Can Space Be Infinitely Divided?

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How many times can I half the distance between my hands? Assume perfect coordination and the ability to localize my palms to the quantum level. 15 halvings gets them to within a cell’s width. 33 to within a single atom, 50 and they’re a proton’s width apart. Half the distance 115 times and they’re a single Planck-length apart - 1.6x10^-35 meters. Surely we can keep going - .8, .4, .2 x10^-35 m? Bizarrely, those distances might not even exist in any meaningful way.
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Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Adriano Leal & Stephanie Faria
GFX Visualizations: Katherine Kornei
Directed by Andrew Kornhaber
Assistant Producer: Setare Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber
End Credits Music by J.R.S. Schattenberg: / @jrsschattenberg
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[@gabrielpetre3569]

It was proven some time ago that the X to close an ad is indeed smaller than the planck scale

[@Bass17yl]

This seriously needs more upvotes! 🤣

[@TheDamian58c]

I would say its delta x in the uncertainty principle exceeds the area of the ad itself

[@valacarno]

What exactly are these ads?

[@gabrielpetre3569]

@@valacarno pop up advertisemets

[@valacarno]

@@gabrielpetre3569 How can you get them? Is it some Premium thing or extension?

[@edwardstiffler1734]

I'm continually disappointed that the Planck Length is never represented with a tiny wooden plank.

[@vampyricon7026]

Because Planck is pronounced /pla:ŋk/

[@bacicinvatteneaca]

@@vampyricon7026 so is plank ;)

[@T3sl4]

Spacetime has many wormholes, Ed-boy!

[@alphalunamare]

Here is an in depth explanation kzbin.info/www/bejne/lWK8cnpsdp1madE

[@GetawayFilms]

@@alphalunamare And BOOM.. The fun STOPPED!

[@TheRealBoof]

I'm an astrophysics PhD student and this KZbin channel teaches me new things. What an extraordinary time to be alive, when these kinds of resources are readily available and presented in such an engaging way!

[@kornelabramczyk5948]

That's a new time old man

[@geesunn8101]

@@richardromero6193 h huh. Jjjj j. J. Hi j jjj. Jj.

[@Kitsudote]

People start to understand that sharing knowledge helps everyone. It is truly a beautiful shift.

[@sarvhere]

I also want to do phd in astrophysics can u guide me pls

[@zs8784]

N0ob

[@falco830]

Physics: How small can we get? Heisenberg: Maybe.

[@Argonaut320]

yes

[@TheOhhhReallyChannel]

Your god damned right

[@nenmaster5218]

@@TheOhhhReallyChannel Would it be too random to declare my intend to recommend my fellow science-youtuber-fans some... well... more science-youtuber? I mean, in my mind, it just makes sense, but many call me B0t, so... your choice...

[@keonix506]

10:22 "distances are *undefined* " We are all doomed, universe is written in C++

[@leogama3422]

Or Javascript. Makes sense...

[@keonix506]

@@leogama3422 I'm talking about UB - undefined behaviour. C++ specification is full of it, it's a damn minefield and you are at mercy of the compiler to not mess up your logic. AFAIK JavaScript doesn't have UBs, it's just convoluted and unintuitive

[@Merennulli]

@@leogama3422 Yep, we've seen already that particles are dynamically typed based on their energy level.

[@NTmatter]

@@keonix506 That's an interesting take on Multiverse theory. The laws of nature are the same in all possible universes, but the undefined behavior is enshrined in the spec and varies between compilers. Perhaps two differently-compiled instances of the same dynamically-loaded library are sharing the same memory space, giving rise to quantum uncertainty!

[@keonix506]

@@NTmatter "Your measurement of program output caused wrong branch of multiverse to be chosen! You see, it's not my fault it crashed!" I will add this to my list of excuses

[@RR-qp4kp]

Your contribution to communicating physics to the public is brilliant - always concise, but pitched at an intelligent level and understandable. I’m very grateful for what you do and thankful that you’ve been doing it for this long. Just wanted to say thanks to Matt and the team

[@haudace]

You understood this?

[@JohnDeck1]

sometimes (:^)

[@annakeye]

@@haudace I'm uncertain if I did.

[@901craft5]

yes

[@vesawuoristo4162]

I cannot accurately measure whether I understood it or not.

[@nopeno9130]

Planckstronaut 1: "Wait, it's all undefined?" Planckstronaut 2: "Always has been."

[@radishpineapple74]

4:03 I burst out laughing at this animation, I couldn't help it. Video editor, whoever you are: you need a raise.

[@T33K3SS3LCH3N]

"You'll have to stay tuned to the future of physics" well damn that's a cliffhanger if I've ever seen one

[@nkf6025]

😹😹

[@SpindlyScoudrel]

When is the new season of physics?

[@ObjectsInMotion]

@@daedalus-7 Technically quantum mechanics was discovered before relativity, if anything the two revolutions in physics were near simultaneous.

[@T33K3SS3LCH3N]

@@ObjectsInMotion yeah but the release order is different from the watch order!

[@1adamgriffin1]

#entanglement

[@T33K3SS3LCH3N]

Physicists in the 19th century: "It's basically solved, we already know everything" Physicists in the 20th and 21st century: WE DONT EVEN KNOW WHERE THINGS ARE

[@shannonbloom4133]

Nor do we know "What" "Things" are.

[@jari2018]

@@SpecialDepartment 2 . Thruth is always racists. Non gender and gender - equals rasism also which equals some aliens who divides like a worm or makes copies as male or female .Redefine rasism . Good and bad -nneds also redefining -so does success from faliure .The big problem are peoples thought and what conclusion they make -to lie and unlie

[@GodKing804]

BUT GLOBAL WARMING IS 100% MAN MADE

[@misakamikoto8785]

The more you know, the less you know... being ignorant is truely a bless, it saved you from the burden of infinite knowledge.

[@Tim0feyK]

@@shannonbloom4133 Nor even what "what" is...

