Brian Cox is like the Bob Ross of physics. He's so passionate about his craft and explains it in ways we all can understand, and always has a smile while he does it
We used to think we were annoying our physics teacher at school by just going off-track and asking something when learning say, how light gives things colour. Then suddenly a hand would go up and ask "But why is there yellow gold and also white gold?" The next 30 minutes was filled by him drawing on the board and explaining that it's not the gold we see as white, it's what it's mixed with that how those atoms absorb and reflect light and so on. He was genuinely happy to hear us be curious and ask about this stuff and then explain it. Brian Cox is this on a more public scale I would say.
@@LiliarthanSean Carroll and Brian Greene are also fantastic modern science communicators. And then as far as UA-cam science communicators go - Matt O'Dowd from PBS Space Time, Michael from VSauce, Derek from Veritasium, Hank Green and everyone else associated with SciShow and PBS including Reid, Caitlin, Kallie, Michael, Brit, Stefan and anyone else whose name I regrettably can't remember of the top of my head.
@@michaelmay5453 I believe she is referring to Sandy. I think Sandy is an excellent emcee, host, leader of the pack. She has a quick wit and I think she is very funny.
the only british show that I loved to listen during work days, Stephen Fry - an intellectual giant - as a host was prime time. rarely smiled so much as when listening his and Alan Davis' bantering.
God I love Prof. Brian Cox. The fact that he had an answer to the ewok question straight away was brilliant. It could have been complete bollocks but sounded convincing enough to me! Total package, smart, funny and he's not hard on the eyes either ;)
The way he trailed off while saying it, realizing how ridiculous it sounded after he blurted it out, was more the funny bit for me. He's quite a glompable fellow.
That last bit about quantum entanglement, and Alan saying about making a copy of yourself. Funnily enough, that is essentially the basis of how transporters work in Star Trek. They break you down to the molecular level, record that information in the transporter, beam said information to the target location and assembles what is for all intents and purposes a copy, and the original you is gone.
Problem is that is not teleportation. That is deconstructing and reconstructing. The result is not the same person. What Star Trek is doing is more like the Prestige or what the X-men are doing in the newer House of X. If it is not the same being/item, then it is not teleportation.
Actually, the real problem is Star Trek *isn’t real*. Sorry to be the one to break that bit of bad news to you. Deep breaths. Now, who’s the woman who’s sitting in Stephen Fry’s seat in some of these clips?
The thing with the table tennis rackets isn't unexplainable, it's university mechanics/physics. It's actually fun to calculate (or was when I was still able to do it). Object usually have 3 main axis of rotation (in uniform objects that HAVE symmetry, they are usually the same as the axes of symmetry, I'll get back to that). 2 of them are stable, one is unstable. (Some objects have MORE axes, for example a uniform sphere has an infinite number, as does a wheel. One through it's axis, an infinite amount perpendicular to it, "in the plane of the wheel"). It has to do with the 'moment of inertia' of those axes. The one with the largest and smallest moment are stable, the one with the middle/medium one is unstable. How do you define them? Let's just pretend (simplified) that the moment of inertia of an axis is defined by how far away it's mass is from the axis of rotation. The further away, the larger. Or, thinking about it differently, "how much force do I need to spin the object up along this axis?". In objects with uniform density these axes are reasonably simple to find. Let's us a phone and assume it's density is uniform throughout (it isn't). ONE axis is through the middle of the screen. Thats the axis of the largest inertia, the MOST mass is far away from this axis, it's stable and you can spin it that way. On the table tennis racket, that's the one through the red and black sides. ONE axis is through the charging port. That's the axis with the smallest inertia, it's also stable. On the table tennis racket, that's the one along the handle. The third one on the phone goes through the 'sides' (e.g. power button on many phones). That's the instable one. You can not rotate your phone along that axis (i.e. 'flip it'). It will always flip on you and you will catch it with the screen to the back. On the table tennis racket, that's the one Sandy (badly) points out at 28:40, using her fingers (".. that you don't think will come into play"). Same works for bricks, etc. UNLESS (and they missed that) if you throw it such that it flips TWICE, not ONCE in the air. By the time you catch it THEN, the screen will be up again. On wheels, etc, symmetric objects in a special way (think 'round') the medium and the small axes have the same moment of inertia, i.e. there IS not 'middle' one. That's why you can spin a wheel perpendicular to it's axis just fine. (Sorry, some smart-assery here, but I just think it's very interesting)
Thanks. I thought it must be some such sort of instability. What I did find surprising was the fact that a table tennis bat can be 'any size you like'. Obviously a bigger bat makes it easier to hit the ball, but it will also have more mass and inertia, so there must be an optimum size. (I thought there must be a regulation specifying thickness, or mass per unit area, to prevent someone making an extra-large bat from super-lightweight high-tech materials. But apparently not. So evidently there must be an optimum weight and too light a bat must have its disadvantage too - maybe not enough momentum to impart the necessary impulse to the ball.)
I really enjoyed your explanation. To be honest I am still working on understanding it though. One slight issue I have is the aberrant apostrophe on the fifth line of the post but I would still rather be able to fully understand what you said.
I used to pass Michael Winner's house when taking my son to Holland Park. Sometimes you would see Michael eating at the Belvedere in the park. Jimmie Page was his neighbour and though I imagine Michael didn't like the noise, they were decent friends by all accounts. When Michael died, Robbie Williams bought the house and there ensued quite a feud between Jimmie and Robbie.
The cloud chamber the Americans were selling as safe reminds me of school. During one lesson we all had a small cloud chamber and a radioactive source to play with. I now glow in the dark 😁😁😁😁 Seriously I found it facinating.
At school in the early '70s we were given trays onto which were poured pools of mercury and we were encouraged to explore its properties by rolling it around and poking and prodding it with our fingers. I don't think any of us came to any harm, although an ex tried on occasions to tell me I was insane! Cats can teleport. I used to sit and watch my cat walk past me through the living to go out multiple times, but not back in. No windows open, no other door, and both exit doors from the living room were in full view - she had to walk past me to come in or go out. I never did work out she did it.
