tag:blogger.com,1999:blog-22973357.post4889566808813328706..comments2023-09-27T07:44:19.769-04:00Comments on Sabine Hossenfelder: Backreaction: Sorry, the universe wasn’t made for youSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger38125tag:blogger.com,1999:blog-22973357.post-47075436094420685942016-09-12T13:50:36.295-04:002016-09-12T13:50:36.295-04:00Bee,
Anthropic arguments simply state that we'...Bee,<br /><br />Anthropic arguments simply state that we're in a "typical" part of the region of parameter space that supports complex life. (Of course, "typical" requires a measure to explicate...) It would be a <i>further</i> claim that that allowed region is essentially unique (or that there is only one "maximum"). It is fine to criticize anyone (Weinberg Jimhttps://www.blogger.com/profile/04960139332297164539noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30462063734829710952016-09-09T21:28:58.052-04:002016-09-09T21:28:58.052-04:00The other Jim points out that evidence that other ...The other Jim points out that evidence that other universes with significantly different physical constants can develop structures and chemistries analogous (but not identical) to those in our universe is not proof that these other universes could develop life. True, but it is also true that we cannot say definitively that any other set of random physical constants could *not* produce any form ofJimVhttps://www.blogger.com/profile/10198704789965278981noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-33518605011398010552016-09-09T16:21:08.725-04:002016-09-09T16:21:08.725-04:00Bee wrote: "You need a meta-theory to have a ...Bee wrote: "You need a meta-theory to have a probability measure for the distribution of a theory's realizations."<br /><br />So string theory fails to be a theory of everything because it can't provide the needed meta-theory? Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-65300310433731677642016-09-09T11:35:08.295-04:002016-09-09T11:35:08.295-04:00Jim,
What I meant was that the theory be the sole...Jim,<br /><br />What I meant was that the theory be the sole maximum. That's the whole idea of our universe presumably being "finetuned for life". You can Google that phrase to see which people have popularized it. Among others, I believe Weinberg already alluded to this in his "Dreams of a final theory", that the theory we are after might not be the only consistent Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51955206083897491142016-09-08T16:31:13.930-04:002016-09-08T16:31:13.930-04:00"the anthropic princple hasn’t solved the pro..."the anthropic princple hasn’t solved the problem it was meant to solve, because it does not single out one unique theory". Meant by whom? Most parameters being continuous, we'd expect some (perhaps "very small") volume of parameter space to allow life, not just a "unique theory" (which sounds like a point in parameter space).<br /><br />"This study is Jimhttps://www.blogger.com/profile/04960139332297164539noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-9655541601816330552016-09-08T08:08:10.514-04:002016-09-08T08:08:10.514-04:00The anthropic principle is a distraction. The impo...The anthropic principle is a distraction. The important fact is that the universe has both patterns and pattern recognizers - and we wonder how it is that those Dirac Matrices actually have anything to do with electrons ! Wigner thought it 'unreasonable' that math is so effective. But it might just be possible that not only is it Reasonable, but Necessary !joel ricehttps://www.blogger.com/profile/06048310899055838262noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-8183824824173087812016-09-08T05:11:08.621-04:002016-09-08T05:11:08.621-04:00Arun,
I can only not forget about the word "...Arun,<br /><br />I can only not forget about the word "fundamental"; because naming something "fundamental" is just discarding the possibility that something more fundamental exists. Best,<br /><br />J.akidbellehttps://www.blogger.com/profile/12292741599925116131noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-65816702263228568192016-09-08T01:34:15.899-04:002016-09-08T01:34:15.899-04:00Arun,
No, it doesn't. It can't. You need ...Arun,<br /><br />No, it doesn't. It can't. You need a meta-theory to have a probability measure for the distribution of a theory's realizations. The problem is much like the idea of having varying fundamental constants or laws, for which you need laws etc. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-21924850988106111382016-09-07T17:03:13.720-04:002016-09-07T17:03:13.720-04:00Forget about fundamental parameters, does String T...Forget about fundamental parameters, does String Theory provide a probability measure for compactifications? Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-27569247021316237592016-09-07T12:55:22.996-04:002016-09-07T12:55:22.996-04:00akidbelle,
