18:18 "Ah... so *-wooooooooooooAAAAAAAAAAAAAAAAAAAAAOOOwww!* I mean where did that come from?! _Unbelievable!"_ -Pure joy.

I absolutely love this guy. The pendulum example was an event on itself

In the 1980's we knew that the universe was expanding. We knew that we did not know the rate at witch the expansion of the universe was slowing. We did not know that we did not know why the the expansion rate of the universe was accelerating. In the 1990's, in an effort to measure the rate at which the expansion of the universe was slowing we made the astonishing discovery that it was not slowing at all, it was accelerating. In an effort to discover something we knew we did not know, we discovered something we did not even know to ask about.

he's my favourite on the stand-up science circuit!

Always good to see Marcus giving a lecture. Never ever disappointing.

i love the way he is excited about science thanks man you are inspiration to me

I love Marcus - Hes such a wonderful speaker!

13:25 Chaos theory: Predicting the future 28:00 Quantum mechanics: Heisenberg uncertainty 39:14 Quantum cosmology: The origin of the universe 43:12 Quantum physics: The "smallest" particles 44:12 Astronomy: Seeing past the observable universe 45:36 Cosmology: Time and events before the Big Bang 46:44 Neuroscience: The origin and definition of consciousness If the "Theory of Everything" (M-Theory or similar) can ever be confirmed and completed (even if by indirect observation), then we may have insight into all of the above on some level. For example, Heisenberg uncertainty, quantum fluctuations/gravity/cosmology, the source of the fundamental particles, and even events before the Big Bang may all be more knowable from this unified theory. Chaos theory may also depend on quantum fluctuations. Even consciousness may arise from quantum effects since neurotransmitters are close to the de Broglie wavelength. Also, we could see past the observable universe if we could build a telescope with a warp drive. This is something that is theoretically possible, but is practically impossible due to the present inability to generate gravitational waves. However, a unified theory could help us understand more about gravity as well. While highly speculative, all the above may actually be potentially knowable, at least in part. I think it would have been interesting to discuss NP complexity as well as Gödel's incompleteness theorem that he references at 46:15. While more abstract, these two topics more conclusively show what cannot be known given a certain approach.

I work in a casino. If my boss sees that pendulum it will be the newest Roulette game.

What a compilation of idea. Amazing work prof. Thanks for the talk.

Watch with 0.75x speed to sound normal!

I love listenignto the ri lectures used to watch them when very young now 48 not a scientist and still enjoythem. ;-)

This video holds the record of "largest number of words spoken in under an hour" on youtube

Does infinite amounts of coffee give infinite amounts of energy? Marcus seems to have tried to test this theory...

I loved when he was explaining how we might know which side the dice would show and it unexpectedly flew right off the desk.

3 years to late. Love these RI videos. Thanks Marcus, appreciate his regular appearances on BBC podcasts & have Music of the Primes book, which is just amazing. Mind you, somewhat worried when he took out the uranium. Jedburgh in Edge of Darkness (BBC series not remake). A scene you'll never forget.

His role in "the code" was a perspective altering experience for me. Marcus's insights sparked my desire for mathematics and by extension my will to persist. For that, I'm grateful for his contributions.

form is emptiness ~ emptiness is form ♡ love all these videos, makes me so glad I am a Buddhist, so grateful for l this life ♢

What better way to explain chaos than to have a seriously chaotic person to present it.

Every new discovery brings up new questions. That process will continue for as long as we do.

This guy is a hoot. He is funny. He knows his science. He talks about things you have not heard a thousand times before. Highly recommended!

that was a brilliant lecture. i need to learn and think more

This is a Spectacular Talk by Marcus, his energy carries you along with him very well thankyou

There is a theorom that answers this: If something can be known, then there must exist a series of questions that if asked and answered, can get you from what is currently known to what one wants to know. This is pretty significant because it means you just have to be able to: 1. Find and ask a question that will get you closer to the answer and can be answered in sufficient time with an affordable amount of resources. 2. Continue to perform step 1 Eventually, you will bridge the gap from what was originally known to what you started off wanting to know.

