Can You Observe a Typical Universe?
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- Опубліковано 31 тра 2024
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The moment you started observing reality, you hopelessly polluted any conclusions you might make about it. The anthropic principle guarantees that you are NOT seeing the universe in most typical state. But used correctly, this highly controversial idea can be extremely powerful. So, how do you correctly use the anthropic principle?
Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Leonardo Scholzer & Adriano Leal
Directed by: Andrew Kornhaber
Executive Producers: Eric Brown & Andrew Kornhaber
End Credits Music by J.R.S. Schattenberg: / @jrsschattenberg
Special Thanks to Dr. Flournoy!!! Check out his lectures Below:
Particle Physics: • Particle Physics 2018
General Relativity: • General Relativity 2019
According to the original definitions by Brandon Carter, the weak anthropic principle states that we must live in a place and time in the universe capable of supporting observers - in our case, a habitable biosphere, and the strong anthropic principle, which states that the universe itself must have the conditions necessary for producing environments that, in turn, produce observers. That means the fundamental constants and initial conditions of the universe must be just right to allow nice habitable planets to one day form. Let’s just call it the anthropic principle: we necessarily observe from an environment capable of producing observers; be that environment a planet within a universe or a universe within a multiverse.
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"Wow," thought the puddle, "this hole is perfectly shaped for me."
Reminded me of the Enigma of Amigara Fault.
Perfectly put.
The puddle thought it was just a puddle, but in reality, the puddle is just water occupying a space. And conforming to that space to form a puddle.
@@Mutantcy1992 Lol, as the vagina disappears to find a new shape!
But the two are more like an entangled pair haha, via synced co-pricing over eons of evolution by natural selection.
Me: Am I watching a physics video, or astronomy, or philosophy?
PBS Space Time: Yes.
'Yes' is not the answer for such a question.
THANK YOU FOR ONCE IN A WHILE USING THAT JOKE CORRECTLY.
This is the second time I've seen it in a year's time.
@@tomsmith4542
Are you correcting *_him_* of all people?
The one guy to use it right?
@@tomsmith4542 stewpeed.
I love how the last sentence is always super long so I can't tell exactly when you're gonna say "Space Time"
And something about his voice always changes when he starts the sentence.
I could sense it coming too and got sad that the video was ending.
Get outta here. John Michael Gordiers ending is more epic.
I love it when fundamental physics turns into existential philosophy. Feels like we've come full circle.
It's almost impossible to do cosmology and elementary physics without wondering about the nature of existence; you'd have to be some kind of robot… and even then, I'm not sure you could
Really? Isnt physics by its nature an existentialist pursuit?
Yeah idk man I'm just saying I like the video
Yes, the Anthropic Principle is powerful when used correctly. But it is far more powerful if you use it wrong.
OMG LOL 😂 .. and now Ima lil 😬 scared too
I majored in philosophy with a concentration in physics. The number of times I've seen that principle used wrong... You'd think it can prove just about anything.
It's also more financially viable if used wrong.
Ooo can you give a good example of bad use (just curious)
@@Sam_on_UA-cam "principle used wrong" So philosophy just philosophizing...
"Stars explode, worlds collide, there's hardly anywhere in the universe where humans can live without being frozen or fried, and yet you believe that a... a bed is a normal thing."
- Terry Pratchett (well, Death, actually) in "Hogfather"
Terry was a deep thinker. Almost every sentence he wrote was amazing.
And from somewhere out there I can hear the sound of a Banjo and a song being sung with great gusto.....
" A Wizard's staff has a knob on the end. It never will buckle, it
never will bend......"
The bed is a normal typical thing, for universes that generate observers. All Aliens gotta sleep.
Nah, Death didn't say that. Death speaks in smallcaps.
Douglas Hauck The Universe is harsch and it’s getting meaner and Iam just at home using my vacuum cleaner.
I like to think I'm a typical observer of 'Space Time'. In fact, it feels like 'Space Time' is made specifically for me.
"Oh no not again" said bowl of petunias.
How come when I read this out loud I sound like Professor Slytherin?
I checked with my friend in another universe. She assured me that our universe is indeed typical.
Hope she didn't call you "typical" cause that aint good comming from a woman.
@@robertl.fallin7062 she did, but it's the evil mirror universe so it's all good.
I also asked your friend, while she was visiting a universe which does not support life. She says she has realized you are in a special place. :)
Aw does she live in Canada, my girlfriend from summer camp lives in canada she’s totally real and typical but very much in a parallel Canadian universe.
Wait ... Did your friend say ours is “a typical” or an “atypical” universe? I am sure there is a space for both! 😉
at first you hurt my brain but now you've hurt my feelings
Nice profile pic of Zero
And that means war, bitch
@@Leynad778 Plenty of people find it entertaining to ponder and learn about that kind of topic. Also I wouldn't rule out the possibility of humanity figuring it out some day, even if it is unlikely. If we do find out the information, who knows what kind of mind bending shenanigans we could use it for?
Leynad Jee
So no one should discuss the scientific origin of existence? We should just shut up and pray to god you are suggesting?
@@burleighsurfography2241 Certainly it's worth to discuss it, but he's wrong anyway. Academics are too narrow minded inside their believe systems and it's like with the fake Apollo-missions: they believe this nonsense because they learned it. Elon Musk doesn't have this problem www.vice.com/en_us/article/8q854v/elon-musk-simulated-universe-hypothesis
As a Colorado School of Mines alum, you have no idea how shocking it was to see my old professor pop up in this video.
Finally!!!! I reached the last video!!!! Somehow I found this channel a month ago when looking for black hole videos and then I got hooked immediately. Of course I could barely understand anything Matt was saying at the beggining (and nowadays sometimes I still get lost in 30 seconds), so I had to go back to the very first video and then try to catch up.
Somehow I ended up learning about GR, Black holes, Hawking radiation, quantum physics and everything in between.
