Monday, June 19, 2017

Evidence and fine tuning

Evidence, at least to me, would be a fact of experience that is more likely to exist if there is a God than if there is no God. Even if the such facts are outweighed by other facts, isn't it pretty cleat that such facts exist? One of them would be the fine-tuning of the universe, the fact that only because the universe began with cosmic constants that fall within some very narrow specifications did life emerge. We might have discovered the life could have emerged on many possible initial cosmic constants, but we didn't discover this. 

17 comments:

Hugo Pelland said...

The so-called fine tuning shows our ability to measure these constants with great degree of precision more than anything else. It does not follow that these are the only possible values, nor that they are unlikely. In our universe, just a tiny tiny change would prevent atoms from forming or stars from burning, etc.. but that means nothing when it comes to interpreting them as being special, somehow. It's very easy to come up with possible scenarios that explain these values and the design argument thus fail, given that the design argument rests on the fact that there are no other possible option. Unless I misunderstand the argument but I have not heard a better defense...

David Brightly said...

Yup. On the scientific picture we have to conceive that an extremely improbable event occurred---though it's hard to say what probability could mean when we are talking about the origin of space, time, and everything that is. On the religious picture we have to conceive of something thinking and acting outside of space and time altogether. Some dilemma!

Aron Zavaro said...

Victor,

How do you respond to the claim that P(FT|~G) is neither low nor high, but rather it is meaningless to discuss probabilities in this context because it is mathematically meaningless to talk about a flat probability distribution over an infinite range?

I've heard the responses of Collins, Pruss, Barnes, and Plantinga, and so far I have been unimpressed.

Mortal said...

Although I personally believe fine tuning to be the work of the Creator, I do not think it makes for a good argument. There are simply too many counter arguments, such as:

- The way things are, is the only way things can be (sort of like, two plus two can only equal four).
- There are an infinite number of universes, and we happen to be in the one with the various constraints allowing for us to exist (the multiverse concept).
- There's nothing remarkable about fine tuning (the ol' "Why should we be surprised if the water in a rain puddle matches the contours of its depression exactly?" line of reasoning).
- etc.

Victor Reppert said...

In this context, I am bringing this up in response to the no-evidence charge. It seems to me that if you were completely 50-50 on God, and you became aware of fine-tuning, this should swing you to the theist side. Therefore, it is, to my mind, a good refutation of the no-evidence charge. If we are atheists, and we haven't discovered it already, we should expect the scientific evidence to point away from fine-tuning. If we are theists, this is what we should expect.

But I am also someone who thinks that the argument from evil provides some evidence for atheism.

I think the only hope for the no-evidence claim is if you make the argument that God is not the kind of thing for which evidence is possible. This is the Steve Zara-P. Z. Myers position that Dawkins has now accepted. The idea that there can be evidence for God, but we don't have it, strikes me as a nonstarter.

Aron Zavaro said...

In order for fine tuning to count as evidence, we need to be able to say that P(FT|~atheism) has a value between 0 and 1. But the McGrews have forcefully argued that this is mathematically impossible

Hugo Pelland said...

Victor,
"and you became aware of fine-tuning, this should swing you to the theist side.
...
we should expect the scientific evidence to point away from fine-tuning. If we are theists, this is what we should expect"

Why? Why expect fine tuned values, or not?

We can even make an argument for exactly the opposite: if the universe were designed, the constant wouldn't need to be fine tuned; a clever designer would make sure that their creation works reliably and thus not subject to failure because of small variation. Hence, the universe was not designed...?

Of course that doesn't really prove anything, and that's the point.

Victor Reppert said...

We can even make an argument for exactly the opposite: if the universe were designed, the constant wouldn't need to be fine tuned; a clever designer would make sure that their creation works reliably and thus not subject to failure because of small variation.

Why would he want to?

Hugo Pelland said...

Bingo, why would he? Or why not? We don't know. You just disproved the argument.

grodrigues said...

@Mortal:

"There are simply too many counter arguments, such as:"

While like you, I do not think much of the fine-tuning argument, I think even less of the counter-arguments you list.

I have recently became acutely aware of this curious phenomenon: arguments from theists that are weak, but where the weaknesses are best exposed by other theists, the atheist counter-arguments being even worse than the original arguments.

Aron Zavaro said...