[@klauskervin2586]

This is the best explanation of the Planck length I've ever heard. Bravo and thank you PBS!

[@BrokenSymetry]

The amount of work this channel has done promoting science on this platform is just amazing

[@dembro27]

The Tortoise sure hopes space is infinitely divisible so Achilles can't ever catch up to him.

[@CharlieQuartz]

Actually the infinite smoothness of space would still let Achilles catch up to the Tortoise, since adding an infinite number of distances/times can give you a total finite distance/time.

[@jiffylou98]

Achilles hopes space is infinitely divisible so his atoms don’t overshoot the tortoise at infinite velocity

[@kaizokujimbei143]

@@CharlieQuartz You can finish an infinite series in finite time?

[@yonatanbeer3475]

@@kaizokujimbei143 yes

[@tonydai782]

@@kaizokujimbei143 If the amount of time given to each term in the series shrinks fast enough, then yes.

[@ativjoshi1049]

This is the most intuitive explanation of plank length I've seen so far.

[@brandonkidd3408]

Maybe photons are the answer to light speed travel or atleast close to light speed

[@davroscaan1318]

So, I'm going out on a limb here and guessing that shouting "I'm hung like a plank!" will get a different response at a party full of sawmill operators than one with physicists.

[@nephilimnameless9809]

This should have more likes.

[@jeffreyjefferson536]

Well done, Sir.

[@djtan3313]

Oh I c wat u did thr . Claps

[@kh_qft762]

The Planck PP

[@sionnach1311]

I've often heard this heisenberg principle mentioned I'm just not certain about it

[@Tom_Quixote]

I understand your position, but I'm not sure where you're getting with this..

[@tomfly3155]

Lol

[@joshurlay]

@@Tom_Quixote I don't understand your position, but I see the momentum in your argument

[@crystaldazz]

"You may see where we're going with this" Me: You vasssstly overestimate my brainpower.

[@chrisd6736]

Ha this one was particularly confusing. There are a few better explanations of plank length I’ve come across (with a lot less math).

[@DemonKyle]

@@chrisd6736 I personally liked this explanation a lot. There are dozens of math-less channels on physics on KZbin, we need more with math in the explanation. Without math, you aren't doing the idea justice.

[@chrisd6736]

@@DemonKyle- I like math and appreciate that they’re not trying to oversimplify the concept- but this much math is definitely gonna go over a lot of people’s heads. Like I understood everything in this vid but I also tutored calculus for engineers in college. Made my wife watch it and she understood exactly nothing. She’s not dumb she just doesn’t understand math.

[@l1mbo69]

@@chrisd6736I do not understand how one doesn't get the math here- he's just rearranging symbols. And yours is not a very good example if she doesn't have much exposure to modern physics beforehand because then too much of the explanation even other than the math would be flying too fast to comprehend, and make you lose focus so you don't get what he did with the math

[@ShadSterling]

@@chrisd6736 Link to better explanation?

[@MrAndersson579]

- Say its name! - Heisenberg's uncertainty principle - You're god damn right!

[@lalala13131315]

It is the one that knocks

[@DragonsFrogs]

Maybe that’s why he wanted someone to say his name? He was uncertain

[@geordi5054]

I can tell the exact moment that the uncertainty principle turned into the Heisenberg uncertainty principle.

[@galaxycoffee933]

let's start calling it the Matt Uncertainty Principle

[@XKloosyvv]

I'm loving this channel. Halving numbers to infinity is always a concept that fascinated me as a child. However, learning about Planck values has completely shifted my way of thinking about an infinite universe.

[@tryst1384]

planck length is smallest possible length....n it was proposed by MAX...😅

[@sodiumsalt]

Omg this is KZbin gold

[@peoplesrepublicofunitedear2337]

Whoa 🤣

[@yoseyoda]

Ever heard of the Min Max Theorem? :-)

[@djbslectures]

Space time tag line: "We need a theory of quantum gravity to answer that"

[@sogerc1]

DJBsLectures Isn't that the truth :D

[@avhuf]

If I had a cent for every time I heard that...

[@adrianordp]

I read this comment at the exact time he says it! O.o

[@PrivateSi]

Start with the simplest possible all-pervasive, quantised physical particle field as the subspace matter-energy (CHARGE) field from which to emerge the forces of nature... -- +ve charge balls (quanta cell, +1, pixie dust) held together by -ve 'subspace gas'.... A close-packed magic crystal ball.. I mean dual particle field theory. -- Cells knocked free form a positron and the hole left behind an electron. These vibrate the field at C, sending out 'blip' spheres. Blips are a cell moving outwards and then back into its balance point... Blips compress the the field laterally as the blipping cell squeezes through the 3 in front, and back... A e- or p+ moving up and down (ie, from-to an atomic ground state) forms, a transverse light wave blip pattern forms. -- All electrons and positrons have the same phase in time but are half a cell apart as electron focals points move from cell to cell, and positrons' from cell gap to cell gap, so their blips are opposite phase... A universal clock emerges as the first load of e- / p+ pairs formed during the Big Bang formed at exactly the same time.. -- Same charge, opposite direction blips repel when they collide, sending repulsive force back to each charge particle... Opposite charge, opposite direction blips are in sync, resulting in a 'flux tube' as an AC field vibration (each cell moves back and forth by half a cell, in unison, with -ve gas and +ve cells moving back and forth in perfect contrary motion, never finding their balance)... Vibration recoil experienced by charged particles at all times pushes the 2 particles together along this smooth, in-sync path. -- When 2 positrons collide with enough energy and/or ar precisely'roughly the right angles another field cell is knocked free, with the newly created electron-positron pair and one of the 2 original positrons forms a Proton in an instant, as 2 half neutralised positrons sandwiching 1 electron,, with the spare positron ejected by the positive Proton... NO ANTIMATTER CATASTROPHE.... Also, when a high energy photon hits a Proton it can bang the two positrons closer together, so they squeeze out another field cell, forming a * NEW * electron-positron pair... -- All atomic structures can be balanced using only Positrons and Electrons as the building blocks of matter... All nuclear reactions can be balanced using * NEW * electron-positron pairs where needed... A 3rd neutral charge to better match QCD is possible but not required to balance nuclear reactions -- POSITRONS ARE GRAVITONS too..... Each positron attracts -1 of -ve subspace gas away from the rest of the universe... This CAN mean voids expanding (DARK ENERGY) as matter forms. possibly with local cell gap and/or size shrinking around matter, possibly with a quantum gravity well around each nucleus as part of The Strong Force... Gravity is an all pervasive subspace charge gradient... -- Relativity can be added in by saying light (electrostatic blip) energy moves from cell to cell in an absolute fixed time + Dark Energy expansion with Big Bang expansion on top leads to red/blue shifted galaxies.. You can have as much or as little quantised gravity and dark energy as you like.. It's a powerful model. -- Double Slit Experiment fires an electron at the right hand slit out of two... The preceding electron blip field diffracts through the slit and interferes, forming regions of turbulence and calm... The electron focal point always goes through the slit it is pointed at, but hits a random calm path as it leaves the slit, then follows the calm path to the detector, forming interference patterns... Extra detectors interfere with the diffracted interference pattern.

