Is the Anthropic Principle scientific?

[@Darkanight]

you're the best. you're incredibly
precise on each and every subject and you are constantly choosing topics that I, as a beginner, would like to understand more deeply. you're demistifying quantum physics.
Thank you, Sabine!

[@moonlifeSW]

Absolutely. It's very important to be exactly precise in what you are saying scientifically. A lot of fuzziness makes people distrust scientists. Sabine raises the bar.

[@toddq6443]

@@moonlifeSW Yes, she does. Plus, I love the way she says version...."Wersion" lol. She is awesome. TNQ

[@svempsvamp5796]

3:30 Thirty years of work on my groundbreaking scientific paper, "There Is Oxygen In This Room" and it was all for nothing. Back to the drawing board. I'll get started on a new one, "Final Absolute Proof That France Exists".

[@ivanfromunion3513]

There is no France in your planet of the apes! For us, captain Picard already proved France's existence: "Spessssss. Zee fun ahl frontieur. Zeez ah ze voyajes of ze spessship Unterpreez"...
(Actually, that IS a Sir Patrick Stewart joke!)

[@svempsvamp5796]

@@ivanfromunion3513 No, there's no France, because...well... _they blew it up!_ Oh, damn them! God damn them all to _HELL!_

[@HarryNicNicholas]

i was writing a paper on youtube commemts, it's virtually finished.

[@bubbathelonepotato2208]

Good luck with the France things. I think its like proving Neanderthals existed. Oh wait, they were in France right?

[@kittehboiDJ]

All you have to do to prove France is real is to go there and experience it yourself.
Hmmm, to what lengths would Belgium go to perpetrate such a hoax?
You then must stay in France to make sure it continues to exist.
I hope you like cheese.

[@jklep523]

My consciousness was completely transformed by Carl Sagan 40 years ago. I've been a student and fan of many exceptional ambassadors of science in the years since, but Sabine comes closest for me of anyone to capturing the essence of Carl's natural gift for making the most complex concepts comprehensible. I became a scientist as a result of that inspiration, and I am certain Sabine is having that same impact on many young people around the world today. Thank you Dr. Hossenfelder.

[@greggstrasser5791]

I used to be a fan until I found out about what he did to Velikovsky.

[@philkenseben7]

Yeah LSD did the same for me

[@johngeverett]

Once again, you explain concepts clearly so that they are no longer obscure. You should get a Nobel Prize for Education.

[@mrtubeyou77]

I am not versed enough in physics to understand everything you speak about in your videos. Sometimes I just have to sit back and take in. I like how you deconstruct, compare, contrast, demystify, explain, clarify, simplify, and critique the physics concepts and theories. You gave me much to think about in this presentation. I wrote down some of the things that you said for future reference. Thank you.

[@abouttime5630]

Dr Sabine. You are amazing. the way you elucidate such information, plus how you follow all claims and arguments to their conclusions is priceless. Your videos make me want to learn deeper about foundations of physics. Thank you :)

[@deckiedeckie]

She's the voice of reason in a fantasy universe of hustlers

[@mikeclarke952]

I think therefore I am in a Universe that allows thinking minds.

[@odomobo]

@Sebaka & Co. "Man thinks that just because he has consciousness he's at the pinnacle of all existence."
Scientists tend to not think this way. The scientific method is designed as such because of the fallibility of humans, especially of the human mind.

[@odomobo]

@Sebaka & Co. Are you saying that theoretical physics theories which have achieved consensus are conjecture? Or that areas of exploration are based on conjecture?

[@rodnorris9532]

I think therefore I am God. Not as silly as it sounds. Many religions/philosophies are based on this.

[@neptasur]

How about: "I think, therefore I am not in a reductive universe." Physics tells us that a table is a mostly porous, odorless, colorless, textureless, vibrating cloud. Yet we perceive it as a table. Reductive philosophers and scientists shuffle this perception off to "the mind" and then go on bragging about being on the verge of explaining everything--everything, that is, accept for "the mind".

[@RalphDratman]

Asserting that you are thinking may be adequate to prove it to yourself, but for others to accept your assertion requires evidence. After all, you could be mistaken or might even be shamming. A robot might say, "I am thinking now," but a computer scientist would be quite skeptical.
But this is all a bit silly, because there is no good definition of "thinking." Even if you happen to be sitting inside an fMRI machine, try asking the operator of the machine to make a series of brain images while you stare off into the distance. Examining the pictures, can the operator be sure you are thinking?

[@DrinkingStar]

Your discussion describing a hypothesis was the best(simple and most concise) explanation that anyone can comprehend.

[@quphys5253]

Thank you so much! Some time ago I gave a 30 minutes presentation on the anthropic principle (in front of academic, but not physicist audience). Now I have to write up my lecture notes. Your video makes an excellent reference! Concise and fair. Could not be better.

[@WaldemarMartens]

That's the best explaination of the Anthropic Principle I have heard. I fully agree about the predictive power and the carbon resonance example that you cite from Fred Hoyle. However, I find it important to note that this is not an a-priori explaination of the phenomenon in the reductionists sense. There is a difference between saying, "the Anthropic Prinicple predicts the carbon resonance" and "the Anthropic Principle explains the carbon resonance in terms of more fundamental principles". And that distinction is rarely made in popular scientific literature in my experience.

[@cq33xx58]

''the multiverse people'' what a term :D

[@jamestheotherone742]

And true. You could even say the "Tribe of the Multiverse People".

[@Nostradamus_Order33]

Multiverse is a religion.

[@UltimateBargains]

More polite than tin foil hat.

[@carlegerard8382]

@@thotslayer9914 👌🏾

[@martinreddy3823]

I wish she had been one of my professors. Clearest and most reasonable I have ever heard. Thank you.

[@billbrockman779]

Thanks for discussing this. Ever since I first heard of the anthropic principle it has fascinated me.

[@martintai3004]

I am watching a compiled series of 15 video. I don't how many years you spent to make all of those, but it is astonishing to see how personal image changes over years. That is why "is time real" is my personal favorite. Thank you.

[@kathleenherrmann436]

I'm so impressed she got through that without saying the phrase "fine tuning" 😅

[@StefenTower]

Your presentation is clear and precise, and that's the kind of scientific presentations I prefer. Subscribed.

