The Lazy Way to Cut Pizza - Numberphile

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Numberphile

Numberphile

Күн бұрын

Пікірлер: 759
@Mechanikatt
@Mechanikatt 4 ай бұрын
Labelling pieces using bits of pineapple is such an obvious comment bait that I'm fully on board with it.
@FedeDragon_
@FedeDragon_ 4 ай бұрын
I just realized those were pineapple slices
@theadamabrams
@theadamabrams 4 ай бұрын
It never occurred to me that those were pineapple slices, although now that you say it, they clearly are. I just saw them as yellow backgrounds so the numbers would be more visible.
@Comeoniwantaccount
@Comeoniwantaccount 4 ай бұрын
I thought its cheese
@jakistam1000
@jakistam1000 4 ай бұрын
I thought they were mini pizzas
@dembro27
@dembro27 4 ай бұрын
Evil was hiding in plain sight. 😮
@RQLexi
@RQLexi 4 ай бұрын
Truly a mathematician's sort of pizza; reducing it to a bare minimum set of ingredients that have been known to make up a pizza (even if they're in an unconventional form), calling it a previously solved problem, and not even bothering to bake it :p
@usernametaken017
@usernametaken017 4 ай бұрын
Every problem is solvable if you bend the definitions enough
@woody442
@woody442 4 ай бұрын
​@@usernametaken017 How does a mathematician catch a lion? He steps in the cage and defines the inside to be free.
@adb012
@adb012 4 ай бұрын
Original pizza didn't have tomato. Tomato was not known in Italy (or anywhere outside America) until the early 1500's, after the Spanish discovery / conquest. Pizza has existed in Italy since before there was a Italy, or a Roman empire.
@Kyle-nm1kh
@Kyle-nm1kh 4 ай бұрын
All you need is crust and cheese technically
@daddymuggle
@daddymuggle 4 ай бұрын
Assume a spherical pizza...
@phiefer3
@phiefer3 4 ай бұрын
12:35 Missed opportunity to have a "tortilla change" transition in the style of the old "paper change" transition.
@AntoClem_it
@AntoClem_it 4 ай бұрын
daaamn u right😂😂😂
@lubomirkubasdQw4w9WgXcQ
@lubomirkubasdQw4w9WgXcQ 4 ай бұрын
yes
@IceMetalPunk
@IceMetalPunk 4 ай бұрын
Librarian: "You can't cook a pizza in the library!" Brady and Tom: "Fine, but you won't like what we'll do instead..."
@Johnny-tw5pr
@Johnny-tw5pr 4 ай бұрын
Did they really have to do this in the library?
@adamplace1414
@adamplace1414 4 ай бұрын
1:00 that IS a good circle!
@jamesboswell9324
@jamesboswell9324 4 ай бұрын
Pure Zen!
@AalapShah12297
@AalapShah12297 3 ай бұрын
The larger a circle gets, the more difficult it is to draw it nicely. No idea how he managed to do that, unless he had a lot of practice.
@eu4um
@eu4um 4 ай бұрын
Never beating the "The English Can't Cook" allegations with this one
@davidioanhedges
@davidioanhedges 4 ай бұрын
This was not allowed to cook ...
@rmsgrey
@rmsgrey 4 ай бұрын
I think this was more "won't cook" than "can't cook".
@N.I.R.A.T.I.A.S.
@N.I.R.A.T.I.A.S. 4 ай бұрын
To be fair, Brady's Australian. We can't cook either, which is why we toss shrimp on the barbie or whatever.
@JustAnotherCommenter
@JustAnotherCommenter 4 ай бұрын
@@N.I.R.A.T.I.A.S. shrimp on the what now??
@XPimKossibleX
@XPimKossibleX 3 ай бұрын
Congrats on 500 likes
@neatnoot214
@neatnoot214 4 ай бұрын
I know its not the point of the video at all, but that library is just absolutely beautiful, you have my envy over being able to see it in person.
@Inuyasha10121
@Inuyasha10121 4 ай бұрын
Love how Brady jumped right in for -1/12, implying that if you take this algorithm to infinity you wind up with a pizza cut into 11/12 regions. Get the Sixty Symbols squad on this, I smell a Nobel prize for topological defects in higher dimensional pizzas!
@Nemelis0
@Nemelis0 4 ай бұрын
Well that proofs then, if you cut through the middle, that infinity is the same as 6 cuts, since that leaves you 12 regions. With the lazy cutting technique infinity using the -1/12 answer is impossible since you either have 11 regions or 16, but no 12. 8-)
@Inuyasha10121
@Inuyasha10121 4 ай бұрын
@@Nemelis0 it's not that you get 11 of 12 regions, it's that you get 11/12ths of "the concept of a region". Think of it in terms of countries, if I cut a country in half I wind up with two countries, I can move the line wherever but I still get out 2 whole units. If I cut an infinite number of times though, I get 11/12ths of a country, 11/12ths of whole indivisible unit.