[@PetraKann]

The Quantum Mechanics and General Relativity theories dont talk to each other. And in the case QM, there is no agreement on how to interpret the theory with serious fundamental problems involving the measurement/observer problem and other issues. GR fails at the singularity. It’s not entirely clear how these issues will be resolved, but one thing is certain, a new theory and approach is required. It’s insufficient to simply say “shut up and calculate” or the equations predict most phenomena with great accuracy. If that was the criteria, scientists would not have moved past Newtonian or Classical mechanics. Of all the Scientific disciplines, Physics is the least complex. It also relies on the most number of spherical cows. It is the soft bed which science rests on - the easy science. It hides behind its idealism and childish mechanistic neuroticism

[@Sk4lli]

What I learned: If I want to measure the distance to a guinea pig very precisely I just end up shooting tiny black holes at it without learning how far away it is.

[@myaccountishacked6417]

It's a Capybara

[@andersjjensen]

You will in fact have fried the poor bugger crisp before you found out exactly where it is. The energy bill you receive for this is astronomic, so you'll be living on fried guinea pig for a while...

[@ballswalls8189]

Good video kzbin.info/www/bejne/pZ60Xnptmd2kbtU

[@JeanPierreWhite]

You have two problems. Your mesurement will not be as precisise as you'd like. Measuing the length will "bump" the capybara a smidgen changing the distance you were trying to measure in the first place.

[@SneakyTravels]

@@JeanPierreWhite What if I shoot/measure capybara 3 times and results show 1m and 25plancks, 1m and 28plancks, 1m and 31plancks. Would this mean that each measurement moved/moves capybara by 3 planck distances and now all I need to do is reduce result by 3 planck lengths?

[@Gnurklesquimp]

I remember this idea was very surprising to me when I first heard it, large and small scales have always been some of the most interesting concepts to me, easily in my top 10 of areas where I'd love to see major breakthroughs.

[@Ncaa67]

Maybe when we look at the largest things consolidated like black holes we are seeing a clear vision of the smallest. After all black holes are supposed to have a quantum singularity inside. We are just in between.

[@brucebrown7691]

If space is discontinuous and quantised, how does the universe expand? If new bits of spacetime are spontaneously created, where is the energy coming from?

[@electronicsandroboticsclub750]

Good question

[@twistedtachyon5877]

This just sounds like another way of asking "what is dark energy?" So, uh... they'll have to get back to you on that.

[@Yal_Rathol]

when someone figures it out, you'll be on the list of people who should know.

[@biblebot3947]

Sabine hossenfelder has a video about what energy is

[@slkjvlkfsvnlsdfhgdght5447]

who said that you need energy in order to create more spacetime?

[@Abstrac888]

I thought the episode was going to end after he said “We’ll come back to the true nature of space another time”

[@7shinta7]

Nope, the ending with "Spacetime" is as constant as the Planck constant. :D

[@genghisgalahad8465]

There was (another) space between space and time...it was purposeful, I imagine! 😀

[@barretprivateer8768]

Matt just works in as many 'space time' title drops / puns as often as he can but completely deadpans it every time. What a legend.

[@Marcel._B]

I thought the same lol

[@84Supervisor]

If he hasn't already, I hope he'll look off camera one day and just say "time" while pointing to a non-existent wrist watch 😁

[@elib2670]

Finally someone explains how one arrives at the planck length

[@phild8192]

I’ve always wondered this.

[@travis5732]

Yea

[@Kumquat_Lord]

Honestly it would make a much better base unit of measure over the meter because it is truly universal

[@mr.rogers1019]

It's funny, the shorter the measurement the longer the explanation. Lol

[@kevincronk7981]

I still don't get if planck length is like a pixel, or the smallest an object can be

[@Tylerwithfire]

Me, high as a kite: I like your funny words magic man

[@MaryAnnNytowl]

Glad I found this - have always wanted to learn more about the Planck length, and this answered a bunch of my questions, and some I hadn't even thought of, yet! 😄 Very well done, PBS - another great video!

[@prashank]

Chief, you just so casually dropped the fact that photons can wrap spacetime which blew my mind, we will need an episode on that.

[@umbrascitor2079]

By my understanding... a photon itself has no inherent mass, but its energy is equivalent to mass (E = mc^2). So as the photon's energy increases, its energy "mass" has a greater effect on space, until at a certain energy the extreme curvature forms an event horizon.

[@AliothAncalagon]

Its really a big realization for many at a certain point. If you direct a flashlight towards a black hole, it also grows. You could even focus so many superlasers to the same point, that you create a black hole in the process.

[@paulgoodwin8840]

@@AliothAncalagon There's actually a specific term for that kind of black hole creation: a kugelblitz.