[@johnkeck]

Thanks for cutting through the gratuitous mystification people are prone to, and clarifying so well that the anthropic principle (despite its name) isn't about human life specifically, but about the preconditions for life! It might as well be called the simian principle or the angiosperm principle.

[@KilgoreTroutAsf]

The anthropic principle is the strongest Bayesian prior imaginable.

[@SabineHossenfelder]

Yes, that's one way to put it :)

[@KilgoreTroutAsf]

@@SabineHossenfelder Love your videos, by the way!

[@EffySalcedo]

@Kilgore Trout Thanks for pointing that out.

[@jamestheotherone742]

That is funny on a couple of levels. Bravo.

[@schontasm]

Commento ergo Tralfamadorian.

[@theklaus7436]

You are about to be my favorite teacher! Very clear and clever explanation I have a lot leaning from. Thank you beautiful clever voman

[@spiderjuice9874]

If we cannot say *why* the physical constants are what they are, then surely we cannot say that they will vary in other universes. Thjey *may* vary in other universes (or even in distant regions of our own universe), but until we know *why* they are what they are, then we cannot know whether or not these hidden reasons actually *require* them to be fixed this way, and therefore impossible to change, even in other universes.

[@darryllyle5250]

This question probably should be on your video about the multiverse but there is one thing I've been wondering. I am not physicist but I do find physics fascinating. I recently heard about a paper that suggests the universe has a positive curvature and that would potentially make the universe spherical. I think that makes sense as other things in the universe we observe end up being spherical. If the universe "began" with the big bang could that big bang be the result of a white hole? This white hole being a black hole in another universe? I think we could potentially make some observations to test this theory. If this is completely wrong and I just don't get something then that would be good to know as well. Thank you for your videos though. I have just found your channel and I've instantly became a fan.

[@wah3094]

delivered once again with so much clarity, thank you!

[@Cavistus729]

i'm definitely going to keep an eye on this channel. i never knew science could be explained so concisely!

[@jamestheotherone742]

Yes it is very much worth a subscribe. Not only does she explain things extremely well and rationally, she has no fear of challenging scientific orthodoxy. Which is very refreshing.

[@TheRocketman136]

Everything can be actually. There's a rule, that if you understand something good enough, you can explain it fundamentally on the most accessible level, period. So when someone goes "ah, it's too hard to explain" they just don't want to or don't understand it good enough themselves.

[@jamestheotherone742]

@Sebaka & Co. That (and Rocketman's statement) is not true. If something can't be explained, you may just not have enough information. Or you could reach a false explanation based upon your incomplete knowledge that satisfies you but is still false. Many things in human experience are like this.

[@TheRocketman136]

@@jamestheotherone742 that's not what I was talking about. Unexplainable phenomena(which is unexplainable because it's _unknown_ ) is a different topic; please don't mix cold and blue.

[@jamestheotherone742]

@@TheRocketman136 But if you incorrectly explain a phenomenon, you are still wrong. Unknown unknowns, etc. Thus is the hazard of the presumption of absolute knowledge. It leads you down dead ends of presumption.

[@hfyaer]

Descartes said "I think therefore I am"
Multiverse guys say "Things exist therefore I am here thinking about them... "

[@chaotickreg7024]

Descartes was a skeptic
I think multiverse believers might be wishful thinkers

[@caricue]

The problem I have with this idea of the Anthropic Principle helping with predictions, in the case mentioned of the resonance of a type of carbon, is that a negative result would not have resulted in all humans disappearing. In fact, the theorists would have simply moved the goal post and assimilated the new data. This, of course, is the right thing to do when your prediction is contradicted by data, but it means that the original premise of the Anthropic Principle was not valid or useful, just lucky.

[@skydivekrazy76]

The strong anthropic principal is utter sophistry.

[@joshuacoppersmith]

Thanks for straightening me out on that. Biased by its use by "multiverse people" and "we-know-just-how-evolution-works-already" people, I'd started to dislike the word "anthropic." I think at times it gets short-cutted to "We're here, so it must have happened the way I'm telling you it did" instead of "We're here, so it must have happened in some way consistent with that fact." But it seems like a dangerous tool. Quickly it can seem like a priori existence arguments, etc., which may have philosophical merit, but are not within scientific philosophy (quickly speaking).

[@aresmars2003]

