The Raven Paradox
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- Опубликовано: 28 апр 2020
- The scientific method is only a few hundred years old. This continues to amaze me. It seems so obvious, now, that you should go and test your theories and, if necessary, revise them. But for much of human history, coming up with a “theory” was all about story-telling and sense-making, not about making quantitatively accurate predictions.
Then again, the scientific method is not set in stone. Scientists and philosophers both are still trying to understand just how to identify the best hypothesis or when to discard one. This is not as trivial as it sounds, and this difficulty is well illustrated by the Raven Paradox, put forward by the German philosopher Carl Gustav Hempel in the 1940s.
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Thank you Sabine...the raven got me almost raving, my morning had joy!
+Frank Childs You are in excellent company, aren't you?
Isso e muito Bom
@@wagnerfelix2100 Sabine, was weißt du über diese Exzellenzinitiative in Deutschland? Ist sie dort weiterhin "wirkmächtig"?..
Sabina,I have a question about our planet earth revolving in its own Axis.what is the science behind this phenomenon.what makes our planet to revolve in its own axis.is there any self own energy or a invisible motor to turn our earth in circle.we know the reason behind the revolution around the sun .what about rotation
The attached clip best describes the current state of the theoretical physics academic community. A MUST WATCH. ruclips.net/video/LFrdqQZ8FFc/видео.html
Just think about it, "and maybe confuse some other people with it." Your mischievous streak is a crucial part of your brilliance!
And the fact, at least in terms of facial expressions, and slight absence of other behavioural cues, it is almost impossible to know she has swept the rug from under your feet! It may be common for her people but some cultures would probably consider her a talking robot because of how expressive they are. Genius should have wit, mischief and a good sense of humour - life would be dull without physicists like Sabine!
But not particularly helpful. Those who seek to work in science would be wise to realize that the days of the lone scientist laboring away in solitude are long gone. Today we work collaboratively. The last thing you want to do is frustrate your colleagues or be mischievous or otherwise be a contentious person. There will be a time when dissent is important to you, it's better to be seen as consensus builder in preparation for that day.
I suspect that Sabine's approach in her lab is quite different than her video conduct portends.
@@PolaOpposite - well well mr. Rumpled Foreskin, the composition of the research group is of no matter. The only thing that matters is the results you bring. I.e. are you making scientific headway or not. Steven Hawking did not work in much of a group. He is not the only example.
As for Sabine, she strikes me as an exceptionally intelligent scientist having fun on RUclips while teaching us something along the way. If she displays some zense ov yoomer alonk ze vay ;-) nothing wrong with that.
@@ittaiklein8541 Don't obsess over my naughty parts. It's no way to live your life.
@Rumpled Trumpskin wtf are you talking about?
I was talking about Sabine's exemplary performance, and nothing else. I may have been poking a bit of fun at some silly sobriquet some people choose for themselves, but that's entirely besides the point & concerns me not.
Thank you for that. I read Hempel's book "The Philosophy of Natural Science" about 40 years ago. It is a slim volume that is a great introduction to fact that the process of acquiring knowledge is by no means simple. The Raven Paradox is a good example of this. Again, I was delighted that you presented the topic and I look forward to seeing you next week.
This was one of my favourite videos of yours thus far. I love the topic of critical thinking and skepticism (the science based kind not the science denying kind). This apparent paradox and the solution has got me thinking. Thanks.
You fascinate me, both the breadth and depth of your knowledge of physics but also the way you fold this knowledge into an artistic/creative side. To me you seem to be a fully self-actualized person. Thank you for sharing your mind with us. I swoon at your ruminations.
thanks very much for taking the time to explain so well all these things of science. I'm always excited to see a new video from you.
Happy to hear you find my videos useful!
@@SabineHossenfelder I have three questions about the Big Bang that created the universe and correspondence Ads / CFT
These three questions relate to correspondence as well as the membranes theory of M-theory
Can correspondence be combined with the membranes theory?
second question
Will merging correspondence with membranes provide an explanation of the emergence of supersymmetry ?
The third question
Are these correspondences able to explain the emergence of primary plasma in the membranes theory?