Thank you, PBS Space Time for putting up such a wonderful series. And I hope it lasts for many more years.
The patreon shoutout they did in this video was for a professor that has lectures up on UA-cam. Check the iCard and you can learn more!
Keep on learning friend. Astrophysics is the best 😍😍😍😍😍 I've be on it as a hobby since I was 16. Now I'm 28. And I will be till the day I check out.
Awesome dude. Power to you!
I can confirm that every universe I have been in looks exactly like this one. :D
Hahah, you sly devil, you. :)
I'm right there with you. I have promised to never share any details about any other universe I have visited!
Rick is that you
Assuming that our universe doesn’t interact with others
how boring
The universe has predetermined that you will do an episode about superdeterminism.
Determinism is an emergent property of quantum mechanics.
Super-determinism makes the most sense of all the current theories.
@@SuviTuuliAllan, How?
@@jeffwads6158, Why?
@@erik-ic3tp He just felt like writing this, that's all
“Today a young man on acid realized that all matter is merely energy condensed to a slow vibration, that we are all one consciousness experiencing itself subjectively, there is no such thing as death, life is only a dream, and we are the imagination of ourselves. Here's Tom with the Weather.” -- Bill Hicks
This video makes as much sense as a mushroom trip. Prying open my third eye.
Wow
Isn't this from the Antimatter Dimensions news ticker?
@@protondecay4607 so I'm not the only one who plays that game
Can I buy some pot from you?
The misanthropic principle: Lock your door to prevent unscheduled sharing.
"unscheduled sharing"..... lol i am usually naked when alone, so this is definitely one reason for me to prevent "sharing" stuff on an "unscheduled" basis.
I mostly dont understand 60% of your episodes but enjoy watching them 100%.
It's because it's all total non sense. It's to capture your imagination. It's all bollox. Wake up
@@invision4236 whats wrong with immagination? I sucked at physics thats why i watch Pbs. Thats how you learn and "wake up". Just saying " its bollocks " is lazy and anti productive.
INVISION how is it bollocks please explain
@@invision4236 And that's why you're not a physicist.
@joecugo He is probably trying to be more specific but does not delve too deep to avoid confusion. He dumbed it down just a bit and not as far as ELI5
so if I figure out how to create my own life bearing universe I get a free t-shirt ? that is so cool
When Hawking claimed we're close to seeing inside the Mind of God, I'm pretty sure he was thinking about Tees, too
If you create your own life bearing universe you get an army of minions to do your bidding and become a god. But the t shirt is the real reason for creating a universe.
@@eliparker4114 *Gru intensifies*
"I created my own life bearing universe and all I got was this t-shirt"
Or you can use that tinyverse to power your car.
Hi, is it possible to add episode numbers chronologically to these amazing videos? It would be easier to both reference them and search when you mention a "previous episode". Thanks for the great work!
The organization of content is a subjective matter, as it depends on the interpretation and perception of the individual. Some may see the implementation of episode numbers as a linear progression, while others may view it as a non-linear system of categorization. However, the utilization of such a system is dependent on the intrinsic motivations and extrinsic factors present at any given moment in time. The concept of referencing previous episodes is a complex dichotomy, as it requires a balance between the preservation of continuity and the allowance for novelty.
@@randomshittutorialsso true, bestie. I'm always saying this
I came upon the anthropic principle independently which I was around 7 years old. I was thinking back on a movie I had finished watching & thought it was weird how the main character was the center of so many situations that they sort of just fell into. I then realized, a story only gets told if the story is worth telling.
You were one smart little kid then. I envy you. I’m pretty the only times I was remotely sentient was when my dad read books to me.
this channel only exists in its actual form because we observe it
Of course. If we stopped observing it, the economic incentive would disappear, and it would cease to exist.
@@EvenTheDogAgrees A UA-cam channel cannot exist without being observed. That's the economical interpretation of quantum physics. Unlike Bohm's interpretation, this one actually has some merit.
@MetraMan09 The uncertainty principle and Virtual particles is just really, really tiny fractional reserve banking.
Wrong.
A = A.
@MetraMan09 that's great. And anyone who keeps those pairs in a continuously anihalating balance will have lots of power in financing.
Alex Fluornoy is a true hero in my eyes. The video lectures on his channel really helped me make sense of my QFT course in college and has been quite elucidative. He is an excellent presenter of physics and I would highly recommend going and checking him out.
Can you provide a link please?
Oh gosh it's in the description I apologize
Alex was my undergrad quantum teacher and made us solve the time dependent schroedinger equation in four spatial dimensions. Aliens bless him.
"The most amazing thing happened to me tonight... I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing!" -Feynman's perspective on the same problem you illustrated with Adam's puddle
That bit about the puddle resonated with me more than I ever thought a bit about a puddle could do.
PBS Spacetime, Matt, Eric, and Andrew, Thank you soo much to the wonderful message of support for Dr. Flournoy! I hope everyone enjoys his fantastic lectures as much as I have.
I've always loved that Douglas Adams quote - perfect demonstration of how design-arguments go wrong, and the dangers they entail.
Don't think it speaks against the anthropic principle, though - as you say, the anthropic principle, just like the copernican principle is about sampling, selection, about humility in how we interpret the evidence of our existance and how the universe seems to work - about careful bayesian thinking... in the end, about epistemology and epistemic constraints on metaphysics and cosmology, not about what the proximal or distal causes of our being here concretely are.
@The Jim Reaper™well... thank you for that valuable, nuanced contribution! I hope it helps you feel superior for a while :*
@@DumblyDorr Everyone's a critic.
@The Jim Reaper™ At least people get pointers to read up on concepts new to them. Thanks, @Michael Bauer!
How many times did you check Google to write this? ;)
Will you agree to replace the puddle by a computer?
"This is rather as if you imagine a computer waking up one morning and thinking, 'This is an interesting world I find myself in - All my pieces so perfectly match, doing exactly what I need them to do in order to execute my programs, and that electric cable and socket - fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made exactly for me!' "
Does the computer argument demonstrate of how design-arguments are so accurate?