Science is so interesting. I only wish it was taught that way in school rather than the boring theories and problems we are taught. Most of the panelists, I'm sure, didn't find it very interesting hence their current professions but are then intrigued when Stephanie and Sandy explain these concepts. I'm sure most of the audience feels that way as well.
I feel the same way! If I was a science teacher I'd just sit my pupils in front of a tv with Brian Cox, Maggie Aderin Pocock, Jim Al-Khalili or Hannah Fry and go play No Man's Sky on the classroom pc for an hour!
The Ross Noble/Ewoks clip should’ve run longer. I know everyone watching this has seen it, but I do so enjoy the “chucking Ewoks into a lake of farts” nonsense.
Your present is not my present. I really like presents, but i love the fact that i’m continually time-travelling at 1 sec/sec from my point of view. So as soon as you’ve said the word present, it’s the past. Even though some presents last..
"i’m continually time-travelling at 1 sec/sec from my point of view." It is, if I'm also travelling at 1 sec/sec. We're in the same frame of reference.
In Star Trek, they don't actually teleport people. Instead, they create an exact copy somewhere else and then destroy the original. If you could do that, you could just as easily duplicate people and then everyone could have a Brian Cox each. That would've been nice.
watch the film with hugh jackman, christian bale, my man Sir Micael (dont chuck them bloody spears..at me) Cain, and Bowie. Its called The Prestige i believe, it is what you just said. :)
It’s not as cut and dry as you’re making it out to be. We’re shown multiple times in the shows and movies that stream of consciousness persists while being transported. There are even conversations that are uninterrupted during the process. Duplication is shown to be uncommon glitch rather than how it usually functions.
@@JosephHeiskell In computing, that's called live migration. It's still a matter of cloning the system, killing the original and starting the clone. For all intents and purposes, you are teleporting the system, but there is no teleportation involved. If you were cloned that way, you wouldn't notice anything because the state of every atom would be preserved and that would include your thoughts and feelings. Duplication in Star Trek occurs in what we call a split-brain situation, where the buffer has been filled and duplicated and the clone has been created, but from transmitters point of view, the teleportation was not completed, so they restore the original. By the way, this is why Bitcoin was a radical invention. Because if you could do this with money, then the whole system would instantly be worthless. :)
"To make it statistically relevant, you would have to have an awful lot of relationships." That´s a very elegant way of calling someone, let´s say, promiscuous.
Actually Stephen Fry is probably wrong . Neutron stars spin so fast that they are not spheres at all they are oblate spheroids. Also I like the Buddhist definition of the present. any action whose karmic effects are still present is still in the present.
The spin very quickly, but are incredibly dense, nearly as dense as black holes. It's possible that density creates gravitational fields strong enough to overcome the centrifugal forces that change it from a sphere.
Religious fanatics are not only Americans. My son was taught Creationalism as being a fact (not a theory) at a Lutheran primary school in Australia in the mid 1990's. I lodged a complaint with the school Board, with nil result.
Johnny wasn't wrong: we observe the universe from a platform orbiting Sol, so Sol being the center (more or less) of our orbit makes it the center of the observable universe.
Many many years ago the Chairman of Belhaven Brewery told me that Belhaven Brewery was at the centre of the known brewing universe and he appeared to know what he was talking about.
Holly's comment about a fax machine isn't that bad an analogy. You have the original in one location and a copy in another. How this would work for even a photon is beyond my grasp, and to teleport anything bigger would have to be hundreds of times more difficult, assuming one could do it at all.
If the quantum states of every atom in your body are somehow preserved, and not only your body but your present consciousness is teleported as well, there would be no "copy", both would be "originals" (if the source doesn't get destroyed in the process) In the same way that it makes no sense the concept of original or copy if a digital file has the same cryptographic hash.
@@xantiom Alas, in order to measure the quantum state of the original using one member of an entangled pair, you must necessarily destroy that state in the process. The resulting measurement can be used to arrange an interaction with the other member of the pair that reproduces the state of the now-gone original in an arbitrarily distant location. Quantum teleportation can't be used as a duplicating machine.
@@Lamster66 Bell's Inequality lets us know that entangled particles don't work the way the banana example tried to show it. Messing with one of them doesn't "immediately change the other". Their states are correlated in an unintuitive way that's impossible to demonstrate with any classical objects. Measuring either of them will give a random answer, but the answers will match up when you check them against each other. There just isn't a way to use quantum entanglement to send information.
@@Lamster66 Nope. Every measurement made says it isn't a possibility. Every proposed explanation of what's happening either 1) fails to match experimental results or 2) says that no information can be transferred using entanglement. Whatever the mechanism is that the universe is using to make the results of measurements end up being correlated, we have no access to it. It's weird, and spooky, and unexploitable for duplicating data. (We haven't tested to confirm that Bell's Inequality works under every exotic situation, like "inside" a black hole or at subatomic distances or within a quark-gluon plasma, but other factors would make data duplication impossible under those conditions anyway.)
@@Lamster66 If by "measurement problem" you mean "need to measure something in order to get an answer", then yes. But if you mean "figuring out how to measure something precisely enough", then no. The act of probing a particle's unknown state using one member of an entangled pair necessarily destroys both the entanglement and the attribute being measured. Quantum teleportation might be considered copying a local state to a remote location, but that local state no longer exists afterward. That's why it's referred to as "teleportation" and not as "duplication".
So in the last part I am not sure what the chinese experiment was. There is such a thing as quantum teleportation and there is such a thing as entanglement. Entabglement however cannot be used to transport informatiin and at least mathematically we understand it quite well. Esentially particles have states and a two particle or multiparticle system can have a joint state.. We call that state entangled when the probability of a particle being in any given state depends on the the other particles states. In the easiest example we have two particles that each habe two possible states. If particle A has state 1 particle B has to have state 2 and vice versa. So if you measure particle B in state 1 you know particle A has state 2 but there is no information transported because particle B being in state 1 and particle A being in state 2 is absolutely equivalent.
