't why it works, or if it is really does the spooky action, or if the particles state is set when they are entangled.

I was also thinking that maybe thinking it more in the sense of parallel universes might make more sense, but I need to give that some more thought. Some reading on that: http://en.wikipedia.org/wiki/Many-worlds_interpretation

[Ecstatic]

Exactly. The value is random so there is no way to distinguish it from the background noise at that instant. Only once the two measurements on the quantum state can be compared can we say that any information can be transmitted. The only way we can do that is by transmitting a classical signal. (i.e. flashing a light down a optical fiber).

You say the value is random and therefore there's no way to distinguish it from the background noise at that instant: yet how does that random value get transmitted across vast distance? Is James Hunt's point (and my presumption) that this is happening outside of space-time true? Then elementary particles don't exist in space-time? And if we have to measure both particles to compare their states via a classical signal, how do we know the particles states are entangled? What about the uncertainty principle?

Arggh, I'm going to bed before my head explodes.

(But thanks for being patient with the math-impaired student at the back of the class.)

[JamesHunt]

That is what I'm trying to get across, there is no distance in the action, just localized symmetry from our frame of reference.

[Ecstatic]

That is what I'm trying to get across, there is no distance in the action, just localized symmetry from our frame of reference.

Yes, which I presumed by saying that it occurs outside our space-time. But I don't see how this would then qualify as a 'transmission.' I guess I got hung up on the language, but I'd say symmetry isn't transmission.

And, like Einstein, I'm spooked. Let's roll some dice.

[JamesHunt]

Arggh, I'm going to bed before my head explodes.


So am I, I can't believe this thread has caused so much interest on a board for hungangels.LOL... this board rocks :lol:

[trish]

sorry, i'm a little bit late tonight in checking this thread. the following is a response to something Ecstatic said back on page 7:


How can two quanta be entangled and appear to interact when separated by a spatial distance so great that only faster than light communication could account for the interaction? Saying that "no useful information can be transmitted this way" doesn't really explain it. I've always tripped up on this

I take it one of the things baffling Ecstatic is the Einstein-Podolsky-Rosen experiment (EPR-experiment for short).

In ordinary Newtonian physics the state of a particle is completely captured by its position and momentum. You know these two things, you every thing there is to know about the particle. Not so in quantum mechanics. In quantum mechanics a state of a particle is a complex valued function called the wave function of the particle. One convenient feature of the wave function is that it can be decomposed into a formal sum of ordinary Newtonian states. When states are decomposed this way we’re merely representing the state of the particle as a superposition of classical states. It allows us to think of the state classically. But it also invites us to think of point particle as having a ghostly presence in several different locations at the same time. This is the case with other particle properties as well. Classically a particle can’t have both up spin and down spin at the same time. However, in the quantum world a particle could have a state which is representable as a superposition of both spin up and spin down. Such a particle does not really have up spin, nor does it have down spin. However, one can pass the particle through a device that changes its spin-state into either up or down. The device is sometimes misleadingly called a spin detector. But in fact it’s a spin polarizer. It forces the particle to abandon whatever spin-state it currently has and choose between being spin up or spin down. The choice it makes will be dependent upon but not uniquely determined by its current state.

So here’s the set up of the EPR-experiment. A pair of spin-orientable particles is created in the lab so that 1) the net spin of the pair is zero; 2) each individual member of the pair has a spin state that is a quantum superposition of up and down; and 3) each individual member of the pair has a spin state that is identical to that of its partner. Then the two particles are separated. Then in a common inertial frame each of the two particles simultaneously passes through a spin polarizer. A corollary of the law of conservation of momentum, is conservation of spin. So if one particle chooses to be spin up the other will choose to be spin down. But if the choices are made simultaneously at different locations, there’s no time for one particle to signal the other about what choice to make! Einstein, Podolsky and Rosen thought this paradox demonstrated that the principles of quantum theory were untenable. So Ecstatic, you’re in good company. However actual experiments seem to show that the crazy prediction forced upon us by quantum mechanics is in fact true.

Personally, I think there is a hitch: one cannot really compare simultaneous measurements made at different locations at the moment they’re being made. One has to wait until reports of the measurements reach a single observer before a comparison is made. This makes the EPR-experiment impossible to directly verify (IMO). To elaborate on this last point: it’s consistent that the measurements and the reports of the measurements are themselves in superimposed states. Hearing the report of a measurement forces the report into a classical state. Both reports can’t be heard until enough time has elapsed for the two hearings to be causally connected. This means there’s enough time for the reports to have communicated with each other before both are finally heard. It also means the two received reports can’t be verified before the particles are causally reconnected; i.e. sufficient time has passed for the particles to have communicated.

Nevertheless, all the indirect evidence seems to suggest what Einstein thought was crazy behavior is in fact the way the universe behaves. Go figure.

[trish]

But how many people here can do simple diff eq based dynamics problems?

i'm a whore, i won't do them for free?

