Six Sequences - Numberphile

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Numberphile

Numberphile

Күн бұрын

Which of these number sequences do you like best? Vote at bit.ly/Integest...
The extra bit of footage is at: • Tony's Favourite Numbe...
More links & stuff in full description below ↓↓↓
This video features Tony Padilla from the University of Nottingham: / drtonypadilla
Here's each sequence on the OEIS:
Khintchine's constant: oeis.org/A002210
Wieferich primes: oeis.org/A001220
Golomb's sequence: oeis.org/A001462
Largest metadrome in base n: oeis.org/A023811
All 7's: oeis.org/A010727
Wild Numbers: oeis.org/A058883
The Aperiodical: aperiodical.com/
Brown Papers: bit.ly/brownpapers
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Videos by Brady Haran
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Brady's videos subreddit: / bradyharan
Brady's latest videos across all channels: www.bradyharanb...
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Пікірлер: 574
@Majorohminus
@Majorohminus 11 жыл бұрын
my favorite sequence is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10... its the natural sequence and its perfect. the number in the nth position is n and its the first sequence anyone learns.
@todabsolute
@todabsolute 4 жыл бұрын
@Adi Septiana 1. It was supposed to be sarcasm 2. This sequence is the base for e
@aforcemorepowerful
@aforcemorepowerful 3 жыл бұрын
It's also the decimal expansion of Champernowne's constant
@TheMagicianLiam
@TheMagicianLiam 3 жыл бұрын
I agree but in base 12. Sorry
@hkayakh
@hkayakh 2 жыл бұрын
How about that sequence but nth position is -n?
@sankang9425
@sankang9425 Жыл бұрын
Ah yes, the A000027... My second favorite.
@m3ntalcas3
@m3ntalcas3 8 жыл бұрын
i could tell khinchin's constant was his fave he went on about it much more than the others
@leo17921
@leo17921 5 жыл бұрын
also cause its more complicated
@rednecktash
@rednecktash 4 жыл бұрын
thats what i thought too even before seeing any other ones
@thomaskaldahl196
@thomaskaldahl196 3 жыл бұрын
But why the decimal expansion? Is there anything special about it?
@olivialuv1
@olivialuv1 2 жыл бұрын
@@thomaskaldahl196 The decimal is cool bc you get to know the approximate value of this godly self-knowing number, as opposed to just some fraction whose value you can't tell by looking at it
@thomaskaldahl196
@thomaskaldahl196 2 жыл бұрын
@@olivialuv1 But what's significant about base 10 as opposed to binary or some other base?
@christosvoskresye
@christosvoskresye 8 жыл бұрын
It would seem to me that the constants in the continued fraction expansion of Khinchin's constant would be more meaningful than the decimal expansion.
@RedRad1990
@RedRad1990 4 жыл бұрын
*Tony Padilla:* "I'm not going to tell you which one I like best" *also Tony Padilla:* proceeds and starts by talking about his fav no hints XD
@numberphile
@numberphile 11 жыл бұрын
Shout-out to Ireland!
@goutamboppana961
@goutamboppana961 3 жыл бұрын
??????????
@overwrite_oversweet
@overwrite_oversweet 11 жыл бұрын
This virol ad said something like 95% of KZbin vid get less than 1000 views and my first reaction was "wow so many KZbin vids get over 1000 views"
@anticorncob6
@anticorncob6 11 жыл бұрын
One of my favorite number sequences is this: 2, 3, 4, 5, 7, 9, 11, 13, 16, 17, 19, 23, 25, 29, 31, 37, 41, 43, 47, etc. It's all the primes, plus all the values of p^(2^n) where p is prime and n is a positive integer. With these numbers, every other number can be written as a unique product of these, without repeats. For instance 99 = 11 * 9, that's the "factorization" and there's no other way to do it.
@DimaVaulin
@DimaVaulin 2 жыл бұрын
Wow!
@bagelnine9
@bagelnine9 11 ай бұрын
Same.
@numberphile
@numberphile 11 жыл бұрын
In the video description there are links to all the sequences, a chance to vote for a winner and other stuff...
