Recent content by gabeeisenstei

I recently understood Bell’s theorem (the inequality and the QM calculation), with the help of you guys. But something still bothers me: assuming for the moment that Bell’s inequalities were NOT violated by experiment, how we would we understand the dependence of the varying correlations on the...

I think I got it. This was a learning experience for me, as I wasn’t sure about some of the vectors and haven’t done much with tensor products. Here’s how I got <Φ|A(a)B(b) |Φ> = 1/√2 (in example from quantiki): |Φ> = 1/√2 (|+x> ⊗ |-x>) - (|-x> ⊗ |+x>) |+x>= [1 0] |-x>= [0 -1] (writing...

Thanks atyy, I should have known that because it says <ABphi | phi>, but I’m still a beginner. ((And by the way I really appreciate how you guys try to feed beginners the right information without knowing their backgrounds.)) But now I’m stuck on how to turn |+x> into <+x| (I guess I don’t...

Dr Chinese yes I was looking for derivations (that I can understand). (Our last posts probably crossed.) Also I don't know what PDC types are.

Thanks folks, I read the quantiki. Can you walk me through it just a bit more slowly…I don’t quite understand where the definitions of B(b) & B(b’) come from. B(b) makes sense for 45 degrees, but I don’t understand the minus sign; nor the minus sign in B(b’). And I can’t quite see how the...

I have read many explanations of Bell’s proof that mention in passing something like “According to QM, the correlation between measurements of spin at different angles should be given by the cosine of the angle between them.” Sometimes they talk about 1-cos(x)/2. Sometimes they talk about...

Thanks very much, I think I've got it. DaleSpam & WbN's posts were both helpful and, I think, complementary. The example of signals sent to the middle of the pole was a good reminder. I suspected all along that the working principle would be to analyze processes in their rest frame, and that...

JVNY thanks for your input too, but I wasn't thinking about length contraction, just mixed states in skewed simultaneity slices. Another off-the-wall idea I had was a pole made of alternately matter and antimatter atoms. There are probably many things wrong with that idea.

Thanks to all responders. I wrote this before seeing PAllen's post: ( pervect's point about FTL interactions is along the lines of what I was looking for: I wanted someone to take a hypothetical interaction between the temporally mixed segments and show that it really wouldn't happen...

Seeing a different shape seems just like seeing the stripes; it doesn't seem problematic to me. My question is about physical processes, like the explosion in my example, generated by the contiguity of features in the moving frame that are not contiguous in the rest frame. Or in my...

In Special Relativity the example is given of a pole that alternates color, as seen in its own rest frame. Someone in a different frame is supposed to see the pole as striped, because he sees a different slice through 4D spacetime--a slice that includes past and future states of the pole mixed...

Thanks very much, I'm reading both the Wald and the Thorne now. It's a lot to digest, especially as regards the interdependence of T and g. But one thing I glean right away is that the time-time component of T is more or less the same as the M in the metric (with relativistic correction, or...

I'm trying to clarify for myself the relation between the stress-energy tensor and the mass scalar term in metric solutions to Einstein's equations. Maybe I should also say I'm trying to understand the energy tensor better, or how it relates to boundary conditions on the solutions. My...

I'm having trouble with the idea of conservation of information. I watched Susskind introduce the concept of entropy as "hidden information", using an example of drops of water filling a bathtub: a message encoded in the sequence of drops is lost for practical purposes, but in principle is...

My question arises in the context of bosonic string theory … calculating the number of dimensions, consistent with Lorentz invariance, one finds a factor that is an infinite sum of mode numbers, i.e. positive integers … but it really goes back to Euler, and his argument that the sum of all...