When he talks of the amount of information in a black hole, what is he talking about? Does he mean information about what my cat had for tea this evening or what? I'm so confused😢
lol yeah i love his casual vibe. He always talks like he is sharing a spliff with some physics students. You know? Like, Neil Tyson is very passionate too, but its more like a cocaine vibe, very loud and in your face. This is excitement on my mellow level😁
Brian Greene put it in this perspective: If you took a single atom, and expanded it to be the size of the OBSERVABLE UNIVERSE, the planck length at that scale would be roughly the size of an average tree. So a tree is to the entire universe, as a planck length is to an atom. Unfathomable.
@Patrick-zr8tv wait until you find out that this comparison is to the OBSERVABLE universe. The actual size of universe is calculated to be 150x bigger than what we can see.
That's a bad reference of scale since we have no idea how big the known universe really is...... we only know how far away we can see has a limit because the speed of light has a limit. That's not the same thing as saying the cosmic background is the fence and nothing beyond it........
@alanunruh7310 I think good to recall that to my understanding he's stating "observable" universe, not the "true" or "actual" universe... which is over hundred (or heck thousands, or even unmeasurable) times bigger.
space occupied the infinite nothing and a tiny universe occupied a tiny tiny bit of that infinite space and in order to function it is a contained syetem and maybe the universe is some 100 trillion light years in diameter then images of parts from the outer parameters [ galaxies random zillions of rocks and suns ] will take trillions of years to get to us the observable universe is the size of a grain of sand millions of miles away we got to exist for 100 trillion years just to see what 20-30 % and there are videos suggesting we can see the outer parameters and even into other universes which I must say is pure ass delusionally ideated bull shit !
What I love about this subject from Brian is his great ability to help a storyteller brain like mine understand the relevance, the issues, the power and the stories that physics brings to humanity. I shared this on my FB. I'll never be one who can do the work of actual scientists and engineers. But since I was. kid, I have always been transported and inspired by the work they do. Much appreciated.
Planck Length: The Smallest Possible Length The Planck length, approximately 1.616 x 10⁻³⁵ meters, is the smallest meaningful unit of length in physics, according to the Centre for Astrophysics and Supercomputing. It's a fundamental unit derived from the speed of light, the gravitational constant, and Planck's constant. At this scale, our current understanding of physics, including general relativity and quantum mechanics, breaks down, suggesting the need for a theory of quantum gravity.
Fundamental scientist's creed: "To the best of my ability to observe, this explanation is valid. Should my observational ability improve, the explanation may change."
This very thought is what helps me sleep at night but also keeps me awake as I ponder every possibility I could imagine, it’s the things I can’t even imagine that really excites.
Love the idea of resurrection, would you call that a personal escape from eschatology ? Science can’t disprove a phenomenon that lacks any empirical evidence.
I've always fondly remembered my college astrophysics class, where in one hour, the professor derived Chandrasekhar's Limit, teaching all the QM reasons why it had to be so. To do it all in an hour on a chalkboard, he had to do a LOT of sloppy math, canceling things out that were "close" but not really that close, making assumptions about function values that really didn't quite work in that context, etc. But still, at the end of the hour he was within something like a factor of 3-4 of the actual value. "Close enough for government work!" he proclaimed. 🙂 And that has always amazed me, that he could be THAT rushed and THAT sloppy, and still get an answer not too far off of the right one. His name is Ron Webbink, and I see he's still a Professor Emeritus at Illinois.
@itsjun2kits probably just his constant smile, he does just generally love explaining these things, its not a malicious smile but one brought from him actually enjoying explaining what he saying
Insane how much just a constant can reveal about our universe and it shows up in various equations. To develop an intuition of just a constant is a great feeling
What a beautiful narration Brian Cox can do. Even if you aren’t a science person, you would have an inner urge wanting to keep listening him! Just a pure raw talent:)
I love getting to listen to him just go, he loves his subject so much. I've seen him in interviews and he keeps getting interrupted when he's trying to express the beauty of the science and its like someone hitting the breaks every 10 seconds.
I love watching Brian’s explanations. Although I never miss the opportunity to watch, I ALWAYS come away knowing less than I started out with, I suppose that is “Cox’s Certainty Principle”.
I think what's most amazing about this video is the fact that Brian simply spoke through what are typically known as very difficult concepts, and made them almost understandable to lay people like myself. I actually closed my eyes for a good portion of it and just listened to his voice. It's amazing that he's able to simplify these heady subjects into something even idiots can almost understand
I really like the analogy that the planck length represents the "pixelation" of the universe. A state beyond which nothing can be measured, quantified, or even matters.
Patiently and beautifully explained by Prof. Brian cox the importance of fundamental measurements of nature and how Plank Scale holds profound significance for the Universe and us. That's why Prof. Brian is very very popular for his explanations of physics, astrophysics and other stuff discovered, painstakingly through ages by many many theoretical investigations and experiments- through the process of science. Thank you Prof. Cox for your slowly (necessary) and patiently explaining the fundamental scales with appropriate and significant examples here. Thank you. This is fantastic! I have loved this! 😍🤩👍❤ Will sure try reading your Quantum Universe to grab more understanding.
I love how often Brian brings up measurements! Because that’s all we have; the only things we know are what we have measured. And to ask if something exists is to ask if it can be measured. The question of what a measurement is is one of the great remaining unsolved mysteries of our universe and the more I read about it the more questions it poses!!
@jjt1881 I mean, you're talking about measuring abstractions. Abstractions require an interpreter (generally a mind). So when we talk about measuring these things, we're really talking about measuring what people think of them or how they react to them. And we can measure that. Abstractions have real implications, so that is very measurable, even if there are fundamentally subjective elements to it. We can also measure aspects of these aesthetics as people create or acknowledge them. For example, you can measure the frequency of certain words in poetry, the syllables, the themes, etc. Obviously that doesn't mean there's going to a universal consensus from that result beyond a purely objective analysis of the aesthetic and the people experiencing/creating that aesthetic.
Professor Cox is masterful in the way he is able to make the frontiers of knowledge, the edges of our understanding of the universe, accessible to all. His enthusiasm is infectious; it's so obvious that he loves his subject and delights in sharing his knowledge. My educational background is in the hard sciences and I love how he develops his thoughts and explains things to a general audience without ever talking down - he lifts up his listeners and is an inspiration.
10,000,000m from North Pole to equator on a line passing through Paris. It had to be *something*, of course, and aligned with the ideals of the French Revolution, which sought to dehumanise much of society… This definition of length also provided a definition of volume and also of mass. One decimeter cubed (ie. a litre) of pure water weighs one kilogram. It’s elegant and allows quick mental estimates of various properties from others. I’m surprised BC associated the metre with a biological property - a strange assertion for him to make…
@roscozone8092I think he was referencing a story that the "yard" in the imperial system was the distance from the tip of the king's nose to the king's thumb when his arm was outstretched.
@roscozone8092 It shocked me that he clings to the medieval ways of thinking even when approaching such a pure scientific measurement system as SI, which he should be more familiar with as a scientist, especially in astronomy where things aren't measured in feet, pounds or barrels. And what he shows as a "metre" is two times smaller than the actual metre.
Thank you for trying to explain in layman's terms to interested people who don't have the capacity for all of it. I appreciate your time and that you share your knowledge with us! I love learning about these things but could never make it through a textbook.
I drank a shot of absinthe every time Brian said the word 'calculation'. I have now collapsed into the universe's first Wasted Hole where nothing, not even beer, can escape it.