A lot of different pieces of data are being clumped together here. Let's separate them:

L=life exists
S=the laws of physics are strict rather than lenient - i.e., they are such that only a small range of values for the constants are compatible with life naturally existing
N=life exists naturally - i.e., the values of the constants fall in the life permitting range, and therefore the existence of life is not in violation of the laws of physics

T is theism and A is atheism

P(L|T)>P(L|A) because God would have reasons to want life, whereas the universe is indifferent, so L is evidence for God, if not big evidence

P(N|T&L)<P(N|A&L) because given that life exists, atheism entails that it must exist naturally (consistent with all natural laws), but on theism, life can exist in ways that are not consistent with natural laws, because a God can do miracles, so N is evidence for atheism, if not huge evidence

P(S|N&L&T)=P(S|N&L&A) because L&N screen off S from T and A. Imagine a spectrum with the most strict possible laws on the left and the most lenient possible laws on the right. Along the spectrum are dots representing universes in which life is naturally permitted. Obviously, there will be more dots on the right side of the spectrum. Given that we know our universe is one with L&N, our universe must be one of the dots on the spectrum. And because there are an equal number of dots located on the S side of the spectrum, regardless of whether theism or atheism is true. So given N&L, the likelihood of S is the same, regardless of whether T or A is true. For both atheism and theism, the likelihood of S being true will necessarily just be (dots representing strict law universes / total dots). This point has been demonstrated by Jonathan Weisberg.

So life is some evidence for God. The fact that life exists in a way compatible with natural laws is some evidence for atheism. And the strictness of the laws of physics is not evidence for either.

Mortal said...

grodrigues,

Well, I didn't say they were good counter-arguments, but they do seem to satisfy those who use them.

A actually think the first one is solid, while the multiverse idea is junk science, and the third argument is a variation of "brute fact" reasoning, sort of like answering a question with "Just because!"

But even if we granted that there was no possibility for our universe to be anything other than what it is, that still does not rule out design. I'd say the idea is neutral to the debate. (I am aware that an atheist might conclude otherwise.)

grodrigues said...

@Mortal:

"Well, I didn't say they were good counter-arguments, but they do seem to satisfy those who use them."

I confess I am only interested in whether the arguments are good or not, not in whether someone is "satisfied" by them. That fact only tells us about the person, not the argument.

"A actually think the first one is solid"

There isn't a single half-decent argument for it, not one -- I do not count sheer assertion, question begging or changing the topic as good arguments.

Stardusty Psyche said...

Victor Reppert said...

" We can even make an argument for exactly the opposite: if the universe were designed, the constant wouldn't need to be fine tuned; a clever designer would make sure that their creation works reliably and thus not subject to failure because of small variation.
Why would he want to?"
--Then who is this clever designer that fine tuned god? God's god?

Perhaps you say god just always existed. Ok, so something extremely complicated and powerful can just exist from negative infinity. In that case, why bother with the god speculation at all?

Perhaps you say god is not fine tuned. So any old sort of existence can make up a god?

The god hypothesis solves nothing, explains nothing, and only makes the problem more difficult.


June 20, 2017 7:04 PM

Edward T. Babinski said...

We donʼt know if any other set of constants and laws are even possible. It could be that the cosmos is as the cosmos is and does what the cosmos does, and asking why makes as much or as little sense for naturalists as the question of why God is as God is—and does what God does—makes for theists.

We also donʼt know that the constants can vary independently from one another. They may all be related to one another or to some more fundamental feature. Kind of like saying that maybe you cannot stretch just one characteristic of the cosmos because it is connected with all the other characteristics, so hypothetical cosmoses with different constants canʼt exist, or, stretching one part a little results in other constants nudging it back into equilibrium, because a cosmos is a single interconnected whole.

Physicists disagree over just how many absolutely fundamental constants there are. We used to think there were as many as 40 fundamental constants, including the boiling point of water. Now we know that this derives from quantum mechanics, and the number of fundamental constants is now down to six or less. So this universe may be the only way it can go. In 2000 Martin Rees wrote Just Six Numbers: The Deep Forces that Shape the Universe, the genesis of the universe elegantly explained in a simple theory based on just six numbers by one of the worldʼs most renowned astrophysicists. In 2007 a team of physicist in Brazil whittled down that number to just two (according to this article). Two constants should be enough to explain the cosmos. Their work shows how some constants are more fundamental than others— some are merely useful, whereas perhaps precisely two are indispensable. While others have argued that no constants are needed: that the universe can be described using ratios alone, so that there are no ‘natural’ units.

