The Big Bang Argument for God

[Tomdstone]

So you’re challenging premise 2. You don’t believe the universe began to exist, but rather believe that the universe undergoes an infinite series of expansion and contraction. To explain to others who might not know, on this view the universe expands with a big bang and then eventually collapses in on itself with a “big crunch.” Some speculate that after the big crunch, the universe might expand again in another big bang. Thus, we have an infinite cycle of universes, it goes on forever. Do you have any good reasons to believe in such a model? I think there are, however, good reasons to doubt the legitimacy of the cyclic model.

The cyclic model only succeeds if the density of all the matter in the entire universe is greater than what scientists call “critical density.” Critical density is the value at which the universe is at balance, and expansion is stopped. If the density of matter in the universe is greater than the critical density, then gravity will overpower matter and pull it back in, thus initiating the big crunch process. But if the density of the universe’s matter can’t succeed critical density, then the gravity is not strong enough to pull the matter back in and initiate a big crunch, and so the universe just expands forever.

However, most cosmologists think a big crunch very unlikely, given that most of the matter in the universe is “dark matter,” which has enough mass and gravitational force to keep the universe expanding forever. The truth is, the current evidence we have doesn’t show that there will ever be a big crunch. For instance, the most recent evidence of space expansion shows that the universe isn’t being slowed down by gravity, but rather is accelerating.

But even if the universe could contract and expand again, this does not show that it could have contracted and expanded forever. This is because whenever the universe would collapse and experience a big crunch, there would be an intense build up of disorder (entropy) that would carry over into the new expanding universe. This build up of entropy would have the effect of creating larger and longer big bang expansions each successive cycle. The physicist Duane Dicus explains this by showing that entropy will only “enlarge the cosmic scale from cycle to cycle” which means if we look backwards in time, we’ll notice that each earlier cycle “generates less entropy,” thus showing it would have a smaller cycle time and cycle expansion. This means as one traces the cycles back in time, each expansion becomes smaller and smaller until you come to the one that is infinitely small (or zero). This would be the beginning of the universe.

In fact Stephen Hawking even says on his own website that this entropy build up disproves the cyclic model: “One would expect that the universe would become more disordered each oscillation. It is therefore difficult to see how the universe could have been oscillating for an infinite time.” Furthermore, Hawking’s formulation of singularity theorems with Roger Penrose imply an absolute beginning to the universe. To quote Hawking one more time from, The Nature of Space and Time, singularity theorems “led to the abandonment of attempts (mainly by the Russians) to argue that there was a previous contracting phase and a non-singular bounce into expansion. Instead almost everyone now believes that the universe, and time itself, had a beginning at the big bang.”

The fluctuation theorem and the Poincare recurrence theorem both allow for a spontaneous decrease in entropy.

 

[YosefYosep]

The fluctuation theorem and the Poincare recurrence theorem both allow for a spontaneous decrease in entropy.

Do you have any good reason to believe in this model of the universe over the Big Bang model? Right now it just stands as a bare possibility, mere speculation. In order to persuade me to accept the cyclic model, you must show me that there is more evidence to believe in such a model and less evidence to believe in the classical Big Bang model.

I just see no good reason to believe in the cyclic model. It’s not just scientific consensus and evidence which makes me disbelieve, it’s also philosophical problems–which show that an infinite time in the past is literally impossible.

 

[fisherman_carl]

You are assuming that the universe had a beginning and was created, which is what you need to prove. According to the cyclical theory, there was no beginning and there is no end to the expansion contraction cycle. A collision of M-Branes in higher dimensions causes the ekpyrotic scenario. Since you can continue to draw energy from gravity continually, there is no violation of conservation of energy when gravitational energy is converted into energy partially responsible for the collision of the M-Branes. Further, the second law of thermodynamics is not violated since excessive entropy can be spread to regions beyond the horizon during periods of dark energy domination.

You are basing this objection on a highly speculative unproven cyclical theory, that you adopted and assumed is true. Meanwhile, that the universe has a beginning is adopted by mainstream science and has all the evidence, as well as philosophical backing. You can’t have an infinite past because you can not have an actual infinite number of things. You can have a potential infinite, but not actual.

 

[fisherman_carl]

Here is a good lecture by dr Craig on the subject
youtu.be/gNma5z3-nCI

Also, he talks about the problems with cyclical theory.

 

[Tomdstone]

Do you have any good reason to believe in this model of the universe over the Big Bang model? Right now it just stands as a bare possibility, mere speculation. In order to persuade me to accept the cyclic model, you must show me that there is more evidence to believe in such a model and less evidence to believe in the classical Big Bang model.