He is amazing with an excellent explaining quality and an ability to hold the listeners..

I love knowledge... It makes me feel smart !

this guy is fantastic. great video!

Ironically for a lecture on chaos I found Marcus's lecture clear and engaging

I've now watched the same lecture nine months later and......it's still fascinating!

I like this guy, I'm not sure about the arsenal thing, but this chap is cool.

The human experience is that we can imagine. So much of what we know came from trying to explain what we observe.

Marcus du Sautoy is actually a Stand-up Physicist... I love this guy...

It is 'turtles all the way down'...

Great Work! Let's get more of this sort of material.

I hope he sold lots of copies of his book. An inspiration, and brilliant communicator. Will look out for more.

Exactly the lecture the RI should produce.

"you've changed the result by measuring it!"

Thank you Marcus. Fascinating as always!

One thing is known for sure, solving the riddle of the universe isn't easy! Even with the powerful tools we have today we still have a long way to go and new information is discovered every day. I think it's amazing that something that looks deceptingly natural and easy to understand (at first glance) have so deep complex roots!

Really enjoyed this lecture.

4:55 -Rumsfeld, conveniently, forgot to add that there are things we know but don't know, that is to say we got it wrong.- Edit: Just notice the speaker pointed out the 4th missing alternative...

"Iphone think therefore iphone am" - last communication with the machines before skynet.

Fantastic!

For youtube, the videos from the RI are quiete long, but worth every second. I'm a huge fan of TED Talks, they are short and offer a brought variety of topics. But this here is jsut brilliant for what it is. Thank you very much for not following the trend of 15min-speeches. Your channel offers good edutainment for months, amybe even years. And some stuff might even bring the world a little bit further. So many thanks for sharing it with everyone :)

When in doubt, please refer to the old Chinese proverb: "You can have anything, but, you can't have everything."

18:20 My favorite part lol. I mean, it really is interesting. Makes me think of irrational numbers. Look at the digits of the square root of 2. Then look at the digits of the square root of 1.9999990. Just that tiny change by 10^-6 causes 88% of all digits after the decimal to change (assuming these irrational numbers are normal numbers). Marcus dropped the double pendulum from positions very close to each other three times, and each of which produced radically different results. It's just like the irrational numbers... What do they have in common? Or, how is it that these two phenomena appear to us to have similar outcomes? EDIT: Okay, it turns out that shortly after that part he went onto explaining how minute changes in such parameters can yield drastically different results. I just related this to irrational numbers instead of magnets.

In my kindergarten class 63 years ago, the was a Marcus with mental disability. Now the best math professor on youtube is my second Marcus with a sense of humor.

Sautoy's brain works at the speed of light as does his speech,but amasingly he is still easy to follow.

In the Harry Potter stories, Ron Weasley's mother has something to say about your iPhone and other AI type intelligences: "Never trust anything that can think for itself if you cannot see where it keeps its brain." Great lecture. Thanks.

Dear Sir, Thank you for a very interesting video. May I please have your take on a completely different subject than your brilliant presentation about what we cannot know? In a documentary about Sir Issac Newton, it said he became the director of a very prestigious post - like the director of the science academy. He apparently burned all of a certain Mr Schock’s ( I am mispronouncing his name ) notes. Strangely, this colleague claimed that he was the author of some of the things Newton claimed that he himself had discovered. I am asking this because everyone points to Newton as the father of so many astounding discoveries, but could it be that he ‘borrowed’ some of the ideas of his colleague who had the misfortune to die before Newton? Why would Newton burn all of his notebooks? I say all of this because people are people and when you read Newton had something like 17 portrait artists paint his portrait, it points to the fact or shows that he knew he was going to be known as a genius. Does it also show a psychological pattern of someone who would perhaps do anything to be in the spotlight?

Describing the fractal for unknowability seems like a great way for people to comprehend this as I kind of got it based on that where as I didn't get it at all before.

It's worth noting that the last loopholes were closed in Bell Inequality violations a short while prior to this talk, which nails the door shut on anything controlling the decay of a uranium atom. There are no hidden variables, local or otherwise. The paper was published in the October 2015 edition of Nature.

