Dr. Michael Strauss @MStrauss discusses several “problems” with the Big Bang often identified by YEC and used to discredit the theory. In this first of two articles in the series, Dr. Strauss deals with the supposed problems of Horizon, Flatness, Monopole, and Expansion.
We don’t actually know whether the world is comprehensible. All we know is that those aspect of the world that we comprehend are comprehensible. But perhaps what we comprehend is only a tiniest part of what’s out there.
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Here is a detailed analysis of inflation using the latest results from Planck.
Inflation is on firm empirical ground now and there is no fine tuning.
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Why do you say that there is no fine tuning?
First of, I think it is too early to claim this:
We will have to wait for Steinhardt and co’s response to see if they agree with this analysis.
I personally find fine tuning arguments to be ill-posed. However, if one believes in the fine-tuning problem, there is an interesting give and take with inflation here:
- There are other fine-tuning problems in physics. Indeed, the fine-tuning problem of inflation is a relatively recent addition to the list of fine-tuning problems in physics. An example is the supposedly fine-tuned ratio of the strengths of the electromagnetic and gravitational interactions.
- The most popular way to explain away these fine-tuned parameters is to assume a multiverse initiated by inflation. By the anthropic principle, we must then live in a universe that looks as if it is fine tuned. See here for more explanation.
- However, as Martin’s paper points out, the inflationary multiverse is a speculation.
- If the multiverse speculation is correct, then inflation has a problem (at least according to Steinhardt and co), as this means that inflation loses predictive power and there is no empirical way to test inflationary theories.
- If the multiverse speculation is false, then we lose our explanation for the other non-inflation fine-tuned parameters.
To reiterate, which would one want to sacrifice: the predictive power (and thus the empirical and epistemological status) of inflationary theories, or the lack of fine-tuning of various physical parameters?
Again, to me this discussion is somewhat moot (or at least premature), as I think that fine-tuning arguments (be it inflationary or not) is ill-posed.
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Or maybe we comprehend 5%. 95% is dark matter and dark energy.
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Why do you think the fine-tuning argument is ill-posed? Is it because of what you said here, namely
?
Yes, this is also the same problem that was mentioned by Sabine in this quoted text from her blog.
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And the last three sentences from that paper really make me wonder about the bias of the author:
“In brief, inflation continues to be an inspiration for many physicists and continues
to fuel new interesting works. So, inflation, trick or treat? Treat, definitively!”
Probably should have left that part out if he wanted people who are on the fence about inflaton to take his article seriously.
This manuscript is not a scientific report, but a chapter in an upcoming book. That’s why most of its expositions are very basic and has a textbook-like pedagogical quality. For such texts, more casual comments like the one you quoted is allowed. The formal scientific report on Jerome Martin’s recent analysis on whether inflation is fine-tuned or not is this paper.
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I changed “report” to “article.”
I wasn’t questioning whether or not it was allowed, but commenting on the impression it left with me. Which is the same, whether it be delivered via article, paper or report.
I agree, the author is definitely biased towards inflation. I suspect that we will hear what the other side has to say soon.
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Well, we do agree on some things, don’t we ! I like this article very much. I have always argued with YEC’s that they are only harming themselves when they oppose the elegance of the BB theory. No, it’s not perfect, but it is getting there. Within the decade or so, I predict the theory will find its permanent lodging in historical cosmology as problems are continually - and now more rapidly - resolved. As for the YEC argument that the BB militates against God’s design and against his Genesis text, I think God just bears with their YEC insolence and smiles.
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Actually, while I am on the line, let me add something about creation day 4. To YEC’s:
The text never said stars were created on day 4.
What it did say is that the moon was created on day 4 to govern the night along with the stars. That is an acceptable Hebrew reading of the original.
When you consider the phrase “In the beginning God created the heavens and the earth” it is pretty inescapable that the entire cosmos - stars included - came into being together early on day 1 and not day 4.