@Yezpahr
@Yezpahr 4 ай бұрын
I'm afraid you need a blade or pizza roller that can cut over 1.00 efficiency. In other words, it needs to cut into non-parallel non-curved spacial direction while being a curved-space object.
@Inuyasha10121
@Inuyasha10121 4 ай бұрын
@@Yezpahr @Yezpahr I mean, moving this from the imperfect doughy world of pizza and into the mathematically pure realm of infinitely thin cuts and infinitely flat planes the algorithm still holds. The algorithm is just a greedy method of partitioning a flat region (doesn't have to be a circle) into as many sub-regions as possible by bisecting it over and over. But in math, you can make the cuts arbitrarily close to one another and the regions arbitrarily small but greater than 0 in area.
@jurajvariny6034
@jurajvariny6034 3 ай бұрын
Or they would end up with enough pieces to make two pizzas as big as he original hehe (Banach-Tarski paradox)
@Ceelvain
@Ceelvain 4 ай бұрын
Now that we know that there is a cut pattern that makes 1+n(n+1)/2 pieces out of n cuts, we could ask about fairness in several ways: - What is the pattern that makes the smallest piece the biggest? - What is the pattern that makes the biggest piece the smallest? - What is the pattern that minimizes the variance of the area of the pieces? - Are some of those questions equivalent?
@bramvanduijn8086
@bramvanduijn8086 4 ай бұрын
The thing to remember is that you don't want to come even close to parallel lines, because each line must intersect each other line. So change the angle the smallest possible amount on each cut, staying just shy of the limit an infinitely small (but not zero) amount. Once you pass 180 degrees you get a parallel line that cannot possibly cut all lines, so your range of motion is half a circle. So between (exclude the limits) 0 and 180 degrees you'll be making cuts with the two outermost cuts as close to perpendicular as you can get. The closer the first cut for both of these is to the far edge of the circle, the less long their adjoining pieces are. And since we're talking about cuts with an angle, we're talking triangular pieces for these, two so the longer they get, the bigger they get. If you plot your intersections you should get a half circle with anywhere between zero or infinite surface area. of intersections. So the question becomes: When I draw half a circle inside a circle, how close away can the start and beginning of that half circle be from the edge? The closer they are, the smaller their pieces. Then again, that's only true if the half circle of intersections is for a smaller circle than the pizza. If the intersection half-circle is infinitely bigger, the intersection half-circle is effectively a straight line, so the closer the line is to the middle, the fairer the cuts. So depending on the difference between the pizza's radius and the intersection half-circle's radius, the best option is either as close to the edge or as far from the edge. I wonder what the middle point would be where the pizza and intersection radius are the same. This is probably basic, but math was a long time ago for me.
@bartolhrg7609
@bartolhrg7609 4 ай бұрын
"Smallest piece the biggest" doesn't make sense. I don't know what you meant by that
@babilon6097
@babilon6097 4 ай бұрын
​@@bartolhrg7609After you make all n cuts you see what's the size of the smallest piece. Now you consider if you can cut differently such that the smallest piece is larger.
@oke5403
@oke5403 4 ай бұрын
@@bartolhrg7609 maximising the size of the smallest piece
@widmo206
@widmo206 4 ай бұрын
@@bartolhrg7609 He means that the smallest piece (out of the set of all pieces) has the largest area it possibly can
@EyalBrown
@EyalBrown 4 ай бұрын
Making the world's worst pizza in a library is exactly the kind of insanity I originally subscribed to this channel for
@skyscraperfan
@skyscraperfan 4 ай бұрын
I once had a pizza with bananas and Nutella. I think that one was worse. It tasted as bad as it sounds.
@widmo206
@widmo206 4 ай бұрын
@@skyscraperfan I mean, it should taste fine as long as all ingredients were dessert-y things
@alquinn8576
@alquinn8576 4 ай бұрын
@@widmo206 it had nutella on it, therefore it did not taste fine
@widmo206
@widmo206 4 ай бұрын
@@alquinn8576 So you just don't like nutella?
@alquinn8576
@alquinn8576 4 ай бұрын
@@widmo206 it should be called sugarella since it is 57% sugar by mass. it is objectively garbage with respect to human metabolism.
@diaz6874
@diaz6874 4 ай бұрын
Numberphile 2014: The scientific way to cut a cake. Numberphile 2024: The lazy way to cut a pizza.
@YouTrolol
@YouTrolol 4 ай бұрын
i thought this sounded familiar...
@handledav
@handledav 4 ай бұрын
who
@TheEd555
@TheEd555 4 ай бұрын
Numberphile 2034: The lazy way to cut a cake
@aramisortsbottcher8201
@aramisortsbottcher8201 4 ай бұрын
Numberphile 2044: The scientific way to cut a pizza.
@diogeneslantern18
@diogeneslantern18 4 ай бұрын
Dr Hannah Fry, our queen
@danielg9275
@danielg9275 4 ай бұрын
That’s the best drawn circle I have ever seen on numberphile
@TomRocksMaths
@TomRocksMaths 4 ай бұрын
ikr?