The measurement of one meter is based on the speed of light in a vacuum. Specifically, the meter is defined as the length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second. This definition also relies on the second itself being precisely defined in terms of the caesium frequency. This modern definition, adopted in 1983 and rephrased slightly in 2019, provides a universal and unchanging standard for length, as the speed of light in a vacuum is a fundamental constant of nature.
Wiki Metre: "The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's polar circumference is approximately 40000 km."
What an absolute way of imagining or getting idea about dimensions of physical quantities. Thanks for giving me the idea and I'm gonna use to get the idea about the measurement of other physical quantities like mass, time, speed etc.,
I wonder why the editors didn’t correct errors before releasing the video. Brian Cox is a great physicist. Did Isaac newton published his Principia in 1687, not in the 1780s or 90s. Also, my understanding is that the metric system is based on the dimensions of the Earth, not parts of the human body.
It is. But the imperial system was based on earthly things. Cox is a communicator and sometimes to do that you have to simplify and introduce inaccuracies.
Yes. But Newton did not know the value of his gravitational constant. It was measured by Lord Cavendish in late 18th century. This measurement also allowed Cavendish to calculate the mass of the Earth, The sun , the moon and other planets using Newton's laws. Google Cavendish experiment if you want to know more.
For gawd’s sake people; the point he is making about metres is that they are contingent - i.e. made up. They are mere conveniences. Yes, yes, he said metres were biological and that’s not strictly true. But that wasn’t his point. Feck, these days we have Americans saying aloomynum, and using “momentarily” instead of “presently” and we let those slip. Chill and let the man do his stuff.
The metre was based on a random piece of metal that Napoleon decided must be adopted by the rest of Europe…primarily because of his obsessive hatred of Britain. It’s strange to think this system exists solely because of the ravings of a power crazed maniac.
The limit of the speed of light is no more significant than a bartender kicking you out at closing time. Someone stays sober to know when everyone else has had enough.
It is only a speed limit in terms of velocity. You could bend the space in front of and behind you so that you travel to a distant star instantaneously which would seem like you have travelled faster than light but you haven't really, in fact you haven't even actually moved, yet here you are a few hundred light years away. Somebody is always trying to limit us by creating laws saying we can't do stuff. According to the 'equations' that literally only a handful of people in the world can understand, there are rules and laws that confine / restrict what we can and can't do. We have to take their word for it because that is apparently what the 'equations' say.
@mikestray76 These circumstances are covered by my metaphor. The Heineken Certainly Principle; ie. 'You don't have to go home, but you can't stay here.'
I couldn't begin to study this in school, but I really enjoy listening to you and learning what I can. The material changes my perspective. So, thank you for your kind, patient and enjoyable presentations. You're a great guy!
He always talks about science with such passion like none other I've seen lately. And it goes in all his videos where they ask him directly questions. If he has someone with him this spark is not there. Thank you for video. Amazing
Brain is infectious everytime. Now imagine that: 1.4 times the Sun’s mass crushed into a 20 km sphere, the minimum needed for a star to collapse into a neutron star instead of a white dwarf. Planck’s constant is the quiet law behind that cosmic pressure. Mind-blowing
I don’t think it’s a stretch to say that Brian has done as much for science as many of the greats that came before him. Maybe not in terms of raw scientific discoveries, but his ability to explain and break down incredibly complex material into understandable explanations is so so so so important.
If another Cosmos series is made, and true to the Sagan series, it should be Brian Cox, as much as I love Tyson, I would love to have Brian Cox be the host.
The meter is based on Earth's size, "One ten-millionth (1/10,000,000) of the distance from the equator to the North Pole." Granted the measurements back then, centuries ago, weren't precise enough and the metal bars that standardized the meter kept changing sizes by themselves, so now the meter has been frozen by pegging it to universal constants. So it is not based on the human body. The imperial system is though.
You misunderstood his meaning. He meant that the metre is of a size we relate to, just like the imperial foot, inch, mile etc, its is of a unit that has everyday meaning. It is similar in concept to thinking of things in relation to the length of a football field, or volume of an Olympic size swimming pool, when thinking about bigger things. The length of a metre is in fact arbitrary. We could simply declare that starting today, a standard metre will be double its current length. That would mean the speed of light then becomes (approximately) 150,000 km per second - of course the physical length has not changed, all we have changed is the length of a standard unit. I think the latest definition of the metre is the distance light travels in 1/C seconds (ie. the reciprocal of the speed of light). Note that the numerical value of C is completely different when we use units of a mile -the distance does not change, just the arbitrary unit changes.
@jumboegg5845 you misunderstood @cesarparra6025 meaning. The length of a metre is in indeed arbitrary. But not based on biology. Prof. Cox could've said that and be more precise and educated some folks ;-)
@jumboegg5845 I did get his point, it is just that he used the meter as a measurement based on the human body, which is not the case. But yeah, measurement systems based on universal constants are better than the ones based on arbitrary stuff.
@cesarparra6025 That is the very point - the metre is a good practical size relative to the human body. It is a good size for the things that humans measure. It is not a measurement based on the human body. We could declare that a metre is the length of an Olympic swimming pool (50 metres) - but that would be a clumsy standard length. Note that one thousandth of metre (a millimeter) is also a very good precise practical measurement - any smaller and its getting hard to see with the naked eye. The whole point of the metric system is the decimal system, the exact definition of the metre is arbitrary.
That length for the meter, however, was chosen because it was a standardizable measure that was close to the length of an imperial yard, as well as to other similar units of length that existed elsewhere in the European world. Those units, though similar, varied from one to the next, a variance which wasn't a huge problem when commercial, technological, and scientific interchange was below a certain threshold, but became an obstacle once those activities surpassed that threshold. But those base measures that were superseded by the creation of the metric system were all dependent on the human body or human actions. The "one ten-millonth" (rather than a millionth or a hundred-millionth) was chosen because of its nearness to pre-existing, human-dependent measures.
To be fair he probably heard it at some point in his life but there's a whole lot of other information crammed into his brain and his subconscious was like "what's this file? Lol yeah, delete"
@ivckins I believe he was disappointed at the accuracy & thought “things can only get better” and forgot about it. We can only D:Ream what else he heard about and forgot. Brian Cox - UR the best thing!
This is outstanding. Brian Cox is among the very best science communicators. He’s just sitting on a chair, talking to the camera, and very effectively describing some of the most abstract physical concepts. No graphics, just voice and hand gestures. Amazing.
Planck time is the length of time that it takes light (a photon) to travel the distance of one Planck length. The "building blocks of the universe" are the Planck units, and it all comes down to the speed of light. That is the fundamental constant. If light, or anything else, could travel faster than that, it would be in different locations at the same Planck time, in other words, in two places (or infinity) at once.
He's not here to discuss the metre. He's using it as an abstraction that we defined willy nilly (willy nilly in the sense it's not rooted in any hard, tangible sources)
Yup, the point he was making still holds - many measures we use are based on things that don’t tell us much about the nature of the universe, which makes them different to the Planck length. The original definition of the meter was based on the size of the planet which we happen to inhabit, it has no further significance anywhere in the universe.
Brian has such a huge brain in complexity it's insane. I understand some bits but he makes it sound so much easier such a class presentation and narrator. Top bloke
This reminds me of an article from The Onion years ago where it was reported that an entire universe had been discovered hovering about 3 meters above a Walmart parking lot. The scientist goes one to describe this distance involved as "mind boggling." (I try to stay with him on this stuff, but really I just like listening to him talk given that I struggled to make it through high school algebra.)
It was from the equator to the North Pole, specifically on the Paris Meridian, kind of but not really because they screwed up the measurement. They were off by about 2000 meters.
I find it kind of concerning that Dr. Cox does not know this. It would seem to be fundamental background knowledge if you're going to explain the nature of measurement systems.