[@jorgepeterbarton]

@@paulgoodwin8840 yes yes isnt there a pbs episode on it from ~5 years ago. Making a black hole from light is *theoretically* possible, sort of, if you find a way to concentrate so much light, which is likely the impossible, but if it were to exist in a concentrated volume (the difficult bit) it would form one.

[@TNaizel]

Energy bending spacetime happens constantly around you when you feel gravity. The mass of our planet and of your own body comes mostly from energy, the energy of the quarks in your body and of the gluons binding them together. The inherent mass of quarks and electrons (due to the higgs boson field) makes up a very very tiny percentage of our mass.

[@shutupimlearning]

that feeling when all the studying and hard work you've put into understanding the individual concepts within this video are beautifully arranged together; when everything just "makes sense now". That is probably the best feeling in the world.

[@kevincronk7981]

But I still don't get it, is the planck length like a pixel or is it just as small as an object can be?

[@aidenstern5254]

@@kevincronk7981 it's the smallest length that you can measure something. measuring takes energy, and measuring the position or momentum of something smaller than the planck length causes a black hole the size of the planck length

[@KohuGaly]

@@kevincronk7981 It's a bit more abstract than that. Planck length is the minimum meaningful distance between distinct features. In case of pixelated images, planck length is the inverse of resolution. If you try to zoom into the image beyond that point, you are no longer getting any more details. You're just getting an upscaled blurrier/blockier version of the original image, with no additional detail. The important bit to understand, is that pixelization is not the only thing that can create this effect of minimum meaningful distance. There are other mathematical ways you can get that effect. Pixelization is just the most intuitive one, that people are most familiar with.

[@l1mbo69]

@@kevincronk7981 No, if the universe was made out of small cube pixels, there would be 3 special or privileged directions. The universe would not be isotropic and we would probably be able to detect that. The creation of new cubes in an expanding universe would also be problematic. This problem is eliminated in theories like Loop Quantum Gravity. Here little loops get created in a isotropic way

[@teardrop720]

Thank you Matt and team for giving us insight, access and update into the vast and ever progressing field of physics...its fantastic to have a place like this to come back to ... thank you!

[@Kuwaie10]

As a casual space enthusiast, this video made me understand the basics of Planck Length and also Heisenberg Uncertainty. Big thanks to PBS for giving us these precious informations with great visualisation.

[@joshyoung1440]

Great comment, but the word 'information' is not countable. So there are no "informations." There's just information.

[@bazpearce9993]

I watch these vids to confuse me, and i never seem to be disappointed.

[@justin79811]

This is easy, just break it down to the simplest equation: Pie ÷ 45 × the speed of light = Fish!

[@MarkusAldawn]

@@justin79811 we derived the ÷45 term by whacking a badger until it told us it's secrets

[@justin79811]

@@MarkusAldawn - Oh that's right, if I remember Correctly it was just after the 45th whack that the badger turned over state secrets and that is when the equation was solved.

[@MarkusAldawn]

@@justin79811 one of the great events in not only scientific progress, but also politics, as that badger provided the first indications of the Watergate scandal. The badger was, in fact, a mole.

[@ballswalls8189]

Good video kzbin.info/www/bejne/pZ60Xnptmd2kbtU

[@wesleybantugan5604]

There’s something unbelievably beautiful about just trying to stretch the limits of quantum physics is thwarted by the fundamental laws which govern it.

[@stanimirborov3765]

@@zarkospasojevic6272 -- the matrix

[@nenmaster5218]

@@zarkospasojevic6272 Would it be too random to declare my intend to recommend my fellow science-youtuber-fans some... well... more science-youtuber? I mean, in my mind, it just makes sense, but many call me B0t, so... your choice...

[@diogocanina7097]

One of the best episodes of them all. From time to time I come back here to check it out again. Really well done! Thank you!

[@bastiaanwilliams8398]

Thank you so much for this video, and all others that you make. Concerning the question: "Can space be infinitely divided?" Yes! Does it make sense? No.

[@CodeKujo]

Just wait for the universe to expand, and then you can divide again

[@nexus3112]

nice one bro

[@lonestarr1490]

Huh. Interesting question. Does the Planck length grow with the universe's expansion? But yeah, I already see the issue with that question: grow compared to what?

[@nexus3112]

@@lonestarr1490 smart thinking ... but our reference frames are not fixed to space-time. If it were then we would have been unable to measure the effects of the expansion at all which is definately no the case(#hubbleexpansion#darkenergy#cosmologicalstandardmodel). So, the answer according to me(I'm just a teenager so I'm not 100% sure tho) is that with the expansion of the universe more of these plank units get added to fill the space or should I say 'spacetime' ... the plank length is just an unit so it does not have to follow any 'conservation of energy' stuff!

[@psantochi]

So, when Aquiles is about to reach the turtle space loses all meaning and he never catches it

[@avhuf]

Achilles.........

[@AhmetwithaT]

@@avhuf Spanish spelling.

[@fighteer1]

An earlier episode addressed this. Once Achilles comes within a Planck length of the hare, his distance to it becomes undefined. Uncertainty in position means he could be ahead of it or behind it, and enough measurements at that instant in time will show him ahead. At that point the distance increases again.

[@MusicalRaichu]

no, he said that when he's within a Planck length of the tortoise, they both get swallowed by a black hole and re-radiate as a new tortoise and Achilles.

[@lomiification]

@@fighteer1 enough measurements will stop him from moving at all though

[@ldbarthel]

So the universe is like building blocks: expanding Planck by Planck....

[@brendawilliams8062]

Lol. Good one

[@sayhellobryan]

I cannot believe how amazing this channel is. I've learned so much over the years

[@MarsJenkar]

"Matt is currently wandering the universe at Planck Length trying to gather new insights for future episodes." So, in order to reveal the secrets of the universe, he's walking the Planck?

[@svennoren9047]

At the risk of getting in over his head...