We hope that you will develop the M-theory through correct mathematical equations in order to explain the super-symmetry and the initial plasma (quarks and gluons in the time of the Big Bang)
Please communicate these three questions, as well as suggestions, to physicists
I finally tumbled to your RUclips channel from the Physics World podcast. I have been reading you for years and wish to thank you for your work, and for challenging oneself to critically examine one's assumptions.
The Sabine Paradox: Such complex subjects, yet so clearly explained
Pfftt. Takes very little to amaze you, eh?
Sabine's paradox causes ambivalences.
To be clear, is the Sabine Paradox a mathemathical hypothethith?
Pfff.... guys please....The only thing this Raven Paradox shows is that the majority of scientists can't think straight. The correct answer is that the sighting of a red bus or a green apple proves that neither the bus or the apple is a raven. By saying all ravens are black, you have simply connected an attribute to a class as being a truth (whether positively or negatively stated does not matter), which has the ONLY logical consequence that the sighting of something (bus, apple) that does not carry that attribute, only means the object in question can't be of the same class (raven). Syntax wise, It has NOTHING to do with proving the statement 'all ravens are black' . If even our top scientists can't think straight anymore than God help us all....Let the bloody Raven just eat the Apple and get run over by a Bus......
@@christiancabrera9495 Astro-Physics Community (with 12,541 likes) has now given the following three writings the thumbs up. TOTAL PERFECTION:
E=MC2 AS F=MA CLEARLY PROVES (ON BALANCE) WHY AND HOW THE PROPER AND FULL UNDERSTANDING OF TIME (AND TIME DILATION) UNIVERSALLY ESTABLISHES THE FACT THAT ELECTROMAGNETISM/ENERGY IS GRAVITY:
A PHOTON may be placed at the center of what is THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the speed of light; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Indeed, the stars AND PLANETS are POINTS in the night sky. E=mc2 IS F=ma. Gravity IS ELECTROMAGNETISM/energy. Time DILATION ULTIMATELY proves ON BALANCE that ELECTROMAGNETISM/energy is GRAVITY, AS E=mc2 IS F=ma. Indeed, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=MC2 IS F=MA. Great. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma. (Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black.) BALANCE and completeness go hand in hand. It ALL CLEARLY makes perfect sense. I have mathematically unified physics/physical experience, as I have CLEARLY proven that E=mc2 IS F=ma in what is a truly universal and BALANCED fashion.
By Frank DiMeglio
Mr. Boris Stoyanov is a super bright and an HONEST physicist. He has agreed that the following post is "crystal clear":
ELECTROMAGNETISM/energy is gravity. This is proven by F=ma AND E=mc2. Accordingly, gravity/acceleration involves balanced inertia/inertial resistance; as ELECTROMAGNETISM/energy is gravity. "Mass"/energy involves balanced inertia/inertial resistance consistent with/as what is balanced ELECTROMAGNETIC/GRAVITATIONAL force/energy, as electromagnetism/energy is gravity. Gravity IS electromagnetism/energy. That objects fall at the same rate (neglecting air resistance, of course) PROVES that ELECTROMAGNETISM/energy is gravity. Think about it.
By Frank DiMeglio
THE SIMPLE, PROPER, FULL, AND BALANCED UNDERSTANDING OF THE SHAPE, FORM, AND RELATIONAL MOTION OF WHAT IS THE MOON IN UNIVERSAL ACCORDANCE WITH THE FACT THAT E=MC2 IS F=MA:
What is THE MOON is moving AND not moving IN BALANCED RELATION to the Earth AND the Sun AS a linked AND BALANCED opposite in accordance with the UNIVERSAL fact that E=mc2 IS F=ma. THEREFORE, the rotation of WHAT IS THE MOON necessarily matches it's revolution; AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the shape AND form of the Moon is basically constant or invariant. The Moon is a BALANCED MIDDLE DISTANCE manifestation or form that is in fundamental accordance with the Earth/Sun BALANCE pursuant to the fact that E=mc2 IS F=ma. GREAT !!! Therefore, the Moon is electromagnetically/gravitationally extended AND contracted ON BALANCE in true agreement with the fact that E=mc2 IS F=ma. Gravitational force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. It ALL CLEARLY makes perfect sense. Gravity IS ELECTROMAGNETISM/energy.
By Frank DiMeglio
Your sense of humor shines in this presentation! Thank you!
Sabine your videos are very thought provoking. You are a charming presenter. I like watching them very much. Keep up the good work.