It may not be that our universe is as special as we think; there could be many others that are special or interesting in different ways. Life could arise through different means or different chemistries or different physical laws, if those even exist.

There may be standard physical mechanisms for producing multiple separate universes with different laws. If so, the existence of one like ours would no longer be unexpected. We might never be able to detect the other universes, but we may able to prove they should be there.

—Richard Smith, a brief excerpt from Scientist-Believers: Troublesome Routes Across the Compatibility Chasm with added edits by EB

Edward T. Babinski said...

Speaking of "fine-tuning"...

Letʼs start small with the question of how you in particular came to be born and became the person you are today. A study of nature tell us that men produce enough sperm on a daily basis to repopulate the earth in six months. However, many of those sperm are deformed, many have two heads, or two tails, or squiggly tails, or heads that are too large or two small, etc. Was that part of some design or fine-tuned plan to make you? And in the average human ejaculate there are two hundred million sperm. If God wanted specifically to make ‘you’ then only one sperm would have been required. Two to decide between a specific boy or girl. But two hundred million? Talk about a roll of the biological dice that made ‘you.’

Sperm are also subjected to physical stresses during ejaculation and contractions of the female tract, and may sustain oxidative damage, or even encounter the defenses of the female immune system meant for infectious organisms.

Also, in a 5 year study of 11 female volunteers Baker and Bellis (1993) examined the characteristics of sperm loss from the vagina following coitus (also called ‘flowback’). They found that flowback occurred in 94% of copulations with the median time to the emergence of ‘flowback’ of 30 min (range 5—120 min). Furthermore they estimated that a median of 35% of spermatozoa were lost through flowback but that in 12% of copulations almost 100% of the sperm inseminated were eliminated. Does the high flowback ratio sound like efficient design? This suggests that less than 1% of sperm might be retained in the female reproductive tract and this supports the notion that only a minority of sperm actually enter cervical mucus and ascend higher into the female reproductive tract.

Even being the first sperm to reach the egg assures nothing, since the eggʼs wall is too thick at that point and has to be weakened first by a couple thousand sperm attempting to breach it. And on occasion two or more sperm enter the egg before it begins to reharden, in which case the fertilized egg divides a few times then stops, or it may grow to the point of early implantation, implant on the uterine wall and then result in a miscarriage. Sometimes after the sperm enters the egg it triggers a second set of female chromosomes to be produced, and the fertilized egg dies. Sometimes the sperm enters the egg but does not go on to form a pronucleus, leaving only the eggʼs chromosomes functional, and again the process of development shuts down.

In short, your genetic compliment appears to be the result of trivial differences between hundreds of millions of dead sperm, i.e., purely statistical odds. CONTINUED BELOW

Edward T. Babinski said...

CONTINUED FROM ABOVE

Now letʼs talk about eggs. During childhood a girlʼs ovaries absorb almost half of the million immature eggs with which she was born. Of the four hundred thousand eggs present during her first menstrual period, only 300 to 500 of them will develop into mature eggs across her reproductive life span. Her body reabsorbs the rest before they complete development. Again, does that sound like efficient design, or a case of the roll of the dice?

Even the circumstances by which oneʼs parents meet, and the time of year or day they make love, and the position they are in during coitus, along with a host of other circumstance, can affect which sperm reaches which egg. So it appears like a crap shoot. Also, what lessons can one be sure that God is teaching us when a baby dies in the womb, or dies during birth, or is born with defects? Up to the mid 1700s half of all children who were born died before reaching the age of eight (according to Buffonʼs estimate). So if we canʼt be sure of what God may be teaching us when lightning strikes one tree or power line rather than another, then what can one say with certainty concerning why one particular egg happened to become fertilized by one particular sperm, or why spontaneous abortions or birth defects occur?

Now letʼs take our discussion to a highest level. If the conception of each individual seems like a crap shoot or toss of the genetic dice due to a plethora of circumstances that do not seem personally planned, then what about the evolution of a species? What if God lets evolution be evolution just as He lets sperm be sperm and eggs be eggs, and lightning strikes be lightning strikes? The human species constitutes one of a small number of extremely large-brained species of mammals on earth, including cetacea (whales, dolphins), elephants, early apes and upright hominids. All with larger brains than average. However many species of cetacea, elephants, early apes, and upright hominids, became extinct, rather like the aforementioned hundreds of millions of eggs and sperm with different compliments of genes that naturally perish during coitus leaving either nothing behind or a single fertilized zygote.