Then “in the beginning” or bara in Hebrew is what an ancient people means as the whole 9.2 billion year process to create the heavens and the earth. That was day 1 and it began at the Big Bang 13.8 billion years ago and ended 4.5 years ago with Sun, moon, and Earth created. Wow they were really smart people back then.
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For who that has understanding will suppose that the first, and second, and third day, and the evening and the morning, existed without a sun, and moon, and stars? And that the first day was, as it were, also without a sky? And who is so foolish as to suppose that God, after the manner of a husbandman, planted a paradise in Eden, towards the east, and placed in it a tree of life, visible and palpable, so that one tasting of the fruit by the bodily teeth obtained life? And again, that one was a partaker of good and evil by masticating what was taken from the tree? And if God is said to walk in the paradise in the evening, and Adam to hide himself under a tree, I do not suppose that anyone doubts that these things figuratively indicate certain mysteries, the history having taken place in appearance, and not literally.
Origen of Alexandria; De Principiis Book VI, 16
Now, if Origen, a man who was born in late second century and knew nothing about age of the Earth and evolution could see that Genesis wasn’t to be taken literally and people today can’t… Well, I don’t know what to say.
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Inflation is to be taken seriously because of Planck final results: There is nothing other than inflation that explains the Planck measurements:
We report on the implications for cosmic inflation of the 2018 Release of the Planck CMB anisotropy measurements. The results are fully consistent with the two previous Planck cosmological releases, but have smaller uncertainties thanks to improvements in the characterization of polarization at low and high multipoles. Planck temperature, polarization, and lensing data determine the spectral index of scalar perturbations to be ns=0.9649±0.0042 at 68% CL and show no evidence for a scale dependence of ns. Spatial flatness is confirmed at a precision of 0.4% at 95% CL with the combination with BAO data. The Planck 95% CL upper limit on the tensor-to-scalar ratio, r0.002<0.10, is further tightened by combining with the BICEP2/Keck Array BK14 data to obtain r0.002<0.064. In the framework of single-field inflationary models with Einstein gravity, these results imply that: (a) slow-roll models with a concave potential, V"(ϕ)<0, are increasingly favoured by the data; and (b) two different methods for reconstructing the inflaton potential find no evidence for dynamics beyond slow roll. Non-parametric reconstructions of the primordial power spectrum consistently confirm a pure power law. A complementary analysis also finds no evidence for theoretically motivated parameterized features in the Planck power spectrum, a result further strengthened for certain oscillatory models by a new combined analysis that includes Planck bispectrum data. The new Planck polarization data provide a stringent test of the adiabaticity of the initial conditions. The polarization data also provide improved constraints on inflationary models that predict a small statistically anisotropic quadrupolar modulation of the primordial fluctuations. However, the polarization data do not confirm physical models for a scale-dependent dipolar modulation.
Just curious, what exactly is your understanding of this era and what evidences/constraints cosmologists are looking at? Are there other models that you find particularly attractive or promising? I’m just trying to ask since I’ve seen you mentioning multiple times not being a fan of inflation which if fine of course, but what does rejecting the inflationary models mean for you and your understanding of the early universe?
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Let’s actually quote from the article to see if there is fine tuning rather than simply claim there is no fine tuning as Patrick does. The article says,
“The overall picture that emerges from this section is that it is difficult to say whether the parameters of the inflationary potential are necessarily fine tuned if one wants to account for the data. It is clear that this question is model dependent. For some potentials, the fine-tuning seems to be present (at least if one adopts a naive definition of fine-tuning) but for others, and in particular those that fit the data well, it is unclear whether this is the case.”
So nowhere at all does the article make the claim that there is no fine tuning. The article says for some models there is fine tuning and for others it is unclear. Unclear means there might or might not be fine tuning. There are absolutely no models where it is clear that fine tuning is unnecessary. So Patrick’s representation of what the article says is completely false. Of course, other articles continue to claim that there is fine tuning because in many of the leading models fine tuning is required.
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