• christian2017
    1.4k
    Sure.

    The OP is based on a misapprehension of how physics deals with causation, and hence the argument fails.

    But that will make no difference to its defenders, since the real point of this thread is to engage in mutual preening.
    Banno

    I disagree.
  • Isaac
    10.3k
    Sure.

    The OP is based on a misapprehension of how physics deals with causation, and hence the argument fails.

    But that will make no difference to its defenders, since the real point of this thread is to engage in mutual preening. — Banno


    I disagree.
    christian2017

    I quite like olives.
  • christian2017
    1.4k


    Olives are good. I like green olives and black olives on Pizza. Lets hope we don't get caught getting off topic. Shhhhh. quick there coming.
  • Banno
    23.1k
    I disagree.christian2017

    Telling me of your mental state is utterly pointless.

    Can you address the objections? If not, then you are of no use here.

    Ah, a far more erudite and accurate reply than mine. :up:
  • Kenosha Kid
    3.2k
    Eternal inflation is a very funny joke - eternal is impossible in time - where eternal inflation takes place. Those nuts think infinity is possible - It's all finite.Devans99

    Can you justify this without personal incredulity? Otherwise you may as well cut out the middleman and say: "I personally can't conceive of a universe without an intelligent creator, therefore the intelligent creator exists, and we call him God". This actually has the benefit of having only one fallacy.

    That has absolutely nothing to do with my probability calculation - have you read it?Devans99

    Yes, and it ain't how Bayes intended. Utter nonsense put forward by Stephen Unwin, creationisms most willing idiot. It's an argument ab rectum.
  • Banno
    23.1k
    I hadn't noticed this:
    1. Start at 50%/50% for the unknown boolean question ‘is the universe a creation?’
    2. Time has a start. 50% probability of a creator due to this gives: 50% + 50% * 25% = 75%
    3. Universe is not in equilibrium 25% probability of a creator giving: 75% + 25% * 25% = 81%
    4. Causality based arguments. 25% probability of a creator giving: 81% + 19% * 25% = 85%
    5. Fine tuning 50% probability of a creator giving: 85% + 15% * 50% = 92%
    6. Big Bang 25% probability of a creator giving: 92% + 8% * 25% = 94%
    7. Aquinas 3rd argument, etc...
    Devans99

    Yea, it is risible.
  • Michael
    14k
    1. Start at 50%/50% for the unknown boolean question ‘is the universe a creation?’
    2. Time has a start. 50% probability of a creator due to this gives: 50% + 50% * 25% = 75%
    3. Universe is not in equilibrium 25% probability of a creator giving: 75% + 25% * 25% = 81%
    4. Causality based arguments. 25% probability of a creator giving: 81% + 19% * 25% = 85%
    5. Fine tuning 50% probability of a creator giving: 85% + 15% * 50% = 92%
    6. Big Bang 25% probability of a creator giving: 92% + 8% * 25% = 94%
    7. Aquinas 3rd argument, etc...
    Devans99

    How about I consider the inverse of this?

    1. Start at 50%/50% for the unknown boolean question ‘is the universe a creation?’
    2. Time has a start. 50% probability of no creator due to this gives: 50% + 50% * 25% = 75%
    3. Universe is not in equilibrium 75% probability of no creator giving: 75% + 25% * 75% = 94%
    4. Causality based arguments. 75% probability of no creator giving: 94% + 6% * 75% = 99%
    5. Fine tuning 50% probability of no creator giving: 99% + 1% * 50% = 100%
    6. Big Bang 75% probability of no creator giving: 100% + 0% * 75% = 100%

    So it is certain that the universe isn't a creation?

    Aside from pulling these probabilities out of thin air, the way you've added them together like this makes no sense at all.
  • Wayfarer
    20.6k
    Especially in light of the fact that everyone knows that physics says the universe should not exist at all.
  • Banno
    23.1k
    Well, there you go; God disappeared all the antimatter. God Certainly Exists
  • Devans99
    2.7k
    Indefinite Causal Order in a Quantum Switch (Goswami, Giarmatzi, Kewming, Costa, Branciard, Romero, White; APS; Aug 2018)

    (also ... the Casimir effect, virtual particle pairs, quantum fluctuations, radioactive decay, spacetime foam/turbulence, the "pressure" of vacuum energy, Fomin's quantum cosmogenesis (successors), Krauss' relativistic quantum fields, ...)
    jorndoe

    These are all micro effects - according to everything we know, all macro effects have causes. The origin of the universe is a macro question - huge amounts of matter.