The "Weak Anthropic Principle" makes sense at the level of physics, but there's another level perhaps working towards the strong version, where we're more ignorant, basically the nature of evolution of life. We live in a universe where complex life can evolve, and we don't know if the physics is sufficient to explain that since we don't know necessarily what life really is, what consciousness is.
For example we can consider natural selection as a necessary but not clearly sufficient explanation for evolution to occur as observed. We can try to simulate complex weather systems in computers to predict how weather systems evolve up to 10 days ahead after which uncertainties explode. Similarly we can simulate solar system dynamics up to 10 million years into the future (or past) and have some confidence of accuracy, while no confidence further out except statistically. And these systems can be considered largely free from life and consciousness and free will of its elements changing the results.
For evolution, we can use "genetic algorithms" along with natural selection rules, and base motives of life to feed, reproduce, and expand by exploiting free energy within a system, and a lot can be learned there. Clearly "life" uses similar tools to evolve, but we have no illusions simple models contain anything like consciousness, the interior of experience, nor memory of the past . And in short, we shouldn't expect any mechanical simulation to take even the first step to conscious awareness, despite what SciFi would like to assert.
My intuition considers that if we tried using a pure "natural selection" model for computational evolution, that even a billion years of work might not be enough to explain what we see. And if we could show that, then we'd be forced to consider what variables we're missing, and we'd know all along consciousness is what is missing, and we've just been hoping it was an emergent property of a dead universe.
But if that hope is wrong, then we can consider the opposite, that the universe was not "dead" before complex life evolved, and then the "strong Anthropic principle" might come out that we need a "living universe" BEFORE actual living creatures in it, that there are intrinsic properties of space-time that contain something of consciousness from the beginning, and it is that aspect of the universe that enabled our evolution, not just mathematical laws of space-time.
How would we model a "living universe" before life existed? We have no basis I think to imagine that, but maybe we can consider what properties are required by looking at what properties life has. Individual living beings have memory, but we can consider perhaps not all memory exists within individuals, and perhaps memory from individuals are not fully lost at their death. So for example we might consider memory itself as an aspect of evolution.
Dead systems just have physical laws, living systems can change their laws if memory progresses, so the next generation doesn't need to depend on relearning everything from scratch in random events. So if there was truth to this in the universe what it would look like is that the laws of nature change over time because the underlying consciousness/memory of the past enables building on the past. We can say all of this is "stored" in the DNA, but overall that seems to strain credulity. DNA contains information like books contain information, but we say that DNA isn't dependent upon experience, only sexual selection, random mutation, and survival. But if memory isn't just what we call memory, but something else as well, something more persistent, then DNA is being aided by something "higher"/"deeper" that directs it.
Carl Jung might call this the "collective unconscious" which certainly is unscientific, but a clear call that there must be something we all have access to that goes beyond our personal memories/experience, and into ancestral ones. And ideas like instincts or archetypes are "patterns" from that unconscious that we have access to, and that help direct individual life to go into directions that its genes alone can't explain.
And again, a consequence of this would be a quickening, so the first time a "pattern" is discovered by life, it took a long time, it had a very low probability of being "discovered", but once discovered, the probability of another individual finding it, especially an individual with a similar DNA and potential, goes up, and its "use" by individuals expands that into the collective consciousness.
It is terribly frustrating to consider perhaps the vast majority of the universe is devoid of living beings like on earth, and we all agree if life existed elsewhere, it would surely be very different, and even completely alien, beyond our imaginations, although the diversity of life on earth itself is vast beyond imagination as well. But if the universe is "living" in some sense, and memory exists, perhaps the "patterns" learned on earth are being stored in that universal awareness and can be reused elsewhere in the universe, without any direct physical transmission of information.
That to me holds some hope, even if humanity becomes a failed species in the future, that other species that follow, either on earth or elsewhere in the universe do gain from our short "quickening" of self-awareness. We might be "first" in the universe, or our evolution might be directed from the experience of self-aware life elsewhere in the universe before us.
Anyway, if this sort of "Strong Anthropic Principle" existed (a subtle hidden requirement for a living universe), we ought to be able to find evidence for it. The "100th monkey" effect is one example, if behavior of individuals change based on critical mass, and more astounding if behavior is changing across locations without direct communication.
en.wikipedia.org/wiki/Hundredth_monkey_effect

[@ivanfromunion3513]

Very impressive comment, @aresmars2003! One quick add-on:
"But if that hope is wrong, then we can consider the opposite, that the universe was not "dead" before complex life evolved, and then the "strong Anthropic principle" might come out that we need a "living universe" BEFORE actual living creatures in it, that there are intrinsic properties of space-time that contain something of consciousness from the beginning, and it is that aspect of the universe that enabled our evolution, not just mathematical laws of space-time." Bravo!
-This is where the Anthropic Principle goes seriously wrong-. Considering that life is what you think it is demeans the concept. Life is not what we think it is. It's a part of the universe already. It's many parts of the universe. And the same goes for consciousness:
Some years ago, after one more incident of "Hi, Ivan, haven't seen you in ages, how are you?" I realized I am mildly face-blind. If i go a few years without seeing people I can no longer connect the faces with the names. That is because I see thought patterns instead of faces, and am much more time-intensive at one than the other. That is a linguistic characteristic, mind you: facial recognition disassembled by thought pattern can only be caused by the fact that you are a collection of thoughts that are themselves already disassembled. What you think your consciousness is supposed to be is not even close to what I see (ignore Chalmers, please, he is a prolific blunder machine), your thought pattern is already disassembled and, let's say, "quantified" to me. (I could say more about eye disassembly but that would be off off topic)
So I feel like cheering when I see a comment like yours, of course. I can not define consciousness and life in any manner other than my own empiricism, it is impossible.

[@GEOFERET]

No more and no less. Simple, elegant and down to earth. Thanks!

[@cezarionescu75]

Would love to see your video on the measurement problem and it's solution. Can't wait for that one. Love your videos, no bullshit, just science with great criticat thinking

[@supremereader7614]

I have the double-bell hit on your videos for a reason. You’re providing great videos, well explained. The internet can be a brutal place, don’t let anyone discourage you. 😊❤️🙏

[@a4k00]

Sabine. You are, simply, amazing. I've though about this topic for so long and am glad to learn its actually a thing.

[@trimetrodon]

Hoyle and his prediction of the carbon-resonance acknowledged, Johanna observes, the multiverse seems to be an attempt to escape the tuning and the tuner. And Hoyle, for his part, wasn’t attempting escape.

[@scotte4765]

I wouldn't call proposing alternative hypotheses or explanations "attempting escape". And even if it were, so what? There have been any number of productive scientific discoveries and explanations made because someone was justifiably unsatisfied with some other popular explanation.

[@quantumcat7673]

Why not call the weak and strong anthropic principle, weak and strong "life principle" since it is exactly what it's all about here. The human connotation is not necessary and that bias brings doubt of anthropocentrism to my ears. I love your lectures because you bring a lot of questioning when big claims are made in physics. That in return gives me a lot in term of understanding and brainstorming for I'm truly fascinated about the way "nature" works. Thank you Sabine, I appreciate your work.

[@jamesdriscoll9405]

You've convinced me, there is a use for the anthropic principle. Thank you for explaining it so well.

[@petea]

My concept of the anthropic principle: we have this band of wavelengths that permeates air, allows us sight to navigate, but short enough wavelength not to overlap with thermal ratiation and long enough wavelength to bounce off of most objects. It strikes me as somehow "lucky"... that to me is the anthropic principle. The "way we are" works so well, but I don't believe it was designed by some entity. Then it must be chance, but isn't that too lucky? Change anything in the universe and it becomes difficult to imagine life existing. And yet we do. I'm not religious but I do feel awed by that.

[@garethcroson8851]

Thank you. It's as simple as that. In that other universe I was completely confused about this. I love your videos, BTW.

