kev said:
Hi,
Do you think that the universe has infinite mass?
If you think that the universe has infinite volume and has isotropic and homogenous density everywhere on large scales then your answer should probably be yes.
The question is specifically about "our" universe and does not include concepts of infinite multiverses. The question does however include mass that is beyond the visable universe that we see.
I am in doubt here about what you see as "multiverses".
This is maybe not unambigious. Same as for "our universe".
Let me try to explain:
When we talk about the spatial and time dimension, we normally talk then about a continuous, connected space, and without making special assumptions, without boundaries, edges or gaps.
And my metaphysical assumption then is that neither space nor time have "begin" or "end" points.
Nor is there a closed loop, and to my knowledge, this would only allow for infinite space and time.
Now a multiverse can arise in diverse ways.
For example, if you allow there to be gaps, you could end up with multiple separated universes, for which there is no connection between them.
They would be for all practical purposes (and based on scientific reasoning) to be considered "non existent" for the reason that they could not in any way effect us or each other and are by definition unobservable.
A different "multiverse" is from the idea (such as in inflation) that they were co-developed with ours, or otherwise, but for which in any case it is true that there is some spatial/temporal connection possible.
The latter I assume is simply part of "our universe".
But perhaps you use a different reasoning to define "multiverse"?
And for the question itself, the amount of mass in a universe which would not have any spatial extend and flat, and with an overall density > 0, there would indeed be no limit to the amount of mass.
But in the physics meaning, all observables have finite values. Like: even on an infinite line, the distance between any two points on such line always yield a finite distance. Infinite distance does not exist, neither as infinite mass, at least not as observable measurements.
Yet, as there is no upper limit that can be defined, in that sense they can be said to be infinite.