    I suspect all micro effects have causes too - its just our physics is not unto the job of identifying them.

    I am not familiar with everything you listed, but: the Casimir effect has an alternative explanation that does not involve quantum fluctuations. Virtual particles / quantum fluctuations are caused by fluctuations of the underlying field. Radioactive decay is caused by activity within the nucleus as I already explained. Suspect the same sort of thing applies to the other phenomena you listed.

    No. (FYI, the link is the earliest reference in the literature I know of.)jorndoe

    Finite and unbounded is plainly impossible. I'm not even going to waste my time reading that link.

    I linked to the Stanford article on supertasks, which clearly explains what they are and how they are not logically impossible. In the face of that your insistence is fractious.Banno

    That Stanford article is wrong. I will explain the problem fully in a separate post later.

    Well, no. "Every action has a cause" is not one of Newton's laws, nor is it implied by them.Banno

    Both Newton's 2nd and 3rd law describe matter (=cause) acting upon matter (=effect). So Newton's laws are the embodiment of causality.

    Neither. This is a loaded question.Banno

    You seem to have disregarded the LEM! - not acceptable in my book. 'The Big Bang has a cause' is either true or false not both true and false at the same time.

    This is a description of your personal psychological state.Banno

    And yours. And all of ours. We all believe in causality.

    In my thesis, I interpret the baseline nothingness as the normal state of Ontology (BEING), which is also the eternal state of Logos, the Enformer. An act of Creation (Enformation, Causation) causes the neutral state to transition into positive-but-transitory existence (real, actual, Energy), which soon dissipates into (unreal, potential, Entropy). I go further to imagine fast oscillations (lightspeed) as Energy, and slow oscillations as MatterGnomon

    'Nothing' is an interesting concept:

    Space is expanding - 'nothing' can't expand - so space must be 'something' (substantivalism) rather than nothing (relationism). I imagine spacetime maybe like some sort of finite block, maybe surrounded by, and expanding into a wider, timeless, universe. That wider universe is also finite and surrounded by 'nothingness'.

    I imagine 'nothingness' as no space, no time, no dimensions - just absolute nothing. It cannot be said to be infinite because it has no dimensions and does not exist.

    I am unsure if any matter/energy was actually created - the conservation of energy seems very well respected by nature. It seems more like the container of spacetime has a start (the Big Bang / start of time), so that container was somehow created / initiated. But some or all of the matter/energy must of come from outside spacetime - a seed of matter/energy must at least be planted within spacetime to generate the rest of the matter/energy. Or otherwise, all the matter/energy is sourced externally to spacetime.

    The Copernican principle, otoh, is something we want to hold on to if we can.Enai De A Lukal

    Fine tuning does not run contrary to the Copernican principle - it says the whole universe (or even whole multiverse if you prefer) was tuned for life and is packed full of life - all those exoplanets we have discovered.

    We know from Godel and related work that any system advanced enough to explain arithmetic must either be incomplete or inconsistent.Banno

    Self-referential statements are pathological entities that should not be allowed anywhere near maths or logic. Godel was wrong. I might do a separate post to discuss this at some point later.

    We know you believe time must have a start, that you want time to have had a start. The problem is of course that the evidence and logic of the matter doesn't tell us firmly either way: again, hence scientific models of both varieties remaining viable.Enai De A Lukal

    I've already proved time has a start to you! Did you not read my reply? Once again:

    - The past is either a finite number of days long, or greater than all finite number of days long
    - Nothing can be greater than all finite numbers; they go on forever
    - So time has a start

    Please kindly read and properly consider the above proof.

    Supertasks or infinite sequences may strike you as conceptually difficult to imagine or grasp, but if they do not entail a contradiction, then they are not logically impossible. If you claim that something is logically impossible, stating why it is implausible or weird is not sufficient: show us where it involves a contradiction.Enai De A Lukal

    Supertasks are impossible. I'll do a separate post to discuss this in the coming weeks.

    Your hands are full at the moment. I don't want to distract you from better discussions. Au revoir.TheMadFool

    Mad Fool: I like to hear from you too!