But you can have information in the form of a message be transferred this way. Let me give an example, we have two quantum entangled particles, one on earth and one on the spaceship travelling proxima centauri, when it arrives at proxima centauri, the state of the particle will change (how to do this /shrugs) and thus the people of earth will know that the spaceship arrived, instead of waiting four years for a message. This is how we can beat the speed of light transmission but the meta-data (meaning of the state change) will be outside of the entangled particles.
@@chasindigo No. They won't. They can only know it changed when they measure it but they don't know if they measured it first or second and they don't know the initial state before it was measured.
Its not radiocarbon dating, that is only useful for dating relatively recent objects. They date older ones using isotopes of other elements. So if you fill the atmosphere with neutrons from an atomic explosion you alter the natural, background, radiation level and associated isotopes.
The last bit. Before she answered fax machine I really thought too as well 😂 and I'm not even on the age when its usage circulated. But like yes, it feels like fax machine.
Regarding the very first part with Brian Cox: Time doesn't exist. It doesn't affect us, we don't affect it. It is merely a measurement from one point to another on a path we can't visualize without it. Time is not a physical thing, it is an abstract idea, just like numbers in general. Numbers don't exist. They are merely what we use to measure. We watch too much media regarding time travel, because people are really believing we might be able to do such a thing someday. Even just the simple fact that they think time slows down the faster you move. It doesn't. Time doesn't do anything. The object is still aging like we are, we just don't understand how to measure the time difference with the added stress of the speed. The speed is affecting the instruments.
Funny, in that Brian Cox had previously said that "at the same time" was meaningless, yet in the same video we hear that events to entangled particles happen "at the same time". I know it's a science geek thing, but it was a kind of "what?" moment.
@@B-A-L In geeky science terms, "Now" travels at the speed of causality. ie. '"c", or the speed of light. For example, we can't tell if Betelgeuse has gone nova because it's "now" hasn't arrived yet. Brian Cox actually details this on one of his talks to A Level students.
Are neutrons stars ever that round though? Unless the thing collapsed with zero angular momentum, it would still have some centrifugal forces forcing out of round. My answer is the new kilogram standard silicon sphere.
It's a misunderstanding that quantum entanglement transfers information, the instant change on the other end is faster then light, but no information is being shared, just a change on both sides. A way of looking at this is imagine if both sides have a closed shoebox, when 1 side opens it and observes whats inside, the act of observing determnes wether its 1 or 2 shoes, and at the same time the box on other side changes to that same result of 1 or 2 shoes, but they also have to open to box to observe the result on the other side. My explenation is probably missing some stuff, this stuff is difficult, but in short, since no information is being transfered, no laws of physics ie speed of light, are being broken, it would lead to all kinds of time paradoxes with instantaneos messages over vast amounts of spacetime being able to travel back in time to before the message was send in the first place, the universe will not allow it.
Is there some reason we could not agree ahead of time that some specific action is to be taken when we see the change on the other end? Similar in idea to saying "once I turn on the light and you see it, you then press the button" (whatever that button happens to do), such that you can send a message of "press the button now" long distances at the speed of light. Only this time, it moves faster even than that. Or is there something inherent to the process that prevents this? Or do we even know the answer to that at all yet?
@@riluna3695you can only see the light being turned on at the speed of light. You can't use entanglement to send a message faster than the speed of light. Any measurement of an entangled system is random and unpredictable. To confirm that measurement would require communication between both parties using conventional methods.
@@riluna3695 because the other side has to open the box to see what changed, its just randomness moving faster then light. The inherent thing that prevents it is that information cannot travel faster then light. Your specific example would translate to something like morse code, but you are forgetting the act of observing matters then, the only time we see if its randomly 1 or 2 shoes is when we open the box, and a closed box tells us nothing so theres no way to signal with it. And again, this would create time paradoxes over vast spacetime, the universe simply does not allow this, any faster then light travel is nothing more then fiction. Since you are intrested enough to mess around witht the concept you will probably like this: ua-cam.com/video/BLqk7uaENAY/v-deo.html That vid explains it much better then me, and that channel is on another level for theoretical space civilisations and other cosmic phenonema, highly reccomended.
Poor old Johnny getting laughed at, but he is not wrong. We can "observe" a different part of the universe every night of the year, which depends on our rotation of the sun. So the centre of the observable universe is the centre of gravity (barycenter) between the sun and the earth which is really close to the center of the sun.
@SamuelBlack84 I am no scientist, but I don't think so. All matter would have had to have been ejected from the big bang in an incredibly even way for the big bang to still be the centre of the universe. As large clusters of mass would act upon each other and travel away from the big bang slower than less densely packed clusters of mass. Again, I am no scientist, and this is just what I think.
If you believe in intelligent design, then you must believe in intelligent design warranties. All designs and warranties have an expiration date. And yours is by Tea Time tomorrow. I got a peak at it up in the old man's shop yesterday during the cricket match. Nice knowing you. Don't make any long term plans. 😂
Which episode is this from? I'd like to purchase a copy as well as the appropriate book of QI that covers the foreskin topic. As an atheist, I really want to add it to my collection. Thanks.
It's instant but you can't use it to communicate. The description about doing something to the banana that then is copied on the other half is not actually what happens. What actually happens is that you make an observation of one half of the banana and you observe that it is identically correlated with the other half, the weird thing is that the outcome of your observation is completely random and you can't predict what it will be, but it will always correlate exactly with an observation made on the other half of the banana.
Carbon dating before 1950 is also unreliable for the exact same reason. There’s no way anyone could know, and no reason for us to assume that the level of carbon dioxide in the atmosphere has remained constant over time (the core assumption of carbon dating).