[trish]

There is some kind of connection which is outside space-time

As I said above, outside of our space/time, in a completely different frame of reference.

i'd rather think not. i just think of it these simultaneous correlations as representing a global symmetry in our four dimensional universe. after all, in general relativity all times exist at once. the entire history and future of the cosmos is represented as a distribution of energy and structure within one single four dimensional manifold. in this sense there's no need for communication between simultaneous correlated events. they just exist as a symmetry in the universe. this however is just my quirky way of dismissing the mystery and shouldn't be mistaken for science.

[CaliGuy]

Yes, and it always moves forward unless you can travel faster than the speed of light.

[trish]

Actually you move forward through it or relatively speaking you stand still and it moves backwards past you. Events in the future hurtle toward you and recede backwards into the past.

[CaliGuy]

Time might also move backward if mentally disturbed? lol Few people on here understand the concept well.

[iloveshemales77]

This thread rocks! Can't remember the last time a maths numbskull like me learnt so much! My hat off to trish, brendaGQ and Ecstatic! Awesome! :-) I'm printing it out for future reference.

[BrendaQG]

There is some kind of connection which is outside space-time

As I said above, outside of our space/time, in a completely different frame of reference.

i'd rather think not. i just think of it these simultaneous correlations as representing a global symmetry in our four dimensional universe. after all, in general relativity all times exist at once. the entire history and future of the cosmos is represented as a distribution of energy and structure within one single four dimensional manifold. in this sense there's no need for communication between simultaneous correlated events. they just exist as a symmetry in the universe. this however is just my quirky way of dismissing the mystery and shouldn't be mistaken for science.

Your basically right according to David Bohm's interpretation the quantum mechanical world should be though of as one connected whole and not isolated parts. Which is true. Looked at a certain way all we are is fields of energy (mostly E.M.) Bound together chemically and held on this planet by another energy field (gravity). All things are are inherently quantum mechanical.

I belive that entanglement is at the heart of many unexplained phenomena. like when a spouse, sibling (in particular a twin), or friend dies some people seem to get a feeling something is wrong. Even when they are thousands of miles apart. Or in the case of twins separated at birth. There have been many cases where the twins will go on to live very similar lives...right down to having some of the same types of things happen at about the same times.

[Ecstatic]

sorry, i'm a little bit late tonight in checking this thread. the following is a response to something Ecstatic said back on page 7:


How can two quanta be entangled and appear to interact when separated by a spatial distance so great that only faster than light communication could account for the interaction? Saying that "no useful information can be transmitted this way" doesn't really explain it. I've always tripped up on this

I take it one of the things baffling Ecstatic is the Einstein-Podolsky-Rosen experiment (EPR-experiment for short).

In ordinary Newtonian physics the state of a particle is completely captured by its position and momentum. You know these two things, you every thing there is to know about the particle. Not so in quantum mechanics. In quantum mechanics a state of a particle is a complex valued function called the wave function of the particle. One convenient feature of the wave function is that it can be decomposed into a formal sum of ordinary Newtonian states. When states are decomposed this way we’re merely representing the state of the particle as a superposition of classical states. It allows us to think of the state classically. But it also invites us to think of point particle as having a ghostly presence in several different locations at the same time. This is the case with other particle properties as well. Classically a particle can’t have both up spin and down spin at the same time. However, in the quantum world a particle could have a state which is representable as a superposition of both spin up and spin down. Such a particle does not really have up spin, nor does it have down spin. However, one can pass the particle through a device that changes its spin-state into either up or down. The device is sometimes misleadingly called a spin detector. But in fact it’s a spin polarizer. It forces the particle to abandon whatever spin-state it currently has and choose between being spin up or spin down. The choice it makes will be dependent upon but not uniquely determined by its current state.

So here’s the set up of the EPR-experiment. A pair of spin-orientable particles is created in the lab so that 1) the net spin of the pair is zero; 2) each individual member of the pair has a spin state that is a quantum superposition of up and down; and 3) each individual member of the pair has a spin state that is identical to that of its partner. Then the two particles are separated. Then in a common inertial frame each of the two particles simultaneously passes through a spin polarizer. A corollary of the law of conservation of momentum, is conservation of spin. So if one particle chooses to be spin up the other will choose to be spin down. But if the choices are made simultaneously at different locations, there’s no time for one particle to signal the other about what choice to make! Einstein, Podolsky and Rosen thought this paradox demonstrated that the principles of quantum theory were untenable. So Ecstatic, you’re in good company. However actual experiments seem to show that the crazy prediction forced upon us by quantum mechanics is in fact true.

