Problems and Questions in Atheism

[37818]

Are you claiming that mathematical models of a universe with a past-infinite time dimension cannot account for red shift in the CMB? Or perhaps red shift in the motion of galaxies?

Not if that math can be shown. The red shift makes the dimensions larger when the universe was smaller. Based on every where moving away over infinite time.

[Boxing Pythagoras]

Not if that math can be shown. The red shift makes the dimensions larger when the universe was smaller. Based on every where moving away over infinite time.

The red shift tells us that the universe is expanding in a particular direction of time. It does not imply that this expansion has been occurring for all moments of time. Any model which contains a period of expansion which corresponds to known data will account for that red shift.

The red shift doesn't tell us that the universe had a beginning. The red shift simply tells us that the universe has undergone a period of expansion. In order to get to the idea that the universe had a beginning, one needs to build a mathematical model which extrapolates beyond the direct implications of the data.

So, again, the only support for the claim that the universe had a beginning are mathematical models, exactly as the only support for claims that the universe could be past-infinite are mathematical models.

[psstein]

So, again, the only support for the claim that the universe had a beginning are mathematical models, exactly as the only support for claims that the universe could be past-infinite are mathematical models.

Yes, to some extent. The issue for proponents of past-eternal models is that the evidence that currently exists is much better explained on a past-finite model.

Too many people have this belief that science is by nature certain. Science is tentative and based upon inference, not certainty.

[Boxing Pythagoras]

Yes, to some extent. The issue for proponents of past-eternal models is that the evidence that currently exists is much better explained on a past-finite model.

I really don't think that's the case. Again, the evidence which we have only tells us that the universe has undergone a period of expansion. Any model which has a period of expansion matching the data will explain that data equally well, regardless of the finitude of its time dimension. At best, one might claim that a past-finite model is preferable on the basis of Occam's razor, but even that point is debatable.

Too many people have this belief that science is by nature certain. Science is tentative and based upon inference, not certainty.

Definitely agree, here.

[shunyadragon]

Yes, to some extent. The issue for proponents of past-eternal models is that the evidence that currently exists is much better explained on a past-finite model.

Actually the current models do not explain nor conclude either.

Too many people have this belief that science is by nature certain. Science is tentative and based upon inference, not certainty.

This is so true of those that claim 'the evidence that currently exists is much better explained on a past-finite model.' like WLC. Scientists themselves thrive on uncertainty.

[37818]

The red shift tells us that the universe is expanding in a particular direction of time. It does not imply that this expansion has been occurring for all moments of time. Any model which contains a period of expansion which corresponds to known data will account for that red shift.

The red shift doesn't tell us that the universe had a beginning. The red shift simply tells us that the universe has undergone a period of expansion. In order to get to the idea that the universe had a beginning, one needs to build a mathematical model which extrapolates beyond the direct implications of the data.

So, again, the only support for the claim that the universe had a beginning are mathematical models, exactly as the only support for claims that the universe could be past-infinite are mathematical models.

Red shift is a time dilation. Gravitational: t' = t/sqr(1 - 2GM/(rc^2)) and/or motion away: t' = t / sqr((c - v)/(c + v)). And distance places everything in the past. With everywhere moving away, only leaves evidence for a finite past.

The mathematical models for an infinite past, I have only heard rhetoric.

https://www.technologyreview.com/s/4...d-a-beginning/

[Boxing Pythagoras]

Red shift is a time dilation. Gravitational: t' = t/sqr(1 - 2GM/(rc^2)) and/or motion away: t' = t / sqr((c - v)/(c + v)). And distance places everything in the past. With everywhere moving away, only leaves evidence for a finite past.

I'm honestly unsure why you think time dilation implies a finite past. Once again, the only thing in evidence from this red shift is a period of spacetime expansion. You don't need a past-finite model of spacetime in order to be able to account for a period of expansion. The formulae which you quoted in regards to time dilation certainly don't imply anything about the past-finitude of time, just as the similar formulae for space do not imply that space is finite in any direction.

The mathematical models for an infinite past, I have only heard rhetoric.

As opposed to what? I presume that you are not a cosmologist, and that you're not an avid reader of peer-reviewed journals on the subject. As such, I'd be surprised if you HAD heard anything about such models beyond rhetoric. Are you very familiar with the mathematics which are utilized in cosmology? If not, why should you expect to have heard anything other than rhetoric about these models?

https://www.technologyreview.com/s/4...d-a-beginning/

It's somewhat ironic that, immediately after complaining about rhetoric regarding mathematical models, you post a link to an article which is nothing but rhetoric about mathematical models.