No one assumes (or at least scientists don't assume) that carbon dioxide levels have remained stable over time. However, carbon dating is definitely reliable, if samples aren't tainted and everyone understands the limitations of the process ie that the dates it gives aren't ever going to be pinpoint accurate but the most probable range. Also, there's definitely ways to estimate what CO2 levels used to be, such as analysing ice cores since their trapped bubbles of air preserve the chemical composition of the atmosphere at the time they were laid down. Going back millions of years, you can't do carbon dating anymore of course, but you can still tell CO2 levels through things like counting the stomata of plant fossils, which are fewer when atmospheric CO2 is high. How much CO2 is in the atmosphere at any given point in time is a highly variable and important measure, but scientists have a number of ways of calculating it.
Umm.... Living organisms absorb carbon-14 which, when they die, starts breaking down into other atoms. It's by measuring that decay that the dating is established. The metric is the current atomic state being an indication of time passed. The levels of atmospheric carbon are irrelevant.
It's not about the amount of carbon in the atmosphere. It's about the ratios of carbon isotopes that remain in the samples, since 2 of those 3 isotopes has a half life while the other is stable. Your argument has been said a million times and a million more times we have answered it. Yet the question keeps being asked.
For the love of all that is holy, QUANTUM ENTANGLEMENT ISNT TELEPORTATION, no information is transmitted or transferred. Its like having two decks of shuffled cards and whilst you dont know what way the decks are shuffled, you do know that both decks are shuffled the same. And like two decks of cards the second you shuffle or add a card to one deck, you now no longer know they are ordered the same So no its incorrect to state "whatever you do to one will happen to the other", it is only correct to say "the state which one is observed will be the same state the other is"
Brian Cox is like the Bob Ross of physics. He's so passionate about his craft and explains it in ways we all can understand, and always has a smile while he does it
Him and Neil Degrassi Tyson - we are so spoiled to be able to access their genius for free!
We used to think we were annoying our physics teacher at school by just going off-track and asking something when learning say, how light gives things colour. Then suddenly a hand would go up and ask
"But why is there yellow gold and also white gold?"
The next 30 minutes was filled by him drawing on the board and explaining that it's not the gold we see as white, it's what it's mixed with that how those atoms absorb and reflect light and so on.
He was genuinely happy to hear us be curious and ask about this stuff and then explain it. Brian Cox is this on a more public scale I would say.
@@LiliarthanSean Carroll and Brian Greene are also fantastic modern science communicators. And then as far as UA-cam science communicators go - Matt O'Dowd from PBS Space Time, Michael from VSauce, Derek from Veritasium, Hank Green and everyone else associated with SciShow and PBS including Reid, Caitlin, Kallie, Michael, Brit, Stefan and anyone else whose name I regrettably can't remember of the top of my head.
Except that Brian Cox explains things as if to an adult who isn't up to date with physics. NDT explains the same stuff, but for an eight year old.
😂
Two of Britains best, Stephen Fry and Brian Cox. These are the people who should lead the nation.
Agreed, both better than HI RISK ANUS
Yes yes yes.❤❤❤❤❤
at least better than the lesbian statue they have now.
@@a.akacic I have no idea what you are on about.
@@michaelmay5453 I believe she is referring to Sandy. I think Sandy is an excellent emcee, host, leader of the pack. She has a quick wit and I think she is very funny.
“I’m sorry. I don’t know why I laughed “😂😂 that was brutal
The Holy Foreskin….sounds like a Monty Python skit.
it is...
@@hansdampf640sauce or it's not real
Or what 1960s Batman might say….
Sounds more like Douglas Adams
Ol' Jezza Christ has acres of hood.
"That's no way to treat the elderly" was an amazing line
When someone does something nice for me at work , holding a door open or whatever, I say thank you for being kind to the elderly.
I love that , I will use it my self.❤❤❤❤
Elderly Saturn rings
I had all the Gilbert science kits including the U235 atomic lab. I can still, over seventy years later, be easily found in the dark.
We need Brian Cox back on the show. And Ross Noble!
I'd watch a show of them with Brian just blowing Ross's mind and Ross talking about what pop culture character he'd like to toss.
@@Pagliacci_Rex"that's no way to treat the elderly."
Not sure Ross is essential beyong the tap room of your local
@@LoscoeLad I mean... a decent Tap room is where all the best surrealist comedy happens...
Sandi does not have the scienceboner for Brian as Stephen did.
You have to love Brian Cox 😊 He's brilliant and cool at the same time 😅
and he was the keyboard player in D-ream
And the way he said "and so you'd need to be...furry" - just that slight pause, for scientific AND comic effect.
"Achilles!" Oh, wait, wrong one.
Too bad for his last name though... :p
but jokes aside yeah he's a blast to watch as a guest
'THAT'S NOT ROUND!' lol! 😂
1st Jan 1950? As I was born in December '49, I am, by definition, prehistoric. Yay!
the only british show that I loved to listen during work days, Stephen Fry - an intellectual giant - as a host was prime time. rarely smiled so much as when listening his and Alan Davis' bantering.
"when is the present?"
"just then. you blinked and missed it."
But when will then be now?
@@Pagliacci_RexSoon
brilliant thought provoking and hilarious. such a treasure of a show. its the one show i can share with my 79 year old mum.
Excellent programme! Always fun, educational, entertaining & frankly, a bloody good laugh. Due to great guests & superb Hosts.❤😊
Yes Brian Cox is really very special. I love him.❤❤❤❤❤❤😊
God I love Prof. Brian Cox. The fact that he had an answer to the ewok question straight away was brilliant. It could have been complete bollocks but sounded convincing enough to me! Total package, smart, funny and he's not hard on the eyes either ;)
The way he trailed off while saying it, realizing how ridiculous it sounded after he blurted it out, was more the funny bit for me. He's quite a glompable fellow.
That last bit about quantum entanglement, and Alan saying about making a copy of yourself. Funnily enough, that is essentially the basis of how transporters work in Star Trek. They break you down to the molecular level, record that information in the transporter, beam said information to the target location and assembles what is for all intents and purposes a copy, and the original you is gone.
Problem is that is not teleportation. That is deconstructing and reconstructing. The result is not the same person. What Star Trek is doing is more like the Prestige or what the X-men are doing in the newer House of X.