Sabine you are a superb communicator - thanks for all your excellent content.
I'm not a scientist. But it seems to me, the "paradox" is being manufactured (by false logic)? There would be no paradox, if the person wasn't engaging in false logic. Or at least, that's the impression I get.
please show specifics. your claim is vague
Thanks for upload, i really enjoy these videos.
I'm really enjoying your videos Sabine.
Your videos are so informative! Thank you!
Your science video series is easily among the best on RUclips thank you.
Mrs. Hossenfelder, I was talking about this yesterday! You’re amazing!
This channel is delightful!
Thanks again for your unique video's!
More on formal bayesian inference would be very useful! Many outside physics need to understand these concepts
Love your vids. Thanks for keeping me curious.
You definitely inspire me to something .. Sabine.
I love how you look direct into the camera and never smile once.
german.
Slowly working my way through your great videos. Love how you explain the unexplainable. Cheers from Canada👍😎🏹🇨🇦
I love philosophy of science, great video! I'd be very curious to hear what you think about Popper's demarcation criterion.
Sabine, you are terrific! Would you consider devoting an episode to the topic of resonance? Having been a patent lawyer for almost 30 years in the wonderful field of photonics, the concept of resonance and resonate frequencies has had a domineering impact on significant scientific discoveries. Thanks.
Your videos make me happy.
That pink panther passing by definitely supports the hypothesis!
That is inspiring. I enjoyed that lesson. Thank you!
Excellent video -- short and interesting.
Thank you. Very interesting talk!
it is so cool that you have a physics chanel, but also talk about psychology and philosophy!
That was really well done!
"This is bunch of nonsense," concluded the albino raven, having watched this video.
Found the non-black item that is not a non-raven!
@@davidwuhrer6704 Astro-Physics Community (with 12,541 likes) has now given the following three writings the thumbs up. TOTAL PERFECTION:
E=MC2 AS F=MA CLEARLY PROVES (ON BALANCE) WHY AND HOW THE PROPER AND FULL UNDERSTANDING OF TIME (AND TIME DILATION) UNIVERSALLY ESTABLISHES THE FACT THAT ELECTROMAGNETISM/ENERGY IS GRAVITY:
A PHOTON may be placed at the center of what is THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the speed of light; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Indeed, the stars AND PLANETS are POINTS in the night sky. E=mc2 IS F=ma. Gravity IS ELECTROMAGNETISM/energy. Time DILATION ULTIMATELY proves ON BALANCE that ELECTROMAGNETISM/energy is GRAVITY, AS E=mc2 IS F=ma. Indeed, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=MC2 IS F=MA. Great. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma. (Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black.) BALANCE and completeness go hand in hand. It ALL CLEARLY makes perfect sense. I have mathematically unified physics/physical experience, as I have CLEARLY proven that E=mc2 IS F=ma in what is a truly universal and BALANCED fashion.
By Frank DiMeglio
Mr. Boris Stoyanov is a super bright and an HONEST physicist. He has agreed that the following post is "crystal clear":
ELECTROMAGNETISM/energy is gravity. This is proven by F=ma AND E=mc2. Accordingly, gravity/acceleration involves balanced inertia/inertial resistance; as ELECTROMAGNETISM/energy is gravity. "Mass"/energy involves balanced inertia/inertial resistance consistent with/as what is balanced ELECTROMAGNETIC/GRAVITATIONAL force/energy, as electromagnetism/energy is gravity. Gravity IS electromagnetism/energy. That objects fall at the same rate (neglecting air resistance, of course) PROVES that ELECTROMAGNETISM/energy is gravity. Think about it.
By Frank DiMeglio
THE SIMPLE, PROPER, FULL, AND BALANCED UNDERSTANDING OF THE SHAPE, FORM, AND RELATIONAL MOTION OF WHAT IS THE MOON IN UNIVERSAL ACCORDANCE WITH THE FACT THAT E=MC2 IS F=MA:
What is THE MOON is moving AND not moving IN BALANCED RELATION to the Earth AND the Sun AS a linked AND BALANCED opposite in accordance with the UNIVERSAL fact that E=mc2 IS F=ma. THEREFORE, the rotation of WHAT IS THE MOON necessarily matches it's revolution; AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the shape AND form of the Moon is basically constant or invariant. The Moon is a BALANCED MIDDLE DISTANCE manifestation or form that is in fundamental accordance with the Earth/Sun BALANCE pursuant to the fact that E=mc2 IS F=ma. GREAT !!! Therefore, the Moon is electromagnetically/gravitationally extended AND contracted ON BALANCE in true agreement with the fact that E=mc2 IS F=ma. Gravitational force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. It ALL CLEARLY makes perfect sense. Gravity IS ELECTROMAGNETISM/energy.