Being a sentient being in the universe is such a strange phenomenon. We have the ability to debate things that we can never understand. Even if a god were to come and take credit for the universe we would be left with the question of what / whom created god. Alternatively, even if we can explain what created our universe or what trigger inflation we will be left with the question of what triggered the triggering of inflation. It's such a strange and inspiring question in which the answers present new questions.
I know right! It's awesome!
at that point it might be better to start asking questions about yourself, e.g., why you expect infinite causes, why you care, and what you would do with the answers if they were discovered or provided.
We are the universe trying to understand itself.
This series on Anthropic principle has made it interesting on a next level. Please keep going at it.
That intro was so loud compared to your voice.
Noticed the same thing. It was uncomfortably loud in comparison.
It definitely felt a bit louder than usual.
It's the first time I've needed to turn the volume down for the intro and back up to hear him speaking. Definitely an issue with this episode. Sadly, other UA-camrs have said it's problematic to re-upload small fixes like that when I've seen similar comments on other videos, but maybe they'll fix it before uploading for the next video.
If you think the intro was loud wait for the outro
Agreed.
you talking about the puddle being alive was like an acid trip
Wadim Zeller I felt like it kept my brain from rolling about
Science is a trip honestly.
I wonder what the puddle thought about when the pigeon walk through it.
@@CosmicCleric "That tickles!"
And then you wake up.
10:30 That's Botanical Garden in Curitiba - Brazil
Vinícius Santos I was looking for this comment hahah
Yeah, it was kinda of a surprise when i realized that... lol
@@marcoknabben Me too! hahaha
I smiled thoroughly after seeing it and finding these comments ;)
I saw an interview with Larry Suskind where he said that conceivably, a (daughter) universe could be created in a lab. I think mostly we would be interested in creating habitable universes. If such a thing is possible, and if the daughter universe either inherits the parameters of the parent or can have them set by the creators, then that makes habitable universes self-propagating.
In fact, if parameters can be tweaked, universes might even be said to evolve as intelligences within them fine-tune their experiments to improve habitability.
Now, that's a very long chain of its. I'm not intending to say that this IS happening, but instead to illustrate a version of retrodiction that I don't think can be dismissed out of hand.
That would be amazing if we could play God. Like a premature K4+ civilization. :)
@@erik-ic3tp Well my understanding of his speculation is that it's less omnipotent-y than that, more just triggering some other universe's big bang. I don't know if you have any control over its initial conditions or laws of science at all, and the universe pinches off and evolves on its own almost immediately.
And keep in mind that's A) assuming I got Suskind's point right, and B) assuming he's right. I don't think even he would put money on any of this right now. I merely bring it up because it's a scenario where retrodiction has some basis in what we know (or at least think might be possible). (Review: retrodiction is the idea that the universe exists the way it does because intelligent life would someday form. At first glance, that means a divine plan or time travel, but this is my attempt to formulate a version of retrodiction that doesn't require either.)
If new universes can be created artificially, and if the new universe inherits the properties of the old one or can have its characteristics tuned by its creators, then the multiverse might be packed with these lab experiment universes and make habitable universes more likely than they would otherwise be.
This is more about Matt dismissing retrodictive theories and that making me wonder under what conditions retrodiction might be something worthy of serious investigation.
@@erik-ic3tp Actually, now that I think of it, this works in reverse, too. What if some phenomenon exists that would destroy the universe altogether? Some phenomenon that is extremely unlikely to occur naturally, but that intelligent life might stumble into. Ooops. Fermi Paradox explained: we're alone in the universe because if another race was much older than us, it would have accidentally destroyed the whole thing. So habitable universes are unstable and short-lived, hence why we shouldn't be surprised that we live in a very young and seemingly uninhabited one.
@@theprogram863, Cool hypotheses that you wrote down here. :) Also, do you think there's something beyond the Multiverse? It could be possible. See this wiki: verse-and-dimensions.fandom.com/wiki/Metaverse
@@theprogram863 Damn, I had thought intelligences could off themselves, their whole planet or maybe solar system, but not to dial it to 11 with their whole universe !
That said, the opposite applies too: We know our planet, solar system and likely whole universe are ultimately doomed. Unless we find a way to change that !
I find it interesting how the view of the cosmos changes over time. Newtons universe of clockwork was replaced by the Maxwellian analog version with waves and fields. Now with the information age it's all digital. I'm not sure if these points of view are actually useful or if they are just the fashion we dress our thoughts in.
I'd actually be quite interested in watching a documentary, reading an article, ... on our evolving view of the cosmos. From ancient times right up to present day, presented in an accessible format for us laymen who don't work in the field.
So true, our description always uses analogies from the technology of the time.
Have definitely started to become super aware of this, and am quite surprised there are hardly any videos addressing this.
And to add to your example of the digital age, comes the idea of us living in a simulation. Every technological generation has a theory of the universe that fits what would be the most advanced tech of their own time periods
What exactly is 'digital' about this theory or indeed any of the leading theories in our current understanding of the cosmos? They don't seem to be digitised much to me, in fact the opposite.
@@curiodyssey3867 Great example, if you have a shiny hammer, everything starts to acquire nail - like properties.
Of course, this also illustrates how paradigms shift. A man form 1919 might understand "simulation", but not as one of today. In 1819 they had the concept, but to suggest it applied to the universe writ large, and themselves, almost anyone would not understand.
I predict that Bioengineering is the next flavor of the week.
I love the graphics used to represent the other universes in the multiverse (e.g. at 3:57). These are a clear and appealing way to represent the concept of a multiverse with fundamental constants that vary between universes, and I offer my kudos and thanks to whoever created them!
Imagine how it looks beyond the Multiverse. :) Like this: beyond-universe.fandom.com/wiki/Megaverse
If they came in contact, they would mutually annihilate each other.
