User talk:Wodan

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[edit] Nazi Contradiction (Gun politics in the United States)

The criticisms of the Nazi example in this article are at the very least poorly worded but more likely historically misleading. Based on your comments on the talk page you seem qualified to correct the problem, which I hope you will do. Thanks, Audioweevil 04:16, 3 December 2006 (UTC)

  • Which page are you referring to? Wodan 22:44, 3 December 2006 (UTC)

[edit] EPR Paradox

1) The trouble is that you can't transmit any useful information FTL. I observe one particle. Another person observes the other particle. It isn't until we compare notes that we know that something odd is going on, and we can't compare notes without normal slower than light communication.

2) If you observe one particle at 1/2 spin, the other one will always be at -1/2 spin. This is due to basic conservation of momentum. The obvious answer is that well, particle one was always at 1/2 spin and particle two was always at -1/2 spin. No mysterious changes, no need to invoke FTL travel or any other weirdness.

This seems to explain perfectly quantum entanglement. However the trouble is that Bell's inequality will give you a situation in which the logical simple answer for what is going on breaks......

Let me know if this makes sense. One thing that needs to be put into the EPR paradox is that there is a simple inituitive logical non-mysterous explanation for it which unfortunately just won't work.......

Roadrunner, thanks for your reply. I understand my misunderstanding about information travel not being FTL, as it is fundamentally no different than a third party sending notes out to distant players in universe. However, what you said about spin doesn't make sense yet:

As I understand from QM, things like spin cannot be known until measured, due to the fact that every particle-wave only has probabalistic properties which are not expressed until measured.

You are getting to the heart of the issue. There are a number of ways to interpret the results of quantum mechanics. The idea that objects really don't have a real value until

they are measured is one way of looking at things. Einstein didn't like that way of looking at this, and his point in bringing up the EPR paradox was to argue that the idea that objects didn't have a real value until they are measured would bring up a whole bunch of problems.

But if we measure one spin of an entangled particle, does that not mean we then know the spin of the other? Which would mean that "the spin was always there," which is what you said but also seems to violate QM? Or does it just violate my understanding of it?

You are getting to Einstein's argument that QM is incomplete. Einstein was saying that if things didn't have a value until you measure them them if you measure one object then somehow an entangled object "magically" gets a value. Therefore in Einstein's view, the standard interpretation of QM had some big problems.

Similar result when dealing with location. If we measure the location of one particle, can't we determine the location of the other based on conservation of momentum? And if we know the location, we can measure speed and know both, which according to QM is impossible.

Funny thing. If you measure the location of one particle, you can't measure the speed. Now what about measuring the location of one particle and the speed of the other entangled one. Funny thing, if you work through the math, you find out that you can't.

So what does QM say to explain this?? Another way to look at it, is that probabilistic location is not possible if conservation of momentum is to hold for the quantum world, else it would mean that locations must always be fixed and not probabelistic in nature. ???

This is where the weirdness comes in. All of the measurements that you do end up showing the conservation of momentum holds exactly. So one would think that this means that particles actually have real locations that we can't measure, but if that were true then you can show that it turns out that all of the particles in the universe have to talk to all of the other particles in the universe to make sure that the bookkeepping comes out right. This *doesn't* come directly out of the straightforward examples we've been talking thus far, but it does come out of a slightly different experiment using Bell's inequality.

Wodan 16:45, Aug 29, 2004 (UTC)

Roadrunner 01:13, 30 Aug 2004 (UTC)

Something to keep in mind here is that quantum entanglement was intended by Einstein in order to show that the standard interpretation of quantum mechanics (i.e. the notion that objects don't really have measured values until you measure them) leads to all sorts of problems (and it does). If you use the standard interpretation of QM to explain the quantum entanglement, you start to sound silly.

The trouble is that if you accept Einstein's notion that entanglement shows the standard view of QM is wrong, you can set up a different experiment to show Einstein's alternative is mathematically impossible if QM is correct. So yes you do sound silly when you use the standard intepretation of QM to explain entanglement, but "sounding silly" is better than arguing something that is mathematically impossible.