By Frank DiMeglio
Hossenfelder is not a genius. She's political. She's lying about physics.
For those interested in what Frank is talking about, here's a video picking apart the pill he's swallowed: ruclips.net/video/T9q-v4lBGuw/видео.html
Tell u what ..i cant understand why there is so MANY MANY people that dont think with logic...but are just ignorant and REALLY stupid🤣🤣🤣common sense people common sense❤❤❤open your mind to other possibolities.
i love the way you say the word "Hypothesis" lol, great videos, thanks.
Even explaining a confusing paradox you still seem to explain things so clearly
Thanks for the great video. Could you please do one about the recent discovery where the universe is not the same everywhere? Thanks again
This is a great explanation of the paradox! I also love to puzzle people with it :)
nevermore!
Ha 😀
T'was the wind, and nothing more.
waka waka waka wak
Now that’s a hypoethesis.
What about Schrodinger's raven,it's black and not black at the same time..
Really really REALLY tiny ravens exhibit this phenomenon.
But barely there.......Where?
Thank you for refuting this paradox, it's bothered me for years.
I can finally understand episode 3 of umineko
I enjoyed that, thanks ah lot miss.
This may well be your most important video! BTW, I'm from Ireland an grew up with crows who had grey heads (merely relabelling them as crows but not ravens doesn't solve anything!) I like Bayesianism, bit have to confess that it is a religion sometimes - based on your belief of a prior distribution - the mechanism for updating your beliefs is the key algorithm . Faith (sorry to use religious terms again) in scientific method is basically a belief that updating your knowledge based on empirical evidence leads to a convergence to an ultimate answer - a more useful and relaxed view is an iterative process that it leads to a more comprehensive and simpler model. What is nice is that we sometimes have to row back and reconsider older theories, dismissed long ago, as having some new insight!
I just love her clear descriptions.
I'm definitely gonna use this in a way to proof to my employer that I deserve a substantial raise
But, counting daisies when studying ravens seems pretty unproductive.
Fire that biologist.
@@a.randomjack6661 That is the nice one on the formulation: If it is not black, it is no raven. So what you found mighr in all other properties perfectly matching with what is called a raven, but missing that color property and using that definition it is no raven.
Andreas Krause I learned long ago, there is always exception to the rule.
Oxeye daisies are an invasive species in many countries. if you live in Europe, at least parts of Europe, they may be a very pretty flower, but in North America, especially the Rocky Mountains, oxeye daisies are a noxious weed that choke out beautiful mountain flowers - pretty is relative!
Ralph Stewart Always? Or are there also exceptions to the rule that there are always exception to the rule?
Lovely. Absolutely endearing maam.
Good video..... and I glad you wear the same cloth of last week... I was just starting to wonder... how large is your closet ????
This was fun, a twist for us. I have someone in mind to bother. While fun to listen to, it is quite provocative especially the discussion of Bayesian Inference - where does one get all those priors anyway? Vielen dank, SH.
I wish she was a friend in my life- she is so knowledgeable.
Sabrine you are amazing... Much love from morocco
Sabine, you illustrate the point beautifully, being a non-black non-raven. yourself! Wonderful graphics. That raven managed to look both cuddly and optimistic. Unusual, in a Raven! thanks for the presentation,as usual.
Dr Hossenfelder is one of very few professional physicists with a youtube channel. Please keep going!
I wish you would do a second video on how mathematics and quantification can bring a much greater degree of clarity, precision, and power, at least in some cases.
It can help in bringing the Raven Paradox into sharper focus, especially when combined with the linguistic aspect.
Thanks for the confusion 😁
'A million experiments can't prove relativity correct, but it only requires one experiment to disprove it.' AE.
What about dark ravens, is it logical to say that they are here even though we haven't detected them
And, are dark ravens Black?
COVIMPS?