This is 1 of 137.036 possible combinations of constants that could create observers
Wow. Hahahaha. :)
That tribute to Dr. Flournoy was amazing. I have no idea who he is, but clearly he has had a huge, positive impact on his students. That is awesome to see and I am touched to know they made the effort.
Typical or not, it is the one we have to observe, we cant rely on anyone else observing it, and we can only observe it.
If this universe is a simulation, there might be someone out there observing.
maybe we can not only observe it...we will controle it!! muahahahaaha
This is an observable universe. There are many like it, but this one is observed. Without observers, the universe is useless. Without the universe, observers are useless.
@@Fsilone Every observable universe is observed. For beeing observerable, you need just different fields / forces / particles / whatever which can (and will) "interact" with each other.
Lets say, there would be a universe, which has laws that makes it possible to interact, but no particle would meet another. Because of this, that universe does not belong to the group of observable universes, because it seems to have a mechanism to avoid crossing world lines / paths.
@@yourguard4 I take it you didn't get my FMJ reference?
Says one fish to the other in the fish bowl: "This round universe we live in - what are the odds that it developed in such a way that it was able to create us, and furthermore, that we are capable of consciously observing it? I call this question, The Fishotropic Question. But...what is that moving background radiation?"
Says one person to the other, as he is gazing at the fish in the bowl: "Do you think those fish have a form of consciousness? And if so, could that consciousness evolve in such a way that it becomes like a cancer, where the fish just can't stop thinking about nothing else but that consciousness itself?"
Says the other person as she approaches the fish bowl: "You mean, will they become philosophers?"
*Pescatropic
Or Pescotropic
Man! This is underrated..!!!
Thanks Matt - I've been waiting for this episode for a long time: a treatment of the apparent contradiction between the "we are in a typical universe" and "we are in a fine-tuned universe" perspectives. I'm still not sure that I understand the resolution but I greatly appreciate that you have directly targeted the issue. Looking forward to more episodes on this topic.
I love this channel. The videos are always pure insight on difficult topics. Also great production and animations.
I'm captivated by the implications of the Anthropic Principle, but also somewhat skeptical of some of its assumptions. First, the observer selection bias makes sense: we are alive and observe the cosmos, therefor the universe must hold the right conditions to support our life to emerge. However, isn't it dangerous to say these conditions are "fine tuned"? Isn't that a retrograde projection of our evolutionary history that confuses cause and effect? It seems like it would be more accurate to say our life emerged _as a response to_ certain conditions in the universe, and that our life is _one way_ the universe supports life. The universe is _not_ "fine tuned" for habitable planets to form and support life: rather, life emerged within conditions that support life to emerge. I know, that's a bit circular, but at least it doesn't assume that the conditions for life were pre-programmed into the conditions of the universe.
I think one of the biggest questions is, how exactly life did life form on Earth? We seem to know the general process, but the exact parameters and conditions are still somewhat unclear. If we could discover these parameters to a much finer degree, perhaps we could determine just how rare or typical we would expect life (at least Earth-typical life) to be in the cosmos. And perhaps we would also discover other parameters that would support different life forms to exist, based on silicone or adamantium for example. ;)
With the Anthropic Principle, I think there's a danger of feeling empowered to make sweeping claims about how the universe must be set up, given that our own ability to observe the universe is still in its infancy. If we discover life to be abundant throughout the universe, we would quickly find a more complete theory how the universe's fundamental conditions would lead to the emergence of life.
On the other hand, we are the only life we have yet observed, and we can glean some exceptionally meaningful insights about how our evolutionary history is so intimately connected with the evolutionary history of the universe. And perhaps that is the real value of the Anthropic principle, because we find that we are so intrinsically connected to every piece of the universe, and we are at least one way, one strange, wonderful, perplexing, and awesome way the universe knows itself.
This is also how I think. And it concerns me the way anthropic principle is used. The fact that you are trying to introduce Bayesian statistics must not mean confusing the causal hierarchy. We are the result of those 20 parameters and some unique conditions on earth. They cause and explain why and how we are the way we are.
I think you misunderstood the 'fine tuning' problem. The constants aren't fine tuned for the emergence of life, life is just a byproduct of the physics they are tuned for. The question of the fine tuning problem is why are these constants the way they are. Why those exact values? What is the background mechanism that produced these values to be the exact ones that they are today?
We are aware that we are the result of these constants, not the other way around, but we ponder what made these constants to be the way they are that resulted in us as the observers.
Betteridge's law of headlines states that "any headline that ends in a question mark can be answered by the word no"
I lol'd
Let's test this: "Did time start with the big bang? No."
"How many universes are there? No."
"Could we Terraform Mars? No."
"Is Earth's magnet field reversing? No."
"Will you travel to space? No."
"Neutron stars collide in new LIGO signal? No."
This doesn't work out very well...
@@T33K3SS3LCH3N neither does yer mom
Can That Be True?
@@T33K3SS3LCH3N It is intended to be humorous and actually it is true more often then not when you consider that most of what you read is pseudoscience nonsense that relies on this:
"See, i didn't say that evolution isn't true i was just saying that if you look at the evidence in the bible then you might realize there is more to life then you think."
You certainly know how to spark up the old imagination. I get lost in thought and end up having to watch your videos multiple times bc I end in a sci fi daydream related to the topic of your video. Thank you so much and this quality makes content stand out (imho)
Fascinating video's - you do a great job - including by engaging your fans/challengers. I'm not arguing - just loving your videos!
Alright, thats it!
I'll re-read hitch hikers.
I love these alternative universes designs 3:56
Excellent philosophical episode.
That's so awesome that you guys shouted out Dr. Flournoy! I've never met him but have heard of him from his students before, and it's just generally really cool that you guys were available for his students to reach out to, so that you and they could honor him in this way!
The second law of thermodynamics states that the entropy of an isolated system never decreases over time. But is our universe isolated in a multiverse cosmos?