[@marcelo55869]

Next project: 1 - Program Minecraft with blocks of Planck length instead of 1m. 2 - Simulate reality. 3 - ??? 4 - Profit

[@WillArtie]

Lol

[@JohnnyWednesday]

That's why quantum states break down when observed - the computer is running an approximation of electromagnetic waves - until higher precision is called upon. This suggests that the simulation isn't to study life like us - a super-intelligence wouldn't allow us to see anything afoot if it cared that WE did. Probably just studying the formation of a universe and we are just emergent properties of a highly detailed simulation.

[@ghabsterlol7768]

so i need 1 billion years to make a torch i guess

[@sparrowthesissy2186]

@@JohnnyWednesday I've also considered this, that when we get to measuring stuff that's too small, the system just relies on random number generation to give us any kind of answer, because it doesn't really matter that much in terms of how things are observed at whatever scale the simulation is built to model. Much like a weather simulation doesn't need to map the temperature of every last inch to get an overall picture of how the air pockets are going to interact over miles and miles. Of course there's no way to prove this idea, but to me it seems like a possible answer as to why we can't be certain about things that are so small.

[@williamcrosby1061]

Quantum gravity research on youtube is trying to simulate physics with a penrose tile related higher dimensional quasicrystal with imagined planck scale tetrahedra. The system may naturally develop into an effective AI aswell. kzbin.info/www/bejne/rHvMZJKwo9JqkKc

[@zombieinjeans]

Please do an episode on emergent spacetime! Theories where the graviton is a composite particle, bypassing the Weinberg-Witten Theorem by not just emerging the graviton, but the entire spacetime metric. I've been trying to understand and you're so good at explaining these things 😅

[@burkhardstackelberg1203]

This is the best explanation I have heard of what happens at Planck scale I have heard so far! My personal idea on Planck scale, partially derived from this show: At Planck scale, space and time do not get foamy, they get fuzzy: You get a whole spectrum of virtual metrics, curvatures, parallelisms (and, maybe, even torsions) that even out at larger scale to give us macroscopic spacetime.

[@asmithgames5926]

This is excellent! So suppose mass and energy produce more of these small scale curvatures and torsions. On a macroscopic scale, they might be experienced as a sort of fluid friction. Which would slow things near the massive or energetic particle down a little. Which would cause it to look like spacetime was bending!!!

[@asmithgames5926]

Mass and the passage of time would be emergent properties of plank space curvature rippling!

[@ponyote]

Okay. I just have to know what you have against that poor capybara.

[@nenmaster5218]

Would it be too random to declare my intend to recommend my fellow science-youtuber-fans some... well... more science-youtuber? I mean, in my mind, it just makes sense, but many call me B0t, so... your choice...

[@NewMessage]

Space Time: Making Plancking cool again.

[@Cassandra_Johnson]

No, pretty sure that was Cosmic Inflation actually ;-)

[@genericytprofile852]

Beyond the Planck Length are just a bunch of quantum dudes plancking over the fabric of our reality. Some call them strings but I prefer the former description lol

[@Hy-jg8ow]

@@genericytprofile852 Or maybe we are in a simulation and Planck length is the smallest bit-size?

[@innocentbystander3317]

@@Hy-jg8ow If simulation is possible, then I bet you an entire universe that we are simulated...

[@nenmaster5218]

Would it be too random to declare my intend to recommend my fellow science-youtuber-fans some... well... more science-youtuber? I mean, in my mind, it just makes sense, but many call me B0t, so... your choice...

[@Michael-hn5cj]

I love this youtube channel so much. I love PBS and Matt O'Dowd. This is the only youtube channel that I always make the spacetime for... for spacetime.

[@worc2187]

I'm an English teacher but boy has this channel made science and math so interesting for me. Thank you for allowing me to understand reality less but teaching me alot all the same. 🙏

[@joshyoung1440]

You're an English teacher, and you don't know that "alot" isn't a word? 🤦‍♂️ it's things like this that make me glad I stopped college before becoming a music teacher. I'd rather change my job than not be well-suited to it or passionate about it.

[@thezipcreator]

@@joshyoung1440 _alot_ (adv.) (nonstandard, proscribed) Alternative form of a lot (compare to awhile). according to wiktionary

[@WarmongerGandhi]

Zeno: That which is in locomotion must arrive at the half-way stage before it arrives at the goal. Planck: I'm about to end this man's whole career.

[@0urmunchk1n]

Credit where credit it's due. Gottfried Leibniz and Sir Isaac Newton did that with calculus.

[@umeng2002]

The aliens need a new GPU to up our universe's resolution.

[@berkeliumk]

They can't afford new GPUs. Damn Crypto miners.

[@khai96x]

@@berkeliumk They somehow managed to utilize the Matrix itself for mine crypto?

[@AntonAdelson]

Actually a lot of physical limitations like speed of light is a strong case that we live in a simulation

[@ganeshkumarnalachandiran3413]

@@SimonWoodburyForget I agree with some of the implications you listed. I also like that you indicate we are better off considering ourselves as part of a "machine" rather than being in a simulation specifically. There either are beings with the ability to model our observable universe or there arent. If there are then we are in a system with a purpose relevant to our creators, whether it's a simulation or a dictated "pocket" universe. However ,I dont think that we should use the subject of the simulation (our universe) as the basis of an argument againt the likelihood of there being some structure that can run the simulation. If we are, in fact ,a contained virtual structure, we cannot directly interact with the physical universe running the simulation, and without any knowledge on the set of" possible universes " we cannot make any meaningful comments on its feasibility. Perhaps I did not understand your claims properly, in which case I hope you can elaborate. Otherwise, I mostly agree with you!

[@aislingvandegejuchte9818]

@@SimonWoodburyForget although I'm not buying into the simulation thing as anything more than a fun flight of fancy, you made a false assumption in stating that 99.99% of the simulation is star dust. if the goal is to provide a consciousness simulation, then we only need THINK there is a universe out there, with models of physics that agree that there should be stars and such going on. Only the bare minimum of data needs to ACTUALLY be rendered out; some data from our long-distance probes and then a bunch of data from our telescopes and other local observations. We don't have the technology to inspect and verify the inner workings of a star and can hardly even manage to verify the inner workings of our own planet. TLDR: we only PERCEIVE the universe as being complex. in reality, it's a cardboard cutout designed for our consciousnesses

[@gregboi183]

That's a really intuitive explanation of the uncertainty principle. I'd never really understood it before, except from the perspective of the mathematics. Thanks!