    No, I'm not talking about the mere gathering of other people's thoughts. I'm talking about the judgement of them. How do you know they are wrong? Even when obviously intelligent and knowledgeable people, basically the vast majority of the mathematics community, have told you you're wrong, you still consider yourself to be right, so their conclusions, arguments and demonstrations have had no effect on you whatsoever.Isaac

    1) Mathematics defines points to have zero length.
    2) How many points are there on a line segment length one?
    3) Line length / point length = 1 / 0 = UNDEFINED.
    4) That can’t be correct. Euclid, Cantor and co MUST all have it wrong.

    I will explain the implications of the above result in upcoming posts.

    I feel we should concentrate on the God issue with this thread.

    I have no objection to you doing this, of course, you can do what you like, but I am a) very interested in why you would then consult the very community you've already decided you will reject the wisdom of the moment it doesn't suit, and b) slightly annoyed that you're being so evasive about this, which makes me suspect you're motives are hidden and disingenuous.Isaac

    a) I don't reject others wisdom. I consider their points carefully and adjust my position if required.
    b) I can't explain all my ideas in one post. Please bear with me - I will cover it all eventually.

    Can you justify this without personal incredulity? Otherwise you may as well cut out the middleman and say: "I personally can't conceive of a universe without an intelligent creator, therefore the intelligent creator exists, and we call him God". This actually has the benefit of having only one fallacy.Kenosha Kid

    As I already pointed out to you, eternal inflation theory mandates a first cause.

    As to why eternal inflation theory is wrong, I will have to do a separate post on it in the coming weeks; don't want to crowd this already busy thread with other loosely related issues.

    Yes, and it ain't how Bayes intended. Utter nonsense put forward by Stephen Unwin, creationisms most willing idiot. It's an argument ab rectum.Kenosha Kid

    Just because you don't understand something, does not mean it's wrong.

    Aside from pulling these probabilities out of thin air, the way you've added them together like this makes no sense at all.Michael

    I'll explain my method:

    1) Assume we have a trial and someone is accused of murder.
    2) Before hearing any evidence, we assign a neutral 50% guilty, 50% innocent, probability outcome.
    3) The first piece of evidence is finger prints on the knife.
    4) We assess that [3], on it's own, means it is 75% likely he is guilty.
    5) That gives 50% guilty + 50% innocent X 75% = 87.5% chance he is guilty after considering one piece of evidence.
    6) The second piece of evidence is blood on his cloths
    7) We assess that [6], on it's own, means it is 50% likely he is guilty.
    8) That gives 87.5% guilty + 12.5% innocent X 50% = 93.75% chance he is guilty after considering two pieces of evidence.
    9) You can obviously continue adding as many separate, non-overlapping, pieces of evidence to get a better estimate.

    I can't quite work out how to extend this method to take into account negative evidence. Any ideas?
  • Michael
    14k
    4) We assess that [3], on it's own, means it is 75% likely he is guilty.
    5) That gives 50% guilty + 50% innocent X 75% = 87.5% chance he is guilty after considering one piece of evidence.
    Devans99

    If 4) means that it is 75% likely he is guilty then it means that it is 25% likely that he is innocent.

    If we then use your logic in 5) we have 50% guilty + 50% innocent x 25% = 62.5% chance he is innocent.

    So your reasoning leads us to the contradictory conclusion that there is an 87.5% chance that he is guilty and a 62.5% chance that he is innocent.

    It should be obvious from this that you're calculating probabilities wrong.
  • Devans99
    2.7k
    If 4) means that it is 75% likely he is guilty then it means that it is 25% likely that he is innocent.

    If we then use your logic in 5) we have 50% guilty + 50% innocent x 25% = 62.5% chance he is innocent.

    So your reasoning leads us to the contradictory conclusion that there is an 87.5% chance that he is guilty and a 62.5% chance that he is innocent.