@Ix Suomi,
Maybe this. :) Link: verse-and-dimensions.fandom.com/wiki/Multiverse
What are some testable predictions of the refined anthropic principle?
Yes, I didn't hear that either.
It seems this is philosophy, not science. But I could be wrong.
@Ix Suomi "Testable" is a commonly ccepted term when discussing theories and predictions. It means the principle needs to make an assertion that can be falsified by some sort of scientific observation. Without a falsifiable prediction, a hypothesis isn't scientific.
From what I understood, Matt explained that this principle predicts that, if the big-bang was just the result of a random localized entropy fluctuation in a high-entropy environment, then our universe should have been much smaller (as small as it can be while still producing life). The universe being larger means that such a random fluctuation isn't a sufficient explanation for the origin of the big-bang. That is a testable prediction. I found this episode quite mind-blowing (in spite of the lack of maths or need for much prior knowledge!), so I could well be wrong.
@@tekrunner987 its a great episode, but how would someone test the assertion that the universe doesn't come from a single fluctuation?
Excellent video, very thought provoking, as usual. Thanks!
I absolutly love this video! (currently at 10:20)
Was going to comment about you not mentioning that idea, which I thought of as a counterpoint to what you previously said. And just as I finish formalizing it in my brain, that sentence pops up. I feel like the idea that there are many universes is making more sense to me with each passing day. And it has already been my main "belief" since I've read a ~100 pages book of feynman talking about QED.
Is that Jardim Botânico of Curitiba (10:30)? Loved it. Greetings from Br.
;)
Mano BR eh uma desgraça mesmo a gente tá em tudo
Br só não domina o mundo porque churrasco e cerveja é melhor
It is! And there's even a Capybara!
loving this series on anthropic reasoning
I keep watching them, but I'm always busy doing something else and can not seem to hear him actually explain what the different types of correct and incorrect reasoning are. I'm like "Just come out and say it, dude. I don't have all day."
I'm too am trying to grasp onto the anthropic reasoning. I too am struggling to find meaningful understanding in it.
Best I have reasoned so far is that it is an extension from quantum physics where we learned that reality is initially probability and then collapses to be defined. That concept applied then to our universe as if what we see is one outcome and we are trying to work backwards to guess at the probabilities that might have been.
I watch every video from this channel. Fascinating!
I posted that Douglas Adams quote about a week ago and when I started watching this it came to mind so I was blown away when it was actually referenced.
I feel like the Anthropic Principle can be used to avoid ruling out non-observer friendly reality, but that it cannot be used to make conclusions whatsoever.
Doing so operates on the assumption that by sheer statistical guesswork, we are typical observers, based on unobtainable statistics and an unreliable frame of reference. There are zero indications that our probability guesswork reflects all of reality, due to the nature of the theory being tested.
You lost me at "I feel like"
Wow, I love that
Again, the most likely explanation for these “fine tuned” variables is that they are not fine tuned at all. They cannot have different value, because they are not input parameters, but mere consequences of the underlying logic of physics. Pi cannot have different value then 3.14, this value is not by chance. Only it has a simple enough logic for us to understand, unlike the universe.
This episode is like talking about the impossibility of life if we would set the value of Pi to 4.14, because closed circle wouldn’t exist, and amongst the infinite number of universes with different Pi values, we are “lucky” to live in the one with the value of 3.14.
Dude I couldnt agree more. I tried saying this in the last fuckin video. It's like they're out of things to makes videos about so they make these incredibly convoluted wishy washy philosophical videos trying to make something out of nothing. Shit isnt fine tuned. It just is how it is. I laughed when he brought up the puddle subject because others in the comments on the last video called out his "were lucky to be this fine tuned" bullshit by quoting the exact same puddle line.
I was thinking this too! You said it really well.
Absolutely correct these variables and properties of matter are not finely tuned but have the values that are stable and make the universe work at all possible levels. If they did not then this universe would not exist, this does not include the assumption that the universe was made to create life, it just happened according to the conditions extant as defined by said values of the universe, life exists in a few places but due to the huge size of the universe we are unlikely to encounter other life forms.
Other multi-verses where there is no "fine-tuning" of quantum stabilising events are unlikely to have existed in the first place or were destroyed soon after creation.
"They cannot have different value" But there is no evidence for that.
Ahh Yes. "It is what is." The highly complicated common sense principle. Thus you reach the true limitation of the philosophy of Modern Science. It can never tell you "Why", in terms of reason, anything is. It can simply show what and how. Yet we still have this burning question, often answering it by adamant denials that the "Why" doesn't matter or can't be known. Still others philosophize about it; surely the "what and how" will tell us "why".
Kudos for the mention of Douglas Adams. From a distance, his books were my introduction to the ideas of quantum mechanics as a form of thought experiments. Not, perhaps, the correct interpretation of quantum mechanics, but still a popular one at the time. He even included the multiverse.... ;)
_Oh no, not again_
Im happy to see alex fluornoy getting a shout out here. His lectures are the most engaging and understandable ones on UA-cam. He helped me a lot with understanding GR.
"Therefore, I can clearly not choose the wine in front of you"....
Incontheevable
Anyone else notice how PBS has been uploading TONS of "multiverse" themed videos as Rick & Morty season 4 is unfolding? 🤔🤔
Assuming the big rip would happen, could we see black holes as windows on the big rip ? If our friendly monkey is flying toward a black hole, he would then see the lambda cosmological constant / dark energy increasing indefinitely as his obersvable universe would fast forward. Thus, could we consider black holes as an infinite expanding space where dark energy would torn apart every particules ? (your work is awesome Matt O'Dowd btw)
Wow, so cool that such thought provoking content is being produced and watched on such a successful channel.
2:00 Why should we assume the ability to produce us is a "non-typical quality"? That assumes we are special, not typical. The anthropic principle only violates the Copernican principle if you first assume it does.
The anthropic principle has its uses, giving philosophers something to talk about, but those uses are outside the domain of science.
