SGU Prem #130 - Feb 27 2021
Added 2021-02-27 16:55:58 +0000 UTCFull interview with Philip Goff about the finetuning - multiverse problem.
Comments
I'm a little late to the party here, but I've been banging my head against this for a week now and think I have things straightened out in my own mind at least. First, I'm taking for granted that the universe is ~10^120 times more likely to be empty than it is to contain stars, galaxies, black holes, etc.. If there were only one universe, it would be extremely unlikely that it would contain stars, so the fact that we observe a universe with stars is equally surprising. If instead there was a multiverse with a few star-containing universes, it would not be at all surprising that we find ourselves in one of those not-empty universes. This is obviously different from the lottery scenario in that the number of other players doesn't change the probability of you ticket winning, whereas the number of universes in the multiverse does change the probability that at least one is not empty. My confusion has been that similar logic seems to apply even in the lottery scenario. Say I tell you that one person one the lottery this week and that the probability of winning the lottery in 1 in 10^8. It seems completely reasonable that you would guess that around 10^8 people played the lottery this week. You could even justify this guess using, for example, maximum likelihood estimators for a binomial distribution which would predict that there were exactly 10^8 players given these conditions. The weird part seems to be extending this logic to the case that that YOU won the lottery. All I'm doing is adding information, but now your previous guess no longer feels reasonable. I think the solution to this is to reframe the guess as a test of whether the game is fair. Say you won the lottery this week with a probability of 1 in 10^8. If I then told you that by some fluke you were the only person that played the lottery that week, you would probably be justified in assuming the game was rigged in your favor. But if 10^8 people played, you would just assume that you were the lucky winner.
Jon
2021-03-07 19:52:28 +0000 UTCI think you're misunderstanding the fine tuning problem slightly. Take the cosmological constant (Lambda) for instance, which is about 10^120 than smaller than the value predicted from first principles. If it were even slightly larger than that, the universe would have expanded so rapidly that no stars or galaxies would be able to form, and the universe would be empty. If we assume that Lambda can take any value from 0 to the expected value with even probability, that means that a generic universe is about 10^120 times more likely to be empty than it is to have any sort of complex structure. If there is only one universe, then it would be extremely unlikely for it to be not empty. If there are many universes then it's not surprising that a few of them would be not empty, and we would obviously only find ourselves in one of the not empty ones. On a side note- I think it's much more likely that the apparent fine tuning points to a problem with either the first principles calculation or the assumption we made for the probability distribution, or both. But I do think a multiverse solves the problem.
Jon
2021-03-07 19:26:04 +0000 UTCTotally agree!
M R
2021-03-02 12:35:36 +0000 UTCMy last comment was for Ted.
Sean Helferty
2021-03-02 12:29:35 +0000 UTCTrue, but I wonder if we should leave room for some unknown solution that we haven't thought of. The scenario seems to be a binary choice though.
Sean Helferty
2021-03-02 12:25:04 +0000 UTCSean, and that was exactly my point. Steve seemed to be making the positive claim that a multiverse is the more or even most likely answer because it makes our universe’s existence more likely. I confess that that the multiverse theory, if we discover evidence of its existence, does have the benefit of making the math easier. The problem is, at least in my non-expert understanding, we haven’t found any evidence that the multiverse exists. It absolutely could, but so could Sagan’s Dragon or Russell’s teapot. Just because it makes things more likely, in and of itself, does not mean it’s confirmation of its existence.
M R
2021-03-02 12:18:25 +0000 UTCWhat third choice could there be between only one universe existing and more than one universe existing? You can't have zero universes existing or a negative number of universes existing.
Ted Apelt
2021-03-02 11:47:04 +0000 UTCYou have explained some of the reasons why the only possible reason to believe in "God" is for this being to communicate with us, but then you have a problem of definition. There are about as many different definitions of this as there are people, and to make matters worse, these definitions are constantly shifting. Pick a definition and show it to be false, and it’s “That’s not what I mean by God!” OK, so what exactly do you mean by the word “God”??? They never give you a straight answer. EVER! Then, because you can’t prove that all possible definitions of the word “God” (including ones you have never heard of before) are false, it must mean that “God” exists. Well, I’ll make it easy for you. I will precisely define what I mean by “God”. “God” is any being that: (1) Assumes the title of “God” and (2) Answers this request: If there is anyone out there who can understand what I am saying, and you are not a human (or something programmed by humans), and you want me to know that you exist, please let me know you exist. I have been saying this for many decades, so far no response.
