2013/1/17 Bruno Marchal <[email protected]> > > On 17 Jan 2013, at 13:32, Telmo Menezes wrote: > > Hi all, >> >> Naive question... >> >> Not being a physicists, I only have a pop-science level of understanding >> of the MWI. I imagine the multi-verse as a tree, where each time there is >> more than one possible quantum state we get a branch. I imagine my >> consciousness moving down the tree. >> >> Suppose Mary performs the Schrodinger's cat experiment in her house and >> Joe does the same in his house. They both keep the animals in the boxes and >> don't take a peak. Don't tell PETA. They meet for a coffe in a nearby >> coffeeshop. >> >> So now we have four possible universes where Mary and Joe can meet. But >> from the double slit experiment we know that the cats are both still >> dead+alive in the current universe. Right? So are Mary and Joe meeting in >> the fours universes at the same time? >> > > Let a = alive, d = dead, and the subscript 1 and 2 distinguishes the two > cats, which are independent. Both cats are in a superposed state dead + > alive: > > (a1 + d1) and (a2 + d2), > > so the two cats configuration is given by (a1 + d1) * (a2 + d2), with "*" > the tensor product. > This products is linear and so this give a1*a2 + a1*d2 + d1*a2 + d2*a2. >
I think it is d1*d2 and not d2*a2. Regards, Quentin Mary and Joe don't interact with any cats, so the global state is also a > direct tensor product M * J * (a1*a2 + a1*d2 + d1*a2 + d2*a2), which gives: > > > M * J *a1*a2 + M * J *a1*d2 + M * J *d1*a2 + M * J *d2*a2 > > You can add the "normalization" constant, which are 1/sqrt(2) times > 1/sqrt(2) = 1/2= > > 1/2 M * J *a1*a2 + 1/2 M * J *a1*d2 + 1/2 M * J *d1*a2 + 1/2 M * J *d2*a2 > > So the answer to your question is yes. > > To be sure, the normalizing factor does not mean there are four universes, > but most plausibly an infinity of universes, only partitioned in four parts > with identical quantum relative measure. To get the exact "number" of > universes, we should first solve the marriage of gravity with the quantum. > And with comp, we should also derive the Quantum from arithmetic (but > that's not true, actually: with comp we have directly the infinities of > "universes"). > > Best, > > Bruno > > > http://iridia.ulb.ac.be/~**marchal/ <http://iridia.ulb.ac.be/~marchal/> > > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To post to this group, send email to > everything-list@googlegroups.**com<[email protected]> > . > To unsubscribe from this group, send email to everything-list+unsubscribe@ > **googlegroups.com <everything-list%[email protected]>. > For more options, visit this group at http://groups.google.com/** > group/everything-list?hl=en<http://groups.google.com/group/everything-list?hl=en> > . > > -- All those moments will be lost in time, like tears in rain. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