Thank you for this.
Best explanation of the raven paradox I’ve heard.
Hallo Sabine,
many thanks for your videos. May can ask a question that way?
If we see gravity how it works and we calculate out of the theory of relativity that at a critical mass all movement, also light, stops could we predict that the moment we measure is a temporary constallation of energy in states which is not disappearing but only elsewhere in space? If the fundamental force of the universe is C=0 it could say the measurement we have with the big bang is a consequence of one massive black whole falling into another. Because the space time is in a maximum curve the event happens again and again and all constellations within it. We only measure a movement because we are a part of this.
Have fun thinking into it.
When I was taking a Logic class there was a chapter on Indian Logic and the instructor had a question about “a white horse” ... i tore into it so many ways and pondered that I cannot put the question back together and here comes a Raven.
Thanks Sabine.
Do we prefer theories which have accurate blackometers and ravenometers ?
I think it is highly preferable, if possible.
Theories which don't and suggest no such instruments can exist are.... tricky.
Keep exploring, keep theorising.
1:25 In case anyone wonders, these are "logically equivalent" due to _modus tollens_ ; this, however, is not equivalent to introducing _the same_ empirical proposition, because those regard the _predicates_ (in this case, blackness) of given _objects_ (in this case ravens). So, in order to establish the truth of the "all ravens are black" statement empirically, we must examine the _predicates_ of sample objects (i.e., pick up lotsa ravens and see if they're black), rather than sample objects from a pool of known predicates. Simple as that.
I feel lucky that I'm not "smart" enough to be confused by this sort of logical pretzel. For me, the really stupid part is that the moment they found a few white ravens, they would simply add "except when they are not" to the original corollary, so what is the point of overthinking it anyway?
exactly. We need to focus on the question of ravens, not the infinite universe of non-ravens which has no direct bearing to the object in question.
@@caricue the problem is. if you define all ravens as black you will never find a white raven.
Modus tollens and black swans are the current rage in the flat earth playpen.
I'm ashamed to admit I know that bit of useless trivia.
Here's another bit of trivia that will never bring home a pay raise - modus tollens comes from the Latin for "mood that denies." How appropriate for flat earthers to hang their hats on denial.
@Hilmar Zonneveld not B not not be
"nothing is as trivial as it sounds" - hypothesis destroyed
Some cosmological arguments I've seen suddenly make a lot more sense now.
I think it would be really interesting if you did an episode covering Thomas Kuhn and the Structure of Scientific Revolutions.
In defining a raven, you’d need to take a population of ravens and a set of attributes and log them all. If a pink raven shows up, you can then ask is that a raven.. Logic is dependent on framing, the component of awareness that decides what is relevant. Somebody still has to pick the attributes.
I am wondering, does the raven paradox example show how a correct theory can be also incomplete? Without an explanation regarding the pigment in the feathers having a molecular structure with resonant frequency that emitted photons appear black, then the theory is correct but incomplete since there is an underlying more generalized theory, that all feathers that resonate black color photons are black feathers.
Don't over think it. That would be serendipity. The raven paradox is about the logical fallacy of using a null hypothesis to prove a theory.
Very good thanks.
i think this is the first time i've ever heard someone mention baesian statistics along with this paradox, and at this point it makes very intuitive sense as a story of information. I require no further experimentation or testing, and shall pass this on as absolute fact.
Consider this:
If the information gathered by observing non-black non-ravens actually gave any evidence to support the hypothesis, then it would even do so regardless of the wether the hypothesis was actually true or not. Substitute ravens with doves in the example, and all of a sudden all non-black non-doves that you encounter are becoming evidence for the hypothesis that all doves are black.
Similarly, all non-white non-ravens would become evidence that all ravens are white. So you would even gather contradicting information by every object you encounter. Say you see a green apple. It is by this logic evidence for the the hypothesis that all ravens are black as well as for the hypothesis that all ravens are white.
I think there is a logical fallacy at play here and it has to do with probabilities:
If you encounter anything at all, there is already a much higher chance for it to be a non-raven than a raven (the actual likelihood can even be empirically determined). So if you encounter an object and it is not black you could already with the previously determined likelihood assume that the object is not a raven. So if you then observe the fact that it actually isn't one, you have gained almost no information, because you were already almost certain of this fact anyways.