51 minutes without drawing breath! Is this a new world record?

starts at 13:25

It is obvious that we cannot know everything. If we start from there with an optimistic sense of adventure we can rejoice in the journey to learn more. Chaitan gives strong support to the idea that shoving off from the shore is likely to be fruitful for some and catastrophic for others.

Btw he is getting me energized. No sleep inducement here!

I always tell people I gave up organized religion for Lent one year and never looked back.

The ultimate point of knowledge is to know we don't know everything.. When I forget what I forgot I am cured...lol. שלום

Thank you. That was fun.

Actually according to thermodynamics it's fundamentally impossible to know everything by default as you'd have to measure everything everywhere and keep track of energies used and measured, but you can't measure what you use to measure to an exact amount. Not even in the sense of knowing just factual data we could never know everything, not just because of what I just mentioned, but because we also always have to assume there is something we don't know.

Does RI have a podcast? I'd love to listen to this in the car!

I won't lie, I watched the double pendulum bit twice! (erm and applauded it!! :D )

THANK YOU SIR...!!!

I think an important issue that need to be included in the equation of truth searching is discovered through the neural network of our nervous system which is no matter how complex limited!

We are always on the event horizon of the unknown.

A known unknown: We can never know how many birds are in flight on the earth at any given moment, even though we know there is a quantitative, accurate answer.

Thank you. Some things will always be unknowable.

I wondered about that red/blue/yellow magnet ending point plot: He said it is an infinite complexity, but if space itself is quantizied, there are discrete starting spots, a finite number of starting spots. So why cant you just increase the resolution to that planck length and definitely predict for EACH spot of space where it will end?

"We've have proven there are things that are true that we can not prove are true." Gödel, the ultimate troll.

his reaction from the third pendulum swing was awesome lol

We cannot know what we are totally unaware of. We do not know what we are totally unaware of. We are becoming aware of so much data today we don't even know how to organize it.

wow, I loved that, thanxxx!

This video has a really interesting talk. ☺️👍

thats the indian philosophy: "know everything there is to know" indeed before the bhakti movement made all indians forget their religion was science

Great speaker.

This gentleman gets an award for the longest book plug in history. I was highly interesting and thoughtful though.

"Heisenberg was here....or somewhere thereabouts."

The universe is constantly moving.

The guy never spits...his mouth is sheer talking power, remarkable

I believe that the h in Heisenberg's formula was found before relativity was set down. That h pertains to a initial frame of reference between two bodies that are at rest with respect to each other. If you stop to think about that it just goes to the argument of what we know and yet never apply to what we previously knew.

I think Marcus should be the new Dr Who

around 41:50 he is wrong. It does not matter if it is a particle or antiparticle that falls into a black hole. The infalling particle always have negative energy. That is why the black holes shrinks by Hawking radiation.

Really good talk. I was hoping that Gödel's Incompleteness Theorem got some attention, but the other subjects were very interesting.

To me it makes sense. Unknowns are questions you can ask about. Unknown unknowns are questions you don't know to ask about. Probably a scientific way to say that. Maybe the 2nd derivative of understanding. Don't know ... doesn't matter.

What about Gödel's Theorem?

I wonder what is "everything"...

Marcus is very good to explain only I can not match the speed he talks

16:55 i think I know how to create conditions to have similar results in several pendules simultaneously.(need testing) So is possible to get the same motion multiple time?

I’ve got a Ph.D. in General Knowledge. ;)

44:10 TLDR: Turtles all the way down!