@HJV24 i think you've nailed it, they needed something that would be large enough that a prototype and it's copies could be accurately made, but small enough to be handled on a human scale. 10m would be too big to handle, 0.1m has only a tenth of the accuracy.
If only math, chemistry and physics were this understandable in high school. It would be nice to have a study hall for those interested and motivated to show up and to get help from tutors. Maybe show a few videos at the beginning of the semester on why the class so historically important to the society and civilization.
There are theories that suggest that Planck grid is a real thing and when photon moves from one planck length to another then it moves like suddenly one planck length and then waits for a little while to compensate the speed of light. Then magically the next planck length etc
You misunderstood his meaning. He meant that the metre is of a size we relate to, just like the imperial foot, inch, mile etc, its is of a unit that has everyday meaning. It is similar in concept to thinking of things in relation to the length of a football field, or volume of an Olympic size swimming pool, when thinking about bigger things. The length of a metre is in fact arbitrary. We could simply declare that starting today, a standard metre will be double its current length. That would mean the speed of light then becomes (approximately) 150,000 km per second - of course the physical length has not changed, all we have changed is the length of a standard unit. I think the latest definition of the metre is the distance light travels in 1/C seconds (ie. the reciprocal of the speed of light). Note that the numerical value of C is completely different when we use units of a mile -the distance does not change, just the arbitrary unit changes.
@jumboegg5845Let us agree you do not know the story well enough to really understand my point. The idea of using a standard system of units for both science and trade has been born long, long before, but mostly an empire brought the standard just by winning battles and wars. Later trade organizations like the Hanse tried to set and use standards, each craft in each city had its own ones. Which made trade between cities or crossing regional or country boarders a nightmare. You will end up with N^2 re-calculation tables. The definition of the meter based on the circumference of the earth also defines the volume and the weight (cum grano salis) using a substance nearly abundant on the earth: water. A decimeter cubed has the volume of a liter, a liter of water and some standard temperature and pressure has the weight of a kilo. Now you see where you end up by doubling the meter. Using this method people were able to walk in with a meter stick and rebuild a standard volume and a standard weight. A physicist should know the history of these units since we are using them for the one and only thing that matters in physics after thinking about new theories for years: The measurement! In 2019 the whole system has been redefined based on universal natural constants. Finally: The system is still arbitrary in a way that I am as unwilling as Brian to keep all the natural constants in mind. The second is still an approximation of the 1/86400 part of an average earth day. The speed of causality is based on this definition, the meter now depends both on c and the definition of a second. When talking alien intelligence it might be more easy to use a binary representations of some mathematical constants like e, pi, the golden ration and others and send those over to get started.
@HJV24 I just explained the story above - the standard metre (originally one ten-millionth of the distance from the North Pole to the equator) is a good practical length. Being the metric system, there is no difference between one 10 millionth and a millionth, except where you put the decimal place. The story would be completely different, and no better than the imperial system, if they had of decided a metre is some weird fraction of the distance from the North Pole to the equator. Note that the distance to the north pole was just used as a relatively constant reference - if an Olympic swimming pool was a constant, then we could be measuring things in pools, millipools, kilopools, etc.
"The meter is based on biology." The good professor, bless his heart, skipped one too many history class. The one about the huge effort the French made to measure a quadrant of the Earth to create a unit of length that was distinctively *NOT* based on biology. It was precisely the entire point.
How are half the comments people getting a real kick out of correcting him on this one detail 😂 Still, it was based on an arbitrary, "human-centric" distance. Telling an alien about the quadrant of the earth or whatever it was would be about as informative as the length of an arm.
Do you think it was an accident that the meter came out to be about a yard? No, they wanted the meter to be about a yard first (the basis) and then invented a definition (the definition) in such a way that it turns out to be about a yard. There is a difference between basis and definition.
The origin of the meter was not related so much to the size of humans but to being one tenth millionth of the distance from Earth’s equator to one of its poles along its surface.
On the meridian that runs through London, I believe that is the Prime Meridian. All that said he quantifies these fundamental principles in a very concise manner and qualifies the complexity.
The metre is still at human scale, though, that was the point - he didn’t say it is *defined* against the human body, but it is close to the existing imperial yard.
@stereoroidevery system is a human contrivance. More and more they are based on human perceived characteristics of nature. Why is water the basis for C°? Why is a lightyear based on the duration of the Earth’s orbit? Why is Earth the only planet that isn’t named after a god? why in a nanometer ten times is long as an angstrom? Why is the word long used both in distance and duration?😂
@HJV24yep, if they would have done one millionth tape measures would weigh 6.6 lbs or 3 kilos and be the size of a briefcase. Yard…I mean meter sticks would be over 30’long-I mean pert’ near just about 10 meters long and a millimeter would be almost a centimeter and that would mess up the whole nanometer and angstrom thing. That would really foul up conversion tables, everything would have to be times ten to the first. Just imagine buying boots, do you get size 1.15. I’m thinking we’d be using miles, bushels, pints, pecks, and the good ol’ 7.480523 gallons per cubic foot instead. All wrenches would be SAE and you wouldn’t need two sets of sockets. 10 and fourteen millimeter bolts would only be found on mega equipment. Hey buddy, can you pass me that 1.4 mm socket or just grab a 9/16”. Okay, I’ll 🛑 😂😂😂
I remember a while back there was a persistent incongruity of measurement results for the Planck constant. Has that been reconciled yet? (Haven't had time yet to finish this).
The meter is not based on the body of some random human, it is based on the measurements of the earth, the tenth millionth part of the longitudinal arc that goes from the equador to the north pole
Whilst I found the exploration of the uncertainty principle and the planck constant and white dwarfs fascinating, I didn't hear anything at all that justifies the planck length as being a meaningful length, just an arbitary measurement with about as much meaning as the foot, which has then been used to make some measurements. But to my mind that doesn't make the planck length fundamental, and until the theories of relativity and quantum mechanics have integrated, its really nothing more than an arbitrary guess at what might be a fundamental measurement. Essentially no more meaningful than any other measurement that humans have invented in their imaginations.
Would be worth thinking about Planck length as the answer to this question: "if we look at every equation that humanity has, that includes any calculation involving length - what is the lowest common denominator?" That length is the planck length, pl. The actual number can be calculated based on a similar question: "if we look at every equation that humanity has, that includes a calculation involving speed - what is the highest common denominator?" . That is c, expressed as length-per-second. If we then assume that the passage of time, in the background, increments constantly and exactly (and that is an assumption) then we have a bounded limit, we can then create an equation where the maximum limit is where time = 1, the speed is c, and the distance travelled is lp. Can then be expressed as: lp divided by 1 = 1 divided by c. However, this then introduces an inconsistency with other calculations involving distance and time - which leads to the assumption that relative time can be altered (relativity) and/or that lengths can be 'bent'. Assumed to be true - but there's always the possibility that the foundational observations/measurements used are slightly out, or that the calculations used have introduced small inaccuracies that make it looks like space/time bends. I think I saw somewhere a recent analysis of the James Webb telescopes observations re: 'space triangles', that did all of its calculations based on angles in radians (instead of calculations based on lengths) - I think I remember reading that the results surprised the authors as they show that space is flat and does not bend. This mismatch on outcomes between two different calculation methods, suggests that either the calculation methods themselves have a hidden error within them (e.g. if Sine and Cosine are slightly out) - or that the calculations of c and lp are slightly out (in which case, they are slightly out universally for every calculation that ever uses them). Where there's a contradiction/exception to the rule, there's usually a new theorum to be found: It's an interesting contradiction to explore for those that want to go deep!
