1

The universe is expanding in the 3 spatial dimensions, could it not also be expanding in time dimension. In other words, are we stuck in 3 dimensions because we are riding the "bow wave" of the big bang in the time dimension, stuck on a 3d plane perpendicular to our world lines in spacetime? Think of a 3d-printer, are we on the upper surface of the printed object with new time being added continuously.

Would this mean that the quantum foam is the moment when the universe comes into existence, that the collapse of wave functions is when probability becomes reality? In that way there would be no need for the many worlds interpretation of quantum physics. Ahead of now is "outside" the universe i.e. there is nothing so the extra quantum states never "existed" in any sense, they were only ever mathematical probabilities. The act of observation is simply being in the now and that's why quantum systems are different depending on where you measure them - it's a different locus of the 3 spatial dimensions and "now".

Update

I don't believe that this is a duplicate question. After some discussion elsewhere it turns out that what I am describing is the Evolving Block Universe. It is well (and more formally) described by South African cosmologist George Ellis in this paper:

http://arxiv.org/abs/gr-qc/0605049

There is also a YouTube presentation, recorded in 2012, here:

http://www.youtube.com/watch?v=It6Me78dal8

JohnnyD
  • 217
  • See also Surely proper time expands like proper space? – John Rennie Aug 08 '14 at 07:25
  • 1
    I mean expanding in the sense of growing and being created rather than in the sense of being stretched. For example, a point 100m from where I'm sitting now is currently outside the bounds of the room I'm sitting in but if the walls of the room were to move outwards then the after some time the point would be within the room. The distance (co-ordinates) would still be exactly the same. I'm asking if "now" is like the walls of the room and the point currently outside the room is in the future (but doesn't exist in any sense). The wall sweeping through space is the moment of "creation". – JohnnyD Aug 08 '14 at 08:31
  • I'm not sure what it is you're asking. Are you asking about the flow of time? If so it's been asked before, and the answer is that there is no answer. – John Rennie Aug 08 '14 at 08:53
  • 1
    Time is like building a railway, the age of the universe - the total length of track gets bigger (though the track itself doesn't - the distance between sleepers remains the same - thus creating new track (the past); the point at which new track is laid down is "now". Where the track is going to be is the future but there is nothing there - it is outside the universe of the track and inaccessible. If you are fixed to the leading edge of the track then time would appear to flow but really it's being constantly created. It's not that all the track exists and we're simply moving along it. – JohnnyD Aug 08 '14 at 09:08
  • 1
    No, this is quite incorrect (sorry!). When you solve the equations of GR the result is a metric, and the metric gives us the time and space axes from $-\infty$ to $\infty$ (unless a singularity gets in the way). The flow of time is merely the advance of the observer's time coordinate along the time axis. The time axis is not constructed, like a railway, as the observer moves along it. The time axis already exists. This is an absolutely vital point to understand. The solution to Einstein's equation is a spacetime - the whole spacetime. – John Rennie Aug 08 '14 at 09:38
  • But, for example, if you plot some function like y = kx on a graph then say everything below the line is the past and every above the line is the future. The y-axis exists at all points even when the line has yet to reach it but before the line reaches it there is nothing (the future), after the line reaches it there is something (the past). Any given point on the line represents a "now" moment. I don't think this disagrees with you. Sorry if I'm being dim. – JohnnyD Aug 08 '14 at 09:46
  • You say before the line reaches it there is nothing (the future) but this isn't true. GR is a deterministic theory. When you fix the initial conditions at any time you determine the behaviour of your entire universe for all times future and past. If you don't mind stepping out of physics and into philosophy you might be interested in Googling for the Block Universe. – John Rennie Aug 08 '14 at 09:50
  • Yes, I'm familiar with the concept. But is GR deterministic? This suggests not... http://plato.stanford.edu/entries/determinism-causal/#GenRelGTR. In any case I believe that GR breaks down at the quantum level. Is that because it is describing the past rather than "now" or the future. – JohnnyD Aug 08 '14 at 10:08
  • Yes it's causal subject to caveats such as the occurrence of singularities (the past singularity is why the FLRW time doesn't extend to $-\infty$). QM may or may not be causal, thats an open question, but we weren't talking about QM or at least I wasn't and your original question wasn't. – John Rennie Aug 08 '14 at 10:11
  • I would suggest asking a new question that specifically refers to the paper you link, rather than reopening this one. I think that would be clearer. – John Rennie Aug 11 '14 at 06:00

1 Answers1

0

Note: I am not allowed to write comments yet, so I have to post this as an answer.

Besides of John Rennie's formal objections to the concept of expanding time (at "Does time expand with space"), I still like the explanation of the quatum physical state of superposition that is provided with your question:

The idea that i.e. the interference pattern which shows up within the double slit experiment is not the consequence of different possibilities that are somehow happening at the same time but the consequence of a quantum physical event (the photon's path through the double slit) being beyond the realms of time and therefore only existing as its mathematical probabilities.

To stay within the framework of your thought and by using your analogy of the 3d printer it could also make sense to assume that the time is printed out in discrete portions, chronon by chronon. Then the single quantum physical event might be beyond time because it's too small to absorb a whole of those elementary time-units. This is only until the event gets observed, because then the event becomes a macroscopic event, which spans across lots of time units, which means that the event is not longer beyond time but - as you called it - "in the now". Hence the wavefunction collapses.

jimmyorpheus
  • 113