If it is not the same being/item, then it is not teleportation.
@@DarthPoyner Yes, continuity of consciousness is of paramount importance imo.
Actually, the real problem is Star Trek *isn’t real*. Sorry to be the one to break that bit of bad news to you. Deep breaths.
Now, who’s the woman who’s sitting in Stephen Fry’s seat in some of these clips?
@@mattp422 Sandi Toksvig.
@@mattp422you've broken every Trekkie's heart!
That, is Sandy Toksvig. As much as I love Stephen Fry, she is the better QI host!
Brian Cox slapping all archaeologists is some hardcore energy
Also, fundamentally incorrect and missing the practice by a wide margin
HE's missing the point.
Time flies like an arrow. Fruit flies like a banana.
underrated comment!
Genius!
Time flies - you can't - they go too fast.
Why not an apple? That would be a better echo for an arrow.
I first heard that in an old black and white Marks Brothers film.
This is so much like a chaotic classroom. How hilarious.
It's wonderful listening to two great minds 😅
The thing with the table tennis rackets isn't unexplainable, it's university mechanics/physics. It's actually fun to calculate (or was when I was still able to do it).
Object usually have 3 main axis of rotation (in uniform objects that HAVE symmetry, they are usually the same as the axes of symmetry, I'll get back to that). 2 of them are stable, one is unstable. (Some objects have MORE axes, for example a uniform sphere has an infinite number, as does a wheel. One through it's axis, an infinite amount perpendicular to it, "in the plane of the wheel").
It has to do with the 'moment of inertia' of those axes. The one with the largest and smallest moment are stable, the one with the middle/medium one is unstable.
How do you define them? Let's just pretend (simplified) that the moment of inertia of an axis is defined by how far away it's mass is from the axis of rotation. The further away, the larger. Or, thinking about it differently, "how much force do I need to spin the object up along this axis?".
In objects with uniform density these axes are reasonably simple to find. Let's us a phone and assume it's density is uniform throughout (it isn't).
ONE axis is through the middle of the screen. Thats the axis of the largest inertia, the MOST mass is far away from this axis, it's stable and you can spin it that way. On the table tennis racket, that's the one through the red and black sides.
ONE axis is through the charging port. That's the axis with the smallest inertia, it's also stable. On the table tennis racket, that's the one along the handle.
The third one on the phone goes through the 'sides' (e.g. power button on many phones). That's the instable one. You can not rotate your phone along that axis (i.e. 'flip it'). It will always flip on you and you will catch it with the screen to the back. On the table tennis racket, that's the one Sandy (badly) points out at 28:40, using her fingers (".. that you don't think will come into play").
Same works for bricks, etc.
UNLESS (and they missed that) if you throw it such that it flips TWICE, not ONCE in the air. By the time you catch it THEN, the screen will be up again.
On wheels, etc, symmetric objects in a special way (think 'round') the medium and the small axes have the same moment of inertia, i.e. there IS not 'middle' one. That's why you can spin a wheel perpendicular to it's axis just fine.
(Sorry, some smart-assery here, but I just think it's very interesting)
Thanks. I thought it must be some such sort of instability.
What I did find surprising was the fact that a table tennis bat can be 'any size you like'. Obviously a bigger bat makes it easier to hit the ball, but it will also have more mass and inertia, so there must be an optimum size. (I thought there must be a regulation specifying thickness, or mass per unit area, to prevent someone making an extra-large bat from super-lightweight high-tech materials. But apparently not. So evidently there must be an optimum weight and too light a bat must have its disadvantage too - maybe not enough momentum to impart the necessary impulse to the ball.)
I find your description intriguing. As I read, I got smarter. Thanks!
I really enjoyed your explanation. To be honest I am still working on understanding it though. One slight issue I have is the aberrant apostrophe on the fifth line of the post but I would still rather be able to fully understand what you said.
I could listen to Brian Cox for hours.
“Yeah, good luck with that” 😂😂
What did the Pope's librarian say about the rings of Saturn? He said
They're not as impressive as Uranus:)
I used to pass Michael Winner's house when taking my son to Holland Park. Sometimes you would see Michael eating at the Belvedere in the park. Jimmie Page was his neighbour and though I imagine Michael didn't like the noise, they were decent friends by all accounts. When Michael died, Robbie Williams bought the house and there ensued quite a feud between Jimmie and Robbie.
That bit about intelligent design would get you killed in America.
The cloud chamber the Americans were selling as safe reminds me of school. During one lesson we all had a small cloud chamber and a radioactive source to play with. I now glow in the dark 😁😁😁😁 Seriously I found it facinating.
Well, we've been doing that for ages. Remember Red Dye no. 3?
Brian Cox started talking and I immediately fell in love
It's 50,000 miles across man thats some girth. 🤣🤣🤣. Brilliant
At school in the early '70s we were given trays onto which were poured pools of mercury and we were encouraged to explore its properties by rolling it around and poking and prodding it with our fingers. I don't think any of us came to any harm, although an ex tried on occasions to tell me I was insane! Cats can teleport. I used to sit and watch my cat walk past me through the living to go out multiple times, but not back in. No windows open, no other door, and both exit doors from the living room were in full view - she had to walk past me to come in or go out. I never did work out she did it.
Maybe intermittent failure to recognise familiar objects is a symptom of mercury poisoning...
I had this on in the background, but my head whipped up at 'which moon' because i knew Ewoks kicked into lakes of liquid farts was coming.
And was instantly disappointed
ua-cam.com/video/5r_TlPwZOvU/v-deo.htmlsi=vXP7FWCyA2h3nfaH
The rooms were actually "tossed" into the lakes of liquid farts which caused Brian Cox to lose it altogether. That clip should have been included...
I don't hate Jar Jar Binks, but I love that Stephen dissed him! 🐲
LEGO, meanwhile, has brought Darth Jar Jar to life!
“Galileo was a genius” - Brian Cox, also a literal genius.