I was under the impression that the meter was meant to be based on the measure of the earth. Google, AI search: The meter was initially defined as one ten-millionth of the distance from the Earth's North Pole to the Equator, measured along the meridian passing through Paris. This definition was established during the French Revolution as part of a broader effort to create a decimal-based, universally applicable system of measurement. Later, the meter was redefined as the length of a specific platinum-iridium bar kept at the International Bureau of Weights and Measures. Today, the meter is defined based on the speed of light and the second. Nothing to do with the human body.
Correct Sherrie. Good explanation, thanks. I'm surprised Brian didn't reference that. Compare 'cubit'. Now, that's an ancient historical measure of the length of Brian's fore arm !
We are the microbes in the petri dish trying to define the experiment from inside the experiment. It may be that we can never in a trillion years nail down every principle of the universe, but that doesn't mean we should stop trying. In the meantime, quantum mechanics can not explain that haircut.
The unit of length called the meter was not defined with the human body as its reference. When created, it was defined as the distance from the equator to the pole divided by 10 million.
In the Operational Superunification Theory (OST), the cosmological constant is understood as the ground state energy density of a supersolid condensate, which is kept naturally small by the presence of a Planck-scale lattice structuring spacetime.
Wiki Metre: "The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's polar circumference is approximately 40000 km."
Yeah. Brian's Britishness was showing there. Not only has the meter never been associated in any way with anatomy, it's not remotely close to a forearm's lenght (it would be a full arm plus the distance from your shoulder to your nose, roughly). The whole point of the invention of the meter was to move away from the complete madness of arbitrary units and tie them to rational constants. But of course, that would require everyone to get on board.... Also why does the planck length have any special meaning in the measurement of the volume of a black hole? Presumably you can use any units of measure you want, including meters....
@1ifemare I think it's the granularity of information that fits on the surface (event horizon) of a black hole and that is equivalent to the information needed to describe the black hole. Information can't fit in pieces smaller than the planck length, and because the surface is two dimensional you get square planck lengths describing the surface as a fundamental measure.
@pon1 Thank you for the explanation. Was pretty sure there had to be some deep reason for Brian to cite that example, but these types of videos don't generally dive deep enough.
I suppose they measured the distance first and then decided on the fraction somit would be "round" and about "human" size. I am pretty sure that's what the guy in the video meant.
Something reflections of the system, the range of influence and the rate of times procession. (when you get to that interesting part about the proton) thank you
![YoungBoy Never Broke Again - HeadTap [Official Video]](http://i.ytimg.com/vi/RwlT3hESUBA/mqdefault.jpg)
It appears that "as thick as a Planck" is not the insult I thought it was
😂
When he talks of the amount of information in a black hole, what is he talking about? Does he mean information about what my cat had for tea this evening or what?
I'm so confused😢
What about, ‘as thick as two short Plancks’? Surely must be doubly thick?! 🤔
@MrSpodULikeunless a short Planck is less than half a normal Planck ❤
🤣🤣🤣
He almost giggled when he explained the uncertainty principle. That kind of genuine excitement is infectious. I smiled.
You lucky skunk!
lol yeah i love his casual vibe. He always talks like he is sharing a spliff with some physics students. You know? Like, Neil Tyson is very passionate too, but its more like a cocaine vibe, very loud and in your face. This is excitement on my mellow level😁
I would definitely smoke a spliff with Brian Cox
I did not recognize Heisenberg's picture here as being Walter White, that must be due to the uncertainty principle.
@Tubemanjac lol take your updoot
Brian Greene put it in this perspective: If you took a single atom, and expanded it to be the size of the OBSERVABLE UNIVERSE, the planck length at that scale would be roughly the size of an average tree. So a tree is to the entire universe, as a planck length is to an atom. Unfathomable.
A deep dive into something so unfathomable, it took me out of my depth.
Surely that can't be right. I have no specific reason why I don't believe that, but that is a ridiculous disparity in scale. Surely not.
@Patrick-zr8tv wait until you find out that this comparison is to the OBSERVABLE universe. The actual size of universe is calculated to be 150x bigger than what we can see.
That's a bad reference of scale since we have no idea how big the known universe really is...... we only know how far away we can see has a limit because the speed of light has a limit. That's not the same thing as saying the cosmic background is the fence and nothing beyond it........
@alanunruh7310 I think good to recall that to my understanding he's stating "observable" universe, not the "true" or "actual" universe... which is over hundred (or heck thousands, or even unmeasurable) times bigger.
Alternate title: "Cox explains length"
Cox Length
“We measure, Cox”
Cox length does need to be a thing
space occupied the infinite nothing and a tiny universe occupied a tiny tiny bit of that infinite space and in order to function it is a contained syetem and maybe the universe is some 100 trillion light years in diameter then images of parts from the outer parameters [ galaxies random zillions of rocks and suns ] will take trillions of years to get to us the observable universe is the size of a grain of sand millions of miles away we got to exist for 100 trillion years just to see what 20-30 % and there are videos suggesting we can see the outer parameters and even into other universes which I must say is pure ass delusionally ideated bull shit !
👏👏👏👏👏👏
Now we know that a "quantum leap" is something almost unimaginably small.
What I love about this subject from Brian is his great ability to help a storyteller brain like mine understand the relevance, the issues, the power and the stories that physics brings to humanity. I shared this on my FB. I'll never be one who can do the work of actual scientists and engineers. But since I was. kid, I have always been transported and inspired by the work they do. Much appreciated.
Ah, but what is mathematics other than a form of story telling?
Planck Length: The Smallest Possible Length
The Planck length, approximately 1.616 x 10⁻³⁵ meters, is the smallest meaningful unit of length in physics, according to the Centre for Astrophysics and Supercomputing. It's a fundamental unit derived from the speed of light, the gravitational constant, and Planck's constant. At this scale, our current understanding of physics, including general relativity and quantum mechanics, breaks down, suggesting the need for a theory of quantum gravity.
He needs to get rid of that Karen haircut though. He's too old for that. Check his hard drive
⁰⁰😊⁰
Try Richard Feynman
I hope people who enjoy these Big Think videos don't skip over this one; it's as profoundly mesmerizing as any of them.
Fundamental scientist's creed: "To the best of my ability to observe, this explanation is valid. Should my observational ability improve, the explanation may change."
This very thought is what helps me sleep at night but also keeps me awake as I ponder every possibility I could imagine, it’s the things I can’t even imagine that really excites.
@JBHinCJBHImagine the possibility that Jesus Christ actually resurrected. As impossible as that sounds it changes everything.
@flamingphoenix824 no
The opposite of terminal delusion, when people cling desperately to invalid ideas regardless of the preponderance of factual evidence refuting them
Love the idea of resurrection, would you call that a personal escape from eschatology ? Science can’t disprove a phenomenon that lacks any empirical evidence.
I've always fondly remembered my college astrophysics class, where in one hour, the professor derived Chandrasekhar's Limit, teaching all the QM reasons why it had to be so. To do it all in an hour on a chalkboard, he had to do a LOT of sloppy math, canceling things out that were "close" but not really that close, making assumptions about function values that really didn't quite work in that context, etc. But still, at the end of the hour he was within something like a factor of 3-4 of the actual value. "Close enough for government work!" he proclaimed. 🙂
And that has always amazed me, that he could be THAT rushed and THAT sloppy, and still get an answer not too far off of the right one. His name is Ron Webbink, and I see he's still a Professor Emeritus at Illinois.
He’ll always be Emeritus
Brian Cox does a great job of explaining these things in a way we common folks can somewhat understand. I also think his shirt looks pretty cool!