Yes, that's possible, but not in t...akidbelle,<br /><br />Yes, that's possible, but not in the framework of the standard model. It was certainly a hope for string theory, but that didn't work out either. I'm not saying it's something we should give up on. I certainly hope (and most of the time believe) that it's possible to at least derive some of the presently unexplained parameters from a suitable more Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-13192966277143399792016-09-07T12:25:06.547-04:002016-09-07T12:25:06.547-04:00Hi Sabine, I agree with your statement, so let me ...Hi Sabine, I agree with your statement, so let me precise my thoughts and revisit my wording:<br /><br />..only one set of parameters, symmetries, and particles listing can exist TOGETHER because it is constrained for some (self-?)consistence reason. <br /><br />Here "consistence reasons" may refer to some underlying physical laws that we don't know of. For instance if you move akidbellehttps://www.blogger.com/profile/12292741599925116131noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31478316328938387162016-09-07T12:09:45.050-04:002016-09-07T12:09:45.050-04:00Jo,
You say you got the point, but then you state...Jo,<br /><br />You say you got the point, but then you state that you think the anthropic principle is falsifiable. That's wrong. The anthropic principle is not a hypothesis. It's a requirement based on observations that have already been verified to extremely high precision. To falsify it you'd have to show that actually there's no life in our universe. I don't think you got Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51101566906713074972016-09-07T11:11:04.384-04:002016-09-07T11:11:04.384-04:00
Uncle Al,
Thank you for sharing three interest...<br /><br />Uncle Al,<br /><br /><br />Thank you for sharing three interesting videos on chemical reactions. Watching the first one on Belousov-Zhabotinsky already evoked the notion of creationism. The title of the second one reinforced that thought. Actually watching that video suggests, tongue-in-cheek (!), the Creator may suffer from Parkinsonism.<br /><br />In appreciation of your 3 chemistryAnonymoushttps://www.blogger.com/profile/04389414419592801755noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-53283898461431785432016-09-07T10:52:00.993-04:002016-09-07T10:52:00.993-04:00Think I got the point, I am just not sure if your ...Think I got the point, I am just not sure if your post means in a strict and general manner that arguing with the anthropic principle is a waste of time and we should stop it at least in science. It is falsifiable, but just as a placeholder for better explanations and does not make verifiable predictionsAnonymoushttps://www.blogger.com/profile/06563464315592668687noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-87693463848660477622016-09-07T10:51:04.406-04:002016-09-07T10:51:04.406-04:00At the moment of particle-antiparticle 180° impact...At the moment of particle-antiparticle 180° impact there are photons (lepton collision) or photons plus neutrinos (hadron collision) disassembling at lightspeed. Why should any other particle appear?<br /><br />Detonate high explosive. Why should anything but small molecules (H2O, CO2, CO, NOx, N2) appear? Pop TNT/RDX underwater, obtain up to 90% carbon yield as detonation nanodiamond (~5 nm Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-23177993743428731142016-09-07T10:28:46.889-04:002016-09-07T10:28:46.889-04:00"One could of course instead just discard all...<i>"One could of course instead just discard all theories with parameters that don’t match the measured values, but that would be so last century."</i><br /><br />:) :) :) :) Arunhttps://www.blogger.com/profile/03451666670728177970noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-1520758113132421192016-09-07T07:51:47.947-04:002016-09-07T07:51:47.947-04:00Imagine the horror though, if it was actually made...Imagine the horror though, if it was actually made for "some-body"/something else entirely!<br /><br />http://www-history.mcs.st-and.ac.uk/Biographies/Fantappie.htmlTheophanes Raptishttps://www.blogger.com/profile/01269614280130174555noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-58036788582055867732016-09-07T06:33:51.867-04:002016-09-07T06:33:51.867-04:00Jo,