@mr.z111
@mr.z111 Жыл бұрын
Ш vs Щ
@gmdFrame
@gmdFrame Жыл бұрын
@@mr.z111 Прив
@numberphile
@numberphile 11 жыл бұрын
Do you know what - I kind of get it and never really mind it.... It is human nature to get a thrill from being first (or among the first) to do or see something...
@WilliametcCook
@WilliametcCook 7 жыл бұрын
2:53 But I thought God's Number was 20... James Grime was in your video on it...
@annevanderbijl3510
@annevanderbijl3510 4 жыл бұрын
Nice
@ToxicGLaDOS
@ToxicGLaDOS 11 жыл бұрын
Could you do a video on the Tree function? I've looked up some things about it but it's over my head without intense explanation. Mostly about TREE(3) and how it compares to grahams number and other big numbers.
@alecbader7433
@alecbader7433 2 жыл бұрын
You were ahead of your time...
@asheep7797
@asheep7797 6 ай бұрын
4 years ahead of your time.
@unecomedy13
@unecomedy13 10 жыл бұрын
for the wild numbers, just add 0.5.
@NeoUno866
@NeoUno866 11 жыл бұрын
1,11,21,1211,111221,312211, ... You split it up and describe the previous number, where the next number in the sequence is the description.
@peligrosacurva-cz4ev
@peligrosacurva-cz4ev 19 күн бұрын
See and write 🎉
@smoorej
@smoorej 4 жыл бұрын
Khinchin’s constant is absolutely mind blowing. That any continued fraction expansion of “almost all” numbers gives you Khinchjn’s constant is just jaw-dropping. Question: is the “almost all” numbers all real numbers except the rationals?
@vocnus
@vocnus 3 жыл бұрын
It is really incredible and yet ture for ''almost all'' numbers... however it is NOT containing each and every irrational number! For example fi=1.618... or the base of natural exponential e=2.718... are irrational numbers which are not under this rule. The fi's fractional expansion goes this way: [1;1,1,1,...] which is the notation for 1+1/(1+1/(1+1/(1+...))), and with the ''e'' it goes this way: [2;1,2,1,1,4,1,1,6,1,1,8,1,1,10,1,1,12,...] = 2+1/(1+1/(2+1/(1+1/(1+1/(4+...))))). In the first example the geometric mean is constant 1, and in the second it goes to infinity as we deal with more and more terms...
@Catman_321
@Catman_321 Жыл бұрын
you can show pretty easily that no quadratic irrational number has this property. Since the terms in the continued fraction repeat periodically, it will not converge to an irrational number. Same with numbers where the terms in their cf strictly increase, which diverge to infinity. e is similar to these numbers and doesn't converge to khinchin's constant for similar reasons however most generic irrational numbers do have this property
@GladionD.Pierce
@GladionD.Pierce Ай бұрын
NERD
@joegamewaffle5967
@joegamewaffle5967 11 жыл бұрын
False, the best name is not Solomon Golomb. It's Nebuchadnezzar, solely because it's pronounced something like "Ne-buh-kuh-ne-zur." ...My Global Studies teacher is quite awesome...
@jikojj3680
@jikojj3680 6 жыл бұрын
Joe GameWaffle global studies 🤣 ought to be usa uni
@amoledzeppelin
@amoledzeppelin 6 жыл бұрын
Yep because most of other world learn how it's pronounced from watching the first Matrix movie in original.
@maxnullifidian
@maxnullifidian 6 жыл бұрын
The best name might well be Arup Gupta - at least according to Click and clack, the Tappet brothers...from Car Talk. ;-)
@benjaminnewlon7865
@benjaminnewlon7865 5 жыл бұрын
Hes in the bible
@CraftQueenJr
@CraftQueenJr 5 жыл бұрын
Walt F. Those end credits were always hillarious.
@AymanB
@AymanB 11 жыл бұрын
Solomon Golomb ! That is a great name.
@numberphile
@numberphile 11 жыл бұрын
hello!
@jadenchen8921
@jadenchen8921 4 жыл бұрын
Hi numberphile!!! I’m a huge fan
@annevanderbijl3510
@annevanderbijl3510 4 жыл бұрын
@@jadenchen8921 hi
@happypiano4810
@happypiano4810 4 жыл бұрын
Hi!!!
