Welcome

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Welcome!

Hello, Mastertek, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are some pages that you might find helpful:

I hope you enjoy editing here and being a Wikipedian! Please sign your messages on discussion pages using four tildes (~~~~); this will automatically insert your username and the date. If you need help, check out Wikipedia:Questions, ask me on my talk page, or ask your question on this page and then place {{help me}} before the question. Again, welcome! RJFJR (talk) 14:02, 15 September 2011 (UTC)Reply

Expert tags

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Hi. If you're going to tag something as needing expert attention, you should really state on the article's talk page what specific issue needs attention, as explained here: Template:Expert. Im specifically saying this in regards to Bell's theorem. Clearly the article could be improved, but the expert tag is meant to highlight specific problems.... Isocliff (talk) 00:42, 18 October 2011 (UTC)Reply

Your recent edits

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  Hello. In case you didn't know, when you add content to talk pages and Wikipedia pages that have open discussion, you should sign your posts by typing four tildes ( ~~~~ ) at the end of your comment. You could also click on the signature button   or   located above the edit window. This will automatically insert a signature with your username or IP address and the time you posted the comment. This information is useful because other editors will be able to tell who said what, and when. Thank you. --SineBot (talk) 08:44, 20 October 2011 (UTC)Reply

Entanglement, etc

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Hi,

The entanglement page is getting a bit busy, so I thought I would write to you here. The idea of instantaneous communication went out some time ago when the speed of light was measured. Einstein argued that there is a maximum speed for transmission in the universe, and that the fact that light can't go faster is the result of this speed limit. I think the idea was to rule out the possibility that there could be anything else that could go faster than light. (Now there is some concern because neutrinos seems to be able to go faster than light. Who knows where that argument will end up.) Anyway, the idea was that anything "here" that makes a change "there" has to go through space and time. So anything that goes from here to there has to obey the same speed limit.

Now we've got something that evidently goes from here to there, but it doesn't go by way of space, and it doesn't take any time no matter how great the physical separation. It is very upsetting to people, and most people will twist and turn to try to make things turn out looking as they always have looked. After all, how can we deal with the picture of two things being "entangled" in some lab on earth, and then while one is kept "in a bottle in the lab" somehow, the other one is shipped off to the moon or to some other solar system, and when we make one of the two "decide" whether it is spinning one way or the other by doing an experiment in this lab or at the remote lab, then the other one will be discovered to have "decided" to spin the other way? Sometimes we hear stories of human twins who seem to know what is happening to each other over vast distances. "I woke up in the middle of the night and knew my sister had died in a car wreck in Nairobi." The claim is generally that the knowledge arrives instantaneously, so in that respect it is like entanglement. But it is much easier to reproduce entanglement results.

If you want to fry your brain, take a look at the quantum eraser experiment of Kim, et al., Delayed choice quantum eraser. Detector 0's behavior is determined by whether a photon shows up at Detector 1, 2, 3, or 4. However, Detector 0 is closer to the starting point of the entangled photons, so it has to get its photon first. Nevertheless, what happens afterwards determines whether it will behave "as it ought to behave" for a double-slit experiment, or whether it will behave as though one of the double slits was blocked. It's like if twin Iris were going to see their maternal grandmother, and she ordinarily gets along with her very well, and twin Erma were going to see their paternal grandmother where everything depends on which side of the bed grandma got up on that day. There is a fifty-fifty chance that they will have a spat. Iris gets to their maternal grandmother first and has a spat with her, and the only reason is that Erma encountered (half an hour later) the other grandmother who was in a vicious mood that day. On another day Iris got along fine with their maternal grandmother, and Erma encountered their paternal grandmother who was happy because she had won at canasta the night before. Even if their brains were wired together by radio, that would not make sense. If anything, since Iris always arrives as her destination first, and she gets along fine with grandma, then Erma should be coerced to have a good time with the paternal grandmother because she has been put in that state of mind by Iris's good experience. But that's not what happens. It all seems to hinge on the fact that, in the real world, in the experiment of Kim, et al., the only situation in which one possible outcome can be eliminated is the situation that they have deliberately set up to occur later. (The experiment, for the "Erma" side, is like a pachinko game with four holes at the bottom. A ball rolls in the top, goes does through a chance path, and has to come out in only one of four places. Two of those places will let the other "ball" do what it ordinarily would do anyway, and the other of those places will make the other "ball" do what is should not be able to do.) I'm probably going to confuse you by trying to talk about the experiment in analogical terms. But even when you get a clear idea of how it works it will still fry your brain.

The whole thing almost sounds like a medieval scholastic wrangle about the number of angels dancing on the point of a pin. It sounds like the reality is that two entangles photons are one and the same photon, no matter that they are in different places (what an irrelevancy). So when something happens to the one of them then it happens to the "other"/"same" one of them. If the same thing happens to the same thing how can there be two times involved.

Anyway, for physicists dealing with normal things, nothing is instantaneous. Even your hand turning a key in a lock does not mean the tip of the key moves simultaneously. It's like twisting a longish length of old garden hose. It's just that the key has a little less stretch in it, more like new garden hose. P0M (talk) 02:43, 3 December 2011 (UTC)Reply