The anthropic principle is arguably correct, ...Jo,<br /><br />The anthropic principle is arguably correct, there's no doubt about this and no discussion about this. And I just told you that theory selection by the anthropic argument does *not* relieve you from having to search for other explanations, exactly because that selection does not single out a specific theory. Best,<br /><br />B.Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-57181609607004280952016-09-07T05:36:20.836-04:002016-09-07T05:36:20.836-04:00Can't we be more naively pragmatic (ignoring e...Can't we be more naively pragmatic (ignoring extended philosophical discussions about what the anthropic principle actually is)? Might the anthropic argument be true or not, we will never finally know. There ever might be a law behind finetuning rather then a (in some sense arbitrary) selection from random - what the anthropic argument basically is. The physicists of the late 19th century Anonymoushttps://www.blogger.com/profile/06563464315592668687noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31232982530091661202016-09-07T05:34:16.062-04:002016-09-07T05:34:16.062-04:00akidbelle,
"Now assume exactly the opposite:...akidbelle,<br /><br /><i>"Now assume exactly the opposite: only one set of parameters, symmetries, and particles listing can exist because it is constrained for some self-consistence reason (I don't even need to know how). "</i><br /><br />That's not logically possible. It would mean that you can derive a theory based on self-consistency alone, but self-consistence isn't Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-74643457003899021172016-09-07T05:24:28.997-04:002016-09-07T05:24:28.997-04:00A helpful reminder to anthropos is that not only &...<i>A helpful reminder to anthropos is that not only "Sorry, the universe wasn't made for you", it did just fine for tens of billions of years, without any humans around.</i><br /><br />This is indeed a good argument against overstating humans' influence (e.g. "someone must have collapsed the wave function of the universe"), but it doesn't rebut the anthropic Phillip Helbighttps://www.blogger.com/profile/12067585245603436809noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81529471332062134052016-09-07T05:21:52.990-04:002016-09-07T05:21:52.990-04:00"The general argument against the success of ...<i>"The general argument against the success of anthropic selection is that all evidence for the finetuning of our theories explores only a tiny space of all possible combinations of parameters. A typical argument for finetuning goes like this: If parameter X was only a tiny bit larger or smaller than the observed value, then atoms couldn’t exist or all stars would collapse or something Phillip Helbighttps://www.blogger.com/profile/12067585245603436809noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-83690067030035315272016-09-07T01:19:35.830-04:002016-09-07T01:19:35.830-04:00PhilG,
I don't know who you think wants to &q...PhilG,<br /><br />I don't know who you think wants to "destroy the anthropic argument". The anthropic argument - that we live in a universe hospitable for life and our theories must be able to accommodate this - is of course correct. What I have said is wrong is the idea that our universe is finetuned for life. You don't have to show that most of the space of parameters support Sabine Hossenfelderhttps://www.blogger.com/profile/06151209308084588985noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81215754546805147232016-09-06T14:59:43.085-04:002016-09-06T14:59:43.085-04:00Who claimed that "anthropic selection can sin...Who claimed that "anthropic selection can single out a unique theory"? I don't see that as an element of anthropic reasoning or fine tuning arguments at all. If you want to destroy the anthropic argument this way you have to show that most of the space of possible parameters supports complex life. It certainly is not enough to show that there are some other points that support it.PeteHHhttps://www.blogger.com/profile/08545699636937390967noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30881072754922251872016-09-06T14:34:24.194-04:002016-09-06T14:34:24.194-04:00@KC Lee "we know that entropy always increase...@KC Lee "<i>we know that entropy always increases</i>" Empirically wrong. All oscillating chemical reactions spontaneously reverse entropy. Large scales, too - the Belousov-Zhabotinsky reaction. Energetic systems with positive feedback (e.g., life) can be very naughty. Ergodic systems can cycle (closed trajectories in phase space; strange attractors).<br /><br />https://Uncle Alhttps://www.blogger.com/profile/05056804084187606211noreply@blogger.com