What's more: If you encounter something randomly than you can also be pretty certain that it is not black, because most things aren't black. Again: observing that it is in fact not black then gave you almost no new information.
Finally: The paradox seems to assume that the objects you encounter are being picked randomly depending on their color. You can not pick something at random depending on its color in the real world though. This only works in a theoretical thought experiment where you can pick randomly anything at will. In the real world there is no way to encounter an object and make that encounter only be determined by its color. That is because an objects color in general is being highly dependent on its nature and not so much other way around.
Therefore I would say: The "paradox" actually isn't one. It is only paradoxical if you assign false likelihoods of your observations.
A truly randomly by its color selected object will actually give you the information as described. But that is simply just not how we encounter objects.
This maybe even comes down to how language works: We give names to objects based on their properties. So encountering any object AND categorizing it to be of a specific kind, means that we have already noticed its properties, particular its color in this case, and used that to determine, what that object even is. Maybe, if you encountered a white raven, you might even categorize it to be a different bird just based on its color property, so off course your very definition of what a raven even is determines what a non-raven is, based also on its color.
A more rigourous hypothesis might hold up more strongly, but ultimately I must assume that there are no truly well-defined hypotheses of the kind: "All X are Y" since no physical object can be described so precisely by any language that it allows for all encountered objects to be determined to be an instance of X. That would require infinite precision since there are infinitely many different objects to encounter.
I shall therefore conclude:
Definitions, definitions
Ravens, black, as seen before
Confidence in our positions
Gave green apples nevermore
I think the issue is conflating ‘logic’ with ‘reality’. Logic deals in tautologies, where everything is assigned a probability of zero or one. That is, 100% true or false.
Science is empirical, and deals with degrees of certainty. In science, no hypothesis obtains a 100% (or 0%) certainty.
The original statement ‘all ravens are black’ is not a scientific statement, but a logical one. The scientific version of the statement would be ‘there is a 99.99999% chance all ravens are black’.
Thus, inverting this statement, does not lead to the certain conclusion that all non-black things are non-ravens.
Instead, it leads to ‘there is a 99.999999% chance that all non black things are not ravens’.
It is those tiny 0.000001% gaps that given wiggle room to allow new evidence to adjust degrees of confidence.
In logic, you are stuck with 100% or 0%, no wiggle room, and hence paradoxes.
I think your assertion that ‘all non-white non ravens’ is evidence that ‘all ravens are white’ is not completely thought through. This is because it fails to take into account the ‘prior’ probability - in other words, the existing degree of confidence that all ravens are white. This number is very low (assuming we have only ever seen black ones) so seeing non-white non-ravens does not add much in the way of evidence towards the conclusion all ravens are white. It is likely it adds more to the conclusion all ravens are black, thus while you could argue it increases the likelihood of white ravens, this is outweighed by the amount in increases the likelihood they are black, because the prior for black is larger than the prior for white.
I have a black 4 legged creature in my house that meows a lot, is it a Raven.
Keep up the good work.
"all ravens are black" does not mean "all black things are ravens"
In this case, the raven is inside the cat AND it is probably dead.
It is an interesting question. That is, does something that is not a raven, but is black, support the hypotheses or impugn it? I have the question in my head, but haven't yet arrived at the answer.
I smiled every time Sabine said Hypothesis, at least every time she attempted to. :)
The syllogism have been formulated by ancient greeks , i find the Raven paradox not well making sense or centering what you wanted to say or maybe it was just not argumented well Who is the story writer of this episode ?? Anyway i love all other episodes and you
But, black with a yellow beak is a blackbird and not a raven …;-)
See? You're illustrating perfectly why the paradox works and can be a trap. And why the paradox supports the experimental method as the major engine for modern science.
Why? Because not all black birds with yellow beaks are blackbirds either. Alpine choughs are crow-sized black birds with yellow beaks.
Just like the raven paradox cannot be construed to say that all black birds are ravens.
@@raminagrobis6112 Exactly…;-)
Only the feathers are black, have to pluck off the feathers to see the true color
Or was it a gorilla in disguise on the way to a basketball match?
Okay Holger, I knew a fellow bird nerd would point that out. However, I'm sure you know that not all blackbirds have yellow beaks either. 😉
It seems to me that this is really about necessity vs. sufficiency. Also, the original form is trivially falsifiable, while the second form is not.
