(August 21, 2019 at 9:31 pm)Lek Wrote: I'm more of a philosopher than a scientist, but I'm taking what I understand from science and I'm philosophizing. If energy and matter cannot be created or destroyed, that means that they share an intrinsic quality with God. They have always existed with no beginning, and they will continue to exist into infinity. Those are qualities are also given to God. Could this match up in any way with a pantheistic understanding of the universe? If I use science as a basis for my understanding, there couldn't have been an occasion when nothing existed, so energy and matter could not have been created.
First of all, the law of conservation of energy actually says that if you take a region of space and look at the energy it contains at two different times, then the amount of energy at the earlier time, minus the amount of energy that flows out of the boundary of the region gives the amount of energy at the later time. if energy flows in, it is counted as negative energy flowing out, so it gets added to the total.
Now, a couple of aspects of this.
1. Usually, we look at a 'closed system', which just means the energy flow across the boundary is zero. In this case, the energy totals at the two times are then the same.
2. This law relates the energy of a region at two different times. This means that it only applies *within* spacetime.
3. If time has a beginning, it is literally nonsense to talk about 'before the universe' since the word 'before' requires time. So there is no issue with the law of conservation of energy with requires the energy *in a region of space* and at *two different times*.
It is quite possible for time to have had a beginning without any violation of the conservation law. It is also quite possible for time to go infinitely into the past. There is NOTHING in science that eliminates this as a possibility.
It is also quite possible for time to end. And, again, if this happens, there is no issue with the conservation law.
(August 21, 2019 at 10:19 pm)Lek Wrote: (August 21, 2019 at 9:56 pm)wyzas Wrote: Hi Lek, haven't seen you in a while.
God is a man made concept only, energy and matter are not a concept, they actually exist. You can't rationally combine the three.
Yeah. I've been on quite a spiritual journey for the last couple years. So do you think it is possible for energy and matter to be infinitely existent?
Yes, it is possible given everything that we know. In fact, if space is actually flat, it is even likely.
Also interesting, it is possible for time to be infinite into the past. Of course, it is also possible for it to be finite into the past. The same is true for the future.
(August 22, 2019 at 8:25 pm)Grandizer Wrote: @Lek, regarding the expansion of the universe into "something", see this:
http://curious.astro.cornell.edu/about-u...termediate
Read the first paragraph at least, if not the whole answer.
The actual answer for this question is a bit trickier.
The first thing to realize is that modern cosmology regards space and time together as a single, geometric entity. Space is three dimensional and time is one dimensional, for a four dimensional geometry.
In general relativity (which is the underlying theory of gravity for the Big Bang), spacetime has, itself, a curved geometry where the curvature is determined by the density of energy (and mass, momentum, etc).
When we talk about the universe at a single time, we are looking at a 'time slice' of this four dimensional geometric object.
This can be a bit hard to imagine, so let's drop down two dimensions. Imagine a sphere (like the Earth) with latitude and longitude and suppose that the latitude represents 'time' in this geometry. We can talk about 'north' being the direction of time 'into the future'.
In this analogy, the 'universe at a given time' would simply be a latitude line (well, a circle).
Now, imagine starting 'at the beginning of time', in other words, the South Pole. The 'latitude line' at the South Pole is a single point (a singularity!!). As we move forward in time (north), the latitude lines get larger (space expands). Well, at least that's what happens until we get to the equator when the latitude lines start to get smaller (space contracts) until we get to the North Pole where the latitude 'line' is, again, a single point (another singularity).
Now, suppose I look at one of those latitude lines in the southern hemisphere, where 'space is expanding' and we ask 'What is space expanding into'?
If you understand this analogy, the obvious answer is 'into the future'. That is the direction in which the latitude lines are getting larger. North=the future.
Now, this is a reasonably good analogy to what happens in actual cosmology. There is a difference in the number of dimensions, but that isn't particularly relevant here. The basic answer to the question remains the same:
The universe is expanding into the future.
Another analogy, which has just one 'singularity' can be had by imagining three dimensional space. In this analogy, time will be the distance from some fixed point and spacetime will be three dimensional.
So, in this, t=0 corresponds to that fixed point. There is no 'previous time' since all distances are positive.
In this, a 'time slice' is a sphere. Later 'times' (which means a larger radius) correspond to larger spheres.
In this analogy, space is expanding as we go away from that center point (the singularity) and it continues to expand 'forever'. And, once again, it expands 'into the future'.
Conservation of energy simply means the amount of energy on each sphere is the same as every other sphere. But there is still a 'beginning to time'.