Excellent

You can use a very simple math function : abs(ln(x)) , absolute value of the neperian logarithm of x . Let start with x=2 , apply the function , & apply again with the result you got , & so on , injecting the last result in the function again . Which value do you get at step 1 234 567 ? You can't predict this , you have to do each step ... But what happens happens

Consciousness is certainly not one of the 'unknowable' things. Firstly, it's not a 'thing' at all. It is a property. And we understand more about it all the time. Most of the confusion around it is because we do not have good words with precise definitions for many of the things we wish to ask. When someone says "is the red you see the same as the red I see?" they can't actually explain what they are asking. They generally can not even answer why they make the baseless leap in thinking that after being unconscious for a night they are the 'same person' when they awake. They could not tell you what makes the self of the past and the self of the present the 'same person'. They can't explain what a 'person' is at all really. Our knowledge is meager thus far, but there is no reason to think that it can't advance quite far. Unlike certain questions, we can at least imagine what an answer would look like. We can know, right now, for instance, that a body in an environment similar to the environment we inhabit is absolutely required to give rise to a consciousness that would be recognizably "like us." We can know with great certainty that no machine-based consciousness, absent a body (though a simulated one might do), will be anything like a human consciousness. We know this because cutting off sensory input from our environment to a human conscious brain results in extremely rapid total dissolution of consciousness. Extreme sensory deprivation, along with mountains of evidence showing profound changes in a persons subjective conscious experience of the world and themselves due to changes in the body such as traumatic injury, is informative. Everywhere there is an alteration to consciousness, or a cessation of it, or the emergence of it, are opportunities to learn. And, mostly, to develop precise language to discuss the topic which is a very large part of the journey. You can't talk about subatomic particles if you've not even conjectured atoms yet and think of objects in the world only through a lens of intuitive essentialism.

In the intro when he reference what some have thought to be entirely unknowable to science, I was eagerly awaiting a reference to Immanuel Kant's famous quote, "There will never be an Issac Newton for a blade of grass," Charles Darwin obviously being that Issac Newton. But, alas, such a reference newer came.

The really exciting state of knowledge involve the unknown knowns. What if I'm blissfully unaware of the fact that I'm actually a highly regarded expert in the field of knitting or perhaps south african poetry??

Love Rumsfeld"s quote!

I liked the presentation, but I should tell that even it is not trivial, consciousness is just an illusion arising from our evolution. If you look at other humans, you can just say they are programmed robots by the evolution. Even you can program a robot to do similar things and behave similar. We can easily accept that there is no such thing as consciousness and it is made up, as the distinction between living and non living things. But when we turn to ourselves, we find feelings and talking voice in our heads, which we call consciousness, but we just saw it is just irrelevant. I think it is caused by feed back loops in the brain where different parts of the brain interacts. Such as, your word processing unit sends words to your speaking center, then you speak, the feed back loop goes from ear back to the word processing center where the data should be updated because you heard the word. And other parts of the brain recognizes the patterns and say this happened before, this is your voice and the new word you hear is actually coming from your part of the brain. So those parts of the brain have to be in extremely complex interaction, which I suspect that the consciousness arises. We may call it a phenomenon. As actually everything we know is a phenomenon, so why get surprised about that :) Again, the universe is so amazingly beautiful, it just created with the evolution phenomenon a machine that will get surprised by itself. Of course this surprise is expected just because we are the learners, the universe is what it is. And who put those phenomena into existence? Well, probably the question "who" is irrelevant. "How it came into existence?" is a much better question to ask. And, as our little machines try to understand, I'm sure the results (if we would be able to have any) would be quite surprising :)

little hole; Information does NOT travel at the speed of like; Entanglement is gonna be big in the next few decades. Closing in on the prize !!!

It seems to me that we are trying to measure the position of the electron which is obviously, from the fact of entaglement and that they pop photons in and out of existence, multidimentonal so we are trying to measure it to a three dementonal spot; wouldn't it be like measuring an irational number with only whole numbers? And as we calculate each decimal and hone in on placement or speed photons entangled with it's electron pop back and forth and since we are holding it in the whole number slot we think it's in all of those energy changes are applying to the other end of the equation increasing our uncertainty of what that has become.

Its so cool when you get the universe, and can ask questions like these. My personal 'Solution' takes it all in and describes it beautifully. However, My vision of the universe Requires a God, and is so easy to understand. As soon as I heard the introduction, faith, God, etc. All would have to be constant unknowns. We may push the stage back, by our discoveries, but the curtain is still pulled down. Almost makes you think of 'What are the unknowns that we SHOULD not know"; 'To look at the face of God' And I'm not religious.