Agree 1000000%
There's a third option on the "fundamental constants setting the dials" issue - there may be a stability issue involved. Each of the dials relates to a particular kind of force/energy, and those forces/energies must be present for the "dial" to exist. So the presence of those forces/energies should tend towards finding a stable state, otherwise the dial will effectively "break off" and cease to be present along with its associated force/energy.
Under this assumption, inability to give rise to complex interactions may actually be evidence that these may simply not be stable state "dial" settings - consequently either universes could not be those states, or those universes cease to exist very rapidly.
It may not so much be "getting lucky" or "retrocausality" - it could be cosmic natural selection.
Yeah it's probably just the only way energy knows how to behave because it doesn't it has to. Like you said cosmic natural selection. But that would raise the question how does it know?
Anyway I love this videos as a hobby astrophysicist and I love the science of it all. It makes me more accepting of death because I always wonder how the universe will be after I'm gone. Then get worked up in panic attacks. So learning the fundamentals of it all makes it easier to sleep. ☺️
@@bane4743 It doesn't need to know. There's a minimum energy level each kind of field needs to maintain (its "zero-point energy" state) for the field to continue to exist. If it can't hit that, the field just doesn't exist for that universe.
Baryonic matter (the stuff we're made of) is dependent on a couple of different fields, if they don't exist then matter doesn't form. So universes that fail to hit the energy level required for those fields to stabilise don't get to be universes like ours in the first place.
That's why I suggested it's a kind of "cosmic natural selection" - if the "dials" aren't set right, the universe doesn't survive to be like ours. So its existence is naturally selected against.
@@Zahaqiel so you are basically saying that "our universe" is typical because it has to have it for us to observe it. That those "dials" that were discussed typically are always in mode because without it there is no us? So do you think it's flaw in the anthropic principle and thus stating there is multiple of our universes or just one?
@@bane4743 I would put it like this:
It is possible that our universe once had more fields than it currently does, and that some of them didn't stabilise - meaning that those "dials" broke off our universe and possible forms of matter/energy that could have existed in our universe just don't. This is an avenue by which our universe could be the only one in existence - a massive field flux occurred and what remains is what became stable.
It's also possible that there _are_ other universes with different field settings to our universe that have stable versions of those kinds of fields, or other kinds of fields we never had. But if a field type is not capable of stabilising to a zero-point energy state, then no universe has those fields, so maybe there aren't other universes that are different to ours.
What can be said with certainty is that our universe is probably typical _for observers that are anything like ourselves._ But as a corollary to that, we may not be able to perceive or interact with universes that are set differently to ours, or only be able to do so in the ways our universes share the same settings. We don't know what things that live in those universes might be like or how they would experience anything. Fundamentally such universes are entirely alien to the experiences we have in this universe.
But we can be pretty sure that for the fields our universe has, different settings are unlikely as the fields likely wouldn't remain stable. We have reasonable confidence that if any of the fields our universe currently observably has were to slip even a little below their zero-point state anywhere in our universe, the field would collapse entirely and we would experience a major stability issue with what our universe contains.
Wait wait wait i've heard it a hundred times & it finally occurred to me to question the ASSUMPTION that we're in a typical universe. The statistics may be such that we should definitely BET we are if some multiverse-spanning entity sets up a pool, but this reminds me of my brother-in-law getting mad when a 90% chance of snow utterly failed to show up & he said he'd swear off forecasts. I didn't think at the time to explain that one in ten storms forecast at %90 have to miss or fizzle for the forecaster's overall average to be accurate.
You've published a lot of great videos, but this is by far my favorite yet.
If planetary colision was one extremly rare things for how the earth formed.
But turns out planetary collisions are more common in other solar systemed
The collision itself may not be rare but the combination of planet sizes, makeups, and orbits required to give us the Earth-Moon system in a stable orbit smack in the middle of the goldilocks zone seems to be.
@@ColeDedhand you do know most Rocky planets in Galaxy are larger the earth. Plus a planets atmosphere. If a planet or like Europa only larger enough to have an atmosphere . It could life on the surface
@@osmosisjones4912 Technically except for some exceptional circumstances we still lack the ability to detect true Earth analogs due to a combination of masses too low to use radial velocity or astrometry alone to detect Earth mass planets around the habitable zone of "Sun like" (K,G or F type stars) and the transit methods extreme bias towards planets very close to their stars. Around M dwarf stars there does seem to be a large population of massive close rocky planets and Ice giants with only a few small gas giants but that doesn't mean there aren't smaller rocky worlds there. (Not to mention we now know it is highly unlikely for an M dwarf star to support life at the so called "habitable zone" for M dwarf stars within the current age of the universe)
Interestingly objects the size of Pluto or larger are technically capable of supporting an atmosphere it is just without a protective magnetosphere or high mass said atmospheres have been lost either due to the solar wind or in the case of Jupiter's moons the probable inward migration into the inner solar system. Even our moon likely once had an atmosphere before it lost its magnetosphere.
Just like Mars it couldn't keep it.
@@ColeDedhand
Interestingly Venus might actually still be within the "habitable zone" as simulations suggest that if it ever had water oceans is isotopic analysis of hydrogen, suggest Venus could sustain those oceans for billions of years, although at the expense of being tidally locked due to having water and being closer to the sun. It is possible that were it not for some additional external trigger inducing a "planetary resurfacing event" around 700+ Mya Venus might still have been able to support oceans.
Mars were it to have maintained its magnetosphere could have probably held on to oceans as well alas since it lacked a dense core like the other rocky planets in the end it's magnetosphere faded allowing the solar wind to strip away the planets atmosphere along with its former oceans.
With three possibly formerly life bearing planets it becomes far more realistic to me that one of them could maintain habitability to this day.