    It should be obvious from this that you're calculating probabilities wrong.
    Michael

    You have that wrong - if we start at a 50% chance that he's guilty - and assess the first piece of evidence means he's 75% likely to be guilty - then the chances he's innocent must go down, and not up as you have calculated above.
  • Michael
    14k
    You have that wrong - if we start at a 50% chance that he's guilty - and assess the first piece of evidence means he's 75% likely to be guilty - then the chances he's innocent must go down, and not up as you have calculated above.Devans99

    Yes, it must, which is why your calculation in 5) is wrong. If the first piece of evidence means he's 75% likely to be guilty then he's 75% likely to be guilty after considering one piece of evidence. The calculation you do in 5) to derive a likelihood of 87.5% makes no sense, as shown by the fact that this calculation also entails the contradictory conclusion that he's 37.5% likely to be guilty.
  • Devans99
    2.7k
    Yes, it must, which is why your calculation in 5) is wrong. If the first piece of evidence means he's 75% likely to be guilty then he's 75% likely to be guilty after considering one piece of evidence. The calculation you do in 5) to derive a likelihood of 87.5% makes no sense, as shown by the fact that this calculation entails the contradictory conclusion that he's 37.5% likely to be guilty.Michael

    The first 'piece of evidence' to consider is that 'is he guilty?' is an unknown boolean question. So we should start with the assumption of 50% guilty / 50% innocent to reflect this. IE our evidence is that we are assuming the chances that he is guilty/innocent are normally distributed. This is evidence of a sort and I think it has to be built into the overall calculation.

    Then we apply the individual pieces of evidence on top of the starting point. If there is a 50% chance that he is innocent and we have a piece of evidence that says he is 75% likely to be guilty, we reduce the innocent % and increase the guilty %: 50% guilty + 50% innocent X 75% = 87.5% chance he is guilty.

    This method then gives a way of combining multiple independent pieces of evidence into a single consolidated probability estimate.

    I see your point about whether we should start at 50% guilty or 75% guilty. I am not totally sure on this question. But whichever point we start at, it makes little difference to the results of the calculation - either way, the probability of the universe being a creation comes out very high.
  • Michael
    14k
    The first 'piece of evidence' to consider is that 'is he guilty?' is an unknown boolean question. So we should start with the assumption of 50% guilty / 50% innocent to reflect this. IE our evidence is that we are assuming the chances that he is guilty/innocent are normally distributed. This is evidence of a sort and I think it has to be built into the overall calculation.

    Then we apply the individual pieces of evidence on top of the starting point. If there is a 50% chance that he is innocent and we have a piece of evidence that says he is 75% likely to be guilty, we reduce the innocent % and increase the guilty %: 50% guilty + 50% innocent X 75% = 87.5% chance he is guilty.
    Devans99

    This calculation makes no sense. Let's say that the first piece of evidence says that he is 50% likely to be guilty. We don't then say 50% guilty + 50% innocent x 50% = 75% chance he is guilty. We just say that he is 50% likely to be guilty. As above, we can use your logic to say that because the first piece of evidence says that he is 50% likely to be innocent then 50% innocent + 50% guilty x 50% = 75% chance he is innocent.

    Your reasoning leads to the contradictory conclusion that there is a 75% chance he is guilty and a 75% chance he is innocent.
  • Devans99
    2.7k
    This calculation makes no sense. Let's say that the first piece of evidence says that he is 50% likely to be guilty. We don't then say 50% guilty + 50% innocent x 50% = 75% chance he is guilty. We just say that he is 50% likely to be guilty. As above, we can use your logic to say that because the first piece of evidence says that he is 50% likely to be innocent then 50% innocent + 50% guilty x 50% = 75% chance he is innocent.

    Your reasoning leads to the contradictory conclusion that there is a 75% chance he is guilty and a 75% chance he is innocent.
    Michael

    But what happens if 90% of people accused of murder actually turn out to be innocent? Then your logic says the first piece of evidence is that he's 50% likely to be guilty. Well, that seems no good - it seems we cannot ignore the fact that 90% of accused turn out to be innocent - we have to use 90% as our starting point:

    10% guilty + 90% innocent X 50% = 55% guilty.

    You see I hope how this combines the initial probability distribution we know (that 90% of people accused of murder actually turn out to be innocent), with the first piece of evidence.
  • Michael
    14k
    But what happens if 90% of people accused of murder actually turn out to be innocent?Devans99

    Then either we have lots of misleading evidence or you should revise the probability that the evidence suggests guilt.

    10% guilty + 90% innocent X 50% = 55% guilty.