@googelman
@googelman 3 жыл бұрын
ae
@ajeydevadiga6652
@ajeydevadiga6652 8 жыл бұрын
numbers are just awesome......what a beauty...
@ChristianPerfect
@ChristianPerfect 11 жыл бұрын
Thanks for your votes, everyone! Golomb's sequence won the vote, but the only sequence we could fit on the trophy was the Wieferich primes so we said that won instead. Look at the trophy on The Aperiodical, it's magnificent.
@whatno5090
@whatno5090 7 жыл бұрын
My favorite integer sequence is and will forever be the look and say sequence.
@IMortage
@IMortage 5 жыл бұрын
Numberphile had Conway himself talking about the look and say sequence
@ckmym
@ckmym 4 жыл бұрын
1 11 21 1211 111221 312211 13112221 1113213211 ...
@Cernoise
@Cernoise 6 жыл бұрын
Maybe I misunderstood something, but if the first one is just the sequence of digits in a real number, and the integers in the sequence aren't actually used as numbers, it's not really significant as an integer sequence. It's not s very integ sequence at all, let alone the integest.
@Ensivion
@Ensivion 11 жыл бұрын
I love how Tony's collar was popped for most of this.
@VeteranVandal
@VeteranVandal 9 жыл бұрын
I knew it was the first one, because I knew he would just be able of holding himself in the sequence he liked the most if it was presented first.
@Leadvest
@Leadvest 8 жыл бұрын
Could you do a video on A027746? It's a list of n by prime factors.
@kurzackd
@kurzackd 3 жыл бұрын
7:20 -- umm... in unary numerical system, 0 is actually ... empty. Not 0. Just ... nothing. No numbers. Empty string.
@Onoma314
@Onoma314 11 жыл бұрын
I'd love to see these guys do a video on the 216 digit Shemhamphorasch. It's produced using only the 24 digit reduced Fibonacci series and the numerals 1 - 9
@Epaminaidos
@Epaminaidos 11 жыл бұрын
The one I like most: 1, 11, 21, 1211, 111221, ...
@XenophonSoulis
@XenophonSoulis 4 жыл бұрын
312211 RIP John Conway
@evanknowles4780
@evanknowles4780 4 жыл бұрын
13112221
@manmanman4825
@manmanman4825 4 жыл бұрын
@@evanknowles4780 1113213211
@Lahbreca
@Lahbreca 8 жыл бұрын
Why was 67 twice in the wild numbers, if that was just the list of numbers that would result from the operation being done on any given number?
@doublelxp
@doublelxp 3 жыл бұрын
I was thinking a more interesting "all the sevens" would be 7 in each of the bases, but it would just be 111, 21, 13, 12, 11, 10, 7, 7, 7, etc.
@Spitzenhund
@Spitzenhund 11 жыл бұрын
Its a nice technique that helps with concentration. We are trained to see brown as a constructive material so writing on it makes us think we are doing more than just writing on paper. The tactile sound and feel of the paper also helps with concentration and I honestly think it sounds nice and prefer it over just normal paper or a white board
@CoyMcBob
@CoyMcBob 9 жыл бұрын
Couldn't you start Golomb's sequence with a 0? 1 appears 0 times. it would be: 0, 2, 2, 3, 3, etc.
@earfolds
@earfolds 9 жыл бұрын
0 would appear one time, so the sequence would be 0, 1, 2, 2, 3, 3...
@CoyMcBob
@CoyMcBob 9 жыл бұрын
No, there is no zeroth place, and each element tells you about the next element, not the previous. The first element will tell you that there are 0 ones. Thus you know that the second element has to be a two, and so on and so forth.
@CoyMcBob
@CoyMcBob 9 жыл бұрын
In fact, even more than that, you can just dump zeros wherever you want. Examples: 00000666666777777... is completely valid. So is even 10005555566666 and so on. This sequence only works out if you do it by indexing and not by counting, or you define the range as n >= 1
@earfolds
@earfolds 9 жыл бұрын
I guess that would work, but then you could even argue the sequence is valid as a string of infinite zeroes. The most interesting one is the one with positive nonzero integers only because zero is trivial.
@CoyMcBob
@CoyMcBob 9 жыл бұрын
Or, you could just define the sequence as one that every single number in it is referenced to in the sequence. That would also work.