@b1oodzy
@b1oodzy 4 ай бұрын
Cutting a pizza like a drunk person, with a metal ruler in a library, while being recorded with a big camera. Absolutely amazing setup.
@RaptureWillRiseAgain
@RaptureWillRiseAgain 4 ай бұрын
7:52 Brady's -1/12th joke love it
@mystifoxtech
@mystifoxtech 4 ай бұрын
Joking about a false statement is a mathematician's favorite passtime
@rainerzufall42
@rainerzufall42 4 ай бұрын
@@mystifoxtech sum_k=1..inf(k) = -1/12 isn't a false statement, it's just the golden nugget of a true statement!
@mystifoxtech
@mystifoxtech 4 ай бұрын
@@rainerzufall42 It's only true for very specific definitions of the words "sum", "equals", and "number"
@rainerzufall42
@rainerzufall42 4 ай бұрын
@@mystifoxtech You didn't get my point, or you don't know the history of this channel well enough!
@chriswebster24
@chriswebster24 3 ай бұрын
It wasn’t that funny, really.
@mbalicki
@mbalicki 4 ай бұрын
The pineapple numbers! 😂 I love this attempt at keeping the engagement in the comments high. 😁
@jimmyzhao2673
@jimmyzhao2673 4 ай бұрын
More like getting peoples hackles up.
@ig2d
@ig2d 4 ай бұрын
Did you know that the volume of a pizza radius "z", thickness "a" equals pi.z.z.a
@aimeerivers
@aimeerivers 4 ай бұрын
technically only true when z = 2
@kennygeheim4230
@kennygeheim4230 4 ай бұрын
​@@aimeeriverswrong. Pi times z squared (which is the same as z times z) times a is correct. So it of course does not matter how long z is. It can be 1cm or 349388383 lightyears. 😮
@aimeerivers
@aimeerivers 4 ай бұрын
@@kennygeheim4230 oh i thought the equation was the diameter times pi (the diameter being 2 times the radius) ... but it is a very long time since i went to school 😂
@Mechanikatt
@Mechanikatt 4 ай бұрын
@@aimeerivers Diameter times pi gives you the circumference. The surface (and then volume) requires the radius squared. Hopefully that clears up the confusion :)
@aimeerivers
@aimeerivers 4 ай бұрын
@@Mechanikatt thank you, that does help!! and now i can always remember the equation thanks to the pi.z.z.a formula!!
@Gr8Sc0tsman24
@Gr8Sc0tsman24 4 ай бұрын
I have not attempted to learn mathematics or work with mathematics since I last studied it a couple years ago and this is my first time in a long time I have had to think mathematically. It really feels uncanny but awesome how all of this kind of stuff just *makes sense*. Thank you for presenting these kind of simplified versions for people like me to get back into mathematics!
@jruthenberg
@jruthenberg 4 ай бұрын
"Pizza is not one of my favorites." Literally cannot be trusted now.
@Caio_Myguel
@Caio_Myguel 4 ай бұрын
Distrust any "man" who dislikes pizza
@IceMetalPunk
@IceMetalPunk 4 ай бұрын
I thought the same thing. I was immediately like, "Y'know, Tom, I respected you, but now I'm not sure I can anymore..." 😂
@CasusUniversum
@CasusUniversum 4 ай бұрын
Yeah he lost me the thing he said
@CasusUniversum
@CasusUniversum 4 ай бұрын
0:03 "It's not one of my favorites" and you've lost me
@robertdunagan5807
@robertdunagan5807 4 ай бұрын
Based on this I now understand that the total size of a cut pizza is 11/12 pizzas. I've weighed the crumbs left on the pan after cutting and believe this to be accurate.
@plackt
@plackt 4 ай бұрын
I refuse to believe that cutting a single pizza turns it into almost 12 pizzas. =P
@gdclemo
@gdclemo 4 ай бұрын
@@plackt it can, but only if the axiom of choice is true. Also you end up with some pretty weird cuts.
@robertdunagan5807
@robertdunagan5807 4 ай бұрын
@plackt this is what is beautiful about mathematics, such an unintuitive answer that it seems impossible but then apply it to a real world situation, and the surprising result confirms that what we once thought of as nonsense is indeed innovation.
@7186B
@7186B 4 ай бұрын
I was screaming in my Head " MINUS a TWELFTH" each second, and then finally brady said it :D I love it. I love you brady. I love Math.
@Liebestod0001
@Liebestod0001 4 ай бұрын
thanks. now some of my 22 guests are angry at me after I handed them their "piece"
@randomjapsi
@randomjapsi 4 ай бұрын
more like 19 are unhappy but 3 people are quite happy with their amount
@isavenewspapers8890
@isavenewspapers8890 3 ай бұрын
@@randomjapsiYes, 19 is some of 22.