This reminds me of the balloonist asking a groundling "where am I", to which the groundling replies, "you're about 40 feet in the air." This is true but not useful.
How come the second form is not falsifiable? If you see something non-black which is raven it would contradict the hypothesis "all non-black things are not ravens."
Also, the neccessity vs sufficiency in this context is not relevant: both claims are logically equivalent, thus necessarily must hold simultaneously if one of them is true.
@@tetraedri_1834 but "all non-black things are not Ravens" does not necessarily mean "all black things are Ravens."
The raven statements are actually an example of a logical fallacy in philosophy. Another example is "All cats die, Socrates is dead, therefore Socrates is a cat."
Gary Bickford Correct, “all non black things are not ravens” doesn’t say anything about black things, it says something about ravens. It’s equivalent to “all ravens are black”.
Damo No that’s incorrect, “all cats die” only says something about cats, not about things that die.
I was "introduced" to the raven paradox a long time ago, when I was a student, reading a pleasant book written by Martin Gardner (I just know the title in french : "La magie des paradoxes"). This paradox made me think a lot, and I still remember my own opinion about it : if you find something which isn't a raven and isn't black, it confirms partially your statement (all raven are black), but so few... because, as you explain, there are far more things like that than there are ravens. But it only works in a finite universe : if it is infinite, with a finite number of ravens, then any none black none raven thing doesn't contribute to the result (because any finite ensemble of these things is nothing, compared to infinite). In a finite universe, to explain how a green apple helps to believe that all raven are black, you could say : "It helps, because when you remove that apple from the universe, there is now less matter to built something different than a black ravens, when at the same time, the number of black ravens remains unchanged".
Sorry if it's not that clear, my English sucks...
It's clear (= therefore not a raven!😁).
Interesting: I asked ChatGPD whether this is really a Paradox. And the answer was like I assumed: No it is not a Paradox. It is a suggestion of what to take care about hypothesises.
Ouch, my head! very enjoyable and funny.
When will you interview Prof. Wendy Freedman? Her new method of measuring the Hubble constant is very important.
It's actually sleight of hand. As soon as a thing is a bus, it tells us nothing about ravens. The fact that it's red is not the reason it isn't a raven. If it were a raven in all other respects, we would expand our category "raven" to include red ones (a new species, or one that fell in paint, one that's blushing etc). The non-ravenness of the bus derives from its being a bus, man-made, not a living thing, made of metal etc. This is easier to grasp if you stay closer to home, with say a swan or even a crow. Crows *are* black, and they are very similar to ravens. But they are not ravens. The reasons are points of specific anatomical detail. The "paradox" is really an instance of A and not-A classification and it shows the error of that approach.
Consider also that using the example of real ravens in the real world, we know that the caveat “usually” is in there: “Ravens are *usually* black.” We know there are exceptions, individual ravens are occasionally white not black, but a bird that is in all other regards a raven isn’t excluded from being labeled a raven just because it isn’t black (though we might be careful to label it a “white raven”)
At the risk of being oversimplistic, set theory would say that, within the universal set of all things, there is a subset of all things black. And within that subset would be the set of all ravens. It is obvious that the complement of ravens is not the same as the complement of all things black.
As far as I can see there's no paradox in the given example. Mismatching elements of different sets invalidates the logic.
Agreed.
"All snarfeglugerins are black"
Then we know that a red bus or a green apple can not be a snarfeglugerin, but a black bus or black apple may be, for some value of "snarfeglugerin". She and Carl use previously acquired knowledge that seems to be "commonplace" to make their arguments, and then try to apply this "science is settled" arguing from authority tactic far beyond the domain of what is "common knowledge".
She is more of an activist than a physicist.
Consider the Riemann Hypothesis. It's not enough to calculate more and more non-trivial zeros of the zeta function (verifying that all have a real part equal to one half) to conclude that the RH is true. Either you find a non-trivial zero whose real part is not one half (disproving the RH) or you prove that having a real part of one half is a necessary condition for a non-trivial zero. It's obvious also that you can't conclude a thing about the RH by checking the real part of the zeros of ANY other function.