Personally, I think there is a hitch: one cannot really compare simultaneous measurements made at different locations at the moment they’re being made. One has to wait until reports of the measurements reach a single observer before a comparison is made. This makes the EPR-experiment impossible to directly verify (IMO). To elaborate on this last point: it’s consistent that the measurements and the reports of the measurements are themselves in superimposed states. Hearing the report of a measurement forces the report into a classical state. Both reports can’t be heard until enough time has elapsed for the two hearings to be causally connected. This means there’s enough time for the reports to have communicated with each other before both are finally heard. It also means the two received reports can’t be verified before the particles are causally reconnected; i.e. sufficient time has passed for the particles to have communicated.

Nevertheless, all the indirect evidence seems to suggest what Einstein thought was crazy behavior is in fact the way the universe behaves. Go figure.

Trish, you rock! I actually understood (I think I understood) all of this, and it makes total sense to me. This is a very coherent and concise description of concepts very difficult to put into words. My niece, and various physicists that I've read, have said that representing physics in English is at best only a metaphorical representation because language isn't capable of expressing the concepts accurately, hence the need for the math, which unfortunately strands most of us who are very interested but lack the math.




There is some kind of connection which is outside space-time

As I said above, outside of our space/time, in a completely different frame of reference.

i'd rather think not. i just think of it these simultaneous correlations as representing a global symmetry in our four dimensional universe. after all, in general relativity all times exist at once. the entire history and future of the cosmos is represented as a distribution of energy and structure within one single four dimensional manifold. in this sense there's no need for communication between simultaneous correlated events. they just exist as a symmetry in the universe. this however is just my quirky way of dismissing the mystery and shouldn't be mistaken for science.

Excellent! Again, my difficulty most assurdedly stems from attempting to understand in English what is best represented in math, but this is how I see it: there is no communication or transmission [of data--random or determined--or matter or energy] between the two entangled particles, but due to their symmetry, when one changes so does the other. Measurement or communication of this requires as Brenda says a classical communication over space-time, and thus there's no way for us to actually confirm this occurance simultaneously when the particles are separated by, say, 100 lightyears of space-time, but that doesn't matter since we're not transmitting (moving over distance) any information.

And hey, I don't mind being in Einstein's, Podolsky's or Rosen's company. :lol:

[Ecstatic]

Your basically right according to David Bohm's interpretation the quantum mechanical world should be though of as one connected whole and not isolated parts. Which is true. Looked at a certain way all we are is fields of energy (mostly E.M.) Bound together chemically and held on this planet by another energy field (gravity). All things are are inherently quantum mechanical.

I belive that entanglement is at the heart of many unexplained phenomena. like when a spouse, sibling (in particular a twin), or friend dies some people seem to get a feeling something is wrong. Even when they are thousands of miles apart. Or in the case of twins separated at birth. There have been many cases where the twins will go on to live very similar lives...right down to having some of the same types of things happen at about the same times.

Fascinating. I tend to put things in a Buddhist perspective, where the quantum mechanical "field" (or whatever you want to call it) corresponds to the Buddhist concept of sunyata or emptiness. As the Dalai Lama puts it, "According to the theory of emptiness, any belief in an objective reality grounded in the assumption of intrinsic, independent existence is simply untenable. All things and events, whether ‘material’, mental or even abstract concepts like time, are devoid of objective, independent existence. To intrinsically possess such independent existence would imply that all things and events are somehow complete unto themselves and are therefore entirely self-contained."

Sunyata is the quantum reality, samsara (the manifest world or maya) is the classical universe superimposed on the quantum level. Classical models are quite useful for driving cars, building bridges, and exchanging ideas on the Internet, but in a quantum view, these are all impermanent and only apparent existencies.

[trish]

thanks for the compliments, Ecstatic. personally,even though i'm comfortable with mathematical arguments, i feel that if i can't put it into english, then i haven't yet understood it. i welcome these threads (when i have the time for them) because often they force me toward a better understanding by putting things into english. i should also confess that i also never feel like i totally understand something unless i can model it mathematically. what can i say, it's a character flaw.

we part ways when it comes to putting quantum mechanics into the Buddhist perspective. but again you're in good company. more than a few physicists have found what they feel to be significant parallels between science and spirit. i regrettably am not one of them.

[JamesHunt]

Trish, what's your opinion on Bell's Theorem???

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

[trish]

Trish, what's your opinion on Bell's Theorem???

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

Actually, in a sense, this is exactly what we’ve been talking about for the last page or three. Bell’s inequalities result from a more in depth analysis of the EPR experiment referred to above. Einstein et al thought the predictions given by quantum theory to the EPR setup were nonsensical.

Why did they appear to be nonsense? Because if you disbelieve action at a distance but believe particles have definite states that determine all their measurable properties, then you can’t believe that a transition of state of a particle at one location can simultaneously correlate in a predictable way to a change of state in a different particle at a different location?

The disbelief in action at a distance is the basic tenant of special and general relativity. It says all actions are local; i.e it takes time for an action to propagate from one location to a more distant location.

The belief that a mechanical system must have definite state that determines all of its measurable properties is called realism.