    You see I hope how this combines the initial probability distribution we know (that 90% of people accused of murder actually turn out to be innocent), with the first piece of evidence.
    Devans99

    I've already pointed out that your reasoning leads to contradictory conclusions. That's a mathematical fact that can't be refuted by suggesting a hypothetical situation where innocent people are predominantly found guilty.
  • Devans99
    2.7k
    I've already pointed out that your reasoning leads to contradictory conclusions. That's a mathematical fact that can't be refuted by suggesting a hypothetical situation where innocent people are predominantly found guilty.Michael

    I don't follow you - I see nothing contradictory at all about the method I am using.

    If you disagree with my method, maybe you can explain how I should do this calculation?

    - Lets ignore the initial distribution of the answer space for now
    - Lets assume that the first piece of evidence says 50% guilty
    - Lets assume that the second piece of evidence says 25% guilty
    - What is the combined likelihood of him being guilty?

    My method give 50% guilty + 50% innocent X 25% guilty = 62.5% guilty.

    What method would you suggest I use instead?
  • Michael
    14k
    I don't follow you - I see nothing contradictory at all about the method I am using.Devans99

    Then read my previous post because I showed you. The math that leads to the conclusion that there is a 75% chance of guilt also leads to the conclusion that there is a 75% chance of innocence. This is a contradiction.

    - Lets assume that the first piece of evidence says 50% guilty
    - Lets assume that the second piece of evidence says 25% guilty
    - What is the combined likelihood of him being guilty?

    My method give 50% guilty + 50% innocent X 25% guilty = 62.5% guilty.
    Devans99

    This is the same as:

    - Lets assume that the first piece of evidence says 50% innocent
    - Lets assume that the second piece of evidence says 75% innocent
    - What is the combined likelihood of him being innocent?

    My method give 50% innocent + 50% guilty X 75% innocent = 87.5% innocent.

    Your method leads to the contradictory conclusions of 62.5% guilt and 87.5% innocence.

    What method would you suggest I use instead?

    I don't know, and nor do I care to find out. I'm only interested in showing you that the method you've chosen is nonsense.
  • Kenosha Kid
    3.2k
    Well, there you go; God disappeared all the antimatter. God Certainly ExistsBanno

    Woah there! Take it easy, Banno. The probability of God's existence is only 50%. Despite this, the universe was created, so the probability goes up to 75%. Within that universe, matter and antimatter was created, so the probability goes up to 87.5%. Then for each electron that didn't annihilate a positron, there's a 50% chance that God stopped it. That's, what, say a trillion electrons? So the most you could say here is that God exists with a probability of 99.99999999999999999999999999999%.
  • jorndoe
    3.2k
    The origin of the universe is a macro questionDevans99

    Nope.
    Why do you think extrapolation sufficiently far back is increasingly problematic, and why we cannot extrapolate to a singularity (of infinite density and temperature)?
    Because once things become sufficiently small, quantumatics become increasingly pronounced, and we have no established unification.

    Finite and unbounded is plainly impossible. I'm not even going to waste my time reading that link.Devans99

    Rejection by title-reading? :D As mentioned earlier, these ideas have been expounded upon to some extent by Hartle and Hawking.
  • Devans99
    2.7k
    This calculation makes no sense. Let's say that the first piece of evidence says that he is 50% likely to be guilty. We don't then say 50% guilty + 50% innocent x 50% = 75% chance he is guilty. We just say that he is 50% likely to be guilty. As above, we can use your logic to say that because the first piece of evidence says that he is 50% likely to be innocent then 50% innocent + 50% guilty x 50% = 75% chance he is innocent.

    Your reasoning leads to the contradictory conclusion that there is a 75% chance he is guilty and a 75% chance he is innocent.
    Michael

    Your math is wrong. Assume the initial distribution is 50% guilty/ 50% innocent, and the first piece of evidence is 50% likely that he is guilty:

    1) 50% guilty + 50% innocent x 50% = 75% chance he is guilty
    2) 50% innocent + 50% guilty x 50% = 75% chance he is innocent

    The problem is [2] - if we think a piece of evidence indicates that he is guilty (50% chance), then that piece of evidence can in no way INCREASE the likelihood he is innocent.