[@ITSME-nd4xy]

Years ago as a teenager I was greatly interested in physics, especially quantum mechanics. I remember coming at an impasse, when learning about spacetime and some of its conundrums. After one exploration, I remember asking myself, "So maybe space itself is quantized?" For years I asked every physics teacher, professor, and professional I met, but none could answer it (most didn't even understand what I was asking). One cosmology professor at a top university sidestepped the question, not answering it. This video answers that question -- many years later. Thank you! This video also gave me a better understanding of "quantum foam" - more detailed. :)

[@tehlaser]

This one faked me out a few times. A lot of sentences there at the end could've ended in "spacetime."

[@SpineshatterFilms]

Ikr! I end up trying to predict how his sentences will end at the last couple minutes of every video in anticipation

[@nopeno9130]

I hope I'm not the only one who makes a game out of stopping the video before he can say it.

[@paulembleton1733]

@@nopeno9130 Based on me being average and never doing that, you are definitely in a minority. Viva la difference.

[@naveen513]

Yeah especially when you are listening to the audio, with minimised video and you can’t see the time bar, of this episode of SPACETIME . . Ha!

[@Efrendo]

Can we get a super-cut video of all the times Matt has said "Space Time"

[@RandallStephens397]

Actually, quantum mechanics forbids this.

[@EvenTheDogAgrees]

If you think the world needs this, what's stopping you? ;)

[@stevensheffey731]

Then drop a beat to it...

[@calbetheastonish7970]

@@RandallStephens397 man you made me choke on my burrito from laughing

[@jiffylou98]

Make it like the “hi, billy Mays here” supercut

[@AJBlue98]

When I think about space-time being quantized on the smallest scale, I imagine a 3D grid of Planck-length cells. Never minding how they’re arranged, wouldn’t the idea of a particle/photon moving from one cell to the next be identical to its instantaneously disappearing from one cell and appearing in another? If so, what’s to guarantee that any such move would have to be to an adjacent cell? Also, wouldn’t this mean movement itself must be quantized, so that certain motions must be fundamentally disallowed?

[@daemonxblaze]

That's pretty much the basis for quantum teleportation.

[@biblebot3947]

The plank length is the smallest length MEASURABLE, not the smallest length that exists

[@michalbreznicky7460]

I'm not a physicist, but I think a cell-like quantisaton would be problematic because it would violate the principle that physical laws work the same regardless of one's position and velocity. For example, if we use a 3D cube grid, then the movement along axes x,y,z of that grid would (presumably) be fundamentally different from a diagonal movement. Moreover, one would be able to tell if they're moving with respect to the grid or not (which is not allowed either). I wonder if there's a way to quantise the space that does not suffer from these violations.

[@AJBlue98]

@@biblebot3947 If you’re going to contradict Matt, please back it up.

[@biblebot3947]

@@AJBlue98 I’m not. I’m going with what he said.

[@ms-ds3wv]

Great episode as always, also best in a while. If you are open for suggestions on future episodes. How about more episodes on thermodynamics, would be awesome to have an episode that delves deeper into Gibbs free energy and Helmholtz free energy.

[@spindoctor6385]

Excellent episode, please do not be afraid to continue to use the equations. Even if not everybody understands them, they help a certain % of us better than the words or diagrams alone.

[@nenmaster5218]

Yep

[@brianjlevine]

The distance between my computer and my bathroom exists in a very meaningful way.

[@DrOtto-sx7cp]

🤣

[@kreechrr]

And I swear that distance is expanding. Idk why else I'm becoming less and less sure I'll make it in time!

[@robinsonhere4820]

Does your pee come out in quantum chunks?

[@feebleterrance]

dude get a laptop and poop while you browse, or better yet, get a chamber pot

[@yto6095]

@@kreechrr you're trying to measure energy too precisely. according to the uncertainty principle, a low energy uncertainty makes the time uncertainty large.

[@habibaghasafari2237]

I love this episode. It's so good. Proud to be a patron member.

[@ClayFarrisNaff]

I realize that I'm nearly the 3,000th person to comment, but even if no one hears I have to say it: this is incandescent exposition of physics. As a professional science writer, I've studied physics for decades, and I'm familiar with the topic here, yet I've never understood it so well -- and I've never encountered anyone able and willing to explain it so well, and to make the fine distinctions -- e.g, no meaningful measure of distance versus no actual length below Planck -- without losing sight of the topic. To do all that in 12 minutes is astonishing. I can only imagine how many hours of careful writing, editing, and crafting went into those minutes, but know that you've inspired admiration and gratitude.

[@ChilledfishStick]

There's a video from the early days of the channel about the Plank constant, explaining its origin in the "Ultraviolet Catastrophe", how it solved the problem, and gave rise to the field of Quantum Mechanics. I highly recommend watching it. This is a great video on its own. I managed to follow along (when my mind wasn't drifting) pretty easily, and that's no easy feat.

[@christopherblack3610]

That is a great video, makes the whole thing easily understandable without oversimplification. I internally refer to it often when musing on the quantum world.

[@chrisrobinson7728]

Introducing the little known ‘capybara uncertainty principle’.