[@tenforce]

I don't see how the anthropic principle should make sense WITHOUT a multiverse. Without it, we first have to accept the incredible huge amount of chance that was involved in receiving a single universe with such fortunate laws of nature. And considering this unlikeliness, it is again much more attractive to look for theories that explain the properies, instead of relying on the anthropic priniple in this case.

[@OpenWorldRichard]

Very well explained and it is agreed that human life is possible because the laws of nature are such that human life is possible. This is clear when we assume that we live in a single universe as we observe. Where it becomes problematic is when it is applied to the multiverse concept by saying that there are many universes out there with all varieties of physical properties and we just happen to be living in one that has the physical properties that support life. There is no observational or theoretical evidence for a multiverse.
I have devoted my attention to trying to resolve the explanation for the physical universe that we do observe. It is only when we really understand the physics of our universe that we will understand the nature of matter and the evolution of the universe which has evolved in such a way that life is possible. An example of one of the most fundamental question that we can ask is "Is it by chance that a neutron decays into a proton and an electron, or is this an inevitable result of the fundamental character of these particles?".
In drawing up this explanation I have had to discard the Big Bang theory and the Standard Model of particle physics:
www.academia.edu/5009126/The_evolution_of_the_universe
www.academia.edu/5038836/The_Unification_of_Physics
www.academia.edu/5927513/The_Spacetime_Wave_Theory
Richard

[@mikepenske9943]

Please do a video going into what the "Amplituhedron" is and how it relates to physics.

[@magicmulder]

Mike Penske // Haven‘t heard of any progress in that regard for years. Are they still in the „only works for a very simplified model of reality“ phase?

[@nagodio]

I came to the realization the interconnectedness of all things in the universe by comparing it to a vast organism. In this analogy, the universe functions akin to a living being, with Earth representing a tiny yet integral cell within its grand body. Just as cells work together to sustain the health of a body, humanity plays a role in maintaining the equilibrium of the universe. This perspective highlights the interdependence of all life forms and emphasizes our responsibility in nurturing the harmony of the cosmic order. It's a captivating way to contemplate our existence within the vastness of the cosmos and our interconnectedness with something greater than ourselves. In this metaphorical framework, the concept of cancer could be likened to destructive forces such as Hitler and wars, which threaten to disrupt the harmony of the cosmic order. Just as cancerous cells endanger the health of an organism, these destructive forces jeopardize the balance and well-being of the universe. Humanity's struggle against such destructive forces mirrors the body's immune response to combat cancer, working diligently to prevent them from overpowering and harming the larger whole. It underscores our collective effort to preserve the integrity and vitality of the cosmic order, ensuring that harmony prevails over discord.

[@piwi2005]

According to your definition, you are correct. You are consistent, and good for you.
On my side, I have always interpreted this principle as : every winner of the lottery feels himself very lucky, yet there is always a winner. Feeling lucky has nothing to do with the odds for a particular person to win, as long as there are enough players to balance these odds. The anthropic principle, with that meaning, tells you that the small probability there was to have that universe instead of any others are irrelevant. It does not say that the multiverse is real, but it says that there is no particular reason to think that we should be in the most probable universe, and that the ridiculously tiny probability needed to be in ours in a multiverse theory is not an argument against the multiverse itself. It is the ones that want the most probable universe for theirs which are wrong, and nothing substantiate such claim. With that meaning, the anthropic principle is not constructive, like in yours. It is not a proof of anything, but an argumentation to reject another argumentation as non sequitur. In the end, asking us why we are in that particular universe in possibly so many, reals or imaginary, is meaningless.
every time

[@1010xxx33]

well your lottery analogy is a strong interpretation and the host only said that the weak one is correct. A lottery demands a winner, and we have no evidence that the universe prefers the one with a winner.
While the weak interpretation is a truism statement that goes like (intelligent lifeform) are in the universe because the universe happens to support it, you can insert any existing object in the bracket and it will still technically be true. But because it's also unfalsifiable it doesn't count as science.

[@piwi2005]

@@1010xxx33 The lotery analogy is neither strong nor weak interpretation, as interpreted by the host. I disagree with how she interprets anthropic principle within the multiverse, or string theory, or any theory that imagine as many posible universes as you want. Yes it is not scientific, but nobody claimed it was, but the host. It's a red herring. It is a logic argument, and goes exactly opposite to what the the host said about computing distributions. It tells you that you do not care about probabilities, as long as you have possibility. If you have only one universe with humans, among 10^100, this low probability is not an argument, because only in this one universe can you get people wondering how lucky they were and falsly stating that it was not possible to be so lucky, and thus concluding wrongly that there can not be 10^100 universes with us in only one. This, for sure, does not prove anything, including the multiverse, but it does take an argument against it out. The odds for you and me to exists were even smaller than 10^100, yet we exists and we can not use these low probabilities to prove we don't exist.

[@volkerwendt3061]

Simply loved it.

[@francesconicoletti2547]

The other suspicion I have with the anthropic principle is the egoism. It could have been expressed as any significantly complex object exists ( for instance the rings of Saturn ) if the underlying laws of the universe were different that object would not exist. Instead making it about us makes the principal sound both important and paradoxical.

[@williambunting803]

Anthropogenesis can provide a perspective on aspects of science theory. Quantum physics suggests that particles can spontaneously appear and disappear. Where this happens inside a rock there would be no real impact or evidence, however if this happened in the genome of a cell of a living creature the impact could be visible and significant. Considering the stability of bone structures over millennia, the incidence of particles spontaneously appearing and disappearing would have to be extremely rare, or more likely a mathematical probability rather than a real one.

[@rclrd1]

The word “anthropic” in this context is grossly misleading. The dictionary definition is “anthropic: of or relating to human beings or the period of their existence on earth.”
As I understand it, the physicists' meaning of “anthropic principle” has nothing whatever to do with “human beings” specifically. It refers to the fact that the laws governing elementary particles are such that they are capable of interactions that bind them to form ever more complex structures (nuclei, atoms, molecules, stars, planets, and eventually the _formidably_ complex systems that we call “living things”). For the basic building blocks to be capable of this seemingly “miraculous” behaviour their physical properties have to be “fine tuned" to a remarkably precise degree. That is the “principle”, and it is a profound mystery.