He low-key creeps me the fuck out though I won't lie
@itsjun2kits probably just his constant smile, he does just generally love explaining these things, its not a malicious smile but one brought from him actually enjoying explaining what he saying
@itsjun2k yo another Junaid
Amen. He is the best at explaining super complexity to the common. To the point it excites us to try to learn more. He is special.
It's called the Brian Cox explanation measurement based on oration of simplicity...
Insane how much just a constant can reveal about our universe and it shows up in various equations. To develop an intuition of just a constant is a great feeling
What a beautiful narration Brian Cox can do. Even if you aren’t a science person, you would have an inner urge wanting to keep listening him! Just a pure raw talent:)
It’s that winning smile!
I love getting to listen to him just go, he loves his subject so much. I've seen him in interviews and he keeps getting interrupted when he's trying to express the beauty of the science and its like someone hitting the breaks every 10 seconds.
It’s always been a pleasure to listen to Brian Cox speak ❤
I love watching Brian’s explanations. Although I never miss the opportunity to watch, I ALWAYS come away knowing less than I started out with, I suppose that is “Cox’s Certainty Principle”.
Brian Cox has grown on me, and he's helped my mind grow
I think what's most amazing about this video is the fact that Brian simply spoke through what are typically known as very difficult concepts, and made them almost understandable to lay people like myself.
I actually closed my eyes for a good portion of it and just listened to his voice. It's amazing that he's able to simplify these heady subjects into something even idiots can almost understand
Your right, Mr Brian explain in a very simple way that we are uncertain about anything, in this universe.
I've read that if you scaled a plank length sphere up to the size of a proton, that ratio would give the proton a radius the size of the solar system.
😯😯
I have read that if you scale the observable universe size to an atom, the planck length would be equivalent to the real size of that atom.
I love listening to Brian as he makes these physics topics understandable.
I really like the analogy that the planck length represents the "pixelation" of the universe. A state beyond which nothing can be measured, quantified, or even matters.
Apart from some fascinating information - listening to Brian Cox is also so easy!
Patiently and beautifully explained by Prof. Brian cox the importance of fundamental measurements of nature and how Plank Scale holds profound significance for the Universe and us. That's why Prof. Brian is very very popular for his explanations of physics, astrophysics and other stuff discovered, painstakingly through ages by many many theoretical investigations and experiments- through the process of science. Thank you Prof. Cox for your slowly (necessary) and patiently explaining the fundamental scales with appropriate and significant examples here. Thank you. This is fantastic! I have loved this! 😍🤩👍❤
Will sure try reading your Quantum Universe to grab more understanding.
I love how often Brian brings up measurements! Because that’s all we have; the only things we know are what we have measured. And to ask if something exists is to ask if it can be measured.
The question of what a measurement is is one of the great remaining unsolved mysteries of our universe and the more I read about it the more questions it poses!!
That's true but only about physical things. You can't measure beauty, love, or poetry.
@jjt1881 gotta get into a different field to study those things friend
@jjt1881 I mean, you're talking about measuring abstractions. Abstractions require an interpreter (generally a mind). So when we talk about measuring these things, we're really talking about measuring what people think of them or how they react to them. And we can measure that. Abstractions have real implications, so that is very measurable, even if there are fundamentally subjective elements to it. We can also measure aspects of these aesthetics as people create or acknowledge them. For example, you can measure the frequency of certain words in poetry, the syllables, the themes, etc. Obviously that doesn't mean there's going to a universal consensus from that result beyond a purely objective analysis of the aesthetic and the people experiencing/creating that aesthetic.
measuring something is comparing it to something else
It's almost as though everything is relative!
To put its size in perspective, if a proton were the size of the solar system, the Planck length would be about the size of a virus.
Acrtually it’s an optimistic view, it would be much smaller than a virus.
As this guy has aged he has become the pinnacle of explaining the most minute details about everything!!!
Professor Cox is masterful in the way he is able to make the frontiers of knowledge, the edges of our understanding of the universe, accessible to all. His enthusiasm is infectious; it's so obvious that he loves his subject and delights in sharing his knowledge. My educational background is in the hard sciences and I love how he develops his thoughts and explains things to a general audience without ever talking down - he lifts up his listeners and is an inspiration.
he talks absolute rubbish. if you are amazed about his babble, you are lowiq
this is one of those rare videos that make me actually grateful for the internet -- it's not only a curse and blight upon us.
i agree ... actually i don't think it's rare, if we remain critical, ask questions etc
imma take a drink every time he says 'Fundamental'
We need to know if you made it out alive
RIP
Don't throw your life away! 😭
For science, right?
You will be very drunk🎉😅
Stunning clarity in explaining such an important idea in modern physics. Hurrah, bravo!
I loved this guy in "Super Troopers."
I remember when this dude was young. I was getting old then.
Think I need to go sit down for a bit.😵💫
Don't worry about getting older, it's far preferable to the alternative.
Pal, we are lucky we can even stand up out of a chair!
@BirkGedhow long before we need a bubble wrap landing strip just to go to the bathroom safely.😕
congrats. that makes you a dead person. 🤣🤣
@JohnDoe-rm1kw I can still out work two twenty year olds _with_ a cigarette hanging out of my mouth.💪🏻😂
1:20 The metre's defined by some measurement of Earth.
A billionth of the Earth's circumference or something.
10,000,000m from North Pole to equator on a line passing through Paris. It had to be *something*, of course, and aligned with the ideals of the French Revolution, which sought to dehumanise much of society…
This definition of length also provided a definition of volume and also of mass. One decimeter cubed (ie. a litre) of pure water weighs one kilogram.
It’s elegant and allows quick mental estimates of various properties from others.
I’m surprised BC associated the metre with a biological property - a strange assertion for him to make…
@roscozone8092I think he was referencing a story that the "yard" in the imperial system was the distance from the tip of the king's nose to the king's thumb when his arm was outstretched.
Originally, one ten-millionth of the great-circle distance from the North Pole to the equator through Paris.
@roscozone8092 It shocked me that he clings to the medieval ways of thinking even when approaching such a pure scientific measurement system as SI, which he should be more familiar with as a scientist, especially in astronomy where things aren't measured in feet, pounds or barrels. And what he shows as a "metre" is two times smaller than the actual metre.
I do 30 sec planks every now and then, until my core collapses... I guess I reached my planks limit?
This is underrated top tier 😂
😂😂😅😅
No physicist so much as smiled at this comment, sorry.
@Steve-v8t3tshut up
You're under arrest.
Thank you for trying to explain in layman's terms to interested people who don't have the capacity for all of it. I appreciate your time and that you share your knowledge with us! I love learning about these things but could never make it through a textbook.
Wasn't there meter based on the northern hemisphere by newton?
The Yard is based on the length of the forearm, not the meter.
After he was wrong about the science behind the metric system I did not take him serious for everything he said afterwards
@edutwin thats fine, i guess brian cox is not allowed to make mistakes or miss speak
I drank a shot of absinthe every time Brian said the word 'calculation'. I have now collapsed into the universe's first Wasted Hole where nothing, not even beer, can escape it.
Good drinking game, that😂
This is an excellent drinking game! Only problem is that stairs become much faster…but infinitely more painful
You're my people!
This is either false or you typed that with one eye closed
Just don't play with scissors when drinking absinth.
First of all….. i thought a meter was based on the circumference of earth. Second…. That is all..
Your dead right ,
Hate to break it to you but the circumference of the earth is bigger then a meter. /s
The measurement of one meter is based on the speed of light in a vacuum.
Specifically, the meter is defined as the length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second. This definition also relies on the second itself being precisely defined in terms of the caesium frequency.