Roadrunner 01:33, 30 Aug 2004 (UTC)

Roadrunner, as you probably expected, I do not understand this comment:

Funny thing. If you measure the location of one particle, you can't measure the speed. Now what about measuring the location of one particle and the speed of the other entangled one. Funny thing, if you work through the math, you find out that you can't.

I'm not trying to resolve the QM paradox, but simply to understand it. The above makes no sense to me. We can measure a particle's position, and we can measure another particle's velocity. Why then can't we measure them in the context of an entangled pair? What sorts of results do we see that stop this from happening?

O.K. you have an entangled pair starting from zero momentum. If you measure the momentum of A, and the momentum of B you will always find that momentum is conserved. Now there is nothing that keeps you from measuring the momentum of A and the position of the B. Einstein argued that from this thought experiment, we now know the position and momentum of both particles. The standard QM interpretation of the situation is that you don't, that when you measured the position of B, you destroyed the momentum information of the B, and that when you measured the momentum of A, you destroyed the position information of particle A. The QM interpretation position seems a little silly that you can make inferences about A from B when you are measuring one thing, but not when you are measuring another, and that was Einstein's point.

I realize the math is almost surely above my knowledge, but as my dad always said; "if one really understands what he is saying, he can explain it in simple terms to somebody who doesn't." So can you please clarify your statement a bit further? What sorts of results do we see that stops the measurement of one particle's velocity and another particle's position. Isn't that indeed something that is done on a regular basis?

You can always do the measurement. The funny stuff happens when you try to make inferences from those measurements.

Now to see if I understand where things stand correctly. According to QM's accepted position, quantum properties are indetermined. Measuring one entangled particle determines the properties of its entangled pair through instantaneous action at a distance, because these two particle-wave functions are actually representations of a single, higher particle-wave function. This obviously implies that all or nearly all particle-waves in the universe are just expressions of a single massive particle-wave function that describes all matter and energy in the universe with non-local laws.

Actually no. The weirdness only happens when you have entangled particles. It's actually pretty difficult to get particles to entangle with each other. Also, replace "determines" with "*seems* to determine". There are a number of ways to deal with the issue, some of which involve assuming that covert information gets sent at a distance, some of them don't. See the wiki article on interpretations of QM.

I realize this sounds "weird," but is my understanding of the standard interpretation of QM correct?

There are about four or five interpretations about what is going on. What you are describing is one of them (i.e. the Bohm interpretation).

And if it is, and it is indeed so weird, then are there any leading theories with credibility in the science world to make sense of it, such as the hidden local variable theory? Is that still in contention?

It can be mathematically shown that if hidden local variables is correct, than quantum mechanics is wrong and vice versa. It is possible that QM is wrong (though most people don't think so). Some people (including one of the major contributors to the Bell inequality article) are of the opinion that QM must be wrong because it violates local realism. Experiments are ongoing.
The demonstration that QM is incompatible with local realism is as follows. Say particles "really" had a spin up and spin down. Now you set your detectors so that instead of being straight up and down, they are skewed a little so that sometimes the detector will "flip" the value that is being measured. Now the "flips" should not be coorelated because whether one detector flips the value shouldn't affect whether the other detector "flips" the value. But QM shows that the "flips" will be coorelated in a way looks like the detectors are passing information back and forth.

Are there any other viable theories which remedy the problems in the last paragraph, and if so, what are they and what problems do they have themselves?

So I guess in summary I have three new questions, as presented by the three previous paragraphs:

  1. Why/how is it in practical terms that we can't measure the velocity of one entangled particle and the position of the other?
You can. But QM says that you can't draw some obvious inferences from that measurement.
  1. Does accepted QM imply that all matter and energy is described by a single master particle-wave equation which acts in a non-local manner?
There are four of five interpretations of quantum mechanics. Actually you don't need both a master non-local particle-wave. If you have a single master particle-wave, then you can keep locality. You can also not have a single particle-wave, but then you can't keep locality. QM says that you can't have both real values and locality, you can have one, the other, or neither.
  1. Are there any viable theories that are trying to remedy the previous question?
Local realism won't work. The trouble with the different interpretations of QM is that they give exactly the same answer (or seem to), and so it's not obvious how one would perform an experiment to test them. See quantum suicide for one proposed but very impractical experiment.