@fanthomans2
@fanthomans2 4 ай бұрын
I love the enthusiasm of this guy.
@TomRocksMaths
@TomRocksMaths 4 ай бұрын
@abigailcooling6604
@abigailcooling6604 4 ай бұрын
Love the detail of the little pizza-loving rat in the animations 😊
@zirize
@zirize 4 ай бұрын
Next subject : The Lazy Way to Cut Pizza "fairly".
@PopeGoliath
@PopeGoliath 4 ай бұрын
My intuition is that the intermediate value theorem would allow you to make equal areas for any given solution by rotating and translating the cuts, without changing which overlap which.
@sergiokorochinsky49
@sergiokorochinsky49 4 ай бұрын
I assume that calculating the sequence of angles g(n) that ensures the f(n) portions have the same area is out of the scope of this channel.
@minamagdy4126
@minamagdy4126 4 ай бұрын
I highly doubt that it could possibly be fair even for the 3-cut case. An interesting query is how fair can it get for a number of cuts, in terms of narrowing the range of slice areas? Also, how many fair slices can be achieved? (For that, we have the lower bound of 2n for the normal radial cutting method and the upper bound provided here. I don't expect the actual upper bound to be better than linear).
@xenontesla122
@xenontesla122 4 ай бұрын
Yeah, what's the maximum number per cut when you have to make every slice equal area?
@JennaHasm
@JennaHasm 4 ай бұрын
The slices look a lot like life, though. The "normal"/"fair" way is the PC version. This version is how life really is. Mine is the the tinny tiny one in the left corner.
@soberhippie
@soberhippie 4 ай бұрын
I bet the dialogue of that teacher with the young Gauss went like this: "Can you calculate the sum of all integers from 1 to 100" - "Ahh, well, fifty-fifty"
@omicronflux
@omicronflux 4 ай бұрын
The animations are getting more sophisticated by the day. Love
@MegaSpartan007
@MegaSpartan007 4 ай бұрын
What happens if you have a non-euclidian pizza?
@freedomlinux
@freedomlinux 3 ай бұрын
oof, then I hope you didn't invite Euclid to the pizza party. He's going to be mighty annoyed that he didn't get any.
@TheCairn
@TheCairn 4 ай бұрын
I found an easy way to cut the pizza into the maximal number of pieces from n cuts (I don't know if this is how they do it in the paper or if this is even correct): if n is odd, construct a regular n-gon, and extend all the sides as infinite lines. Then, draw your circle big enough around the n-gon so that all the line intersections are contained. Each line will intersect every other line in the circle, as needed. If n is even, do the same with n+1 and remove a line. Kinda cool!
@litigioussociety4249
@litigioussociety4249 4 ай бұрын
After watching this I realized making the least number of pieces is incredibly simple, since you just keep cutting parallel lines to add one strip at a time.
@HunterJE
@HunterJE 4 ай бұрын
They don't even have to be parallel so long as their crossing points are on or outside the rim of the pizza
@rmsgrey
@rmsgrey 4 ай бұрын
Who says you need the cut lines to intersect the pizza? Or be distinct from each other?
@MarcGauch
@MarcGauch 4 ай бұрын
just cut outside of the pizza
@HunterJE
@HunterJE 4 ай бұрын
I think it could strongly be argued that a line that does not in any way divide the pizza does not fit a reasonable definition of the word "cut"...
@Kyle-nm1kh
@Kyle-nm1kh 4 ай бұрын
Simple. Eat a slice every time you cut so answer is always 1
@picassodilly
@picassodilly 4 ай бұрын
2:10 There should be a follow up video on if it’s possible to “Lazy Cut” a pizza into equal area slices. Intuitively, this seems possible with 7 slices and 3 cuts, but with 4 or more cuts, it becomes a lot less clear whether or not it can be fairly divided.
@Caio_Myguel
@Caio_Myguel 4 ай бұрын
8:01 Good one, Brady lmao Mathematician: Well yes, but actually no
@andrewmarkowski308
@andrewmarkowski308 4 ай бұрын
Can I ask about Tom's tattoos? Do spaces between rings on his right arm fallow a specific function or sequence?
@PRIYANSH_SUTHAR
@PRIYANSH_SUTHAR 4 ай бұрын
Mathematics wants to show up everywhere.
@dylanwolf
@dylanwolf 4 ай бұрын
Why theory is immeasurably more satisfying than practice.
@maciejmaderek3974
@maciejmaderek3974 4 ай бұрын
Problem showed in one of the greatest math books "Concrete Mathematics" by R. Graham, D. Knuth and O. Patashnik. Great video!
@HoSza1
@HoSza1 4 ай бұрын
This is a greedy algorithm, you try to maximize the number of new regions in each step, but the greedy approach does not guarantee optimal solution in general, so its use should be justified in a case by case basis, right?