This modern definition, adopted in 1983 and rephrased slightly in 2019, provides a universal and unchanging standard for length, as the speed of light in a vacuum is a fundamental constant of nature.
Wiki Metre: "The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's polar circumference is approximately 40000 km."
@JedEckert 1/299,792,458 sounds like an arbitrary yet awfully specific number. Why do think they chose that number?
listening to explinations of the Planck scale, is like listening to the banter on the Heart of Gold in hitchhikers guide to the galaxy
What an absolute way of imagining or getting idea about dimensions of physical quantities. Thanks for giving me the idea and I'm gonna use to get the idea about the measurement of other physical quantities like mass, time, speed etc.,
I wonder why the editors didn’t correct errors before releasing the video. Brian Cox is a great physicist. Did Isaac newton published his Principia in 1687, not in the 1780s or 90s. Also, my understanding is that the metric system is based on the dimensions of the Earth, not parts of the human body.
It is. But the imperial system was based on earthly things. Cox is a communicator and sometimes to do that you have to simplify and introduce inaccuracies.
Yes. But Newton did not know the value of his gravitational constant. It was measured by Lord Cavendish in late 18th century. This measurement also allowed Cavendish to calculate the mass of the Earth, The sun , the moon and other planets using Newton's laws. Google Cavendish experiment if you want to know more.
For gawd’s sake people; the point he is making about metres is that they are contingent - i.e. made up. They are mere conveniences. Yes, yes, he said metres were biological and that’s not strictly true. But that wasn’t his point. Feck, these days we have Americans saying aloomynum, and using “momentarily” instead of “presently” and we let those slip. Chill and let the man do his stuff.
The metre was based on a random piece of metal that Napoleon decided must be adopted by the rest of Europe…primarily because of his obsessive hatred of Britain. It’s strange to think this system exists solely because of the ravings of a power crazed maniac.
The limit of the speed of light is no more significant than a bartender kicking you out at closing time. Someone stays sober to know when everyone else has had enough.
this is actually a goated gauge method, will be applying to my daily life. appreciated 🗣️😂
If you're getting kicked out at closing time, then you haven't had enough.
It is only a speed limit in terms of velocity. You could bend the space in front of and behind you so that you travel to a distant star instantaneously which would seem like you have travelled faster than light but you haven't really, in fact you haven't even actually moved, yet here you are a few hundred light years away.
Somebody is always trying to limit us by creating laws saying we can't do stuff. According to the 'equations' that literally only a handful of people in the world can understand, there are rules and laws that confine / restrict what we can and can't do. We have to take their word for it because that is apparently what the 'equations' say.
how does one turn the matter around them 'elastic' so that it can be squished together like tongs? @mikestray76
@mikestray76 These circumstances are covered by my metaphor. The Heineken Certainly Principle; ie. 'You don't have to go home, but you can't stay here.'
I couldn't begin to study this in school, but I really enjoy listening to you and learning what I can. The material changes my perspective. So, thank you for your kind, patient and enjoyable presentations. You're a great guy!
He always talks about science with such passion like none other I've seen lately. And it goes in all his videos where they ask him directly questions. If he has someone with him this spark is not there. Thank you for video. Amazing
Brain is infectious everytime. Now imagine that: 1.4 times the Sun’s mass crushed into a 20 km sphere, the minimum needed for a star to collapse into a neutron star instead of a white dwarf. Planck’s constant is the quiet law behind that cosmic pressure. Mind-blowing
Brian*
Sorry... it annoys me everytime I see my name misspelled
@brian8507it's not your name. It's the guy in the video's name. Stop making everything about yourself, Brnai
@B3Band i am the guy in video.
He deserves a knighthood. He would be Sir Doctor Cox. 😂
Shirt is soo nerdy and screams of metalhead at the same time😁
🤘🏻😎
Except he played on some hit 80’s music ;)
I don’t think it’s a stretch to say that Brian has done as much for science as many of the greats that came before him. Maybe not in terms of raw scientific discoveries, but his ability to explain and break down incredibly complex material into understandable explanations is so so so so important.
If another Cosmos series is made, and true to the Sagan series, it should be Brian Cox, as much as I love Tyson, I would love to have Brian Cox be the host.
I like B. Cox, but that is a little bit like comparing a good picture of a model to Issac Newton.
He deserves a knighthood.
The way he speaks about stuff that he loves so deeply is astonishing. I appreciate his sharing it.
Wonderful way to explain such complex concepts in such a fascinating manner.
The meter is based on Earth's size, "One ten-millionth (1/10,000,000) of the distance from the equator to the North Pole."
Granted the measurements back then, centuries ago, weren't precise enough and the metal bars that standardized the meter kept changing sizes by themselves, so now the meter has been frozen by pegging it to universal constants.
So it is not based on the human body.
The imperial system is though.
You misunderstood his meaning. He meant that the metre is of a size we relate to, just like the imperial foot, inch, mile etc, its is of a unit that has everyday meaning. It is similar in concept to thinking of things in relation to the length of a football field, or volume of an Olympic size swimming pool, when thinking about bigger things. The length of a metre is in fact arbitrary. We could simply declare that starting today, a standard metre will be double its current length. That would mean the speed of light then becomes (approximately) 150,000 km per second - of course the physical length has not changed, all we have changed is the length of a standard unit. I think the latest definition of the metre is the distance light travels in 1/C seconds (ie. the reciprocal of the speed of light). Note that the numerical value of C is completely different when we use units of a mile -the distance does not change, just the arbitrary unit changes.
@jumboegg5845 you misunderstood @cesarparra6025 meaning. The length of a metre is in indeed arbitrary. But not based on biology. Prof. Cox could've said that and be more precise and educated some folks ;-)
@jumboegg5845 I did get his point, it is just that he used the meter as a measurement based on the human body, which is not the case.
But yeah, measurement systems based on universal constants are better than the ones based on arbitrary stuff.
@cesarparra6025 That is the very point - the metre is a good practical size relative to the human body. It is a good size for the things that humans measure. It is not a measurement based on the human body. We could declare that a metre is the length of an Olympic swimming pool (50 metres) - but that would be a clumsy standard length.
Note that one thousandth of metre (a millimeter) is also a very good precise practical measurement - any smaller and its getting hard to see with the naked eye. The whole point of the metric system is the decimal system, the exact definition of the metre is arbitrary.
That length for the meter, however, was chosen because it was a standardizable measure that was close to the length of an imperial yard, as well as to other similar units of length that existed elsewhere in the European world. Those units, though similar, varied from one to the next, a variance which wasn't a huge problem when commercial, technological, and scientific interchange was below a certain threshold, but became an obstacle once those activities surpassed that threshold. But those base measures that were superseded by the creation of the metric system were all dependent on the human body or human actions. The "one ten-millonth" (rather than a millionth or a hundred-millionth) was chosen because of its nearness to pre-existing, human-dependent measures.
Wow Brian Cox doesn’t know that the meter was calculated based on the dimensions of the Earth.
To be fair he probably heard it at some point in his life but there's a whole lot of other information crammed into his brain and his subconscious was like "what's this file? Lol yeah, delete"
@ivckins I believe he was disappointed at the accuracy & thought “things can only get better” and forgot about it. We can only D:Ream what else he heard about and forgot. Brian Cox - UR the best thing!
This is outstanding. Brian Cox is among the very best science communicators. He’s just sitting on a chair, talking to the camera, and very effectively describing some of the most abstract physical concepts. No graphics, just voice and hand gestures. Amazing.
Thank you for such an understandable description! I wonder how many Planck lengths equal a plank mass?
I could listen to Brian Cox talk about physics for hours.