Roadrunner 16:09, 30 Aug 2004 (UTC)

I realize this may be on the fringe of "there is no answer," but I'm only seeking to "catch up" with what is thought to be the position of QM and its problems. Thanks!

Wodan 13:54, Aug 30, 2004 (UTC)

I think I'm getting closer. You said:

Now there is nothing that keeps you from measuring the momentum of A and the position of the B. Einstein argued that from this thought experiment, we now know the position and momentum of both particles. The standard QM interpretation of the situation is that you don't, that when you measured the position of B, you destroyed the momentum information of the B

Is that because QM says that once you measure the position, the question of momentum is an irrelevent/irrational/imaginary question?

The problem is difraction. If you cause light to have a definite position, difraction causes the wave function of that particle to spread out (i.e. to have indeterminate momentum).

Classically thinking, even if the momentum information is somehow destroyed, knowing the momentum of the entangled particle will reveal the information when it was destroyed. Does QM say that my measuring the position, the concept of momentum was somehow destroyed and it is an invalid inference to determine it by the measured momentum of the entangled particle?

Classically, if you try to localize a wave, then the wave starts to diffract and you have indeterminate momentum.

The above is my main question. But you also said:

The weirdness only happens when you have entangled particles. It's actually pretty difficult to get particles to entangle with each other.

Wouldn't every particle be entangled when they at the very least collide? At that point, one's properties (spin, momentum, etc.) are associated with the other particle. In fact, collision would not be necessary, but even electromagnetic interaction, since they change each other's momentum, and should therefore be able to reveal the other's momentum when measured in a classical sense. In this view, every time a particle directly interacts with another particle, they become entangled. Furthermore, if A is entangled with B, and B is entangled with C, then A should be entangled with C through a chain. So in effect, given enough time, every particle should be entangled, especially if the universe was very dense in the begininning.

Once you observe the particles, they get disentangled. If particles A and B are entangled, once you look at either A or B, the wave function collapses and the particles are no longer entangled. This is why it is hard to get an entangled state to last for very long. The momemnt the particles are observed, the entanglement disappears.

Also, your statement...

The demonstration that QM is incompatible with local realism is as follows...

This implies that entangled particles communicate with each other at infinite/simultaneous speeds across any distance. Is that the correct consequence of QM non-locality?

Or else the information about the particles is not localized in one place. You don't to have particles communicate with each other instantenously if you give up realism. i.e. you can argue that before you observed them, that the particles weren't really there and what was there was a wave function in which the information was spread out across the whole wave function.

Roadrunner 06:23, 1 Sep 2004 (UTC)

Wodan 23:10, Aug 31, 2004 (UTC)

[edit] The Twin Paradox

Hi, I haven't logged in to Wikipedia in a long time, so it's only now that I noticed your message about the twin paradox. Were you looking for answers to these questions or some earlier ones?

  • Then why does one move through time and one move through space? How does timespace decide which is moving through space and which is not, since it's impossible to observe either, and really, is rather meaningless since there is no reference whatsoever...?
  • Additionally, since there are no absolutes, me spinning around at night and watching all the stars in the universe is the same as the universe spinning around me, and no more or less valid. Then how is it that the universe just spun around me, since that would imply matter moving at much greater than the speed of light?
  • Yes, I was looking for answers to these questions, as well as many others... Wodan 01:43, Oct 15, 2004 (UTC)

[edit] AWB page

How's it going over there?

Please answer on my talk page if there's anything I should be doing. Otherwise: Hi! Jimbo Wales 20:35, 19 Nov 2004 (UTC)

[edit] Image:Bowles_Hall.jpg

Image deletion warning The image Image:Bowles_Hall.jpg has been listed at Wikipedia:Copyright problems because it is a suspected copyright violation. If you know that the image is legally usable on Wikipedia, please provide the necessary information.