In quantum theory the latter belief is also known as the hidden variables theory. This is because this version of realism seems, on the surface, to be at odds with quantum theory. In quantum theory mechanical systems have definite states called wave functions, but these states do not determine any of the measurable properties of the system. Knowing the quantum state of a system only allows you to calculate the probability that a measurement of position, say, will have a given outcome. Einstein and others who were unhappy with this feature of quantum theory speculated that there was more to know about the state of a system or a particle beyond the wave function. According to them, the wave function incompletely describes the system or particle under investigation. What ever else that’s required for a complete description are called hidden variables. [As an aside it’s interesting to note that the quantum state of a mechanical system ( i.e. its wave function) does, along with the laws of quantum dynamics, completely and uniquely determine the sequence of all the future states of the system; i.e. a quantum system evolves deterministically until interrupted.]

Put these two prejudices together, locality and realism and you get a philosophy known as local realism. Using quantum theory plus the two added assumptions of local realism Bell was able to show quantitatively how different polarization experiments of particles at one location must correlate to simultaneous experiments of paired particles at a different location. (This is just a generalization of EPR experiment.)

Actual experiments fail to align with Bell’s predictions. The conclusion is that either quantum theory needs revision, or locality must be abandoned or the hidden variables theory must go. The standard interpretation is that there are no hidden variables. There are dissenters but not many and I do not number among them. So what do I think of Bell’s inequality? I think they are correctly derived from the axioms of both quantum theory and local realism. In fact their derivation is relatively simple and straightforward. However, I think Bell’s inequality wrongly predicts the outcome of EPR experiments. When I order my prejudices they line up as follows: First comes “all actions are local.” Second comes “Quantum theory correctly describes the probability distributions of the outcomes of measurements on mechanical systems.” Third, “actual states (the hidden variables) behave classically.” Because Bell’s predictions are wrong, one of these has got to go. For me, it number three.

As discussed in prior posts, there’s an apparent contradiction between the quantum theory and the locality assumption. However, this contradiction is only apparent and cannot be formally derived. I tried to show in those posts how one might think of the EPR experiment in ways that dull the sense of paradox.

[JamesHunt]

Hang on a mo, let's step back a few paces, cos I aint in no state to go in depth. But as I see it, Einstein believed that subatomic particles have a definite postion/velocity/spin, even when not observed, he called it objective reality. But quantum theory flys in the face of this presumption, stating that the particle has no definite position/velocity/spin until it is observed. What is your opinion that an observation/measurement creates the reality?

[trish]

JamesHunt writes:


…as I see it, Einstein believed that subatomic particles have a definite postion/velocity/spin, even when not observed, he called it objective reality.

True enough. There was a point when Einstein made the argument that subatomic particles had states that behaved classically. Knowing the state of the particle should allow one to uniquely determine its position and momentum.


…quantum theory flys in the face of this presumption, stating that the particle has no definite position/velocity/spin....

Again true enough, but misleadingly incomplete. In quantum theory each system (read particle or field) also has a definite state, let’s call it a quantum state (otherwise known as the wave function of the system). Generally speaking a quantum state does not uniquely place a system at a definite location in space, or assign to a system a unique spin or momentum. Usually a quantum will only assign a probability to the statement, “The system is at X right now.” However, there are some quantum states that will assign a definite position to a system, or a definite momentum (but never both). Let’s call these special quantum states semi-classical. If a semi-classical quantum state assigns the system a definite positon, let’s call it a position-state. Some experiments by their design will force a system to transition from its current state to a position-state. Such experiments are called measurements of position. So we can say a system will generally not be in a position-state unless it is put into such a state by a procedure called a position measurement. When fleshed out like this, quantum theory doesn’t sound like idealism or anti-realism; at least not to my ears.


What is your opinion that an observation/measurement creates the reality?

I would have to say no. Quantum theory describes reality differently from the way our common-macro-sense pictures it. A measurement is just procedure that interferes with the natural evolution of the state of a system and forces the system into a semi-classical quantum state. I think all quantum states are equally real. When a system transitions from one quantum state to one that is semi-classical, it’s not becoming more real…it’s just taking on a more familiar and comfortable form.

[Ecstatic]

All of a sudden I'm having visions of cats sealed in boxes with radioactive isotopes and wondering whether the cats are dead or alive....

Open the box, collapse the wave function, grab a beer.....

[muhmuh]

All of a sudden I'm having visions of cats sealed in boxes with radioactive isotopes and wondering whether the cats are dead or alive....

Open the box, collapse the wave function, grab a beer.....