@TheIcyBlade99
@TheIcyBlade99 11 жыл бұрын
yeah when I see it I think its annoying, but when I am first comment I do feel the temptation to say first haha
@ZipplyZane
@ZipplyZane 11 жыл бұрын
I had the same problem, and I wasn't using the subtitles. It just sounded like descending to me. I think it's that T at the end of strict being right by the A at the start ascending. It sounds like strict-d-ascending.
@fearingfearitself
@fearingfearitself 11 жыл бұрын
You didn't unpack the formula behind all the 7s: 7 x 1^n, where n in the position in the sequence.
@annikapeterson4061
@annikapeterson4061 11 жыл бұрын
Can there be a whole video on Fermat's Last Theorem?
@PC_Simo
@PC_Simo 2 ай бұрын
9:11 There *_IS_* an equation to that: a(n) = 7; and it rhymes, too 😊.
@Devilogic
@Devilogic 11 жыл бұрын
When talking about real numbers, "almost all" is typically defined as "all except for a set of (Lebesgue) measure zero". This is the case here as well. The exceptional set here is in fact uncountable! A subset of it is the uncountable set of all reals with only 1 and 2 in their cont. fraction expansions - the geometric mean will be less than (or =) 2, but Khinchin's constant is >2 Another is the uncountable set of reals with numbers >=3 in their expansions - the geo. mean will be >=3, but K0
@peligrosacurva-cz4ev
@peligrosacurva-cz4ev 19 күн бұрын
8:17 how to get 194 in this sequence? 5"3+3*5+5"2+2*5+5"1+5+4=189. No 194
@peligrosacurva-cz4ev
@peligrosacurva-cz4ev 19 күн бұрын
I got, I got 125*1+25*2+5*3+1*4=194 😂😂🎉🎉
@AMotoVlogger
@AMotoVlogger 7 жыл бұрын
@Numberphile look out for a paper with a conjecture on Pi and the "All the Seven's" coming to a computer near you.
@sdvalen7761
@sdvalen7761 8 жыл бұрын
Levy's constant applies to itself and "almost all" numbers in the same sense that Khinchine's does. It's a related property of continued fractions. I nominate A087602 (its decimal expansion) and A086703 (its continued fraction expansion) as my favorites.
@thoughtyness
@thoughtyness 7 жыл бұрын
What is the proper notation for the continued fraction at 1:10? If inputting into WolframAlpha, etc how would you correctly write it?
@MinusPi-p9c
@MinusPi-p9c 6 жыл бұрын
Probably just explicitly. a0+1/(a1+1/(a2+1/(...)))
@lordofedges6487
@lordofedges6487 11 жыл бұрын
Meanwhile at computerphile... "Ok, we have one sequence, it goes like this: 2, 4, 9..."
@electroflame6188
@electroflame6188 4 жыл бұрын
More like 1, 6, 21, 107, ...
@keyofamajor
@keyofamajor 11 жыл бұрын
aha, thanks! looking up "almost all" on wikipedia says that there are "a number of specialised uses" of the term, which continues to confuse ._. definitely not as bad as "mathematical concepts named after leonhard euler" though
@jamespfp
@jamespfp 11 жыл бұрын
I called his favorite after he described its self-referential completeness. Ascribing divinity to it -- I tend to think of that as sentimentality, but it also gave me a chuckle. Nothing is as charming (at present) as completeness, eh?
@kurtiswithak
@kurtiswithak 11 жыл бұрын
What about this sequence? 1, 11, 21, 1211, 111221, 312211, 13112221... It starts with 1 and the next element "describes" the previous, hence the second number in the sequence is "11" meaning "one 1" (describing the previous number). The third number is then "21" meaning "two 1s", and so on. I'm sure there's some very interesting math regarding this sequence..
@cecasiahaan6801
@cecasiahaan6801 7 жыл бұрын
Kurtis Fraser 13112221,413213,21122314,31321314,31123314,13123314,13123314,13123314,loop.