Fax machine fantastic analogy
No. I remember fax machines. If you wrote on the fax you received, nothing changed to the fax that was sent.
'The world doesn't revolve around you!'
'No, but MY world does.'
Science is so interesting. I only wish it was taught that way in school rather than the boring theories and problems we are taught. Most of the panelists, I'm sure, didn't find it very interesting hence their current professions but are then intrigued when Stephanie and Sandy explain these concepts. I'm sure most of the audience feels that way as well.
I feel the same way! If I was a science teacher I'd just sit my pupils in front of a tv with Brian Cox, Maggie Aderin Pocock, Jim Al-Khalili or Hannah Fry and go play No Man's Sky on the classroom pc for an hour!
@B-A-L Nice to meet a fellow Traveller
The Ross Noble/Ewoks clip should’ve run longer. I know everyone watching this has seen it, but I do so enjoy the “chucking Ewoks into a lake of farts” nonsense.
banal crap
@@LoscoeLad You shouldn't have turned around. He told you.
@@LoscoeLad loscoelad the life of the party 🎉
Absolutely Hysterical!
Your present is not my present. I really like presents, but i love the fact that i’m continually time-travelling at 1 sec/sec from my point of view. So as soon as you’ve said the word present, it’s the past. Even though some presents last..
Your present is my present if I decided I liked the look of it, and swiped it!
@@flyawaytodie the best present is one you can share..
"i’m continually time-travelling at 1 sec/sec from my point of view."
It is, if I'm also travelling at 1 sec/sec. We're in the same frame of reference.
The present is the difference between now and now but always referred to in the past tense.
@@squiremc such an elusive gift.
In Star Trek, they don't actually teleport people. Instead, they create an exact copy somewhere else and then destroy the original. If you could do that, you could just as easily duplicate people and then everyone could have a Brian Cox each. That would've been nice.
watch the film with hugh jackman, christian bale, my man Sir Micael (dont chuck them bloody spears..at me) Cain, and Bowie. Its called The Prestige i believe, it is what you just said. :)
It’s not as cut and dry as you’re making it out to be. We’re shown multiple times in the shows and movies that stream of consciousness persists while being transported. There are even conversations that are uninterrupted during the process. Duplication is shown to be uncommon glitch rather than how it usually functions.
@@JosephHeiskell In computing, that's called live migration. It's still a matter of cloning the system, killing the original and starting the clone. For all intents and purposes, you are teleporting the system, but there is no teleportation involved. If you were cloned that way, you wouldn't notice anything because the state of every atom would be preserved and that would include your thoughts and feelings.
Duplication in Star Trek occurs in what we call a split-brain situation, where the buffer has been filled and duplicated and the clone has been created, but from transmitters point of view, the teleportation was not completed, so they restore the original.
By the way, this is why Bitcoin was a radical invention. Because if you could do this with money, then the whole system would instantly be worthless. :)
Well in all truth .. it wasn't GOD who did intelligent design .. it was his underpaid STAFF
And to think that some berat others and seek to put them down by sneering at them saying 'you act as though you're the centre of the universe'.
"To make it statistically relevant, you would have to have an awful lot of relationships."
That´s a very elegant way of calling someone, let´s say, promiscuous.
He wasn't saying that at all
The date that this episode first aired will go down in entropy!
The mayor of Idaho? hahaha
Time is the ever ongoing destruction of the present.
Or the proving of the past. A more positive atitude, surely?
Time is the Law of Conclusion
I would be more interested to know how the rings around Uranus formed. 😄
Great content and presentation. 🇦🇺
Actually Stephen Fry is probably wrong . Neutron stars spin so fast that they are not spheres at all they are oblate spheroids.
Also I like the Buddhist definition of the present. any action whose karmic effects are still present is still in the present.
The spin very quickly, but are incredibly dense, nearly as dense as black holes. It's possible that density creates gravitational fields strong enough to overcome the centrifugal forces that change it from a sphere.
I have the answer to the question 'What can be found at the center of the Universe'...
That would be my wife...
Prepare the basement couch, because that's where you'd be sleeping
We dob't have one... if we had I woulds have for the past 20 years...@@bororobo3805
Religious fanatics are not only Americans. My son was taught Creationalism as being a fact (not a theory) at a Lutheran primary school in Australia in the mid 1990's. I lodged a complaint with the school Board, with nil result.
My parents wanted me to go to a religious high school when I left primary
Thank god I didn't grow up with that rubbish in my head
at the exact center of the universe you'll find the likeness of johnny vegas...tbh...i wouldn't be disappointed xD
nah, he'd definietly want to use your starship
Johnny wasn't wrong: we observe the universe from a platform orbiting Sol, so Sol being the center (more or less) of our orbit makes it the center of the observable universe.
Did anyone else notice that Sandi kept trying to cut in with "Thank you for watch- " in between Stephen's bits? It happened at least twice.. 🙂🙃🙂
This channel has stolen a load of clips from the official QI channel, and isn't very good at editing them together.
Entanglement defines simultaneity of local resents.
2:58 Talk about lord of the rings !
😂😂😂
"Stephen Fry has an enormous cannon here,"
Many many years ago the Chairman of Belhaven Brewery told me that Belhaven Brewery was at the centre of the known brewing universe and he appeared to know what he was talking about.
Holly's comment about a fax machine isn't that bad an analogy. You have the original in one location and a copy in another. How this would work for even a photon is beyond my grasp, and to teleport anything bigger would have to be hundreds of times more difficult, assuming one could do it at all.
If the quantum states of every atom in your body are somehow preserved, and not only your body but your present consciousness is teleported as well, there would be no "copy", both would be "originals" (if the source doesn't get destroyed in the process)
In the same way that it makes no sense the concept of original or copy if a digital file has the same cryptographic hash.
@@xantiom Alas, in order to measure the quantum state of the original using one member of an entangled pair, you must necessarily destroy that state in the process. The resulting measurement can be used to arrange an interaction with the other member of the pair that reproduces the state of the now-gone original in an arbitrarily distant location. Quantum teleportation can't be used as a duplicating machine.