@egorkarpuhin7053
@egorkarpuhin7053 4 ай бұрын
You are right, the greedy algorithm is not always correct, but I think it is proven in the video, that the greedy approach works here, perhaps not explicitly enough 0) f(n) is defined "The maximum number of slices using n cuts" 1) You have to do exactly n-1 cuts before making the nth cut 2) (1) => on the nth cut you can intersect no more than n-1 lines, making no more than n new slices 3) (1) => before nth cut there can be no more than f(n-1) slices 4) (2), (3) => f(n) = f(n-1) + n or less 5) f(n-1) + n slices is achievable by doing the greedy algorithm => f(n) = f(n-1) + n or more (or it would not be maximum) 6) (4), (5) => f(n) = f(n-1) + n (6) states, that the formula at 7:20 is correct and the rest is certainly in the video
@HoSza1
@HoSza1 3 ай бұрын
@@egorkarpuhin7053 Thank you! It's very convincing.
@frankharr9466
@frankharr9466 4 ай бұрын
That library's going to smell like tomato paste for hours. :)
@JohnDlugosz
@JohnDlugosz 4 ай бұрын
So are you going to put that under "special instructions" when ordering the pizza online?
@emersonchaves567
@emersonchaves567 4 ай бұрын
We really need the discussion for the higher dimensions versions of this problem. What about 2d slices of a 3d sphere?
@tidorith
@tidorith 3 ай бұрын
Doesn't even need to be sphere. A sufficiently skilled caterer can cut a pizza in half horizontally. Way more slices that way.
@PeeBee-f2b
@PeeBee-f2b 3 ай бұрын
I would quite enjoy that "pizza" as a snack, despite what haters say. Tortilla bread is delicious. Amazing video by the way. I had taken a hiatus from math, but this reminded me why I love the subject.
@HunterJE
@HunterJE 4 ай бұрын
2:05 "but obviously this one's quite small and no one wants it" I'd say the size isn't even the biggest issue; after all you could rearrange the cuts to make that middle piece bigger if you want. But it'd still be a bad slice of pizza since it doesn't have any outer crust, and thus cannot be easily picked up to eat without getting toppings all over your hands
@hoebare
@hoebare 4 ай бұрын
I prefer pizza without crust. I don't mind getting toppings on my hands or eating pizza with a fork.
@tippyc2
@tippyc2 4 ай бұрын
It's not about the size of the piece, it's what you make of it that counts. 🤣
@mal2ksc
@mal2ksc 4 ай бұрын
That's the problem with rectangular pizzas (cut into rectangles) in general: the bigger they get, the more crustless pieces you have.
@Lemu_with_a_shirt
@Lemu_with_a_shirt 4 ай бұрын
​@@mal2ksc Based on how many people don't eat pizza crust I'd say it's a mixed loss and win.
@Lexivor
@Lexivor 4 ай бұрын
@@mal2ksc Having crustless pieces is more of an advantage than a problem.
@quimicalobo61d
@quimicalobo61d 4 ай бұрын
This max cuts sequence is excelent for distribute potential over dimentions..
@word6344
@word6344 4 ай бұрын
0:14 the Erdos graffiti on the edge of the building!
@MagmaBow
@MagmaBow 4 ай бұрын
?
@word6344
@word6344 4 ай бұрын
@@MagmaBow Erdös is a mathematician whose work has been covered by Numberphile a few times
@MagmaBow
@MagmaBow 4 ай бұрын
@@word6344 ah alright
@lexyeevee
@lexyeevee 4 ай бұрын
if you don't want the middle triangle from the third cut to be too small, don't make the first two cuts meet near the center! that minimizes the possible size of that triangle!
@aeschynanthus_sp
@aeschynanthus_sp 4 ай бұрын
Crawford circles are much more circular than Parker circles
@TheRotMGPerson
@TheRotMGPerson 4 ай бұрын
And don't get me started on parker squares!😂
@Ceelvain
@Ceelvain 4 ай бұрын
The important thing is to give it a go!
@m.rishab4770
@m.rishab4770 4 ай бұрын
6:32 f(1) = 2 but at 7:35 He says f(1) = 1, but formula works fine how ?
@thislooksfun1
@thislooksfun1 4 ай бұрын
I had the same thought! Took me a minute to work it out, but I figured out what happened. `f(1) = 2` because `f(1) = f(0) + 1`, and `f(0) = 1`, so `f(1) = 1 + 1`. Tom misspoke at 7:37 saying that `f(1) = 1`, but everything that was written down was correct. The formula `f(1) + 2 + ... + n` is correct, and expanding `f(1)` and `f(0)` at the same time does lead to `1 + 1 + 2 + ... + n`. TL;DR: the math written down is correct, Tom just misspoke.
@m.rishab4770
@m.rishab4770 4 ай бұрын
​@@thislooksfun1 understood Thank You very much I was thinking the 2 after f(1) should be value for f(1)
@ozAqVvhhNue
@ozAqVvhhNue 4 ай бұрын
What positions would the cuts need to be at to get the most equal(ish) sized areas as possible per cut? I mean 1 cut is straight down the middle. 2 cuts, in a right angle, both meeting at the center point of the circle leaves 4 equal quadrants. But what about 3 cuts and more?