@MrProfetZ
@MrProfetZ 7 жыл бұрын
Conway did some work on this sequence, I think numberphile even has a video about it
@patrickmckinley8739
@patrickmckinley8739 8 ай бұрын
A086703. The continued fraction of Levy's constant. Levy's is closely related to Khinchin's. This constant also embodies a property of the continued fraction of almost all numbers - and this sequence is itself a continued fraction. We say "almost all" numbers. Just to expand on this, the exceptions are somewhat intriguing. Any number that is a root of a quadratic does not comply. Also, Euler's number e.
@CrashSable
@CrashSable Жыл бұрын
The "almost all" annoys me about most pure mathematicians - it's just conflating quantity with practicality. If I attacked the statement from the opposite direction, I could say "almost all numbers aren't used in any meaningful way, therefore if such a small proportion of numbers are actually useful to us (so small, the percentage has to be rounded 0), then we must conclude that working with numbers at all is useless and all mathematicians should be executed for wasting so many of our resources" Obviously, both statements are equally nonsensical...
@StefanReich
@StefanReich 3 жыл бұрын
7:19 WTH is "base 1"? In the only thing that resembles a "base 1" (unary numbers), 1s are used, not 0s.
@tribiz6762
@tribiz6762 7 жыл бұрын
The Poincaré conjecture was proven by at the time a pretty unknown mathematician
@davidwilkie9551
@davidwilkie9551 4 жыл бұрын
Math OCD = Genius, Conjecture.. Nope, Renormalized cynicism between the bounded interval of possibilities is still a personal self-defining assessment by default criteria.
@mrphlip
@mrphlip 11 жыл бұрын
The subtitles for the "metadromes" section constantly says "strict descending" instead of "strict ascending"... I guess the transcriber misheard? But that caused a lot of confusion for me trying to figure out what was going on...
@farstar31
@farstar31 8 жыл бұрын
That's strange, the link to the video with Tony's favorite sequence is broken, perhaps the video has been taken down or something else?
@Lightning_Lance
@Lightning_Lance 8 жыл бұрын
Yeah, noticed the same. The link in the description works though.
@MCLooyverse
@MCLooyverse 5 жыл бұрын
The continued fraction of φ wouldn't yield Khinchin's constant, right? Unless you're going to tell me that (1 * 1 * 1 * 1 * ...)^(1/1) != 1
@whauk
@whauk 11 жыл бұрын
how do you define the percentage? if you have a finite set you can just count out the number of elements with your property and compute the percentage. if you have a countable set you can look at all finite subsets and count the elements with your property in each of them and figure out whether the "limit" exists if you make them larger. however on an uncountable set...? compare lesbesgue-measures in any bounded subset? and then figure out whether a limit exists if you make the subsets "larger"?
@keyofamajor
@keyofamajor 11 жыл бұрын
yes, but when you're dealing with infinities they can't be handled in an intuitive manner such as that. i think of conditionally convergent series and grandi's series as immediate examples that infinity does not obey normal laws. doing so would result in contradiction. you could say that composite numbers are the vast majority of whole numbers by the same logic, but that really doesn't work out.
@keyofamajor
@keyofamajor 11 жыл бұрын
i don't think that "almost all" qualifies as "the vast majority" i suppose that irrationals are uncountable while rationals are countable, but rationals and irrationals are both dense in the reals. i'm having trouble agreeing with the brilliance of this number considering that. also, quick note: at 7:24 the place values being whole numbers is erroneous. the place values represent POWERS of the base number, not multiples. i.e. all the places should be labeled "1s" (which is counter-intuitive, ik)
@BunniBuu
@BunniBuu 11 жыл бұрын
I would like to point out 1:11 he just says,"We know ___" and leaves it at that. Not everyone knows what continued fraction expansion is. It's not like there was a numberphile video on it. 1:35 "Forget A naught" then doesn't explain why. 2:33 "infinitesimally small set"... in which you can name specific numbers? 4:37 "Golomb invented tetris" would be nice if that was relevant to the video? 5:16 "I couldn't put a 2 here, it doesn't make sense" Why not? No explanation...
@BunniBuu
@BunniBuu 11 жыл бұрын
You didn't really explain these very well... you basically just said,"___ doesn't make sense" without really explaining why it didn't make sense. It would help if we knew about what the pattern was trying to do before you showed us how you know what the numbers were... I didn't understand almost any of this because of that >.