@@Lamster66 Bell's Inequality lets us know that entangled particles don't work the way the banana example tried to show it. Messing with one of them doesn't "immediately change the other". Their states are correlated in an unintuitive way that's impossible to demonstrate with any classical objects. Measuring either of them will give a random answer, but the answers will match up when you check them against each other. There just isn't a way to use quantum entanglement to send information.
@@Lamster66 Nope. Every measurement made says it isn't a possibility. Every proposed explanation of what's happening either 1) fails to match experimental results or 2) says that no information can be transferred using entanglement.
Whatever the mechanism is that the universe is using to make the results of measurements end up being correlated, we have no access to it. It's weird, and spooky, and unexploitable for duplicating data.
(We haven't tested to confirm that Bell's Inequality works under every exotic situation, like "inside" a black hole or at subatomic distances or within a quark-gluon plasma, but other factors would make data duplication impossible under those conditions anyway.)
@@Lamster66 If by "measurement problem" you mean "need to measure something in order to get an answer", then yes. But if you mean "figuring out how to measure something precisely enough", then no. The act of probing a particle's unknown state using one member of an entangled pair necessarily destroys both the entanglement and the attribute being measured. Quantum teleportation might be considered copying a local state to a remote location, but that local state no longer exists afterward. That's why it's referred to as "teleportation" and not as "duplication".
Leave it to us Americans to make safe and instructive science sets.
With a healthy green glow 😅
Ross Nobles mind is more complex than the Universe. Toss away Ross :) Also 22:15 also 23:03 also 23:43
I realise I am barking up totally the wrong tree, but I love Sue Perkins! And Aisling Bea, which is slightly more possible...
I had an Erector Set and a chemistry set back in the 60s. Thinking back you probably couldn’t give a kid more dangerous toys.
A friend in college had a gas station at 5th and pine in Wallace Id. Very close to the center point.
A lad in one of my science classes ate a piece of pig heart when we were dissecting it 😂. I was nearly throwing up so I'm not surprised he did 😂.
Hence the Monty Python exclamation
“A bowl of pus?!?!”
🤮
Does not the Way of Mrs. Cosmopolite clearly state that There Is No Time Like The Present?
So in the last part I am not sure what the chinese experiment was. There is such a thing as quantum teleportation and there is such a thing as entanglement. Entabglement however cannot be used to transport informatiin and at least mathematically we understand it quite well. Esentially particles have states and a two particle or multiparticle system can have a joint state.. We call that state entangled when the probability of a particle being in any given state depends on the the other particles states. In the easiest example we have two particles that each habe two possible states. If particle A has state 1 particle B has to have state 2 and vice versa. So if you measure particle B in state 1 you know particle A has state 2 but there is no information transported because particle B being in state 1 and particle A being in state 2 is absolutely equivalent.
But you can have information in the form of a message be transferred this way.
Let me give an example, we have two quantum entangled particles, one on earth and one on the spaceship travelling proxima centauri, when it arrives at proxima centauri, the state of the particle will change (how to do this /shrugs) and thus the people of earth will know that the spaceship arrived, instead of waiting four years for a message.
This is how we can beat the speed of light transmission but the meta-data (meaning of the state change) will be outside of the entangled particles.
@@chasindigo No. They won't. They can only know it changed when they measure it but they don't know if they measured it first or second and they don't know the initial state before it was measured.
QI is basically a middle school substitute teacher in a half-empty class of kids who are not really in the mood of following.
Stephen fry is one of the best human of the last century
Alan's face 😆 3:13
I really miss Stephen Fry on QI, oh that rhymes 😂
Its not radiocarbon dating, that is only useful for dating relatively recent objects. They date older ones using isotopes of other elements. So if you fill the atmosphere with neutrons from an atomic explosion you alter the natural, background, radiation level and associated isotopes.
The last bit. Before she answered fax machine I really thought too as well 😂 and I'm not even on the age when its usage circulated. But like yes, it feels like fax machine.
Great. Never knew Quantum Physics is just essentially a fax machine. Live and learn!
As a certified Pastafarian minister, I am a bit disappointed that he didn't get to say how "intelligent falling" is dupposed to work
Sure lets have an episode on the universe and one of the guests happens to be an astrophysicist....
Regarding the very first part with Brian Cox: Time doesn't exist. It doesn't affect us, we don't affect it. It is merely a measurement from one point to another on a path we can't visualize without it. Time is not a physical thing, it is an abstract idea, just like numbers in general. Numbers don't exist. They are merely what we use to measure. We watch too much media regarding time travel, because people are really believing we might be able to do such a thing someday. Even just the simple fact that they think time slows down the faster you move. It doesn't. Time doesn't do anything. The object is still aging like we are, we just don't understand how to measure the time difference with the added stress of the speed. The speed is affecting the instruments.
19:41 imagine that being said today and the amount of complaints the BBC would get.
how the feck did he work out how much the cows would weigh, while going 99.9999999999999999999% the speed of light in one second is awesome
That definition of Theory is the same definition for a guess or estimation
No it's not 😂
Funny, in that Brian Cox had previously said that "at the same time" was meaningless, yet in the same video we hear that events to entangled particles happen "at the same time". I know it's a science geek thing, but it was a kind of "what?" moment.
At the same time and now are two different things!
@@B-A-L In geeky science terms, "Now" travels at the speed of causality. ie. '"c", or the speed of light. For example, we can't tell if Betelgeuse has gone nova because it's "now" hasn't arrived yet.
Brian Cox actually details this on one of his talks to A Level students.
have you ever noticed that we have trust stephen. show me the round thing
Are neutrons stars ever that round though? Unless the thing collapsed with zero angular momentum, it would still have some centrifugal forces forcing out of round. My answer is the new kilogram standard silicon sphere.
The present is the moment you're reading this. The past is the last sentence you read.
It's a misunderstanding that quantum entanglement transfers information, the instant change on the other end is faster then light, but no information is being shared, just a change on both sides.