[@nm-com]

its not that the constants are "fine tuned" so that our world exists. physics just describes the world with help of some constant numbers. the world itself doesnt need numbers to exist. it just exists. so all the anthropic principle actually tells us, is how fragile our description is to changes. slight changes will lead to some sort of physics, which is unable to describe our world. not vice versa: our world would be "highly unlikely". the latter would be a task for religion, to claim.

[@commonsense1103]

The universe was made with all of its constants. Then, we were made to live in it. So much for the multiverse.

[@Graeme_Lastname]

Made? ;)

[@NoIce33]

IMO the "weak version" is THE anthropic principle, while the "strong version" is just woo. And I guess the connection with multiverse only pops up because it is hard to avoid thinking about other universes when formulating the anthropic principle, even if those others may just as well not exist. Neither of the two ideas (anthropic principle and multiverse) actually depends on the other in any way.

[@giambattistavico1]

@Hilmar Zonneveld I am not a physicist, so maybe I did not get it. But I have always had the impression that the strong version comes close to the notion of Intelligent Design. To put it differently: it is open to the fallacy of finalism.

[@antiHUMANDesigns]

Can't we likewise generalize the anthropic principle into something like a "requisite principle", where any structure that is observed to exist must be allowed to exist by the laws of nature?
We know that there is oxygen in your room if you stand there and talk for a prolonged time, not strictly only because of the anthropic principle because if we see a computer running a program we must also conclude that it is being fed electrical power. Same idea, but no longer "anthropic".

[@tomjohn8733]

Make perfect sense to me, believing in a multi universe is like wondering how the world would be like if, say; hitler had won WWII, the south had won the civil war, or Napolean had won at Waterloo, etc..but wishful thinking does not make something true, like a multi universe. Have you ever wonder how your life would be if you had made different choices...does science make the world a better place or does it lead us down a rabbit hole?? thank you!

[@neilnelson79]

Saying the universe must have the conditions that allow humans to exist seems quite vacuous since we can easily see that humans exist. If we said however the universe must have the conditions that allow Martians to exist, that would be an interesting statement or hypothesis that could be explored one way or the other.
The bit about Hoyle resonance deriving from the observation that humans and other carbon based life exists seems a rather abbreviated, peep-holed perspective on what Hoyle was saying. Hoyle said certain atomic reactions must have occurred in stars as they run out of hydrogen and burn helium that then generates carbon and oxygen required for people to exist. The observation that people and other living things exist is incidental and not even a remote precondition for that hypothesis.

[@ivanfromunion3513]

"Saying the universe must have the conditions that allow humans to exist seems quite vacuous since we can easily see that humans exist":
Agreed. The anthropic principle is a legitimate scientific idea with the worst possible presentation ever, because it is literally upside down! Everything about its public exposition is perfectly wrong. Allow me to try a different approach.
Is a human being without eyes a human being? What about missing ears, is it still human? Poor guy now lost his liver and is in a coma: still human? And so forth and so onth...
There is no known *minimal* set of qualities that makes a human being (even then, yours would be different than everyone else's). The reductio ad absurdum of that is that there are only qualities, not humans. (That goes for Martians too.) That is, humans (life in its totality, in fact) are EMERGENT. Not a property of the universe.
Now we are in the same foot as galaxies, stars, and black holes. All made of the same elements of the universe.
Baited? Here is the switch:
NOTHING ABOUT YOU CAN POSSIBLY BE EXTRA UNIVERSAL.
Do you have a brain? Physical.
Do you have a mind? Physical.
Do you love, hate, trust, fear? Physical.
Do you have an imagination? Physical. (But not necessarily material, mind you, because the imaginary lines of a plus sign are clearly NOT visible in the Nasa tether accident video and if they are "imaginary" they came from... the CAMERA'S imagination!! What that means is that even your imagination is a quality that already belongs to the universe rather than to you! Unless the cameras that Nasa uses are extra universal, of course.)
And that is the point of the Anthropic Principle, even ineptly upside-down as it is presented: give up having a damn imagination, mind, knowledge, or soul: all of it is physical and was kindly borrowed to you by the universe and will return to it. It DOES NOT belong to you.
In no way, shape, or form is this a nasty comment on Dr. Hossenfelder's video, evidently. I just made a technical comment based on what I know empirically, from experience, whereas she already learned it upside-down.
And please note that the badly named Anthropic Principle is perfectly vicious to religion.

[@neilnelson79]

I should add some explanation as to why conclusions about universe conditions from the existence of humans is vacuous.
That humans exist is the premise and from there we want to conclude some conditions in the universe from which the premise is obtained. In order to go from conditions in the universe to humans existing we have to identify some causation sequences for which humans are the result.
Without identifying the causation sequences, we only have a principle of causation, another premise, and the humans premise from which some unidentified conditions can be concluded. This would be an empty result without any scientific utility. It could not be tested.
We then require specific causation sequences that obtain humans. These specific sequences then become additional premises whose selection is conditioned on humans existing.
The Anthropic supporters at this point may be inclined to say that from humans existing we can infer specific causation sequences, thereby getting us from humans existing to specific universe conditions. However, we can not infer these causation sequences merely from humans existing and rather have to have a catalog of causation sequences from which we choose those that obtain existing humans. This catalog is another list of premises.
Now that we have the catalog of causation sequences, causation sequences that exist irrespective of humans existing, it is a separate set of premises, we have the required universe conditions without needing to observe that humans exist.

[@Jean-Pierre-PETIT]

Sabine Hossenfelder is very talented and composes wonderful songs. But she is also a scientist who in 2008 laid the foundations for a cosmological model where the universe is made up of a mixture of positive and negative masses. It is then described not, like Albert Einstein's model which is summarized by a single field equation, but by a system of two coupled field equations.
From this angle Sabine is therefore the successor of Albert Einstein. But she could not build from her model elements that could be compared with the observations.
In France, we developed in 2014 a system also based on similar equations that we have exploited with great success by showing a dozen points where it matches observational data. Sabine accused us of plagiarizing her own model.
But these two systems are not identical. So we looked at how our model could be considered a special case of her model, which would not bother us at all. But we were unable to show it.
Sabine may hold the key to this case. Under these conditions she should, as we have asked her several times, publish an article showing this and we would be happy if this story could be cleared up in good faith because this accusation of plagiarism, formulated in the emails she sends to correspondents, puts us in a very unpleasant situation. Jean-Pierre Petit and Gilles d'Agostini, from France

[@wakingstate9]

This is for me very similar to the number 9 in a base 10 understanding of maths in digital root terms from my limited knowledge of mathemetics.