The metre is actually now based on the speed of light. Previous to 1983 it was based on the distance between the north pole and the equator.
Planck time is the length of time that it takes light (a photon) to travel the distance of one Planck length. The "building blocks of the universe" are the Planck units, and it all comes down to the speed of light. That is the fundamental constant. If light, or anything else, could travel faster than that, it would be in different locations at the same Planck time, in other words, in two places (or infinity) at once.
1:40 I refuse to believe Brian Cox doesn't know what a meter is based on. Makes it all the more weird he's spreading confusion about it.
He was describing an ancient measurement unit named Cubit. Yeah, strange that he would confuse the two...
He's not here to discuss the metre. He's using it as an abstraction that we defined willy nilly (willy nilly in the sense it's not rooted in any hard, tangible sources)
Yup, the point he was making still holds - many measures we use are based on things that don’t tell us much about the nature of the universe, which makes them different to the Planck length. The original definition of the meter was based on the size of the planet which we happen to inhabit, it has no further significance anywhere in the universe.
They regard the metre as the 'scientific' unit so its relationship to the scale of a human body has escaped their notice
He also apparently still believes in evolution. I suppose he gets a pass being a physicist and not a biologist.
Brian has such a huge brain in complexity it's insane. I understand some bits but he makes it sound so much easier such a class presentation and narrator. Top bloke
This is going straight into my favorites playlist
This reminds me of an article from The Onion years ago where it was reported that an entire universe had been discovered hovering about 3 meters above a Walmart parking lot. The scientist goes one to describe this distance involved as "mind boggling."
(I try to stay with him on this stuff, but really I just like listening to him talk given that I struggled to make it through high school algebra.)
1:40 For anyone curious, a meter was originally based on one millonth of the distance from the equator to the north pole, measured through Paris.
Yes, it’s a bit embarrassing that he had no idea about the derivation of the metre. I felt embarrassed for him.
@teresabremner1225"Very little accomplishment is required in order to pity another man's shortcomings." - George Eliot, Middlemarch
The meter was based on the size of the Earth, specifically one 10,000,000th of the distance from the Equator to the Poles.
Yeah 👍
It was from the equator to the North Pole, specifically on the Paris Meridian, kind of but not really because they screwed up the measurement. They were off by about 2000 meters.
I find it kind of concerning that Dr. Cox does not know this. It would seem to be fundamental background knowledge if you're going to explain the nature of measurement systems.
@bigwhiteyeti why was it 10 millionth rather than a millionth? The latter would feel more fundamental (but less human scale)
@HJV24 i think you've nailed it, they needed something that would be large enough that a prototype and it's copies could be accurately made, but small enough to be handled on a human scale. 10m would be too big to handle, 0.1m has only a tenth of the accuracy.
If only math, chemistry and physics were this understandable in high school. It would be nice to have a study hall for those interested and motivated to show up and to get help from tutors.
Maybe show a few videos at the beginning of the semester on why the class so historically important to the society and civilization.
There are theories that suggest that Planck grid is a real thing and when photon moves from one planck length to another then it moves like suddenly one planck length and then waits for a little while to compensate the speed of light. Then magically the next planck length etc
How long is a plank?
The most concise explanation I can find is from 4:47 thru 7:21.
If you scale an atom to the size of the known universe the plank length would be the size of a tree
About 4...
@RobJMeronekit's a joke
@dakota7016it's a joke
The (original definition of the) meter is based on the circumference of our planet. Every physicist should know the story.
You misunderstood his meaning. He meant that the metre is of a size we relate to, just like the imperial foot, inch, mile etc, its is of a unit that has everyday meaning. It is similar in concept to thinking of things in relation to the length of a football field, or volume of an Olympic size swimming pool, when thinking about bigger things. The length of a metre is in fact arbitrary. We could simply declare that starting today, a standard metre will be double its current length. That would mean the speed of light then becomes (approximately) 150,000 km per second - of course the physical length has not changed, all we have changed is the length of a standard unit. I think the latest definition of the metre is the distance light travels in 1/C seconds (ie. the reciprocal of the speed of light). Note that the numerical value of C is completely different when we use units of a mile -the distance does not change, just the arbitrary unit changes.
@jumboegg5845Let us agree you do not know the story well enough to really understand my point. The idea of using a standard system of units for both science and trade has been born long, long before, but mostly an empire brought the standard just by winning battles and wars. Later trade organizations like the Hanse tried to set and use standards, each craft in each city had its own ones. Which made trade between cities or crossing regional or country boarders a nightmare. You will end up with N^2 re-calculation tables.
The definition of the meter based on the circumference of the earth also defines the volume and the weight (cum grano salis) using a substance nearly abundant on the earth: water. A decimeter cubed has the volume of a liter, a liter of water and some standard temperature and pressure has the weight of a kilo. Now you see where you end up by doubling the meter. Using this method people were able to walk in with a meter stick and rebuild a standard volume and a standard weight.
A physicist should know the history of these units since we are using them for the one and only thing that matters in physics after thinking about new theories for years: The measurement!
In 2019 the whole system has been redefined based on universal natural constants.
Finally: The system is still arbitrary in a way that I am as unwilling as Brian to keep all the natural constants in mind. The second is still an approximation of the 1/86400 part of an average earth day. The speed of causality is based on this definition, the meter now depends both on c and the definition of a second.
When talking alien intelligence it might be more easy to use a binary representations of some mathematical constants like e, pi, the golden ration and others and send those over to get started.
What is the story of picking one 10 millionth of the distance, rather than a millionth?
You are aware that the original measurement was wildly inaccurate?
@HJV24 I just explained the story above - the standard metre (originally one ten-millionth of the distance from the North Pole to the equator) is a good practical length. Being the metric system, there is no difference between one 10 millionth and a millionth, except where you put the decimal place. The story would be completely different, and no better than the imperial system, if they had of decided a metre is some weird fraction of the distance from the North Pole to the equator. Note that the distance to the north pole was just used as a relatively constant reference - if an Olympic swimming pool was a constant, then we could be measuring things in pools, millipools, kilopools, etc.
I'm not a carpenter, but I think you can cut planks into pretty much any length you want. I didn't realize it was this mysterious
Also not a comedian
When I started figuring this out I was so shocked🙈
I hope this becomes a bi-monthly release !
everything from the Presentation to the Production just hits right.
GIVE THE PEOPLE WHAT THEY WANT !
Disclaimer: Do not look at Sun in conventional telescope.
People that need this disclaimer aren't going to make it.
"The meter is based on biology."
The good professor, bless his heart, skipped one too many history class. The one about the huge effort the French made to measure a quadrant of the Earth to create a unit of length that was distinctively *NOT* based on biology. It was precisely the entire point.
How are half the comments people getting a real kick out of correcting him on this one detail 😂
Still, it was based on an arbitrary, "human-centric" distance. Telling an alien about the quadrant of the earth or whatever it was would be about as informative as the length of an arm.
If he starts by getting the meter wrong
how can we believe hes not a plank ?
How long are his forearms ?
Do you think it was an accident that the meter came out to be about a yard? No, they wanted the meter to be about a yard first (the basis) and then invented a definition (the definition) in such a way that it turns out to be about a yard.
There is a difference between basis and definition.
@tonupharry The psychology of these kinds of comments is very obvious.
The origin of the meter was not related so much to the size of humans but to being one tenth millionth of the distance from Earth’s equator to one of its poles along its surface.
On the meridian that runs through London, I believe that is the Prime Meridian. All that said he quantifies these fundamental principles in a very concise manner and qualifies the complexity.
The metre is still at human scale, though, that was the point - he didn’t say it is *defined* against the human body, but it is close to the existing imperial yard.