I just see no good reason to believe in the cyclic model. It’s not just scientific consensus and evidence which makes me disbelieve, it’s also philosophical problems–which show that an infinite time in the past is literally impossible.

2013 data from the Planck satellite support the cyclic model and cast doubt on the BB theory.
wwwphy.princeton.edu/~steinh/planckcyc_final3.pdf

 

[YosefYosep]

2013 data from the Planck satellite support the cyclic model and cast doubt on the BB theory.
wwwphy.princeton.edu/~steinh/planckcyc_final3.pdf

The study concludes by saying that “there are no detectable primordial gravitational waves on the scales of cosmological interest.” They pretty much say the cyclic model can’t work unless they find these waves. So it’s still mere speculation because they admit they haven’t found this essential property for the cyclic model to work.

 

[Tomdstone]

The study concludes by saying that “there are no detectable primordial gravitational waves on the scales of cosmological interest.” They pretty much say the cyclic model can’t work unless they find these waves. So it’s still mere speculation because they admit they haven’t found this essential property for the cyclic model to work.

This is a falsifiable prediction of the cyclic model. In the paper he shows that the cyclic model can match all of the cosmological parameters favored
by Planck, but there are problems with the inflationary BB model.

 

[Tomdstone]

You can’t have an infinite past because you can not have an actual infinite number of things. You can have a potential infinite, but not actual.

For any number of time intervals you give me in a given time interval, I can give you one more than your original number. So, in the real world, there is no finite number of time intervals in a given time interval.

 

[YosefYosep]

Even if these researchers are able to find more evidence for this model in the future (as they say they hope to), the Borde-Guth-Velenkin theorem has shown that this cyclic model cannot be past eternal. The theorem shows that any universe which has been expanding at a positive rate must have a past boundary. Vilenkin says that there is a need for an initially singularity and that the cyclic model can’t side step this. Furthermore, there’s a major hole in the cyclic model. How do we get the expansion after contraction?

Even Paul Steinhardt, the researcher in that article (and the man who champions the cyclic model) admits that science doesn’t know how the expansion would begin again after contraction because there are no currently known physics to allow for it. He calls it the “key problem” for the theory. So ultimately, again, such a theory is very speculative, relying on evidence which might hypothetically be discovered in the future. I’ll side with the Big Bang for now.

 

[Tomdstone]

Even if these researchers are able to find more evidence for this model in the future (as they say they hope to), the Borde-Guth-Velenkin theorem has shown that this cyclic model cannot be past eternal. The theorem shows that any universe which has been expanding at a positive rate must have a past boundary. Vilenkin says that there is a need for an initially singularity and that the cyclic model can’t side step this. Furthermore, there’s a major hole in the cyclic model. How do we get the expansion after contraction?

Even Paul Steinhardt, the researcher in that article (and the man who champions the cyclic model) admits that science doesn’t know how the expansion would begin again after contraction because there are no currently known physics to allow for it. He calls it the “key problem” for the theory. So ultimately, again, such a theory is very speculative, relying on evidence which might hypothetically be discovered in the future. I’ll side with the Big Bang for now.

The BGV theorem doesn’t prove anything since it relies on the assumption that the universe is expanding. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past. They show that null and timelike geodesics are, in general, past-incomplete in inflationary models. The cyclical theory is not an inflationary model since there is a contraction phase.

 

[YosefYosep]

It was, however, the philosophical case against a past eternal universe that initially made me conclude that there must have been some beginning of the universe. Here’s an analogy used by Trent Horn: imagine a calendar that depicts the universe’s existence in time. It stretches back in time forever. Time, as it does, moves through the calendar one day at a time (I’m using days as a purpose of illustration). If the universe existed forever, then there would have been an infinite amount of days before today. How could time have reached this present moment if it had to traverse an infinite amount of days to get to today, the present?

Here’s another way of picturing it. Imagine Rob has to clean all the tables at the burger joint before he can go home. If he has three or four tables to clean, he can get home pretty quickly. If he has one hundred, it will be awhile before he can go home. Imagine, however, that Rob has an infinite amount of tables to clean. It looks like Rob won’t be going home. Because there will always be one more table to clean, Rob will never finish cleaning the tables. But if you saw Rob walking home, you would conclude that he didn’t have an infinite amount of tables to clean. Perhaps he had a lot, but not an infinite.