[psstein]

I really don't think that's the case. Again, the evidence which we have only tells us that the universe has undergone a period of expansion. Any model which has a period of expansion matching the data will explain that data equally well, regardless of the finitude of its time dimension. At best, one might claim that a past-finite model is preferable on the basis of Occam's razor, but even that point is debatable.

To my knowledge, the models that attempt to explain inflation and hold to a past-infinite universe are subject to other problems. For example, Steinhardt and Turok's Ekpyrotic model gets the cosmological constant wrong.

[Boxing Pythagoras]

To my knowledge, the models that attempt to explain inflation and hold to a past-infinite universe are subject to other problems. For example, Steinhardt and Turok's Ekpyrotic model gets the cosmological constant wrong.

Well, sure, there are models with past-infinite time which do not match known data, and must therefore be either revised or abandoned. The same is true for past-finite models. This doesn’t mean ALL such models are similarly plagued. If you're going to make that claim, you'll be taking on a fairly enormous burden of proof.

[psstein]

Well, sure, there are models with past-infinite time which do not match known data, and must therefore be either revised or abandoned. The same is true for past-finite models. This doesn’t mean ALL such models are similarly plagued. If you're going to make that claim, you'll be taking on a fairly enormous burden of proof.

You're correct. I'm a historian, not a cosmologist/physicist, hence my limited knowledge.

[JimL]

Cool. Most of the Christians with whom I have had this conversation-- especially those with whom I've spoken in person-- tend to be Charismatic Evangelicals. Because they believe that they have interacted directly with God, they have expressed to me that they believe their personal experiences to be incontrovertible proof that God really does exist. It's something akin to the position Dr. Craig espouses about the proper basicality of the witness of the Holy Spirit.

Oh, there's certainly nothing wrong with appealing to deductive reasoning! I'm a math guy-- I absolutely adore deductive reasoning. It only becomes a problem when the syllogisms which one claims as proof are not actually sound arguments. I've yet to be presented with any logical arguments demonstrating God's existence which are sound.

He's also written about it elsewhere in his published books. I didn't mean to imply that he only presents this material in the Blackwell Companion. I simply meant that he usually omits this material when he speaks publicly on the KCA.

Without trawling too greatly through debate transcripts for examples, one immediately pops to mind. In his debate with Dr. Carroll, Dr. Craig states, "As Jim Sinclair has shown in our article in the Blackwell Companion, all of the models that Dr. Carroll has mentioned have been shown to be either untenable or not to avert the beginning of the universe." This certainly was not "well off the topic in the debate." It was the very subject of the debate. And yet, Dr. Craig seemed content to punt to his published work instead of actually presenting the arguments that the models which Dr. Carroll had mentioned were either untenable or unable to avert a beginning for the universe.

Here, on TWeb, we tend to have people who have given a great deal more thought to the subject than does the average person. However, most of the people who have presented the KCA to me as if it is a knockout-blow for theism are people who don't really spend much time thinking about these questions, but may have had some introduction to apologetics in their local churches or home groups. I'm not saying Craig intentionally misrepresents the argument. I'm simply saying that a great many people who have heard Craig's argument misunderstand it-- whether theist or not.

It's not even that we can "no longer" calculate the physical laws. It's simply that, in one particular case, we cannot calculate some particular physical law.

A lot of people who hear physicists use the word "singularity" are under the misconception that this refers to a physical object. It does not. A singularity is a mathematical term describing particular situation in which the mathematics becomes undefined. The simplest example I can show comes from the function f(x)=1/x, which is graphed as below:

[ATTACH=CONFIG]20417[/ATTACH]

The function is defined for all Real numbers, x, except for the case when x=0. That particular case is called a singularity. Notice that the function behaves perfectly well for x<0 and x>0. We can calculate any of those values with relative ease. It's simply when x=0 that the mathematics breaks down, because division by zero is undefined.

The singularities discussed by physicists are mathematical singularities. In fact, the Big Bang singularity and black hole singularities which you mentioned are examples of division-by-zero type singularities. The mathematics which describe those particular cases leads to a division by zero, and thus we have a singularity. Again, these singularities are not concrete objects in the real world. They are simply undefined operations in particular mathematical models.

Okay, but my argument is the same, however you want to define the beginning of this universe. Whatever the black hole devolves into just prior to its inability to be measured, however you want to define it, the planck length say, it didn't come from nothing, it came from imploding stars. I don't see any reason to assume that the physical nature and the physical laws pertaining to The greater Cosmos, that which is external to our particular universe, are any different than they are with respect to our particular universe. Perhaps we are the result of a sort of reverse black hole eminating from the Greater Cosmos, I don't know, but it seems to me a more logical assumption to make that that we came from nothing. Nihilo ex nihilo!