@stereoroidevery system is a human contrivance. More and more they are based on human perceived characteristics of nature. Why is water the basis for C°? Why is a lightyear based on the duration of the Earth’s orbit? Why is Earth the only planet that isn’t named after a god?
why in a nanometer ten times is long as an angstrom? Why is the word long used both in distance and duration?😂
Why was it not a millionth of that distance? There's a choice in 10 millionth, and that choice is linked to human lengthscales
@HJV24yep, if they would have done one millionth tape measures would weigh 6.6 lbs or 3 kilos and be the size of a briefcase. Yard…I mean meter sticks would be over 30’long-I mean pert’ near just about 10 meters long and a millimeter would be almost a centimeter and that would mess up the whole nanometer and angstrom thing. That would really foul up conversion tables, everything would have to be times ten to the first. Just imagine buying boots, do you get size 1.15. I’m thinking we’d be using miles, bushels, pints, pecks, and the good ol’ 7.480523 gallons per cubic foot instead. All wrenches would be SAE and you wouldn’t need two sets of sockets. 10 and fourteen millimeter bolts would only be found on mega equipment. Hey buddy, can you pass me that 1.4 mm socket or just grab a 9/16”. Okay, I’ll 🛑 😂😂😂
I remember a while back there was a persistent incongruity of measurement results for the Planck constant. Has that been reconciled yet? (Haven't had time yet to finish this).
I really wish you'd make a DARK MODE version available. This isn't daylight content, I usually digest it after midnight.
The Planck Length should be redefined to measure the amount of time it takes to discover if our so-called leaders are incompetent.
Please make science about your political views. Science should be politically agnostic.
🤡
Or how witty you are.
It's not a measure of time. Whoops.
@kokopelli57 It can be a measure of time when converted to Planck Scale moments. Everything is relative. : )
The meter is not based on the body of some random human, it is based on the measurements of the earth, the tenth millionth part of the longitudinal arc that goes from the equador to the north pole
It’s metre
Whilst I found the exploration of the uncertainty principle and the planck constant and white dwarfs fascinating, I didn't hear anything at all that justifies the planck length as being a meaningful length, just an arbitary measurement with about as much meaning as the foot, which has then been used to make some measurements.
But to my mind that doesn't make the planck length fundamental, and until the theories of relativity and quantum mechanics have integrated, its really nothing more than an arbitrary guess at what might be a fundamental measurement. Essentially no more meaningful than any other measurement that humans have invented in their imaginations.
Would be worth thinking about Planck length as the answer to this question: "if we look at every equation that humanity has, that includes any calculation involving length - what is the lowest common denominator?" That length is the planck length, pl. The actual number can be calculated based on a similar question: "if we look at every equation that humanity has, that includes a calculation involving speed - what is the highest common denominator?" . That is c, expressed as length-per-second.
If we then assume that the passage of time, in the background, increments constantly and exactly (and that is an assumption) then we have a bounded limit, we can then create an equation where the maximum limit is where time = 1, the speed is c, and the distance travelled is lp. Can then be expressed as: lp divided by 1 = 1 divided by c.
However, this then introduces an inconsistency with other calculations involving distance and time - which leads to the assumption that relative time can be altered (relativity) and/or that lengths can be 'bent'.
Assumed to be true - but there's always the possibility that the foundational observations/measurements used are slightly out, or that the calculations used have introduced small inaccuracies that make it looks like space/time bends. I think I saw somewhere a recent analysis of the James Webb telescopes observations re: 'space triangles', that did all of its calculations based on angles in radians (instead of calculations based on lengths) - I think I remember reading that the results surprised the authors as they show that space is flat and does not bend. This mismatch on outcomes between two different calculation methods, suggests that either the calculation methods themselves have a hidden error within them (e.g. if Sine and Cosine are slightly out) - or that the calculations of c and lp are slightly out (in which case, they are slightly out universally for every calculation that ever uses them). Where there's a contradiction/exception to the rule, there's usually a new theorum to be found: It's an interesting contradiction to explore for those that want to go deep!
7:33 What exactly is information?
hi, would a black hole singularity be the size of a planck length or not?
thanks
I was under the impression that the meter was meant to be based on the measure of the earth. Google, AI search: The meter was initially defined as one ten-millionth of the distance from the Earth's North Pole to the Equator, measured along the meridian passing through Paris. This definition was established during the French Revolution as part of a broader effort to create a decimal-based, universally applicable system of measurement. Later, the meter was redefined as the length of a specific platinum-iridium bar kept at the International Bureau of Weights and Measures. Today, the meter is defined based on the speed of light and the second.
Nothing to do with the human body.
Correct Sherrie. Good explanation, thanks.
I'm surprised Brian didn't reference that.
Compare 'cubit'.
Now, that's an ancient historical measure of the length of Brian's fore arm !
We are the microbes in the petri dish trying to define the experiment from inside the experiment.
It may be that we can never in a trillion years nail down every principle of the universe, but that doesn't mean we should stop trying.
In the meantime, quantum mechanics can not explain that haircut.
Heard this explained before, never got it till now. Thanks Dr.Cox
The unit of length called the meter was not defined with the human body as its reference. When created, it was defined as the distance from the equator to the pole divided by 10 million.
He didn't comment on the definition. He said the basis.
I like the nod to Carl Sagan with "a mote of dust"
In the Operational Superunification Theory (OST), the cosmological constant is understood as the ground state energy density of a supersolid condensate, which is kept naturally small by the presence of a Planck-scale lattice structuring spacetime.
So how do you calculate the amount of data inside a black hole?
That was a great explanation.
but I did not understood the plank mass definition. Mentioned one time and .. ?
Wiki Metre: "The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's polar circumference is approximately 40000 km."
Yeah. Brian's Britishness was showing there. Not only has the meter never been associated in any way with anatomy, it's not remotely close to a forearm's lenght (it would be a full arm plus the distance from your shoulder to your nose, roughly). The whole point of the invention of the meter was to move away from the complete madness of arbitrary units and tie them to rational constants. But of course, that would require everyone to get on board....
Also why does the planck length have any special meaning in the measurement of the volume of a black hole? Presumably you can use any units of measure you want, including meters....
@1ifemare I think it's the granularity of information that fits on the surface (event horizon) of a black hole and that is equivalent to the information needed to describe the black hole. Information can't fit in pieces smaller than the planck length, and because the surface is two dimensional you get square planck lengths describing the surface as a fundamental measure.
@pon1 Thank you for the explanation. Was pretty sure there had to be some deep reason for Brian to cite that example, but these types of videos don't generally dive deep enough.
I suppose they measured the distance first and then decided on the fraction somit would be "round" and about "human" size. I am pretty sure that's what the guy in the video meant.
Indiana Jones and the Great Circle.
your vid is also a beautiful story, i enjoyed it so much, and i can see you also enjoyed telling it. thank you for you work here.
Is there a length of time that can be measured in such a way?
best measurement is two fingers of whiskey
Something reflections of the system, the range of influence and the rate of times procession. (when you get to that interesting part about the proton) thank you
Thank you Brian, for taking me beyond this concrete and mundane world for a while. I so love your wonderful explanations.
Fascinating stuff. I do have admit that I was hoping his final story would have had an EXPLICIT use of the Planck Length.
Brian deserves all the accolades he receives and more. Bravo.
Beautiful mind. Extraordinary clarity and eloquence. All that masterfulness delivered through such humble demeanor. Really good video.
Is that the skull from Hans Holbein’s ‘The Ambassadors’?
Thoroughly enjoyable. Thanks
Is it the pixel of the universe? Like the ultimate resolution?