The paradox is an example of a logically fallacy as defined in philosophy. My favorite example I use all the time to help clarify is " All cats die, Socrates is dead, therefore Socrates was a cat"
@@steak8278 But we are not claiming that "all ravens are black" because we have inspected some other objects non black non raven. We are claiming though that it is more likely that "all ravens are black" because we have inspected these non black non raven. One white raven will break the statement for sure, but what is actually surprising is that a green apple is endorsing it, even if the statement is not about green apples. You could use the original enunciation "If x is a raven, x is black". We are vacuosly entitled to say so even if x is an apple and x is green.
@@steak8278 You seem to be astray. Nobody is disputing that it is an actual paradox, the name comes from its counterintuitive conclusion, as pointed in the video. How does information about green apples can help us claim that all ravens are black? Sounds nonsensical. But it happens that our first order logic allows it. Logic was supposed to ground scientific thinking. So how come?
hahahahah, "you may confuse some one with it"
Confusing people is fun! One can virtually see the gears in their minds turning.
@@ZardoDhieldor Yes, it is
My favorite youtuber.
And that is why every scientific work starts with describing the boundaries of your study.
I find a simpler way to state a solution is this:
The statement "All raven's are black" makes a truth claim not about a single raven, but the single entity "all ravens", i.e. the set of all ravens.
The only evidence that can support or refute this claim is therefore observations of the set of all ravens, i.e. observing every raven at once.
It is for this reason that neither the observation of a black raven nor of a non-black non-raven provides evidence to the initial claim.
Thus, the problem with our intuition is that the observation of a single black raven tells us nothing about all ravens, not the reverse.
Bayesian inference. Personal subjective probabilities based on updating prior probabilities. The classical scientific method is based on objective (shared) probabilities. But objective probability uses assumptions which are justified by Bayesian inference. Hemkel's paradox is a Bayesian question because it is based on assigning a probability to a general logical statement. Objective probability is only valid in an event model. This allows us to share common priors for the situation in question.
Reminds me of the hypothesis that since a disinfectant such as bleach will kill a virus, it makes sense to inject disinfectants as a cure for a virus infection. Did we recently see the raven paradox in action? It does explain why some people will seriously consider nonsense over sense. There is however a flip-side, where our biases obscure perfectly valid evidence or hypotheses from view, that definitely does happen, probably a lot more than we think.
Interesting that Numberphile recently published a problem, "Lewis Carroll's Pillow Problem", which is an example of an anti-Raven Paradox, since it is working with the smallest possible sample numbers, with which the Raven Paradox can not be "effective". But if we would increase the elements in the sample (I mean the number of red balls) it would lead to the Raven paradox.
Very good
Nice ending :)
In this case I think the problem was associating one quality with a thing, when that quality is not necessarily specifically related to it.
So what are the Bayesian update calculations?
What about black none ravens? Evidence for or against the hypothesis?
And this is why we have peer review...
Another paradoxical construct :)
the word all assumes perfect knowledge that can be used in Deduction , when in actuality you are making an Inductive argument. you only know the color of crows you have seen. it seems not scientific to make the claim using the term "all" with out adding " that i have seen" as a qualifier since Science is based on Observation.
Ravens not crows
Science is always inductive reasoning. But hypotheses can be deducted from other hypotheses. If the observation disproves the conclusion, it also disproves at least one of the the premises.
The hypothesis is "all ravens are black". Disproving this only requires the existence of one non-black raven. If you don't have one of those, the hypothesis is neither confirmed nor refuted, but if you come up with one, it's probably not a raven, but a misidentified grackle.
Correct! “All atoms consist of only one proton” - I can give innumerable examples- none of them are even a scintilla of evidence until further proven statements are made about my hypothesis or my data. Otherwise, your evidence is exactly zero.
Yes. I was also thinking crows when Sabine was talking ravens. Probably because my local park has numerous crows. Strangely enough one of them is grey in colour.
I think a easy way to understand this paradox is:
There are only two ways to *prove* the statement. One is to check every member of the set of ravens. The other is to check every member of the set of "not black." Progress towards a proof clearly progresses each time you check a member(object) from either set, but it also clearly depends on the size of the respective set. Given only the logic statement, there is no way to know the relative size of the sets, but we bring outside info into the equation which is why our intuition does better. While most paradoxes are structured to trick our intuition into giving a wrong answer, this one does the opposite; it deprives the hard logic of the necessary postulates to give a meaningful answer.