@Archangel-cw7mq
@Archangel-cw7mq 4 ай бұрын
To get equal cuts, all cuts must pass through the center. The positions of those cuts would be at degree intervals along the circle, with that interval equal to 180/n. So 2 cuts, 180/2 = 90. Place the first cut anywhere and pass it through the center, then the second cut 90 degrees along the edge of the circle. 3 cuts would be 60 degree intervals, giving 6 equal pieces. 4 would be 45 for a classic pizza cut of 8 pieces, and so on.
@ozAqVvhhNue
@ozAqVvhhNue 4 ай бұрын
@@Archangel-cw7mq obviously I meant while still ultimately trying to achieve the most pieces possible per cut, which is a much more difficult question.
@gdclemo
@gdclemo 4 ай бұрын
For equal area per region, I think it is necessary for each cut to distribute the area of the circle proportionally to the number of regions on each side of it. i.e. if a cut will have three regions on one side and five on the other, it should split the circle area 3:5. I don't know if that's sufficient though. Note that this also means that the equal area arrangements for n cuts is not necessarily the starting point for an equal area arrangement for n+1 cuts. IDK, I'll have to think about this a bit more...
@mikechiu9767
@mikechiu9767 4 ай бұрын
10:10 "Cooking a pizza not permitted in college library" Fair enog...wait, why is it okay to bring food into the library?
@cgsweat
@cgsweat 4 ай бұрын
You are not a true mathematician unless you spend hours playing with your food.
@imkharn
@imkharn 4 ай бұрын
I propose a method to get the most pieces. (5 mins into video) 1) Initial cut 2) Almost parallel but intersects near edge of pie 3) Same thing but intersects the previous one 4) Same thing but intersects the previous two 5) Repeat til you get a dreamcatcher. Your intersection with the first cut changing location slightly each new cut that if linked form a bent chord.
@djsyntic
@djsyntic 4 ай бұрын
Pausing at 6:47 to think about this going the other direction. If I get N new regions when I have made N cuts this suggests when I made 0 cuts I got 0 new regions. This means -1 cuts should ALSO have 1 region. But that would imply that when I made -1 cuts that I lost a region at that time. So if I had -2 cuts I should have 2 regions. And -3 cuts would have been 4 regions and so on.
@blakehawkins3296
@blakehawkins3296 4 ай бұрын
actual footage of teachers before the class pizza party
@chubrik2
@chubrik2 Ай бұрын
Is there some approach that allows you to make a minimal difference between the sizes of the pieces?
@xfrmkx
@xfrmkx 4 ай бұрын
Is there a way to find the best cut such that all pieces are as equal as possible?
@Kyle-nm1kh
@Kyle-nm1kh 4 ай бұрын
I would imagine you'd have to plan for the exact n you're looking for
@rogerkearns8094
@rogerkearns8094 4 ай бұрын
I wonder: given a unit radius pizza, what's the area of the largest possible smallest piece, for n cuts?
@daxafer
@daxafer 4 ай бұрын
“I like to derive my own formulas” … this is why my grade went from 64% to 98% between my first and second semesters of calculus. We had a giant list of trig integrals to memorize for the first end of term 1, and I can’t memorize at all well. Term two, we learned integration by parts and I could derive them instead! I also did this for many years with the quadratic formula
@MK73DS
@MK73DS 4 ай бұрын
Is there such a maximal cut that gives equal area parts? For one and two cuts it's obvious (diameter and two perpendicular diameters) but for three I can't seem to figure out a solution.
@AnonimityAssured
@AnonimityAssured 4 ай бұрын
That's because there _is_ no solution. However, if you make the central region very, very small, it's possible to make the six outer regions almost equal. At the limit, it is possible, with three cuts, to produce six equal regions, but not seven.
@samuraijackson241
@samuraijackson241 4 ай бұрын
The laziest way to cut a pizza is don't, eat the whole thing, in one.
@MrSuperdelf
@MrSuperdelf 2 ай бұрын
This is the only numberphile video that I guessed anything. I had a feeling it was how many intersections there were. Im no math expert so that was exciting for me
@EastBurningRed
@EastBurningRed 4 ай бұрын
real world pizza actually has thickness so you can for example make a cut parallel to the plane of the table, but then the solution to the number of pieces you get with n cuts is (n+1)(n^2-n+6)/6
@jurajvariny6034
@jurajvariny6034 3 ай бұрын
Yep and then 4th cut in another plane orthogonal to all three. But probably 4-dimensional cuts are not allowed in the library either.