The fact that today is happening is like Rob walking home. If there were an infinite amount of days in the past, we would never see today, because there would always be one more day before today. This is hard to conceive, right? That’s because infinity is a concept that we have no evidence of actually existing in reality. Some people claim that placing to mirrors in front of each other shows an actual infinity, but after a certain amount of successive reflections, the light fades and just dissipates into a green hue.

Even David Hume, the Enlightenment philosopher that most skeptics praise, says that an infinite number of parts of time in the past is “so evident a contradiction” that no man of the sciences should believe it. While we can toy with the concept of infinity in mathematics, you won’t find an actual infinity in the real world–like an infinite amount of tacos, or infinite amount of clouds.

But even if you could somehow philosophically prove that time can be eternal in the past, this wouldn’t keep the divine foot out of the door. For instance, Aquinas formed his arguments for God so that they could work even if one assumed a past eternal universe.

 

[Tomdstone]

This is hard to conceive, right? That’s because infinity is a concept that we have no evidence of actually existing in reality.

First of all it is not difficult to conceive because of the real line. Even though the real line extends without limit in both the negative and positive directions, you still have a place for zero and one. Further, there is evidence of infinity in reality if you believe that time is continuous. If time is continuous, then there are an infinite number of subintervals in any given finite time interval. So there would be evidence of infinity in reality. Of course, if time were discrete, and reality were discrete as hypothesized by lattice gauge theory, then the argument would not work. But lattice gauge theory has other problems.
OTOH, I am not sure how you define time. Was there time before the BB and why is the time dimension irreversible, whereas other dimensions are reversible?

 

[YosefYosep]

First of all it is not difficult to conceive because of the real line. Even though the real line extends without limit in both the negative and positive directions, you still have a place for zero and one. Further, there is evidence of infinity in reality if you believe that time is continuous. If time is continuous, then there are an infinite number of subintervals in any given finite time interval. So there would be evidence of infinity in reality. Of course, if time were discrete, and reality were discrete as hypothesized by lattice gauge theory, then the argument would not work. But lattice gauge theory has other problems.
OTOH, I am not sure how you define time. Was there time before the BB and why is the time dimension irreversible, whereas other dimensions are reversible?

Sorry, I meant to say “evidence for actual infinities” in reality. Of course, as you’ve pointed out, potential infinities are possible. However, I think you might have misunderstood the philosophical issues I presented concerning a past eternal universe. Of course, in mathematics you can theoretically have the real line which has numbers extending from zero infinitely in both directions. But with time it’s totally different. How did we get to today if time is infinitely extended in the past? There would always be one more day (again I’m using “day” as an illustrative term) to traverse in the past in order to arrive at today.

 

[Tomdstone]

Sorry, I meant to say “evidence for actual infinities” in reality. Of course, as you’ve pointed out, potential infinities are possible. However, I think you might have misunderstood the philosophical issues I presented concerning a past eternal universe. Of course, in mathematics you can theoretically have the real line which has numbers extending from zero infinitely in both directions. But with time it’s totally different. How did we get to today if time is infinitely extended in the past? There would always be one more day to traverse in the past in order to arrive at today.

Well, we can use a similar argument that Euclid used to prove the infinity of prime numbers. You give me a time in the past and I can always give you a time which was one hour before that. This would work for the cyclic theory, but if time began at the singularity point of the BB, then no.

 

[YosefYosep]

To return to my table cleaning analogy, Rob can go home if he finishes cleaning all the tables. There are a finite amount of, say, 17 tables. Once he cleans 17 he can go home. But if Rob has an infinite amount of tables, he he will never go home because there will always be another table to clean before he goes home. Notice, that even if you say that you could label the tables 0, 1, 2, 3, 4… and so on, this does not negate the fact that Rob has an infinite amount of tables to clean before he goes home. Likewise, just because an actual infinite line is possible in mathematics, where we have real numbers, this does not mean you can avoid the issue of trying to traverse an infinite amount of days to get to today.

 

[Tomdstone]

To return to my table cleaning analogy, Rob can go home if he finishes cleaning all the tables. There are a finite amount of, say, 17 tables. Once he cleans 17 he can go home. But if Rob has an infinite amount of tables, he he will never go home because there will always be another table to clean before he goes home. Notice, that even if you say that you could label the tables 0, 1, 2, 3, 4… and so on, this does not negate the fact that Rob has an infinite amount of tables to clean before he goes home. Likewise, just because an actual infinite line is possible in mathematics, where we have real numbers, this does not mean you can avoid the issue of trying to traverse an infinite amount of days to get to today.