He reached down and lifted up a small kitten, patted it on the head, lowered it gently into the box, and closed the lid.
THE CAT DIES WHEN THE AIR RUNS OUT?
‘I suppose it might, sir,’ said Albert, his manservant. ‘But I don't reckon that's the point. If I understand it right, you don't know if the cat's dead or alive until you look at it.’
THINGS WILL HAVE COME TO A PRETTY PASS, ALBERT, IF I DID NOT KNOW WHETHER A THING WAS DEAD OR ALIVE WITHOUT HAVING TO GO AND LOOK.
‘Er… the way the theory goes, sir, it's the act of lookin' that determines if it's alive or not.’
Death looked hurt. ARE YOU SUGGESTING I WILL KILL THE CAT JUST BY LOOKING AT IT?
‘It's not quite like that, sir.’
I MEAN, IT'S NOT AS IF I MAKE FACES OR ANYTHING.

[JamesHunt]

I'm sorry Trish, I don't get the 'semi-classical' state. If there is any information available prior to a measurement of a previously entangled quantum system, then it would be possible, statistically, to transmit useful information faster than light.

[trish]

I'm sorry Trish, I don't get the 'semi-classical' state. If there is any information available prior to a measurement of a previously entangled quantum system, then it would be possible, statistically, to transmit useful information faster than light.

Sorry if I invented some non-standard terminology. I thought it might be helpful. By a semi-classical state I just mean a quantum state which uniquely determines at least one of the classical properties of the system under consideration. If it means anything to you, a Dirac function would be an example of a quantum state which uniquely determines position. When a position measurement is performed on a system the system transitions from its current state to one which is semi-classical; i.e. like a Dirac function.

I confess, I'm not sure I follow your objection. I assume you're still referring to the EPR experiment. In that setup we know the state of the pair ahead of time and can even write down exactly what its quantum state looks like. But we won't be able to predict exactly the outcome of the simultaneous polarizing measurements (spin up or spin down) performed on the separated elements of the pair, one at location P and the other at Q. Yet quantum theory predicts the two measurements will be correlated and the evidence bears this out. The evidence is indirect because we can't compare the results of the two measurements until the reports of the measurements and the particles have had time to interact again. Nevertheless the evidence of correlation is overwhelming. The fact that the axioms of modern quantum theory are Lorentz invariant demonstrates the theory is consistent with special relativity and hence no one can send messages faster than the speed of light.

Imagine someone at P, successively using the EPR setup, tries to send a coded message to someone at Q using up spins are ones and down spins as zero. The person at P doesn’t have control over the message she going to write because she can’t control the outcomes of the polarizing measurement made on the particles that arrive at P. The fact that she has no control over the sequence and that the message she’s force to write down is absolutely random is a consequence of the fact that there are no hidden variables. This last paragraph is just an informal argument that the EPR experiment rules out hidden variables. The formal argument rests on the fact that Bell’s inequality follows from the assumption that there are hidden variables, but turns out to be empirically false.

[trish]

All of a sudden I'm having visions of cats sealed in boxes with radioactive isotopes and wondering whether the cats are dead or alive....

Open the box, collapse the wave function, grab a beer.....

He reached down and lifted up a small kitten, patted it on the head, lowered it gently into the box, and closed the lid.
THE CAT DIES WHEN THE AIR RUNS OUT?
‘I suppose it might, sir,’ said Albert, his manservant. ‘But I don't reckon that's the point. If I understand it right, you don't know if the cat's dead or alive until you look at it.’
THINGS WILL HAVE COME TO A PRETTY PASS, ALBERT, IF I DID NOT KNOW WHETHER A THING WAS DEAD OR ALIVE WITHOUT HAVING TO GO AND LOOK.
‘Er… the way the theory goes, sir, it's the act of lookin' that determines if it's alive or not.’
Death looked hurt. ARE YOU SUGGESTING I WILL KILL THE CAT JUST BY LOOKING AT IT?
‘It's not quite like that, sir.’
I MEAN, IT'S NOT AS IF I MAKE FACES OR ANYTHING.

First a disclaimer: Schrodinger invented the box to illustrate that one could construct a large mechanical system that featured the same weird quantum behavior that tiny atomic systems exhibit and which only quantum theory seems able to explain. Compared to an atom, Schrodinger’s box is enormously complex. No one can really write down the wave equation describing the initial state of the box and then calculate how it will evolve. Any analysis is open to the critique of being just too simplistic.

The standard analysis goes like this. One component of the box’s state pushes the probability of Puss being dead up, another component pushes that probability down. These components are weighted. Schrodinger, evil genius that he was, designed the box so that the state evolves and the probability that puss is dead increases with time. There’s a moment when the odds are fifty/fifty. At that moment Puss exists. Puss has a physical state. Being alive or being dead are not the only two states physical states available. Puss is neither alive, nor dead. Measuring her vital signs at this crucial moment (or any moment for that matter) is like polarizing or filtering out one of the components of her current state and placed her into one of the “polarized” states…dead or alive. All this sounds weird to be sure. But to me it doesn’t sound like anti-realism. For me, the confusion settles down when you accept that there are physical states besides the ones we’re used to encountering in everyday life. Do you risk killing Puss by checking her heartbeat? Well she was already in a superposed state of being alive and being dead. That can’t be good!