@EastBurningRed
@EastBurningRed 3 ай бұрын
​@@jurajvariny6034 Here's the number if you can make 4d cuts: (24+14n+11n^2-2n^3+n^4)/24
@amirilan4435
@amirilan4435 4 ай бұрын
Apologising to the italians and then setting the numbers as pineapples. 10/10
@rodrigoqteixeira
@rodrigoqteixeira 4 ай бұрын
6:50 I like how fast he changed the upper bound for f(n) from 2^n to n(n+1)/2+1
@slo3337
@slo3337 4 ай бұрын
I work at BlackJackPizza. I'm always pondering different ways of cutting a pizza 🍕 so this video is one I cannot skip 😂
@FattestFish
@FattestFish 4 ай бұрын
Excellent video. Very well explained und visualized.
@Phobero
@Phobero 4 ай бұрын
That's the saddest "pizza" I've ever seen, but Professor guy gets a pass from Italy anyway - because of the interesting content as usual and the strikingly perfect free hand circle 😅
@Hogibaer
@Hogibaer 4 ай бұрын
The lazy way to cut pizza starts with a tortilla, I see you are going full laziness... 😂
@ricardoandre414
@ricardoandre414 4 ай бұрын
I had to solve this looong ago when I was a teenager. I did as in the video and I was rightfully happy with it. Another one did better, though somewhat out of the box. Cut the pizza in half, place one half on top of the other, repeat. We'll get 2^n equally sized pieces of pizza.
@LynxUrbain
@LynxUrbain 4 ай бұрын
Mammamia ! 😱 If I were an Italian mathematician (which I'm not), I'd challenge you to find: "The Lazy Way to Cut Christmas Pudding". In 3D, with planes instead of lines. ... and then label the slices of pudding with pieces of tomato or salami. 😝
@adrian-victor2727
@adrian-victor2727 3 ай бұрын
Around 7:49 there is the mistake that f(0) is counted twice. f(0) is indeed 1 but it's the only way to have just 1 slice
@davidfryer4353
@davidfryer4353 4 ай бұрын
the fact that you're marking the pieces with pineapple makes this so much more cursed
@VulcanTrekkie45
@VulcanTrekkie45 4 ай бұрын
This video got Tom Crawford sanctioned by the Republic of Italy for crimes against gastronomy
@GPLB
@GPLB 4 ай бұрын
Due to the size variation in each slice, is there a way to optimize/normalize slice size when cutting? Or are we locked in with dramatically different slice sizes?
@leefisher6366
@leefisher6366 4 ай бұрын
I'm reminded of the peg-and-string thing where you start off with a pair of perpendicular axes (more than one axis, not more than one axe) and draw the lines (X,1), (X-1, 2), (X-2,3) and so on to (1, X). With a large enough X, you get the image of a quarter circle made out of many straight lines... however the intersections of each new line conform to this lazy algorithm too.
@gmt-yt
@gmt-yt 4 ай бұрын
Awesome video, I can't wait to amaze my friends with the efficiency of this trick at our next pizza party :P
@tsawy6
@tsawy6 4 ай бұрын
Also a classic for the whole "any finite sequence is the first n terms of infinitely many other sequences". Complete the sequence: "1,2,4..." you ask people and they invariably say 8, but if were using this, its 7!
@nashtrojan
@nashtrojan 4 ай бұрын
I am a simple man with complicated pleasures. I enjoy math, science and cooking. Watching someone spread raw tomato paste on dough with a trowel then applying pre shredded mozzarella on top is devestating. 3:40 well with the hyperbolic way that you treated that beautiful piece of dough I think you can find a way.
@anonanon6596
@anonanon6596 4 ай бұрын
8:27 Teacher gave us the same task when we were 12. I did it geometrically. Imagine a tower 1 block high, place a tower of hight 2 next to it, next hight 3 and so on. It starts to look like a triangle. Everyone knows the formula of the area of triangle. Now you have an approximate answer. Look closely at the drawing and notice that the area difference is exactly n/2 and you have the exact answer. The story with Gauss is apocryphal btw.
@woody442
@woody442 4 ай бұрын
Thats even easier to grasp than the pairing method. Well done.
@EasyYoutubeAI
@EasyYoutubeAI 4 ай бұрын
Maximize pizza pieces using the lazy Caterer's sequence, derive a formula, and attempt to cut a pizza into 22 pieces. 00:05: Explore the lazy Caterer's sequence for maximizing pizza pieces. 01:01: Demonstrate cutting a pizza with one to four cuts. 04:00: Discuss maximizing intersections with each new cut for more pieces. 06:10: Derive a formula for calculating maximum pizza pieces with cuts. 10:00: Attempt to cut a pizza into 22 pieces with six cuts.
@joebobjon1127
@joebobjon1127 4 ай бұрын
I was confused for a moment since I vaguely remembered a similar topic in a 3b1b video that results in a different sequence but I realize my mistake now. This sequence is constructed by placing lines through a circle, while the 3b1b sequence was constructed by placing points on the circumference of a circle and drawing lines between those points
@skyscraperfan
@skyscraperfan 4 ай бұрын
Yes, that also confused me. I remember the sequence 1,2,4,8,16,31.