[@FromTheHeart2]

Excellent food for thought!!!! Thank you very, very much!!!! Would have been great with an explanation as to the meaning of "strong" in one and "weak" in the other, and also "anthropic" without making it a linguistics subject since this about physics. In any case, thank you!!!!!

[@ivanfromunion3513]

Found exactly what you want here:
abyss.uoregon.edu/~js/cosmo/lectures/lec24.html
Well written too, but longer than you expect.

[@lehpares]

Sabine, the iron lady of Physics. Love your videos

[@seansullivan2283]

‘The laws of nature must be so that they allow for our existence.’ - I don’t think anyone disputes this; whatever theory is subscribed to. My understanding concerning the Anthropic Principle isn’t to state this rather obvious fact, but to explore how, with the endless variables and constants that exist, how is it that at the point of the Big Bang, ALL such constants and variables arose (seemingly from nowhere) AND were just so that conditions were fit for human (and all other life) existence? The Anthropic Principle therefore exposes a much more philosophical (apologies physicists) and wider reaching debate; was matter consciously or unconsciously assembled?

[@schematism]

By the way, the concept of Force which is used in physic has clerly anthropic features. Of course, the force in general is not only an human beeing matter of fact, because animal have this property too. Another Anthropic principle used everyday in physic is that the universe follows certain laws and these are necessary, but the necessity of laws is something that we experience in political domain as rational beeing, so universe is rational.

[@Librepenseur2007]

". Carter distinguished the WAP from the strong anthropic principle (SAP), which considers the universe in some sense compelled to eventually have conscious and sapient life emerge within it."

[@Steeyuv]

Videos like this are why I love TH-cam so much. The controllers of the mass media think everyone is as stupid as they themselves are, and meanwhile deep and technically detailed material like this gets thousands of views in the first hour of release. Thank you for crediting us with the ability to think.

[@andycordy5190]

There is so much to come out of this brief presentation for me. Whilst reading about Fred Hoyle, whom I believe fully justifies his place in scientific history, I mistakenly took the lid off a can of worms by looking up "Hoyles Fallacy" which I was disappointed was not the title of an obscure album track by Canadian Prog Rock band, Rush. Only to find it was related to the "Junkyard Tornado", not a Rush song either. Did the jumbo jet ever get built in the junkyard? Somewhere in the Multiverse, yes!

[@jaimeriveras]

You almost lost me, but your closing statement saved the day: I understood. 😀

[@nm-com]

the anthropic principle (by prof. heinz oberhummer) shows how rigid physics is already bound to describe our environment. change physics slightly and its not describing anything close to our world. but no sane person derives that our world is therefor very unlikely. prof. oberhummer told me so in person, back in 1997.

[@Hecatonicosachoron]

A heavy handed application of an anthropoid principle will rule out theories where it would seem that do not allow life but upon closer inspection do allow life.
E.g. nobody has done interesting chemistry using the standard model. Several approximations are made first, which amount to assuming that different nuclei exist and are treated more or less classically and then some further approximation is made for the electrons, which are also assumed to exist. With theories different to the ones we are familiar with one wouldn’t know where to start.

[@FourthRoot]

The anthropic principle merely implies that we probably live in a universe where it is more likely than not that at least one intelligent agent would emerge that is capable of thinking about the anthropic principle.

[@stevelenores5637]

In a way the strong (SAP) is probably the correct one because we can only view the universe with our senses. Even if we have measurements of what we can not sense directly, it still has to be interpreted symbolically through our available senses. We can never observe the universe as it actually is but we reach some level of understanding interpreted on a human level. "Tao Ching"
As a supplement, all measurements of standards have to start with human references; whether these are time, length, mass, force, energy, etc cetera. So in a real way the universe is our invention and its limits are human limits.

[@n2185x]

More precisely, the laws of nature *are* such that they allow intelligent, tool wielding life to form. This is an obvious statement of fact.
As for the multiverse, if it exists, all you can say is that there exists at least one universe in the multiverse with a set of laws and properties that allow intelligent, tool wielding life to form. You cannot say anything about the probability distribution of universes that results in this, save for that it must allow for a nonzero probability that a universe winds up with the necessary laws and properties. No more than that can be said about the probability distribution of universes with various laws and properties, because we only have a sample size of one universe: ours. We can guess that our universe is unremarkable and that, thusly, the probability distribution of universes must be such that ours is within a standard deviation of the average or something like that, but nevertheless, that is just a *guess,* nothing more. A sample size of one does not bootstrap a guess into knowledge. In the end, all you have to work with is what you know and what you can infer (either directly or indirectly) from what you know. To my knowledge, we cannot infer the existence of multiple universes based on what we *know* thus far, much less what the probability distribution of those universes must look like. It may be that we have certain explanatory theories that have a multiverse as their foundation or as a natural consequence, but until one of those theories is shown to be substantially better at explaining and predicting observations than others, the existence of a multiverse must be regarded as speculative at best, IMO.

[@blugreen99]

The Universe may be as great as they say but it wouldn't be missed if it didn't exist!

[@iruleandyoudont9]

this is the application of the anthropic principle to cosmology. it applies to other scientific domains as well. in cosmology it is a good explanation for the supposed "fine-tuning" of the universe - not just the cosmological constant - ALL the physical constants. and that's true whether there is a multiverse or not. but do we have any reason to suppose there is no multiverse Sabine? I don't think so. it seems it would violate the Copernican principle if there was only one universe and it just so happened to be one that was capable of producing us.
why do most car accidents happen close to where you live? because no matter where you go, you leave from and come back to the area you live. you spend the most driving time in that area so you're more likely to get in an accident there. that's the anthropic principle.