Back to the disclaimer: There are lots of objections one can make to this simplistic analysis of the box. The box itself has a Geiger counter in it that measures whether or not the uranium sample ejected a particle or not. It’s the Geiger counter that triggers the hammer to break the vial of poisonous gas. The Geiger counter itself, one could argue, forces the system into a semi-classical state. If not the Geiger counter, the cat itself is a detection device. Others argue in the other direction. They say when the doctor opens the box and measures Puss’s vitals that the doctor is himself, along with his measurements, in a superposition of states.

My Moral: There’s always a dozen ways to model a complex situation and all of them will be too simplistic in one aspect or another. When trying to understand quantum theory stick to really simple systems and try to understand what’s going on there before tackling the really difficult and complex systems that were originally outside the theory’s domain of application.

[salvador]

I would say that there is only one single incalculable moment, that's in a constant state of transformation.

[skybuddha]

think it has to do with light acting as a wave...constructive and destructive and a bunch of crap that really bores the shit out of me. Just thinking about that subject made me puke in my mouth a little bit...

If you like puzzles at all I dont think this video presents the basic idea in a boring way:

http://www.youtube.com/watch?v=DfPeprQ7oGc

The problem is we dont yet have the mental toolbox for solving and explaining so much that goes on.

Objectively time is just a way of measuring where you came from and how you got there and also where you are going. Subjectively its something you perceive. For time to be accurate you need all the information. If you can control time this does not mean you can erase history, it would just mean erasing the consequences of history which happened even if this history is forgotten. Just my 2 cents but its only a loan . I want them back with interest :p

[BrendaQG]

@Trish

You speak much of the wave mechanics way of solving problems. I was wondering if you have studied Heisenberg Matrix mechanics yet? It makes some problems easier.

Reconsider the cat-box experiment...
In the outlook of matrix mechanics the cat's Hilbert Space is spanned by two states, dead (|d> ) or alive (|a>). Generically there will be some probability that the cat is alive (A) which determines the probability that the cat is dead (1-A). The super position of states can be written in this form.

|cat>=A|a>+(1-A)|d>

0<=A<=1
A superposition like this one is a mixed state. The addition I used is called a convex combination (http://en.wikipedia.org/wiki/Convex_combination).

This set of vectors would represent the space.
{|a>,|d>,|0>,A|a>+(1-A)|d>}

Simple so far. Perhaps too simple? You brought up the interaction between the cat and the Geiger counter. The Hilbert space of the counter is also by itself as simple as that of the cat. It is spanned by two vectors particle detected |+>, and no particle detected |->. With the probability that a particle will be detected given by P.

|counter>= P|+>+(1-P)|-> 0<=P<=1

Also very simple looking. With a set of vectors like the one above.

Now in this formalism there is a clear and simple way to combine the two systems, the Geiger counter-poison and the cat. It is done using what is called a "tensor product" ⊗ (http://en.wikipedia.org/wiki/Tensor_product) of Hilbert spaces. Let us just consider one such product

|cat>⊗|counter>
=(A|a>+(1-A)|d>)⊗(P|+>+(1-P)|->)
=AP|a>⊗|+>+A(1-P)|a>⊗|->+(1-A)P|d>⊗|+>+(1-A)(1-P)|d>⊗|->

(I hope this all comes out correctly in particular the ⊗ symbol.)

As you can see that is not really very simple at all. In fact that state I calculated is by definition entangled. So there is no may be about it. The cat and the counter are entangled. Which as we have discussed leads to some really wierd stuff.

Trish. The wave mechanics you seem to be most familliar with would be recovered from this formlism by taking the product. <y(x)|a>=Integral[dx,{y*(x)<x|a>}]
=Integral[dx,{y*(x)}] (where I reasoned it makes sense for <x|a>=1 for life and existence of the alive cat and <x|d>=0 for the other case.)

[Ecstatic]

Trish and Brenda, once again you've swooop! gone clear over my head. I love this stuff, in the abstract, but the complexities of the math just lose me. But I try.

Every year at Christmas my neice the physcist and I exchange presents with some sort of playful or punning application of a principle or concept in physics. One year I wrote a note on her present that went something like this: "Can you be sure that the present that you will find inside this package upon opening is in fact the present that was there prior to unwrapping it?" Yeah, that's a sloppy representation, but it was all in fun. Everyone else in the family gathered looked befuddled, but my neice started laughing and then explained, in as simple terms as possible, Schrodinger's cat thought experiment. It was a classic(al) Christmas moment. ;)

[trish]

Thanks Brenda. I am familiar with the matrix representation, and you're right: it is the simplest way to model some systems. When attempting to put my thoughts in English I try not to rely on either the wave or the matrix formalism; i.e. I try to get away with the generic phrase "quantum state" as much as possible. But when pressed, I will described the quantum state as a wave rather than matrix, or worse a normal vector in an possibly infinite dimensional Hilbert space. People can wrap their mind around a wave. Matrices, not so much. These distinctions only become really important in discussions concerning exactly how a quantum system evolves (should we solve the time dependent wave equation or should we apply the unitary dynamic operator?). These are things I hope to avoid in this thread.