Collision wise Mercury, Earth, Mars, Uranus the fragmentary graveyard containing obvious signs of cataclysmic collisions such as Psyche, Vesta, or Hygiea, etc., the rings of Saturn, the dwarf planets Pluto, Eris, Haumea, etc. and perhaps even Jupiter itself* all show significant evidence in favor of truly planetary scale collisions if they are as common as our solar system and alien ones seem to suggest it seems like it was bound to happen somewhere which coupled with the above seems reasonable.
@@Dragrath1 its not the star it's lack megnetic Field.
It's to close spin. But planet Europa where the pulling of Other bodies in System causing Geological warming and larger enough to have an atmophire Discribes Trappist 8or 9.
And Mars lost It's atmophire do to the solar wind.
The core may have cooled sooner. But a paper how the crust cooled sooner.
And if understand wind Erosion . The fact that the sea&River Beds Gullies and sediments are still around shows it have been habbitamble much sooner.
At the rate of Mars losing it's atmophire. How fare back in time before it get thick.
If Remove 90% of Water on Earth. The ground would sink and planet would Deflate. Plus the burning of CO2 Sulfur Hydrogen nitrogen Bonds . Into the atmosphere without a magnetic field . The planetary matterial would blow away with the rest of the atmosphere.
Not to mention metieror impacts.
Mars might been bigger in the past
When you start talking about the entire universe, you need to be clear- are you referring to all physical reality, only observable spacetime, etc?
The biggest issue I have with all these "principles" is the logical fallacies baked into them. The biggest is this unstated Platonic assumption that the 'laws of physics', let alone math, somehow exist prior to & independent of the physical universe. Suppose there is some 'multiverse' and a distribution of possible physical laws. You'd STILL have to explain why that distribution exists, where IT comes from, and why none of the myriad alternate laws of physics aren't MORE conducive to sentient life than ours. Our universe certainly offers far more habitable, hospitable real estate to entities made of plasma than it does creatures like us- stars are WAY bigger than planets and last longer too. I can therefore use "anthropic reasoning" to infer that we should be asking these question from inside the photosphere of Sol, not a comparatively tiny rock orbiting it. Examples like that are why you do NOT do statistical inferences from one data point in real science.
Second is the metaphysical assumption that our minds, our existence, is somehow "not special" despite that being wrong to the extent it's even well defined. Our consciousness is the bedrock upon which all our thinking & inferences about the world rests, yet contemporary science stridently insists on either ignoring or dismissing it as a "fundamental" part of reality. Heck, the idea that the laws of physics really ARE the same in distant galaxies is merely an ASSUMPTION that may very well be wrong. We already know it is in part- the earliest moments of the Big Bang were a universe of unified electroweak forces and such.
Stfu man
*I'm not interested in typical universes* !! I am only interested in atypical universes, that is, universes of a different slant, a different dimension. These are the universes I want to observe.
I look forward to your videos. Keep it up!
Perfect videos to sleep too!
Thanks for the episode, truly gems of knowledge
Spoken 30 seconds after publication of the episode. Congrats folks we caught a time traveler.
@@jpdalvi,
Lol. Hahahaha. :)
@@jpdalvi damn i was too obvious
This video is answer to a question that doesn't exist.
If there is a question which does not exist, is all knowledge the answer?
Thank you, that was much needed.
it was less than a minute after this video began that I thought of Addams' puddle analogy. I was so happy to hear you describe it. but I won't try to claim "great minds" and all.
I like to think of the universe as analogous to the “gaseous state” of some extra-universal “fluid.” The universe was nucleated like a bubble in boiling water and has been expanding ever since.
Yeah, an ether having zero entropy, creating bubbles to acquire a little by letting off some steam, as the Second Law would require. After all, the ether has to obey the Second Law, too, and does so by making all those Big Bangs. Makes sense to me.
When science sounds like philosophy
I did only missed 42 as ultimate Cosmological constance / principle ... but i loved it all! ;) Thank you!
The real question is, is everything that is happening a part of itself? Or a conscious separation occurs, when time is perceived linearly. It could just be, that everything on the macro-scale, has already happened: Time must behave differently, for us to be able to perceive it linearly with our limited biological/technological receptors. For an ant, a puddle can be an ocean, where a bubble blows up instantly for us, but for them, that process could be perceived as a catastrophic natural disaster that seemingly lasts forever. There was a study showing this on a smaller scale, where small animals where observed to perceive time in a "slow-motion-esque" more refined manner, which allowed them to escape larger predators in certain cases. So perhaps, the larger the scale difference of biological observer, the larger the difference of observed phenomenon. As Jiddu Krishnamurti liked to point out: "In order for the observer to observe the unknown, first they should consider, whether the tool they are using to observe is clean, not dull and working as intended." Einstein loved to say : "Time is nothing but a stubborn, consistent illusion". But what do I know, I don't have a PhD in Astrophysics :D
Proposal for naming this modified Anthropic Principle:
The Anthro-Copernican Principle
Does that include self-sampling and Bayesian reasoning?
Including Bayesian reasoning, it becomes the Anthropic Bayesian Copernican Principle. I.e: The ABC principle. To be taught in Grade school!
The Coperthropic Principal
The Self-Sampling Anthrosianican Principle.
Maybe Anthropernican Princinple. Or Copernthropic.
"We are a way for the Cosmos to know itself."
-Carl Sagan
At least for now
We're cells of Spinoza's God
Since we aren't a way for Earth to know itself, we aren't a way for our Sun to know itself either. Why would we be a way for the entire Cosmos to know itself? Poetic thoughts shouldn't be taken as some sort of special wisdom about existence. It's just poetic thoughts, period.
@@lucofparis4819 That's because we are not part of the sun. We are part of the cosmos.
@@jackfrosterton2530 We are part of neither. Spacetime is relative. Ever heard of Einstein? We live in our own little raft of spacetime, interacting very remotely with the rest of the observable universe, and completely cut off of the wider cosmos.
Poesy never describes reality or any approximation of reality, but it sure sounds awesome and we wish it had some measure of truth.