    What you are doing wrong is you are deriving from the fact that 'prints on the knife' indicate that he is 50% guilty that it also implies there is a 50% chance that he is innocent - the fact that there are fingerprints on the knife does not at all increase the chances he is innocent.
  • Michael
    14k
    What you are doing wrong is you are deriving from the fact that 'prints on the knife' indicate that he is 50% guilty that it also implies there is a 50% chance that he is innocentDevans99

    Uh, yes? Guilt and innocence are a dichotomy. If something shows 50% chance of guilt then ipso facto it shows 50% chance of not-guilt, i.e. innocence.
  • Devans99
    2.7k
    Nope.
    Why do you think extrapolation sufficiently far back is increasingly problematic, and why we cannot extrapolate to a singularity (of infinite density and temperature)?
    Because once things become sufficiently small, quantumatics become increasingly pronounced, and we have no established unification.
    jorndoe

    I'm with Einstein on this issue - God does not play dice. The apparent randomness of QM is just due to our lack of understanding.

    Rejection by title-reading? :D As mentioned earlier, these ideas have been expounded upon to some extent by Hartle and Hawking.jorndoe

    Yes, by representing time as a complex number - that's drivel - time does not have a real and complex component - it is a single, linear, dimension-like degree of freedom.
  • Devans99
    2.7k
    Uh, yes? Guilt and innocence are a dichotomy. If something shows 50% chance of guilt then ipso factor it shows 50% chance of not guilt, i.e. innocence.Michael

    You are getting confused:

    - 'prints on the knife' make it 50% likely he is guilty
    - If we assume we have already established that the is a 50% chance he is guilty
    - Then there is a 50% chance that he is innocent
    - But the 'prints on the knife' evidence in no way increase the chances of him being innocent
  • Devans99
    2.7k
    Why do you think extrapolation sufficiently far back is increasingly problematic, and why we cannot extrapolate to a singularity (of infinite density and temperature)?
    Because once things become sufficiently small, quantumatics become increasingly pronounced, and we have no established unification.
    jorndoe

    BTW, if you really believe that science has completely accurately determined the Big Bang right back to just after the Plank era (just after the singularity) - then you need to see a shrink!

    Those numb nuts could not even work out that time has a start! Why should I believe they have the BB absolutely correct to the Nth level of detail?
  • Michael
    14k
    You are getting confused:

    - 'prints on the knife' make it 50% likely he is guilty
    - If we assume we have already established that the is a 50% chance he is guilty
    - Then there is a 50% chance that he is innocent
    - But the 'prints on the knife' evidence in no way increase the chances of him being innocent
    Devans99

    I'm not saying that the evidence increases the chances of him being innocent. I'm saying that your method entails this. This is why your method doesn't work. The way you add probabilities like this is nonsense.

    If we have no other evidence than a knife that suggests 50% guilt then there's a 50% chance of guilt, and that's it. We don't "add" it to the initial 50/50 assumption based on no evidence to somehow derive a 75% chance of guilt. Again, it's nonsense.
  • Frank Apisa
    2.1k
    ANYONE reading this thread quickly realizes that NO ONE HERE can show that "it is more likely that there is at least one god than that there are none" or "it is more likely that there are no gods than that there is at least one"...using science and/or logic.

    Only a few are willing to acknowledge they cannot. Most want to insist they can, despite the fact that none have actually done so.

    None of this is unexpected, because the greatest minds that have ever lived on the planet have tried over the years...and also have not done so. To suppose it could be done here in a rather small Internet forum by what are essentially amateurs, is not astonishing.

    If someone actually could do it...the Nobel Committee would undoubtedly offer an award to the person doing it. No Nobel Prize earned here.
  • Devans99
    2.7k
    I'm not saying that the evidence increases the chances of him being innocent. I'm saying that your method entails this. This is why your method doesn't work. The way you add probabilities like this is nonsense.Michael

    My method certainly does not entail this - and you clearly do not understand my method - just because you don't understand it, does not mean that its nonsense.

    If we have no other evidence that a knife that suggests 50% guilt then there's a 50% chance of guilt, and that's it. We don't "add" it to the initial 50/50 assumption based on no evidence to somehow derive a 75% chance of guilty is, again, nonsense.Michael

    No. If we are considering a question with a 90% / 10% initial distribution of probabilities then we can't just ignore that distribution and start at 50%.
bold
italic
underline
strike
code
quote
ulist
image
url
mention
reveal
youtube
tweet

Welcome to The Philosophy Forum!

Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.