@alexbortolotti3766
@alexbortolotti3766 4 ай бұрын
The transition from pizza cutting to sums was so smooth
@Kram1032
@Kram1032 4 ай бұрын
is there a particular cutting strategy that distributes the lines such that the deviation of the distribtuion of areas is minimized?
@hongkonger885
@hongkonger885 4 ай бұрын
Fun fact: After Cheung Ka Long's victory in the olympics, the Italians were pissed. So Pizza Hut Hong Kong released a free pineapple topping to celebrate Cheung's victory, pissing the Italians even more.
@scaredyfish
@scaredyfish 4 ай бұрын
Natural follow-up question: what pattern of cuts gives you the biggest small pieces/most even pieces. Like for one and two cuts, the centre is obviously the most even place, but for three cuts, it works better if the first two are not central.
@CR0SBO
@CR0SBO 4 ай бұрын
Tom made a right ParkerPizza of that first attempt
@esotericVideos
@esotericVideos 4 ай бұрын
You should do a follow up video where you not only maximize the number of pieces, but you also figure out the cuts that would make the most equal sized pieces. In other words what cuts would result in the smallest difference between the biggest slice and the smallest slice?
@DivinePonies
@DivinePonies 4 ай бұрын
Would it be possible to adjust cuts in such way that you get even pieces every time? I assume you would have to know upfront how many cuts you're making to do so, since any additional cut would make some cuts smaller than the others.
@tiger12506
@tiger12506 4 ай бұрын
Now the next step... Figuring out algorithm to maximize the cut area (of the final pieces) as much as possible, and then determining the distribution of area across all the cuts and see if it fits a pattern.
@antivanti
@antivanti 4 ай бұрын
While getting the maximum number of pieces for that number of cuts is it possible to do so and generate equal area pieces? I'm pretty sure it might be possible for 3 cuts but is it possible for 4 cuts?
@SynthRockViking
@SynthRockViking 4 ай бұрын
Scissoring pizza into power of three, is a sign of actual competence imo 😌
@Tker1970
@Tker1970 4 ай бұрын
PINEAPPLE? You trying to start fights?
@jimmyzhao2673
@jimmyzhao2673 4 ай бұрын
I'm so triggered right now, I need to go to my safe space.
@LukeSumIpsePatremTe
@LukeSumIpsePatremTe 4 ай бұрын
I get that this is a joke, but I don't get why it bothers some if someone who likes pineapple in pizza puts pineapple in pizza.
@tristanridley1601
@tristanridley1601 4 ай бұрын
I imagine it's because they either haven't tried it or they hate fun.
@burnblast2774
@burnblast2774 4 ай бұрын
My question is, does there exist an arrangement of cuts such that you still get n(n+1)/2 pieces and each piece is of equal area? And if so, is it actually possible to find said arrangement for an arbitrary number of cuts?
@EconAtheist
@EconAtheist 4 ай бұрын
Tom makes another appearance! yay!
@thomascrawford1407
@thomascrawford1407 4 ай бұрын
@LucenProject
@LucenProject 4 ай бұрын
I think, a time-lapse of a ladder sliding slowly down a wall would have lines made by the ladder that cross over every previous line. What is the shape created by those lines called?
@ralfbaechle
@ralfbaechle 4 ай бұрын
You may just have explained why my Brazilian friends seem to all cut up their pizza in such an irregular way. I'm sure the mafia, camorra, mafia and ndrangheta are just joining forces to avenge the desecration of a national food relic.
@Moscatinka
@Moscatinka 4 ай бұрын
I applaud you for not getting Fibonacci involved in this spherical cow of a pizza.
@Thimon88
@Thimon88 4 ай бұрын
That drop in subscribers were the Italians.
@patrickkearney1577
@patrickkearney1577 4 ай бұрын
Six cuts can give 32 pieces: 16 from the shown n=5, then cut sideways through the width of the pizza thus doubling the number. What is the formula for the maximum number of cut pieces from a mathematical sphere, also what for a ball?
@Kallyn
@Kallyn 4 ай бұрын
Since each new slice intersects each previous slice, doesn't that mean you can approach those six slices in any order and still have maximum slices for each possible step? Side note: with one slice, you have made two slices. With 6 slices, you have made 22 slices. Is the "slice" the cut itself or the resulting pizza?
@bunnybro5977
@bunnybro5977 4 ай бұрын
Is there a way of finding a pattern that maximises the size of each piece for any given number of cuts? So some sort maximum-pieces-and-area algorithm
@MindstabThrull
@MindstabThrull 4 ай бұрын
So now here's the question: Given N cuts, you can make 0.5N(N+1)+1 slices. Is it possible to always divide it so that if K=2 people are sharing the pizza, both get the same amount, regardless of where the slices are? Can this be done for more than K>2 given sufficient N? Example: With 6 cuts you should get 22 slices. Is it possible to distribute those 22 slices so that two people each get the same amount of pizza?
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