Ted Apelt
2021-03-02 11:40:02 +0000 UTCI think maybe the logical gap here depends on how the rules are interpreted. Steve is basically saying that there are 2 possibilities: (A) one universe and we got lucky, and (B) Multiverse. Probability of A + Probability of B = 1, and Probability of A is low, therefore Probability of B is high. This depends, however, on this narrow scenario where there is a false choice. If there are 3 choices, the low probability of A does not necessarily imply a greater probability of B.
Sean Helferty
2021-03-01 03:19:51 +0000 UTCThe Loki analogy raised the following question in my mind: The question of existence can only be asked if the person exists/was created. If the person does not exist, no one can ask why they exist and Loki just walks off. Doesn't that also play a role? Only in the incredibly unlikely event, is there anyone at all who can ask the question. But the person cannot conclude from his existence that there are several rooms. Loki could just have walked off, because no one exists but then he got really lucky with you. But I have no idea about statistics, so it's just some ignorant questions...
Andres Bucher
2021-02-28 18:39:06 +0000 UTCThanks for the discussion, super interesting! I'll be honest, though: Steve's opinion really felt like a 'god of the gaps' argument to me. I'm sure I'm missing something, but that's what I kept coming back to. In the Loki analogy, all the person would know is that: 1. They are alive 2. The fact that they are alive is extraordinarily unlikely 3. They are in a room Nothing about the above knowledge would indicate that there are monkeys slaving away in other similar rooms, even though if that were the case it would make it more likely that someone would come to exist in one of them. Increasing the probability, by itself, doesn't feel to me like it's an argument for a thing existing. A theologian could invent a concept of a god (as some have invented the concept of a multiverse) and state that that god has agency to create a universe that is fine tuned for life. At this point, I feel like both the god "answer" and the multiverse "answer" have similar explanatory power. They're both things that could exist, and if they did exist they could solve the problem that a universe is apparently fine tuned for life when that should be next to impossible, but for which we do not currently have any other evidence that they do exist.
M R
2021-02-28 18:08:27 +0000 UTCGreat discussion, but I believe there is a threshold issue neither Steve nor Professor Goff addressed. The Fine Tuning argument is only “problematic” if one proceeds from an unstated, unsupported assumption. Namely, the assumption that life has inherent value, i.e., value independent of the value that the living themselves place on life. In other words, the Fine Tuning argument is based on a bias, a bias for Life. (And, in particular, human life. And, in particular, MY human life.) I know this as the “The Universe is Fine-Tuned for iPhones Fallacy.” (All credit to Luke Muelhauser and his previous blog Common Sense Atheism, where I first read the argument many years ago, though he used iPads as the example. Unfortunately, I can no longer find it online, so apologies to him if I botch it.) The Fine Tuning argument is that the odds that our Universe would have the properties necessary for Life to exist are so unbelievably long the fact that the Universe does have these properties demands an explanation (the unstated explanation being “God,” of course). But the odds that our Universe would have the properties necessary for iPhones to exist are even longer. What if the Earth had formed without the rare earth metals necessary for humans to make the “Taptic Engine” that simulates a push-button? Does the fact that the iPhone exists demand a philosophical-slash-logical explanation? One could use countless other examples, but the answer to the question invariably would be “of course not.” Seen this way, it becomes clear that there’s no need to debate the Gambler’s Fallacies. Further, the analogies to gambling are inapt (as is the Loki example). Gambling has a very specific goal - to win money. However, if there was no more point to rolling the dice than to see what numbers come up, if one rolled a thousand sevens in a row it would not invoke any more response than “Huh, how unlikely. But there you go.” It simply would not demand an explanation because, as Steve pointed out, incredibly unlikely things happen all the time. Why does the existence of Life demand an explanation? Why is Life just assumed a priori to be inherently special (again, as opposed to being special to people who appreciate that they are alive)? Why not ask “Why is the Universe fine-tuned for the existence of black holes? Or ball lightning? Or prions?” The Fine Tuning argument requires one to assume that life is a “goal” of universe-creation, but no Fine Tuning advocate I’ve ever heard has articulated even a passably convincing argument this is the case. If there is no inherent value to life there simply is no need to ask why the Universe is fine tuned for it, any more than there is a need to ask why the Universe is fine-tuned for iPhones. That said, I don’t think Professor Goff laid a glove on Steve.
Daniel Balmat
2021-02-28 03:28:55 +0000 UTCThe conversation with Philip Goff was upsetting...not because I agree or disagree with one hypothetical or the other, but because it was two people smarter than me having a conversation about something over which I internally bang my head against the wall way too much, and instead of walking away with a clear answer it just made me bang my head against that wall harder than ever. Can we just find Loki and then get a trillion monkeys with typewriters in a warehouse so we can approach this problem with the scientific method and finally be at peace? Let me know--I'll help.
Brad Gosser
2021-02-28 00:32:28 +0000 UTC