A way of looking at this is imagine if both sides have a closed shoebox, when 1 side opens it and observes whats inside, the act of observing determnes wether its 1 or 2 shoes, and at the same time the box on other side changes to that same result of 1 or 2 shoes, but they also have to open to box to observe the result on the other side.
My explenation is probably missing some stuff, this stuff is difficult, but in short, since no information is being transfered, no laws of physics ie speed of light, are being broken, it would lead to all kinds of time paradoxes with instantaneos messages over vast amounts of spacetime being able to travel back in time to before the message was send in the first place, the universe will not allow it.
Is there some reason we could not agree ahead of time that some specific action is to be taken when we see the change on the other end? Similar in idea to saying "once I turn on the light and you see it, you then press the button" (whatever that button happens to do), such that you can send a message of "press the button now" long distances at the speed of light. Only this time, it moves faster even than that.
Or is there something inherent to the process that prevents this? Or do we even know the answer to that at all yet?
@@riluna3695you can only see the light being turned on at the speed of light.
You can't use entanglement to send a message faster than the speed of light. Any measurement of an entangled system is random and unpredictable.
To confirm that measurement would require communication between both parties using conventional methods.
Yawn...This is a comedy @@riluna3695
@@riluna3695 because the other side has to open the box to see what changed, its just randomness moving faster then light.
The inherent thing that prevents it is that information cannot travel faster then light.
Your specific example would translate to something like morse code, but you are forgetting the act of observing matters then, the only time we see if its randomly 1 or 2 shoes is when we open the box, and a closed box tells us nothing so theres no way to signal with it.
And again, this would create time paradoxes over vast spacetime, the universe simply does not allow this, any faster then light travel is nothing more then fiction.
Since you are intrested enough to mess around witht the concept you will probably like this:
ua-cam.com/video/BLqk7uaENAY/v-deo.html
That vid explains it much better then me, and that channel is on another level for theoretical space civilisations and other cosmic phenonema, highly reccomended.
So said Schrodinger
There is what we know, then there is what we don't know
Poor old Johnny getting laughed at, but he is not wrong.
We can "observe" a different part of the universe every night of the year, which depends on our rotation of the sun. So the centre of the observable universe is the centre of gravity (barycenter) between the sun and the earth which is really close to the center of the sun.
Could the centre of the universe be the point of the Big Bang?
@SamuelBlack84 I am no scientist, but I don't think so.
All matter would have had to have been ejected from the big bang in an incredibly even way for the big bang to still be the centre of the universe. As large clusters of mass would act upon each other and travel away from the big bang slower than less densely packed clusters of mass.
Again, I am no scientist, and this is just what I think.
@@glendaly3344 I would agree with you
If you believe in intelligent design, then you must believe in intelligent design warranties. All designs and warranties have an expiration date. And yours is by Tea Time tomorrow. I got a peak at it up in the old man's shop yesterday during the cricket match. Nice knowing you. Don't make any long term plans. 😂
The dustbin at 23:30 - is that the dustbin of history or of science?
Which episode is this from? I'd like to purchase a copy as well as the appropriate book of QI that covers the foreskin topic. As an atheist, I really want to add it to my collection. Thanks.
I have a follow up question on the photon. Was the change instant or did it take the time light would travel.
It's instant but you can't use it to communicate. The description about doing something to the banana that then is copied on the other half is not actually what happens. What actually happens is that you make an observation of one half of the banana and you observe that it is identically correlated with the other half, the weird thing is that the outcome of your observation is completely random and you can't predict what it will be, but it will always correlate exactly with an observation made on the other half of the banana.
Carbon dating before 1950 is also unreliable for the exact same reason. There’s no way anyone could know, and no reason for us to assume that the level of carbon dioxide in the atmosphere has remained constant over time (the core assumption of carbon dating).
No one assumes (or at least scientists don't assume) that carbon dioxide levels have remained stable over time. However, carbon dating is definitely reliable, if samples aren't tainted and everyone understands the limitations of the process ie that the dates it gives aren't ever going to be pinpoint accurate but the most probable range. Also, there's definitely ways to estimate what CO2 levels used to be, such as analysing ice cores since their trapped bubbles of air preserve the chemical composition of the atmosphere at the time they were laid down. Going back millions of years, you can't do carbon dating anymore of course, but you can still tell CO2 levels through things like counting the stomata of plant fossils, which are fewer when atmospheric CO2 is high. How much CO2 is in the atmosphere at any given point in time is a highly variable and important measure, but scientists have a number of ways of calculating it.
Umm.... Living organisms absorb carbon-14 which, when they die, starts breaking down into other atoms. It's by measuring that decay that the dating is established. The metric is the current atomic state being an indication of time passed.
The levels of atmospheric carbon are irrelevant.
It's not about the amount of carbon in the atmosphere.
It's about the ratios of carbon isotopes that remain in the samples, since 2 of those 3 isotopes has a half life while the other is stable.
Your argument has been said a million times and a million more times we have answered it.
Yet the question keeps being asked.
Ben Goldacre looks like Milton Jones.
Even foes the eyes thing
Alan Davies is like James May
12:16 Stephen Fry looks exactly like a 1970's Michael Parkinson.
Of course nuclear testing is one aspect, but fossil fuel burning would also skew the numbers. The carbon in the atmosphere is now "pre-aged".
For the love of all that is holy, QUANTUM ENTANGLEMENT ISNT TELEPORTATION, no information is transmitted or transferred.
Its like having two decks of shuffled cards and whilst you dont know what way the decks are shuffled, you do know that both decks are shuffled the same.
And like two decks of cards the second you shuffle or add a card to one deck, you now no longer know they are ordered the same
So no its incorrect to state "whatever you do to one will happen to the other", it is only correct to say "the state which one is observed will be the same state the other is"
Time is now and a millionth of a second is then
Einstein didn't 'overturn' Newton's gravitational model, he merely said when you go fast, Newton's model doesn't hold.