[@whoknowsthefuture]

1:45 Hz↑-1 is a very elegant way of writing seconds.😆

[@EspHack]

I've watched through the years at first not understanding a single sentence, later on having to watch more than once, repeat many sections on the video, and so on. now I actually understand more than half of what he says and what it means for the world we live in, its fascinating how sheer perseverance through the seemingly impossible can eventually get you a win. it is so damn important to spread awareness that there's almost nothing left in modern life that can be understood within a couple sentences, before you get angry at something new, realize that it might take you weeks/months/years to even know what it IS

[@hunter2484]

This comment is underrated. And I think applies to ANY field. I had this same epiphany in my early days of computer science. And now much further in my career I realize it's more and more true. So many concepts I just didn't understand. I didn't have that "lightbulb" moment yet of "ohhhh now I get it". But the key is to keep pushing through. Keep learning the new concepts that build on it, and in your own time revisit the concepts you didn't understand. Asking questions is very important at this stage. Eventually - you get your "now i get it!" moment. Every person has this moment at different times. The problem is when you think of yourself as "dumb" because it's taking you longer then others. Every expert in every field had to push through his period of "not understanding" a topic. And don't let any expert lie to you and say they didn't. KZbin channels like this are amazing. They provide the tools to keep pushing yourself and your understanding. and for free! There's a lot wrong with the internet. But this ability to provide raw, unbiased, educational content to the masses is a net positive for humanity. I hope anyway.

[@darshangabani1203]

The time taken by a photon to travel a plank length is how fast my weekend passes

[@Rattus-Norvegicus]

Ha, I got fired a few weeks ago... #eternalweekend

[@brb23960]

The truest words ever written

[@rajarshirayphotography6964]

Drink Vodka and time will come to a standstill!

[@alfacentauri3686]

A shorter weekend is meaningless.

[@sancho7863]

Be glad you have weekends. I own my own business and i work 7 days a week. I’ve been in business since 2011

[@TheRiekman]

Oooo, I did my PhD on what 3D quantum mechanics and thermodynamics would look like on quantized space and we got pretty nice and realistic-looking results. Brings back good memories!

[@michaelmicek]

Did you consider implications of (special) relativity?

[@TheRiekman]

@@michaelmicek No, we first constructed quantized space only in 3-dimensions. However, the grad student who came after me veered into special relativity on these quantized spaces, but ended up focusing their research on 2+1 dimensions instead. My professor does seem like he ended up doing some kind of classical dynamics on a kind of space-time construction. But it would be awesome if some kind of fully relativistic study could be done since the effects of this length-scale limit can only really be seen on incredibly small lengths or in incredibly massive objects like neutron stars/black holes

[@alexneil394]

Hey guys thank you for uploading this great content, and Matt , thank you for brilliantly explaining complicated quantum theories in a way average Joe’s like me, can HALF way understand. I wouldn’t even come close to understanding the fabric of reality, if it wasn’t for this channel, and for that I thank you !!

[@noprobs4552]

I am a bit drunk, but you made it make so much sense all at once I shed a tear

[@MinistryOfMagic_DoM]

Obviously the smallest measure of spacetime is one KZbin Subscriber.

[@altrag]

Isn't the smallest number of viewers KZbin will display something like 23? I forget the exact number but there's some lower limit they stick on there for.. reasons I guess? EDIT: kzbin.info/www/bejne/pXrOmZqXnNuloKs Looks like I had the number wrong, and that its so old its probably changed by now anyway lol.

[@ivancarli1800]

This is mind-blowing

[@anthonymcwhorter6287]

The 3rd eye speaks

[@nkf6025]

@@anthonymcwhorter6287 bruh fr

[@WetPig]

I have had this dumb question in my head for a while. And this is the perfect spacetime video to ask it. If we had multiple reduction gears, to the point where it would take, let's say a googol number (or any really big number) of years for it to make one rotation of the final gear. How would it move, would it hop itself one plank length at a time? If so, what happens to the other gears, the last one isn't moving but the others are? I say this considering the plank length as being the smallest possible length. But even if it isn't, this should still apply, if the moment/per second is smaller than that length? I mean the timescale at which we look at events Is the important part here. My hand must move one plank length at a time, in some time scale, throughout it's movement. I asked the question because if it takes longer, maybe the effect would be more "perceivable"?

[@bobbyshen7826]

Physical gears have defects and and elasticity far larger than gears with a gear ratio like billions. The atoms vibrations will be larger than the average movement transmitted by gears (I am not an expert on these topics. search googol gear box)

[@WetPig]

@@bobbyshen7826 What if we use really small gears, Super small MEMS, and then cool it to near zero kelvin.

[@wolfdomination1905]

@@WetPig Physics also prevents 0 kelvin (absolute zero) from being reached. It would require infinite energy. Also the world of the quantum continues to move in the theorized absolute zero. I’m not an expert but it’s worth a google. Point is those motions would distort the gears motion from being more precise than the Planck length.

[@Dnias1]

I took an intro to quantum mechanics course in university about 10 years ago or so (understanding and describing the fundamentals, and solving the Schrödinger equation in very simple scenarios). My prof was great, but if we had lectures at the quality of this video... Man, we'd have been much better off. Keep the great content coming!

[@Kashis_Corner]

Im not nearly smart enough to get this, but I love it

[@HingleMcringleBerry69]

Watching this while I'm supposed to be working is really fun

[@bumpty9830]

And, unlike most jobs in this world, learning is productive!

[@fahimabid45]

@@Nuttymeemps The discoverer of Quantum Theory of Gravity is here.

[@mjt2231]

boss man is probably doing the same thing

[@init3]

This was incredibly interesting, thank you very much for sharing.

[@brainkill7034]

Wonderful video, thank you for sharing!

[@duncanmacduff559]

"no fair, You changed the outcome by measuring it!"

[@greensteve9307]

I understood that reference!

[@jeemonjose]

"Even when you really want it, the whole universe will conspire in stopping you from measuring anything smaller than planck length" - Paulo Planck

[@naveen513]

Plancko*

[@ITSME-nd4xy]

Fantastic job explaining a very complicated question. You used a technique from mathematics and philosophy, using multiple explanations that each resolve different parts of the boundaries/edges of the central question -- similar to the proverbial group of blind men who are in a dark room together, trying to sense and understand the confusing object also in that room (the "elephant in the room"). These multiple explanations each showed the "tail" and the "trunk" and the "thick leg" and the "big floppy ears" of this elephantine question -- and together provide an intuitive understanding. Bravo!