I agree that a first step toward including more of the complications in a description of Schrodinger's box is to expand the state space by taking the tensor product of the state spaces of all the individual components. What I was getting at in the previous post is: this tensor product is enormous. That is if one is honest about including all the components of the system; the interacting parts of the Geiger counter, the organs and cells of the cat, their organelles etc. Given that we don't really know what constitutes a measurement (some say an encounter with a macro-system, some say an encounter with a complex system, some say an encounter with a sufficiently large gravitational field, some say an encounter with a conscious agent), I believe a serious analysis of the box requires consideration of the box's full complexity. Something I'm not prepared to do.

On a personal note: Quantum theory has never been my favorite subject. My familiarity with it arises out of need. I find the mathematics (regardless of which formalism one uses) cumbersome, tedious and ugly. But that's just me. I know people who just eat it up; apparently not Sweet Cheri though. I'm a much more geometric thinker. I prefer smooth manifolds and metric tensors to function spaces and integrals that refuse to converge. I was just worried people here were getting the idea that quantum theory is my thing.

Hi Ecstatic. Beautiful story. You're just lucky the present didn't tunnel through the wrapping and escape.

(Sorry for the late edit; I just couldn't stand leaving the spelling the possessive of box as "boxes"!)

[Ecstatic]

Hi Ecstatic. Beautiful story. You're just lucky the present didn't tunnel through the wrapping and escape.

Trish, I'm going to have to tell my neice that! :lol: :lol: :lol:

[JamesHunt]

If it means anything to you, a Dirac function would be an example of a quantum state which uniquely determines position. When a position measurement is performed on a system the system transitions from its current state to one which is semi-classical; i.e. like a Dirac function.


Nope! Hilberts space, tensor calculus & group theory is out of my league, I'm still struggling with integration, lol


Trish & Brenda. I know we have these wierd and wonderful interpretations of Quantum theory, Coponhagen, parallel universes etc... and this is primarily what interests me, the philosohpical implications of quantum theory. One of my favourite books is 'ghost in the atom'.

http://www.amazon.com/Ghost-Atom-Discussion-Mysteries-Quantum/dp/0521457289/ref=pd_bbs_sr_1/103-3809746-1322252?ie=UTF8&s=books&qid=1200705356&sr=1-1

And Ecstatic, if you havn't read it, I strongly suggest you do, its an excellent book written in plain english.

Anyway, John Bells interview seemed the best to me, and he says that the resolution of quantum theory will not be trivial, and will require a completely different outlook on how we view reality. What are your views on this Trish & Brenda? Do you believe that someone out there within the next 50 years or so will see the bigger picture, and devise a theory backed up by experiment, that will completely shock us all???

[BrendaQG]

I see where you are comming from on the math. I just could not help myself. Sometimes its hard do remember that this stuff is out of most peoples need to know. I just cant think of a better way to express entanglement.... In particular that it does not depend on the space-time coordinate at all. Using the idea of wave functions one has to include such coordinates.

What you say has me wondering. Have you studied any "hidden variable theories"?

[Ecstatic]

One of my favourite books is 'ghost in the atom'.

http://www.amazon.com/Ghost-Atom-Discussion-Mysteries-Quantum/dp/0521457289/ref=pd_bbs_sr_1/103-3809746-1322252?ie=UTF8&s=books&qid=1200705356&sr=1-1

And Ecstatic, if you havn't read it, I strongly suggest you do, its an excellent book written in plain english.

Sounds interesting. I've read quite a few excellent books over the years, starting with George Gamow's "1-2-3 Infinity" back in high school, Fritoj Capra's "Tao of Physics", David Darling's "Zen Physics", John Gribbin's "Search for Schrodinger's Cat" and "Schrodinger's Kittens and the Search for Reality", Brian Greene's "Elegant Universe", Hawking's "A Brief History of Time" and several others. Like I say, I'm fascinated by the concepts and strive to understand, at least at an elementary (pun intended) level, even if the math makes me head spin up (or is that spin down?).

[trish]

Hi BrendaQ. No. I can’t say I’ve studied any hidden variable theories. I’ve read Manin’s treatment (in his book: Mathematical Logic) of von Neumann’s “proof” that there can be no hidden variable extension of quantum theory. And I’ve also read several treatments of Bell’s inequality and its relation to the EPR experiment. I can’t recall what papers or texts I read except for Quantum Mechanics and the Particles of Nature by Anthony Sudbery. On the positive side one section that same text sketches out the mathematical framework of David Bohm’s pilot wave theory which is a hidden variable theory. I haven’t read any serious works that developed or fleshed out the basic premises of that theory. I understand that no one has ever been able to reconcile his theory with special relativity. I’ve noticed I have an untouched copy of Bohm’s “Undivided Universe: An Ontological Interpretation of Quantum Theory” stuffed into my bookshelves. You may force me to crack it.