Yes, we are here now at some particular time. Assuming the cyclic theory is true, for any time you give me, I can give you a time which was one minute before that. There is no limit to a time in the past found by such an algorithmic method.

 

[YosefYosep]

Well, we can use a similar argument that Euclid used to prove the infinity of prime numbers. You give me a time in the past and I can always give you a time which was one hour before that. This would work for the cyclic theory, but if time began at the singularity point of the BB, then no.

Sure you can imagine a past that extends infinitely hour by hour into the past, but in reality it’s just not feasible (while in mathematics it conceptually is). You can never traverse time with an infinitely extending past. Trying to arrive at the present with an infinite past is like trying to count to negative infinity before arriving at zero.

 

[Tomdstone]

Sure you can imagine a past that extends infinitely hour by hour into the past, but in reality it’s just not feasible (while in mathematics it conceptually is). You can never traverse time with an infinitely extending past. Trying to arrive at the present with an infinite past is like trying to count to negative infinity before arriving at zero.

Well, personally, I don’t see any problem with the idea that each point of time could have a preceding point. From that preceding point you could always move forward. OTOH, I don’t think that you could ever go backward in time, because of the possibility of contradictions. It is wicked and morally wrong, of course, but say for example, someone went backward in time and killed his great grandfather when he was a child. Where would that leave the time traveller? BTW, what is your definition of time? Why do you suppose time is irreversible?

 

[YosefYosep]

Well, personally, I don’t see any problem with the idea that each point of time could have a preceding point. From that preceding point you could always move forward. OTOH, I don’t think that you could ever go backward in time, because of the possibility of contradictions. It is wicked and morally wrong, of course, but say for example, someone went backward in time and killed his great grandfather when he was a child. Where would that leave the time traveller? BTW, what is your definition of time? Why do you suppose time is irreversible?

I see time as a succession of events. Simply put, it is the measurement of change. I’m still having difficulty, though, understanding your idea of being at a certain point in time and having the ability to move forward. I can see how this would work in the real line where I could, say, place my finger down on -5 and go forward. There’s no trouble in that, even if the numbers stretch back to negative infinity. But in reality, what point do we begin on?

Say our universe begins on point 0. You say that it is perfectly acceptable from 0 to move to points 1, 2, 3…and so on. I would agree with you if we were talking about the real line, but we aren’t. With the real line we can arbitrarily choose a point and move forward, like picking 58 and counting to 600. But with time you can’t arbitrarily pick a point and move forward. Time is necessarily successive, meaning you have to pass through all preceding points in time to arrive at others. There is no picking of any point. So to arrive at point 0 one can’t just pick it and move forward. Point zero arrives after all past points have passed. But if there are an infinite amount of past points, how can we ever arrive at point 0?

The question is, since we’re dealing with time, how did time arrive at point 0 if there is an infinite past? We would have to traverse an infinite amount of points to get to the point when our universe begins. Like I said before, it would be like trying to arrive at 0 by counting to negative infinity. It doesn’t make sense.

 

[Tomdstone]

I see time as a succession of events. Simply put, it is the measurement of change. I’m still having difficulty, though, understanding your idea of being at a certain point in time and having the ability to move forward. I can see how this would work in the real line where I could, say, place my finger down on -5 and go forward. There’s no trouble in that, even if the numbers stretch back to negative infinity. But in reality, what point do we begin on?

Say our universe begins on point 0. You say that it is perfectly acceptable from 0 to move to points 1, 2, 3…and so on. I would agree with you if we were talking about the real line, but we aren’t. With the real line we can arbitrarily choose a point and move forward, like picking 58 and counting to 600. But with time you can’t arbitrarily pick a point and move forward. Time is necessarily successive, meaning you have to pass through all preceding points in time to arrive at others. There is no picking of any point. So to arrive at point 0 one can’t just pick it and move forward. Point zero arrives after all past points have passed. But if there are an infinite amount of past points, how can we ever arrive at point 0?

The question is, since we’re dealing with time, how did time arrive at point 0 if there is an infinite past? We would have to traverse an infinite amount of points to get to the point when our universe begins. Like I said before, it would be like trying to arrive at 0 by counting to negative infinity. It doesn’t make sense.

The past does not have a starting point, except for one that you choose it to be. You can start from that point of your choice, but you have to realize that before your chosen starting point, there was a preceding point. For any starting point that you give me, I can always find one which precedes your point.