Help me understand the idea of an infinite past(eternal universe)

[punkdbass]

With my rather limited knowledge of cosmology, both the ideas of a first cause or an eternal universe(meaning SOME sort of tangible thing is eternal) seem illogical to me. My gut feeling, however, feels like somehow there has always been something that has eternally existed, I just don't understand how.

I have been told that if you do not think of time as a linear concept, but rather as circular(at least before the big bang), then imagining an eternal universe becomes a lot easier. Okay, I agree, I think I get this.

What I am having trouble understanding is how something tangible can have an infinite past. The whole idea of an eternal universe is that there wasn't creation out of nothing - rather something tangible has ALWAYS been present. I just don't understand how something physical can have an infinite past - and thus have experienced an infinite number of events.

Intuition and logic tells me that something physical can only experience a finite number of events. The idea of circular time makes sense to me.. but the moment you place anything physical inside that circle, I'm left confused as to how that thing could have an infinite past, which logically points me towards the necessity of a first cause.. but like I said I think the idea of a first cause is of itself illogical.

Help me understand how something physical can have an infinite past Thanks

[swamplizard]

Hi punkdbass,

I don't know that I can help much, but I do subscribe to the eternal is.
Very abbreviated version:
1) Did something (anything) orginate from nothing?
2) Was there always something?

This is the meat of if for me, eternity is now, all that is, was and will be, and this all is within the eternal now.

Hope my rambling at least sparked of some sense.

best,
swampy

[Jayhawker Soule]

Originally Posted by punkdbass

Intuition and logic tells me that something physical can only experience a finite number of events.

That is not at all clear to me -- particularly given that the term 'physical' can be a bit iffy.

[punkdbass]

Originally Posted by swamplizard

Hi punkdbass,

I don't know that I can help much, but I do subscribe to the eternal is.
Vary abbreviated version:
1) Did something (anything) orginate from nothing?
2) Was there always something?

This is the meat of if for me, eternity is now, all that is, was and will be, and this all is within the eternal now.

Hope my rambling at least sparked of some sense.

best,
swampy

This makes sense to me, for if the universe is eternal, then it makes sense that everything right now is within the eternal. What I am having trouble understanding is that, if there is an eternal past, and something physical has ALWAYS been present, then that physical thing has an eternal past and thus has experienced an infinite number of events. And I dont understand how something physical can experience an infinite number of events.

Originally Posted by Jayhawker Soule

That is not at all clear to me -- particularly given that the term 'physical' can be a bit iffy.

By physical I mean something tangible. And the reason why the idea of something tangible experiencing an infinite number of events seems illogical to me, is because of all the paradoxes that would arise from such an idea. Like I said, my gut feeling tells me something tangible has always existed, I just need help understanding how

[HonestJoe]

Originally Posted by punkdbass

Help me understand how something physical can have an infinite past Thanks

Why wouldn't it? Something physical can change state but energy/matter can't be created or destroyed. Everything physical must be infinite.

Infinity is a weird concept to get your head around anyway, and I suspect that's the actual stumbling bock here. I generally go with the idea of imagining the biggest number you can possible conceive, then multiplying it by ten. In this context, imagine the oldest possible physical object in the universe, then imagine it a moment earlier.

Once you're on that track, the question becomes "Why would it stop?".

[swamplizard]

Punkdbass,

Unlearning beginning and ending helps. Our minds conceive of origination and termination based upon perceptions. I think that all exists in the present, the present being within eternity and always being now. I have a long version of this line of thought, but I am too lazy to try and post it.

best,
swampy

[Madhuri]

You know, I don't find the existence of anything logical. I don't find the non-existence of anything logical. There is no scenario regarding existence that makes much sense to me. Any scenario seems too incredible and far-fetched.

[swamplizard]

Hi Madhuri,

If one accepts that existence does not rely upon pre-existence, then the logic becomes a non-requirement.

best,
swampy

[punkdbass]

To quote William Lane Craig in a debate vs Stephen Law, these are some of the reasons I'm having trouble understanding an infinite past:

Philosophically, the idea of an infinite past is very problematic. If the universe never had a beginning, that means that the number of past events in the history of the universe is infinite. But the real existence of an actually infinite number of things leads to metaphysical absurdities.

To give just one example, suppose you had an infinite number of coins, numbered 1, 2, 3, . . . , and so on, to infinity, and I took away all the odd numbered coins. How many coins would you have left? Well, you’d still have all the even numbered coins, or an infinity of coins. So infinity minus infinity is infinity. But now suppose instead that I took away all the coins numbered greater than three. Now how many coins would you have left? Well, three! So infinity minus infinity is three!

In each case, I took away an identical number of coins from an identical number of coins and came up with self-contradictory results. In fact, you can subtract infinity from infinity and get any answer from zero to infinity! For this reason inverse operations like subtraction and division are simply prohibited in transfinite arithmetic. But in the real world such a convention has no sway; obviously you can give away whatever coins you want!

Here’s another example of the absurdity of an infinite past. Take the planets Jupiter and Saturn. Suppose that for every orbit that Saturn completes around the Sun, the planet Jupiter completes two. If Saturn has completed ten orbits, Jupiter has completed twenty. If Saturn has completed a trillion, Jupiter has completed two trillion. The longer they orbit, the farther Saturn falls behind. If they continue to orbit forever, they will approach a limit at which Saturn is infinitely far behind Jupiter.

But now turn the story around. Suppose Jupiter and Saturn have been orbiting the sun from eternity past. Now which one will have completed the most orbits? Well, the correct mathematical answer is that the number of their orbits is identical! But that seems absurd, for the longer they orbit the greater the disparity between them grows. So how does the number of their orbits magically become identical simply by making them orbit from eternity past?

These and many other examples suggest that infinity is just an idea in your mind, not something that exists in reality. But that entails that since past events are not just ideas but are real, the number of past events must be finite. Therefore, the series of past events can’t go back and back forever. Rather, the universe must have begun to exist.

This purely philosophical conclusion has been confirmed by remarkable discoveries in astronomy and astrophysics. We now have pretty strong evidence that the universe is not eternal in the past but had an absolute beginning a finite time ago. In 2003, Arvin Borde, Allan Guth, and Alexander Vilenkin were able to prove that any universe which is, on average, in a state of cosmic expansion throughout its history cannot be infinite in the past but must have a past spacetime boundary. What makes their proof so powerful is that it holds regardless of the physical description of the early universe. Because we don’t yet have a quantum theory of gravity, we can’t yet provide a physical description of the first split second of the universe. But the Borde-Guth-Vilenkin theorem is independent of any physical description of that moment. Their theorem implies that the quantum vacuum state of the early universe—which some scientific popularizers have misleadingly and inaccurately referred to as “nothing”—cannot be eternal in the past but must have had an absolute beginning. Even if our universe is just a tiny part of a so-called “multiverse” composed of many universes, their theorem requires that the multiverse itself must have an absolute beginning.

Of course highly speculative scenarios, such as loop quantum gravity models, string models, even closed timelike curves, have been proposed to try to avoid this absolute beginning. Now these models are all fraught with problems; but the bottom line is that none of these theories, even if true, succeeds in restoring an eternal past. At most they just push the beginning back a step.



Read more: Does God Exist? The Craig-Law Debate | Reasonable Faith

I know a lot of Craigs arguments for other topics are very faulty, but this was just a quick example I could think of.

[swamplizard]

One thing, punkdbass, is that numbers/mathematics are conceptual and exist within the thoughts. Eternity is a reality that relegates numbers to their mental parameters. Infinity and one are within each other.

best,
swampy