Hi Ecstatic. As far as popular works on science goes I recommend

“Into the Cool: Energy Flow, Thermodynamics and Life” by Eric D. Schneider and Dorion Sagan.

“A Different Universe: Reinventing Physics from the Bottom Up” by Robert B. Laughlin

“Black Holes and Time Warps” by Kip Thorne

“Challenging Nature: The Clash between Biotechnology and Spirituality” by Lee M. Silver.

“How the Universe Got Its Spots” by Janna Levin.

“Regrettably none of these is directly concerned with interpretations of quantum theory.

One of my favorite sci fi books is He, “She and It” by the American Poet and Novelist Marge Piercy.

JamesHunt, you ask a difficult question. I thinks its almost certain that in the next fifty years physics will see a mind bending, paradigm shifting breakthrough. It’s just impossible to predict what it will be. The expansion of the universe is accelerating. The cosmological constant models of that expansion have all sort of wild, mind boggling but untestable consequences such as an unfathomable (perhaps infinite) number of bubble universes beyond the cosmic horizon (see Vilenkin’s “Many Worlds in One”). These fantasies are getting us into all sorts of dark Cartesian conundrums (check out http://cosmicvariance.com/2008/01/14/boltzmanns-universe/). The resolution of embarrassing paradoxes often leads to bold new advances in our understanding. I guessing the future will see a reconciliation of quantum theory and general relativity that revolutionizes and our understanding of entropy, spacetime and the cosmic expansion. I don’t think it will involve hidden variables. I think we just have to learn to live in a quantum world, just as we’ve learned, with Einstein, to live in a world without simultaneity.

[Ecstatic]

Thanks for the suggestions, Trish. They all sound fascinating.

[trish]

Hello BrendaQ, Ecstatic, JamesHunt and all the other contributors and readers of this thread. I just ran across a book on EPR and hidden variable theories that I can highly recommend.

Wick, David. “The Infamous Boundary: Seven Decades of Controversy in Quantum Physics.” Birkhauser 1995

It’s roughly 200 pages long. I read it most all weekend and got through about 100 of them. Birkhauser is an academic press and Wick is a mathematician. So book is aimed at a sophisticated audience but it avoids mathematical argument and recondite physics. Wick takes a historical approach to subject. His interest is in giving a clear and concise account of the philosophical motivations behind the various hidden variables theories from Bohm to 1995. So far I found his account to be accurate and crystal clear. I like the way the guy writes. He’s terse but understandable. He doesn’t lollygag but gets to the point as quickly as possible. BrendaQ, if you’re interested in hidden variable theories, find this in the library and read it first. For you it should be a quick and worthwhile read.

[JamesHunt]

:arrow:

http://www.amazon.com/Infamous-Boundary-Decades-Controversy-Quantum/dp/B000WBR17M/ref=sr_1_1/102-7432736-0671354?ie=UTF8&s=books&qid=1200974200&sr=8-1

[JamesHunt]

:arrow:

Typed

'The Infamous Boundary: Seven Decades of Controversy in Quantum Physics into amazon. is this it?'

http://www.amazon.com/Infamous-Boundary-Decades-Controversy-Quantum/dp/B000WBR17M/ref=sr_1_1/102-7432736-0671354?ie=UTF8&s=books&qid=1200974200&sr=8-1

[JamesHunt]

delete, see above

[JamesHunt]

I can't fucking leave this alone. If there are any hidden variables prior to a measurement of the system, then causality must be an illusion. Was Bell correct? We live in a super determenistic universe???? Let's bring back the ether.......

[big_red3445]

ok so wut if the proton and the neutron skip each other and rotate the maduela ablan gotta? it makes an electron! *dont listen to me im retarded*

[trish]

:arrow:

Typed

'The Infamous Boundary: Seven Decades of Controversy in Quantum Physics into amazon. is this it?'

http://www.amazon.com/Infamous-Boundary-Decades-Controversy-Quantum/dp/B000WBR17M/ref=sr_1_1/102-7432736-0671354?ie=UTF8&s=books&qid=1200974200&sr=8-1

that's the one.

[Ecstatic]

Sounds like my kind of book, Trish: in-depth without excessive maths!! :lol:

[Realgirls4me]

Does Time Exist?

Most certainly! Check out just about any escort review here and at other sites and notice how often time is referenced for one reason or another.


... See, no need to get all technical about it. Hee-hee.


Nerds ;)

[El Nino]

Not if you're dead...

[trish]

what is this "dead" you speak of? it sounds ominous.