If your spacetime coordinates for one point are x,y,z,t and for another point are x1 ,y1, z1 ,t1; if one could, in principle, travel between the two at c, wouldn’t they appear, in the RF of the traveller to be superimposed?
Correct .. at c all points in the universe overlap as [0, 0, 0, t] to that observer and there is no problem with that.
Go back to what we discussed above about cause and effect, nothing means anything until you connect two events, that is what the wave function is doing. Again stop thinking in classical physics its wrong has been for 85 years, the overlapping events in space means nothing each individual event is still unique to QM. That is the message QM has been screaming at us for 85 years. QM really doesn't give a rats if those events are separated in time or space they are unique and identifiable.
Now here is the kicker to get in your head .... ready
The only way to measure an event in the QM field, is to use the QM field in a measurement device.That is the irony for those who won't let go of classic physics that everytime they measure something they are using QM. Why? because they need an energy transfer which is the only thing they can measure. You can call it information or energy both are the same thing. So stop worrying about events in the same point of space you can only measure with QM and it still sees them as individual events and that is why it isn't an issue.
The only people who have issues with this are those who want to make space more important than time. Why because apparently space is so important to them because they live in it and time is just this other thing. QM says that is rubbish and happily encodes in either
QM tells you that you can put a very large amount of information in the same point in space and still measure each individual one ... there are hundreds of experiments to show this and one was done last week
http://phys.org/news/2015-10-physicists-experimentally-quantum-hilbert-hotel.htmlIBM holds the current record for overlapping encoding putting 35 bits into a single electron. (
http://news.stanford.edu/news/2009/january28/small-012809.html)
Our poor control of QM and the uncertainty principle are the things that stops them going further.
Technically there are an infinite number of individually addressable states (Coulomb potentials) where quantum bits can be stored in an electron the problem for us is the encode and measurement device aren't that good
Perhaps take the question in reverse? What is the maximum amount of information the universe can hold and Lubos gives you the answer here
http://physics.stackexchange.com/questions/4118/how-many-bytes-can-the-observable-universe-storeThe answer is roughly 1x10E120 bits. A few other comments show the other ways of doing the calculation and end at the same number.
As he notes in that response the encoding and possible future encoding is in all sorts of things, some spacelike and some timelike.
So now you should see the physics of the universe as how it really is with space and time both equally important.
You live in a Quantum universe which sometimes can be simplified to classical physics but can never be understood by it.