[@jamesruscheinski8602]

How to approach the question that if only one universe, humanity exists in that sole universe, with respect to the anthropic principle? Only one universe with humanity in it would tend toward a stronger anthropic principle, while a multiverse with humanity only in one universe would tend toward a weaker anthropic principle? Similar to finding more planets and galaxies leads to a weaker anthropic principle, a larger and larger multiverse would also lead to weaker anthropic principle?

[@euanthomas3423]

Human beings could be said to be the universe's way of understanding itself. This raises a general point of the extent to which any system can be understood by observations coming from inside itself and would (could?) set a limit to our knowledge of the foundations of physics. This problem ought to be generally solvable from general information theory considerations. It also has some analogies to Goedel incompleteness in a logical system (math).

[@SocksWithSandals]

I don't buy the multiverse fantasy but am convinced that most of THIS universe is inhospitable to the point of being instantaneously lethal.
However we shouldn't be surprised to find ourselves observing the universe from a place conducive to a complex ecosystem of life, each species of which is perfectly adapted to thrive in its niche.

[@cmulder002]

" perfectly adapted " ? have you been outside lately? ;)

[@BiggySeth]

Einstein blinking freaked me out. I thought I was seeing things

[@alengm]

Is the following example an instance of anthropic principle?
A: why did the apple fall?
B: because otherwise you wouldn't be asking this question.

[@rtpfixit]

See? This other sub-sack of meat literally validates my existence. They improved my reality just by somehow crystalizing thoughts I hadn't even HAD yet. They have my thoughts FROM THE FUTURE, but improved. Entanglement? ESP? Nope. Just cultural persistence manifesting itself from nothing, the idea of ideas as fundamental attributes, inseparable from the whole.

[@ariochiv]

Any time a "scientist" talks about theories that assume the existence of other universes, my head feels like it wants to explode. I don't discount that such things might exist, but the proliferation of theories that seem to _assume_ that it must be the case (in the absence of any compelling evidence) drives me a little bit crazy... even as a non-scientist. As usual, Dr.H's attitudes reflect my own.

[@NomenNominandum]

One couldn't explain it better. Thanks.

[@Rydonittelo]

The universe was an inside job.
We are not in the universe, we ARE the universe. We are the same as everything else in the universe. But we are the universes ability to understand itself.

[@martenthornberg275]

The anthropic principle is often used to explain fine-tuning. Fine-tuning is often used to imply that there’s some sort of creator (aka god) and the anthropic principle gives a simple but unsatisfactory explanation. I suspect the controversy (if any) is coming from the more religiously inclined who doesn’t want there to be an explanation to fine-tuning.

[@gabrielmarlant6660]

In what the fact that the universe needs to have properties that allow our existence differ from the fact that the universe needs to have properties that allow the existences of anything else we observe, like atoms, strawberries, stars..? Why use a specific principle for the object "human"?

[@schmetterling4477]

It doesn't. One can easily refute the entire idea. There are approx. 20-ish physical constants for which we currently don't have a derivation from first principles. The genome of the land snail Candidula unifasciata is 1.29Gbp in size. One can obviously not generate an ordinary land snail from such a small number of parameters, hence they have absolutely nothing to do with the existence of snails. Does anybody want some garlic butter with that?

[@gabri41200]

It is not for the object "human", the anthropic principle is making reference to any object that can be considered intelligent enough to question it's own reality. Ironically he name "anthropic" reflects our own athropocentrism.

[@nathanboy9866]

I believe that everything is on a set 'timeline' and we discover things and evolve at a rate that has already been chosen. And I think the time in which we discover these answers happens way into the 'future'

[@reallyWyrd]

Ty for explaining about the weak anthropic principle and how it has pragmatic value in helping to shape science theory.
--
Up until now, whenever I heard someone say "the anthropic principle", they were just using to try to argue that god probably must exist or something.
--
P.S. I've nothing specifically against the god thing, but the anthropic argument, the strong one... doesn't really make a lot of sense. Douglas Adams had a good paragraph about a puddle about this.

[@darioinfini]

Not related at all...well partly maybe... I love Sabine's accent. In particular as a specific example of my appreciation of the general German accent. I note that certain accents rub me a certain way. German sounds cuttingly precise, the way you'd expect a high quality German automobile to be designed. Russian and Indian sound kind of comical to me, in different ways. The royal British accent of course sounds incredibly high brow, very polished, and upper society. Australian sounds amiable, down to earth, matter of fact, in a jovial way. Italian sounds happy and very excited. I could go on but I shant. Fuggedaboudit!

[@jimsmith6937]

I sometimes rewatch these to hear you say the word “hypothesis”. Somehow it is more interesting when you say it.

[@douadouard1009]

So basically if we exist, then the laws of nature must be so that they allow us to exist ?
I'm not sure how this is anthropic though.
In general if anything exist, doesn't that shows that the laws of nature must be so they allow that thing to exist ?

[@deluxeassortment]

To use an analogy, if I randomly toss a coin, I have a 0.5 probability that I will get heads. If I randomly toss a hundred times, I still have a 0.5 probability and thus end up with near 50 heads. If, however, I find some way to end up on heads every time, an observer might say that the probability is 7.889x10^-31 when I get a hundred heads in a row. Considering all of the "odds" that had to line up for humans to exist, it appears upon first glance that our odds of being here are diminishingly small.
The strong Anthropic principle would imply a goal-oriented cause of our existence, and thereby that the universe exists in its form soley that we can exist.
However, the weak Anthropic principle considers our existence to be a probability of 1 in our local time and space. Once all of the constants are explained, cyclical and multiverse models considered, along with localized variants of time and space, then our existence becomes much more likely without being unavoidable and goal-driven.

[@ivanfromunion3513]

"To use an analogy, if I randomly toss a coin, I have a 0.5 probability that I will get heads. If I randomly toss a hundred times, I still have a 0.5 probability and thus end up with near 50 heads"
Alkil Fuck Youle, the day you have a less odious screen name I may be willing to tell you where you time gagged. Your screen name is so obviously invented today that we even think your inferiority complex is that of someone, ANYONE, who works for the US gov, dahling. Put up or shut the fuck up.
My precious... Why don't you call yourself Hitler already, asshole? Want an answer? Show me two years of your internet comments. Show up with a documented internet history that is traceable instead of trying to show off your fucking 4 years of chemistry, ok? Or is it 3 years of US gov work, honey? Is that why you smell of pee?

