Q&A - What We Cannot Know - with Marcus du Sautoy

Is there a distinction between something that doesn't exist and something we don't know? Is there a limit to what science can tell use? Marcus du Sautoy answers questions from the audience after his talk.

Is it possible that we will one day know everything? Or are there fields of research that will always lie beyond the bounds of human comprehension? Former Christmas Lecturer Marcus du Sautoy will lead us on a thought-provoking expedition to the furthest reaches of modern science.

Marcus du Sautoy is a mathematician and popular science writer and speaker. He delivered the 2006 CHRISTMAS LECTURES on mathematics, titled THE NUM8ER MY5TERIES. He is currently the Charles Simonyi Professor for the Public Understanding of Science at the Oxford University.

This talk and Q&A was filmed at the Ri on 13 October 2016.

[brettlunden]

A delightful presentation. I wish I had his energy and enthusiasm.

[ossiebird]

Marcus du Sautoy, what a fantastic scientific presenter!!

[FistroMan]

This talk, is like the Rohirrim's King speach before the great battle!

"We must think there is nothing we can' t know"... is like when he scream "Death! Death!".
Scientist must scream "Frustation! Frustation!" because is the way to the victory, to the knowledge.

Thanks for your talking. So epic...

[ahmedabdellatif]

I think this guy is an excellent speaker and what is great about him is that he doesn't give final or definite answers which is generally a good start to answering questions

[CortezHoratio]

Big fan of Marcus du Sautoy and his style. Thanks for uploading!

[RobertSmith-pwio]

He is always incredible in his viewpoints and examples as to astound me!

[AvocaSingleTrack]

@6:37 This is the question I waited to hear him address. He kind of side skirted the question and talked about senses...but the questioner mentioned his dog, which has the same 5 senses we do...but it will never comprehend quantum mechanics. Either way this is a great talk. Thanks for uploading them !

[neilanderson]

At 6:13 he talks about Descartes' famous axiom, "I think, therefore I am" ... I've never fully believed in the importance of that notion because, to me, it seems to boil down to nothing more than something like this: "I think I am" ...
We might all be figments of the imagination of some "higher" being ... until he or she wakes up and remarks to himself, wow, that was a weird dream.

[phyllisstewart]

Superb presentation. Will have to buy your book.

[nothke]

Professor Quirrell was very cheerful indeed until he got possessed by Voldemort

[dhireshyadav]

Everyone and everything (to the level of fundamental particles and whatever comes in the fundamental hierarchy to the very Nature and nature of Nature) is conscious in their own way.

[Krovald]

To 'Define' comes from the French 'De Fine': to end. We end further inquiry into the subject at hand by stating a definition, like a barrier let down on a dark forest path. We choose not to investigate further as the depth of each path is unending and we need a limited concept in order to be able to converse. The word 'Table' describes a couple of billion phisical objects in this world, none of which is equal to another of the sort (let alone the digital This is true for all words. They are rough approximations of a (rather ill-defined) concept we have in mind. Hence I feel we know nothing in absolute detail and our whole world view is perhaps best described with the probability-matrices used in Quantum Mechanics, the 'I' itself included. We can only know for certain by cutting The only reason math seems to be excluded from this and has this inherent logic, may well be because it springs solely from our minds and has no basis in the world outside (no matter how well it seems to fit the outside; We the mathmaticians are also the fitters). Apparently (I am not an educated mathmatician) there exists a whole realm of non-euclidian maths which is completely self-consistent yet fits less well to the world in most circumstances. However, in some circumstances this math works better than euclidian It is, so I find, the human mind.., or better: the 'I',   that is addicted to the definement of the outside in order to protect its Self from danger. "I think ...", "I find ..."; these support the Self in its search for validation. I am doing it right here and I love the tingly eureka feeling I generate with To paraphrase both Decartes and Jesus: The only truth is "I"; and hence the only religion is Solipsism. I am God and so are You.

[rhYT]

More familiarization with Kant's "Critique of Pure Reason" might be helpful in discussions such as this. Kant had demoted Reason to a faculty of the brain/mind, fairly well describing what Reasoning does, it's grounds and limitations, and what it can't do. One major point he made was that Reasoning is fated to be bounded within 3D+TIme (1D and 2D are covered under 3D). The surety that a Reasoned explanation gives to us is a kind of feeling that only arises if the explanation makes sense in 3D+Time. Another major point was that Reasoning can only operate on attributes....meaning something that is different from something else, so for instance, two totally identical objects, identical even in space and time, would be the same and non distinct. He also cited math axioms as being "apriori", suggesting they might be absolute and non-subjective in some way, but they also might be limitations of Reasoning, requirind that Reasoned explanations not violate the axioms, which themselves might be biological oddities embedded in the brain/mind, which play a role in defining and limiting Reason.

As a major conclusion, Kant said that all Reasoned explanations will have the same form regardless of the empirical data fit to those forms as none other is possible, and so the laws of physics are not "out there", . but in the brain/mind. Some of what is in the brain/mind may, by coincidence, get it right about what is out there....but unfortunately, we don't have a way to check on Reason to see how right or limited it really is. Kant claimed Reasoning will, by it's very nature, always seek to provide a deterministic explanation of everything, then consider itself correct, though it can do no other. Friedrich Nietszche took that a step further, citing vanity and as prior to and thus part of Reasoning. He also considered Reasoning to be a human substitute for lack of the fangs and claws (etc) of beasts.

It would be an amazing coincidence indeed if Reasoning turned out to be able to explain and understand everything that humans wonder about. Since that seems like a long shot, the conclusion of Nietzsche (not Kant) was that humans are still wild beasts as wild as the chaos, not order, of the universe and the wildness of it all can't be comprehended by the human because within Reasoning there is no tool to comprehend total chaos and wildness, which resist explanation by their very nature.

[HiddenUsename]

I cannot understand this aversion to the probabilistic nature of the laws of physics. Great talk by the great and fun guy

[darrenheywood]

What this guy doesn't say about the uncertainty principle is that position and momentum are locked in a joint product 'h' aka plancks constant.

[Wilfoe]

Came to the Q&A for the end of the joke. Was not disappointed.

[tatotato]

Im proud to say that i am the like #420 which happened right after i heard "Maybe mathematics is the god which gave raise to everything here and that we are just a piece physicalized mathematics"

[flavio-viana-gomide]

Why do some people believe there will be a theory of everything? What if there will not be?

[chrstfer]

I thought some Corvids (ravens crows and magpies) as well as some cetaceans (I think just dolphins) also passed the mirror test?

[jessstuart]

The idea that the physical constants of nature are essentially random, and that we are just one of the tiny number of "lucky" universes that can support matter and life (anthropomorphic principle) is a huge untestable (nonscientific) assumption. That's fine for philosophers, but scientists should refrain from this kind of speculation.