It's inherent to our desire for spirituality. Even atheists have spiritual needs and thoughts. Recognising it and keeping it in mind is important to avoid doing the same mistakes as theists.
i would LOVE to see you guys do a video on the hypotheses of van Raamsdonk, Susskind, et al. that spacetime is an emergent property of quantum entanglement. huge fan of what you guys and girls are doing with this channel - thx so much for all your vids!
I remember that quote from Douglas Adams! 💜
We as human observers get in the "now" 3D screenshots of an occurring probability in spacetime.
14:56 why should we assume time isnt unique to our universe?
Meanwhile, in the universe next door...
Oh, right...
Because is a core component of 4D space time. Without time entropy cannot exist as energy would be everywhere always. Which would mean there is no energy gradient. And if there is no way to measure distance as everything travels everywhere instantly.
So space wouldn't exist - energy wouldn't exist - matter wouldn't exist. Without time there is no existence.
Time IS, it just IS😂✔️🍻
I might kinda agree with lilsniper here, but I think that it's a reasonable assumption to make that only so much of the laws of physics vary across the entire universe. (The entire universe here meaning everything that exists, for real this time.) It's already a controversial and confusing proposition that the fundamental constants can vary between universes or within universes; the concept that something as fundamental as time could vary will be very hard to reconcile with our understanding of reality.
Time or Timing? Timing is a definite candidate for one of the knobs, length of a "second" could easily differ.
As for Time being all together unique.... Assume there can be at least one universe without time. Similar to other replies, doing so eliminates a factor Einstein has shown us is as fundamental as space itself. Without the effects of time a universe is immutable. Any change to it must be the end of the former universe and the birth of another universe. If that is put into a continuous loop you see time emerge as the generations pass from one to the next.
Speaking in terms of 3+1 spacetime, removing time is removing one of the dimensions. What if instead we remove a spacial dimension? Beings which emerge in that universe find themselves living in flat land. Maybe that is more possible than we "can science" as 3+1 beings. Well, we can science whatever we want... However there is a loss of functionality to put a 3-1 being into a 2-1 universe. It can have a purpose, per say. If a 2-1 being enters a 3-1 universe without gaining functionality, has it really entered that universe?
Coming back to the knob analogy, unique Timing can be considered a specific setting of the time knob, unique Time would be whether that knob can be excluded for X universe configurations.
oh thats sponsorship was so emotional. its nice to see that good teacher gets good students
One possible conclusion we can derive from the anthropic principle is that the universe we live in is a typical universe wherein life *can* form, and somewhat at its minimum size for anthropic conclusions to be formed. That is, while even smaller universes with intelligent brains are possible, perhaps the variables that those universes require for that efficiency of resources are even less probable than a large fluctuation bubble that has less fine tuned variables, but sufficiently so that one or two species can form that may arrive at the AP.
This hypothesis is interesting, especially when you realise it makes a very stark prediction: it predicts we are basically alone in this universe, for we live in (probably) the tiniest bubble required to form intelligences. IOW, it *answers* the Fermi Paradox.
I'm observing one right now as I'm typing this
But it's probably not a typical universe, that's the point I think
14:44 - There might exist a universe in which life is made of energy instead of matter. Scientists already theorize about dark energy in our own universe which might not behave like normal energy, so why couldn't there be a universe where energy works differently and leads to life? To paraphrase Hamlet, _There are more things in space and the multiverse, Matt, than are dreamt of in your science._ In other words, what is, isn't limited by _our_ imaginations.
16:12 - I envy you your optimism. I don't consider the existence of life in the universe as "lucky". ¬_¬ I let the bastards grind me down. :-|
Did Hamlet really have the word Multiverse in it?
Went to your lecture at Lehman college, great job!
Heyyyyyy that’s my professor sponsoring my favorite channel! Love to see it :)
Anyone believing in a Goldilocks universe clearly never experienced English weather.
Or Dutch weather. :)
Or Irish summer
We are (part of) the anti-entropy force of the universe. That IS the meaning of life. 😀
That's basically my personal interpretation of the Force in Star Wars: anti-entropy that causes structures (and therefore galaxies, stars, planets, and life) to form. It holds the universe together, as Kenobi once put it.
But life speeds up entropy
Creating order or retaining it locally (your body) requires more energy globally (the universe) than just a slow descent into disorder
@thrilll yep yep. Life locally creates order by globally increasing disorder. You can prove by the mere fact that we glow in the infrared. Our body's take in energy, use a small bit of it to create the ordered systems that make up the organism and then radiates the rest as heat. Just feel how much your body heats up when actively doing work. That's entropy holding strong. Remember, the "closed system" of entropy is the whole universe, so even great drops in disorder locally are no problem because creating that order caused a lot more disorder all around.
My intuition actually leads me into "retro-causal" territory. On some level i feel consciousness is fundamental before other assumptions, so the nature of things needs to conspire to that end. Assuming the universe exists first, and then consciousness as a happy side effect, seems to be putting the cart before the horse.
May sound strange, but I tend to just listen to your voice while I'm cooking. Makes me seriously think about what it is I'm teaching my children as a mother. My son stares at the sky (6 years old) and askes me questions, that I find I can now answer to watching/listening to PBS Space Time. Thank you
I told my little sister about the billions of stars in billions of galaxies in the infinite universe. I do not think it made her feel special.
@@MostCommentsAreFake-ud8by 🤣 well, there are way to go about it. My son is amazed with it. Even if there is more then one star in the galaxy and it dosnt happen to be him lol
13:50 only you guys can make a thank you incredibly cool _and_ a shitpost at the same time.
Also the puddle example was chilling...or rather not ;)
Hello
Love to hear more on Fluctuation theorem. More specifically, Crooks fluctuation theorem.
Short answer to the title is....Yes!
But if you want the longer version try to jump into the rabbit hole with Mart, he is quite the guide!!!
Another episode that challenges my understanding!!! Love every one of them!