[@TxCwby]

EVER INSIGHTFUL. THX!

[@moses777exodus]

The Cosmological Constant is tuned to a level of 1/10^120. By definition, "a statistical impossibility is a probability that is so low as to not be worthy of mentioning. Sometimes it is quoted as 1/10^50 although the cutoff is inherently arbitrary. Although not truly impossible the probability is low enough so as to not bear mention in a rational, reasonable argument." Therefore, in the fine-tuning argument, it would be more rational and reasonable to conclude that the multi-verse is not the correct answer.

[@bigblukiwi]

Surely the anthropic principle is a statement of the obvious - we are here observing the universe so the universe must have properties that allow the existence of observers.

[@eagle6702]

One problem is that creationists often use this claim to say that the laws of nature prove God. I've seen them do this in many groups.

[@ivanfromunion3513]

See my comment to Nick Nelson a few pages below. The Anthropic Principle is perfectly vicious to religion. And I have been a Kardekian Spiritualist for 44 years.

[@jamestheotherone742]

Like many rhetorical constructs, it can be a tool to support or detract from many different theories and ideologies.

[@Rauschgenerator]

Isn't there a greyish question that lies between the Anthropic Principle and Multiverses?
Because: I think we can agree that it is highly improbable that our universe is the only universe there ever was and ever will be and instantly got the laws of nature right to let us exist.
So there must be an underlying mechanic (or maybe pure random) that defines the laws of nature when a universe (or maybe parts of the only universe there is) comes into existance.
It's trivial to conclude that this is much more probable than only one try ever.
And now we have a look at what is even more probable: some kind of underlying mechanics that produce mechanics suitable for the existance of life that produce universes, or a simple underlying mechanic that produces universes?
For me it's the reason why I find the Inflaton field theories so convincing - they produce an unimaginable number of "universes" (or better: collapsing regions that are interpreted as universes) which also explains the Fermi paradoxon - something I found totally amazing and elegant when I read about it, because the number of civilizations who are the first to have a look at the universe is at any point in time an unimaginable number higher than the number of civilizations in universes who already met other civilizations.

[@dennisdonovan4837]

Concision derives (in principle) a simple unalienable fact - “I think … therefore … I am” (and so are you Sabine) … 😎

[@starfishsystems]

The AP is also a source of controversy outside of the points raised in this video - because it encourages claims which are properly outside of science as well. Sabine is probably right to consider these out of scope for rigorous review, but as they are socially important I think they deserve mention.
Such claims typically run along the lines of "... so the universe was made especially for us." This is the Strong AP taken one step further, a variant of the Watchmaker argument which attributes PURPOSE (or intention or even necessity) to the form of the universe, because its particular form is not likely to emerge at random. Purpose implies agency and so sets up an argument for a CREATOR. But several fallacies are entailed here.
First of course the claim is not falsifiable, so it's not a scientific claim, merely an interesting though probably idle speculation.
Second, the claim is based on an argument from incredulity, in that it supposes that being part of a rare random event is inconceivable, therefore impossible.
Third, it presumes the consequent. Religious claims so often have this quality that it sometimes goes unremarked. Here we have an unexplained phenomenon. The correct explanation is "we don't know." Not knowing is never a warrant to claim something AS true that you personally wish MIGHT be true.
The AP is intriguing in part because we can observe that the dice SEEM to be loaded in favor of our existence, but that is just because of our role as observers. The probability of this particular universe existing may be very small or it may not. But the conditional probability of it existing, given our existence as observers within it, is unity.

[@SimonSozzi7258]

Please explain photons. Do they carry electric signals? Radio signals? Are photons involved in magnetism? I thought all "particles" traveled at the speed of light. Why do they have to make particles travel "close" to the speed of light, in an accelerator? How fast to electrons go out of an electron gun? Do they experience time? If not then how do they make waves and interfere?

[@rtpfixit]

The lady simply states facts, and it's fascinating. Apply the scientific process properly and in theory the universe shall reveal itself around us. But we can't factor out our own existence. Xeno's Paradox pokes fun at the rational human with a child's math to logically prove the impossibly of getting from here to there, and yet, move about we do. Team Weak Anthropic FTW!

[@nathanielhellerstein5871]

Cogito:
Ergo sum:
Ergo carbon resonance.

[@connectingthesciences]

I have the proof that we only model reality and its inconsistency with the reality. I made some videos using physical laws to show how our biology works and how the modern assumptions are impossible without breaking just about every law. I explained how it would have to work based on physics what we know about biology and provided intuition based on how we experience life. I may take the time to make a better video that combines everything for convenience

[@will2see]

5:06 - There is no such thing as a Universe that is not hospitable to life. Why? Because we talk about something we call life, but we don't understand what it is, we don't understand what we are talking about because we haven't defined it. What is life in this context?

[@bluenetmarketing]

Non-living matter/energy = strictly ballistic movement based only on the laws of physics. Living matter/energy = self-determined "movement" separate from ballistic movement and separate from the laws of physics. There is interaction between the two, but both can exist without and separate from the other. One temporarily resides within the other, but does not require it, while the former directs and is separate from the latter. Not all properties of life are described within the latter. There are no multiverses, except in someone's imagination, like a shadow where there is no light. The absence of life does not mean life does not exist. The absence of matter/energy does mean matter/energy does not exist.

[@MatthewSuffidy]

It is genuinely odd that the Universe should exist with some innate structure that allows creatures to build reliable devices, on its own. Even if you are an Atheist, it is like either a collective will brought it into its form, I guess that would be the strong version, or it was almost predetermined like it was made by a God of some sort.

[@OldNavajoTricks]

Douglas Adams is back guys!
The universe only exists because of the universes existence, some have tried to argue that if it only exists because of the pre-existence of the universe, some other schools of thought like to hit these people over the head and get back to their ironing...
Either way, the universes existence has upset a lot of beings no end and is widely regarded as the most annoying thing ever.

[@jamesruscheinski8602]

Can the anthropic principle be used to say that the physical constants of nature will be consistent with human and biological life in universe?