--fbjon4649(talk) 13:17, 9 Apr 2005 (UTC)

In answer to your question on the image page; no, just because there is no copyright information where you found the image doesn't mean that it is PD. For example, how do you know that the page you got it from isn't violating someone elses copyright? --Duk 20:54, 16 Apr 2005 (UTC)

Hi Wodan, thanks for the note. I added a copyright tag to the image page. Every image that is uploaded needs a tag or it will be deleted. The tags are listed at Wikipedia:Image copyright tags and there is a link to this page on the image upload form. Please check and make sure I added the correct tag. --Duk 18:46, 19 Apr 2005 (UTC)

[edit] Silveira v. Lockyer

I began an article on Silveira v. Lockyer. Temtem 02:46, Apr 22, 2005 (UTC)

[edit] Palo Alto high school

Thank you for trying to help the site, but it is obvious you have never been there. While that is the correct street address, you posted a picture of the adjacent shopping center. See the talk page for more information. I suggest not putting in addresses into map services and posting it for places you are not familiar with for the above reasons. Thanks. Wodan 03:16, May 2, 2005 (UTC)

  • Rather than berate me, would you mind fixing the aerial photograph by uploading a better one? A replacement is easily obtainable from Microsoft's Terraserver. Tallyman 20:54, 2 May 2005 (UTC)
    • A newly framed version has been reinserted into the article, along with a photograph of the school billboard. Tallyman 00:08, 4 May 2005 (UTC)

[edit] Rfc

I've recently filed a request for comment against User:Mlorrey at Wikipedia:Requests for comment/Mlorrey. Since I saw you were attempting to talk to him at Talk:gun politics in the United States, I was hoping you could certify it. Thanks very much. Meelar (talk) 18:37, May 26, 2005 (UTC)

[edit] 141.156.208.66

Well, the block of addresses 141.156.208.64 - 141.156.208.79 is assigned to "Brandy (sic) Campaign". Deh 01:42, 8 February 2006 (UTC)

Brady campaign to prevent handgun violence? Would that be Handgun Control Incorporated Lite? I should have known. Funny, when called to the carpet, they cannot back up any of their assertions. Law, case law, popular opinion, and plain ol' logic are on our side. Fear is on their side. Funny that this was an institutional attack, though, and not some punk anti-gunner. It seems that only the well-funded elements of the anti-gun side have the desire to lie and spread their propoganda. I'd be willing to BET that there's no funding of those of us, like you, who stand up for freedom. Thanks.--Asams10 02:43, 8 February 2006 (UTC)

[edit] 1989 and 1998 Executive Orders banning firearms importation?

Figured I'd ask you, since I'm having a hard time locating them.

Various sources reference the 1989 "Import Ban" as being a GHW Bush Executive Order, and the the subsequent additions in 1998 by Clinton as also being enacted by Executive Order.

Do you have any information on this? I'm looking for the actual text of these orders or legislation, which bans a number of firearms, by name, from import.

Many thanks! --Kythri 03:07, 10 April 2006 (UTC)

  • I've done my best to answer your question on your user page. I have more details on your page, but my main conclusion was that the importation restrictions were not Executive Orders, but were rather Department Of Treasury (ATF) studies, which at least in 1998 had the backing of the White House, and probably in 1989 as well. These are therefore neither orders nor legislation, but are incorporated into the Code of Federal Regulations which is created by the agencies responsible for enforcing the United States Code. Wodan 16:46, 13 April 2006 (UTC)
Many thanks! Only other question that I have is - do you know where these lists of banned-from-import firearms are? I've heard 38 (or 30-something) banned in 1989, and an additional 53 banned in 1998. Kythri 11:36, 14 April 2006 (UTC)
I have not been able to get a response from the ATF Technical branch. Those are the people who are supposed to carry that kind of information, which is extremely difficult to get a hold of. If you want to continue the efforts, you can email their Q&A address at eps@atf.gov, though I have not received a response yet. I spoke with the ATF Imports Branch on the phone and they had no idea. Good luck. Wodan 17:15, 24 April 2006 (UTC)
Update: Good news. I found the information for you. You can find it on pages 167 and 168 of publication 5300.4 Federal Firearms Regulations Reference Guide 2005. You can download the entire pdf file here. Wodan 23:11, 5 May 2006 (UTC)
THANK YOU!!! Kythri 11:48, 30 May 2006 (UTC)


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