[Boxing Pythagoras]

Okay, but my argument is the same, however you want to define the beginning of this universe. Whatever the black hole devolves into just prior to its inability to be measured, however you want to define it, the planck length say, it didn't come from nothing, it came from imploding stars.

I'm not sure what you mean by black holes devolving into the Planck length, but I can certainly agree that on current models, they were once stars which became so massive that they collapsed under their own gravity to objects of insanely large densities.

I don't see any reason to assume that the physical nature and the physical laws pertaining to The greater Cosmos, that which is external to our particular universe, are any different than they are with respect to our particular universe.

I don't see any reason to presume that there exists a "greater Cosmos" or anything "external to our particular universe," in the first place.

Perhaps we are the result of a sort of reverse black hole eminating from the Greater Cosmos, I don't know, but it seems to me a more logical assumption to make that that we came from nothing.

I quite agree that the assertion "we came from nothing" is nonsense (or, at the very best, extremely misleading). I don't believe that the universe "came from nothing." I don't believe that the universe "came," at all. Whether the universe is past-infinite or past-finite, there was never a time in which the universe did not exist.

Nihilo ex nihilo!

Sorry, but I'm going to be a bit nitpicky, here... I believe the phrase you are looking for is ex nihilo nihil fit. For what it's worth, I completely agree.

[JimL]

I'm not sure what you mean by black holes devolving into the Planck length, but I can certainly agree that on current models, they were once stars which became so massive that they collapsed under their own gravity to objects of insanely large densities.

Yes exactly, and which at a certain point the physical laws become useless.

I don't see any reason to presume that there exists a "greater Cosmos" or anything "external to our particular universe," in the first place.

I do, because if there is no Greater Cosmos, then that admits to a non-existence within the which is a 14 billion lightyear across expanding existence. A finite existence doesn't make sense to me.

I quite agree that the assertion "we came from nothing" is nonsense (or, at the very best, extremely misleading). I don't believe that the universe "came from nothing." I don't believe that the universe "came," at all. Whether the universe is past-infinite or past-finite, there was never a time in which the universe did not exist.

I believe the universe, that is our particular universe was born, just like everything else of the Cosmos is born, but in the words of Spinoza, I think that the universe, our particular universe, is finite and temporal with respect to itself, but infinite and eternal with respect to its cause.

Sorry, but I'm going to be a bit nitpicky, here... I believe the phrase you are looking for is ex nihilo nihil fit. For what it's worth, I completely agree.

Yep, thats it.

[shunyadragon]

Yes exactly, and which at a certain point the physical laws become useless.

This is not totally known that there is a 'certain point' that this is true.

I do, because if there is no Greater Cosmos, then that admits to a non-existence within the which is a 14 billion light-year across expanding existence. A finite existence doesn't make sense to me.

There is no 'sense' to the claim of a finite existence, because it is an unknown.

I believe the universe, that is our particular universe was born, just like everything else of the Cosmos is born, but in the words of Spinoza, I think that the universe, our particular universe, is finite and temporal with respect to itself, but infinite and eternal with respect to its cause.

This may or may not be the case, but is a good likely scenario.

[Boxing Pythagoras]

Yes exactly, and which at a certain point the physical laws become useless.

Well, no. We just don't really know what happens at the event horizon. Our models simply fail to describe it. That certainly doesn't imply that "physical laws become useless." It only means that we don't understand the physics of that particular phenomenon.

I do, because if there is no Greater Cosmos, then that admits to a non-existence within the which is a 14 billion lightyear across expanding existence.

No, it doesn't. That isn't even a cogent concept. First of all, the visible universe has a radius of between 13 and 14 billion light years. That does not imply that there is nothing more to the universe beyond that which can be seen. Furthermore, even if there is a finite spatial boundary, that doesn't imply that there must exist something beyond that boundary-- if that were the case, it wouldn't actually be a spatial boundary in the first place, but rather just some sort of barrier within space.

A finite existence doesn't make sense to me.

It makes perfect sense to me.

I believe the universe, that is our particular universe was born, just like everything else of the Cosmos is born

You do realize that this brings up an infinite recursion, right? Everything is born, therefore our universe must have been born inside some sort of Greater Cosmos. But everything is born, therefore the Greater Cosmos must have been born inside some Greater Greater Cosmos. But everything is born, therefore the Greater Greater Cosmos must have been born inside a Greater Greater Greater Cosmos. And so on, ad infinitum.

Either you have to admit that there may be something which exists without having been "born" or you are forced to claim that our universe exists within an infinite panoply of shell universes like some sort of unending series of Matryoshka dolls. If the former, then one is forced to ask why you think our universe cannot be that which exists without having been born. If the latter, then you are forced to defend a completely ad hoc and speculative hypothesis with absolutely no basis in either physical evidence or mathematical models.