[@bramaxu]

That black hole part gave me goosebumps

[@fvckyoutubescensorshipandt2718]

So when's the new season and episode of physics coming out, the one where quantum gravity is a tested theory as much as Relativity has been?

[@ballom29]

I prefer the manga over the anime adaptation, sure it's full of complicated formula and sometime quite boring but at least there isn't ton of cut content.

[@BlueFrenzy]

If space is discrete and quantized, would that imply that no force has infinite range? Gravity, for instance, becomes weaker over distance, so, if there's a point where the gravity cannot move a particle one "space pixel" of distance, then the force should stop right there.

[@TeodorAngelov]

@@mertkocogullar6485 So you proved spacetime is not discrete?

If it’s a quantum force then there’s a nonzero probability that the force might move one space pixel even if the objects are separated by a great distance

[@eljcd]

General Relativity and Quantum Mechanics are infamous for not getting along.

[@dennisbrown5313]

Gravity is not really a force - this has been covered in Space Time previously - so, gravity does not move anything but rather, space curvature/time does.

[@Merennulli]

Speed is distance over time. If your distance value is fixed by looking at it on the planck length scale, time is what grows. Gravity could thereby continue to have an effect regardless of distance because there is no maximum time interval.

[@Jcewazhere]

Love these videos, they make my brain hurt, but like in a good way. I feel the warp overtaking me... It is a good paaaaain!

[@davidolden971]

My Brain just generated a footnote for this: “* For any understanding of less than a Plank length, please go back to any understanding OVER a Plank length.”

[@jasondelong83]

It's like, if you are not smaller than a Plank length, you cannot fit into the hole, thus you bounce against the screen/net/universal blanket/fabric of spacetime.

[@TlalocTemporal]

@@jasondelong83 -- That's like how superluminal warp bubble could exists, but there no way to get anything to that speed to make them.

[@pappalasiddhartha5518]

What ar you talking! It's like watching English movie in Japanese language! But I want to become an intelligent person in the world! What's your ambition?

[@david_junior]

I mean your thumbnails ✨✨ Just wonderfully made, just as the content itself Really love this channel

[@LDNpro01]

Me too, i love this channel. What a thumbnail

[@lordcypher5889]

What a wonderful video explaining Satoru Gojo’s power.

[@op-bv7cs]

I was looking for a comment like this

[@aclearlight]

This channel is an absolute treasure. 👍🏼👏🏼💜

[@thomas-beaver]

This and the many worlds episode were immeasurably brilliant.

[@matthewfeldpausch2728]

Love the channel!

[@0whitestone]

My understanding of how Max Planck first conceptualized planck length was by thinking about black body radiation and how if space was truly infinitely divisible, then that would lead to infinite energy levels in a perfect black body, which would be impossible. He realized that if energy levels were divided into discrete amounts, then this would solve the issue, and in fact, this is what we observe in the real world. Assuming that my understanding above is correct, would that not mean that the planck length not only represents what can be measured, but is what actually exists (like pixels in space time)? If the planck length only represented what could be measured, it seems to me that we would still have infinitely divisible energy levels and therefore would still reach infinite energy density, even if we lacked the ability to measure all of the subdivisions.

[@Smitology]

Note that discrete energy and discrete space are not the same thing. Quantised energy is well established and experimentally proven. Quantised space/time is not.

[@rushikeshsisode1533]

Now this is the type of concept I think when I am alone waking up at 2 am

[@humanaesthetic]

Mind blown! Great episode.

[@AndriiMuliar]

This is one of my biggest questions and I even asked young scientists in CERN but they didn't give a reasonable answer.

[@MajorSebbaa]

Last time I was this early, the hare could not overtake the turtle.

[@michellerakowski2429]

😍 I've been wondering about this. Awesome - thanks!

[@brianwarren2042]

I do love how nicely this concept overlaps with the mathematical universe hypothesis. If the Universe is indeed a mathematical construct then so many mathematical paradoxes have obvious solutions.

[@sobreinquisidor]

Mathematical construct = computer program

[@brianwarren2042]

@@sobreinquisidor not really, no, but okay.

[@HypeVectorPrime]

Almost as if whoever is running the simulation doesn't want us to find out.

[@actionms8566]

Same with the incompleteness and (maybe) inconsistency of mathematics itself. As if the universe itelf was made with an intrinsic limit of understanding.

[@ethanwilson9406]

@@actionms8566 I think it's not really The Universe itself that has a limit, just our ability to understand it. We're really pushing the limit on what we have evolved to be able to perceive.

[@JACKRAIDEN97]

@@actionms8566 mathematical incompleteness comes from this reality being a subjective experience with 0 objectivity. Thus the axioms we choose to base math on, math cannot verify the validity of the very same axiom.

[@HypeVectorPrime]

@@SimonWoodburyForget But whoever designed the simulation might not want us to know... If there's any chance that any series of events could occur in which we gain the ability to observe things at a certain scale, there must be something there for us to observe, otherwise we would know we were in a simulation and the whole thing would break. So to say that there would be no reason to process the universe at a specific scale is ludicrous. If atoms didn't work the way they do, you would not exist, and just because we don't understand the quantum universe or whatever you wanna call it, doesn't mean that it doesn't also play a vital role in the continued functionality of the system.

[@lonestarr1490]

@@SimonWoodburyForget Maybe the intent isn't simulating humans, but just simulating a universe. for all we know, we could as well just be a random quirk.

[@augustoo.5099]

I Matt is wandering the universe at Planck Lenght does that mean he will only come back 5 years later when a rat accidentally presses a button?

[@adambrown3918]

This was amazing! Thank you for the video. Honestly, I really don't understand the intricacy's but was glad you tried to explain it in a clear and concise way. I wonder what application of this quantum length understanding will be? Folding space or simply space folds or does any of it "matter"? LOL!

[@toms7986]

That Pair Production explanation for uncertainty was insane.