@topilinkala7651
@topilinkala7651 3 жыл бұрын
But as a phycisist one must concur that in nature everything is by rational numbers based on plank's measures. There is not even irrantional numbers in nature. Complex numbers of course but only rational complex numbers.
@ChristianPerfect
@ChristianPerfect 11 жыл бұрын
The important point for a rational is that the top and bottom of the fraction have to be whole numbers. In a circle, at least one of the circumference and the radius is always an irrational number, so it doesn't make pi rational. It's... kind of a circular argument ;)
@arekkrolak6320
@arekkrolak6320 4 жыл бұрын
Andrew Wiles is a genius but I don't think many mathematicians would tell this about him before he came up with the proof. I am not a mathematician myself so I may be incorrect here.
@Ubeogesh
@Ubeogesh 11 жыл бұрын
How can you hate maths? I mean, it's nothing! Maybe you should look at the most philosophical numberphile's video "do numbers exist?" What I am trying to say is that you can't hate something that you don't even know if it exists...
@d4m4s74
@d4m4s74 11 жыл бұрын
I don't know what this sequence is called, if it even has a name, but I like it 1, 11, 21, 1211, 1231, 131221, 132221, 133221, 232221, 134211, 14131221, 14132241, etc. Wether this sequence has a name or not, try to find out why this is a sequence.
@mac1991seth
@mac1991seth 11 жыл бұрын
When he said that Khinchin's constant is number that supposedly God would have/take, I knew he would pick this sequence his favourite. All others were interesting but not as much as that one.
@Promatheos
@Promatheos 11 жыл бұрын
Whoever came up with all 7's wasn't even trying. I should submit my all 9's sequence. It's just 9 over and over. What does it mean you ask? I dunno, but the all 7's thing is just as pointless.
@uraldamasis6887
@uraldamasis6887 4 жыл бұрын
I don't understand why Khinichin's constant should be regarded as an integer sequence. We always consider pi or e to be numbers, not integer sequences.
@uobscdarkside732
@uobscdarkside732 4 жыл бұрын
for golombs sequence you could have begun it 211 Edit: I looked it up and the sequence is non descending so 211 wouldnt work
@Nathanchooper
@Nathanchooper 11 жыл бұрын
I've thought of a cool sequence that no one at my school could get without me telling them. Can anyone get it? 111111211131222232223333334332... This is my favorite sequence!
@mathmachine4266
@mathmachine4266 3 жыл бұрын
The largest metronome base n is (n^n-n²+n-1)/(n-1)². Special case, n=1, the limit as you go to 1 is 0.
@Bovineprogrammer
@Bovineprogrammer 11 жыл бұрын
That's what I was thinking. Don't care for the decimal expansion, but the continued fraction would make much more sense.
@borntoarun
@borntoarun 11 жыл бұрын
Can you do a whole video on Khinchin's constant? Specifically, can you do an example of how a certain number, when you do the continued fraction expansion of it, approaches the constant?
@ckq
@ckq 2 жыл бұрын
8 years late but essentially if you pick a random number 0-1, It's continued fraction has a 1/1 - 1/2 = 1/2 chance of being 1, 1/2 -1/3 = 1/6 chance of being 2, 1/12 chance of being 3, etc. So the geometric mean is just 1^(1/2) * 2 ^ (1/6) * 3^(1/12)... n^(1/(n(n+1)) which is that constant
@d4m4s74
@d4m4s74 11 жыл бұрын
I see I made a mistake: The full sequence is 1, 11, 21, 1211, 1231, 131221, 132231, 232221, 134211, 14131231, 14231241, 24132231, 14233221.
@NikoRonkainen
@NikoRonkainen 11 жыл бұрын
2:53 if god had a number, it would be 20 aka god's number. Every position of the Rubik's cube can be solved in 20 moves (HTM) or less.
@KINGOFAERODRONE
@KINGOFAERODRONE 11 жыл бұрын
Hi my friend told me that if you keep halving a number you will reach 0 , do you have any videos on this?, I am not sure if he is right.
@TheBalfrog
@TheBalfrog 11 жыл бұрын
Wieferich Primes are hard to explain, but the best I can give it to you is by simply showing it, Wieferich Primes we know of, 1093, so p=1093, 2^(p-1) which is 2^(1092) can be divided by 1093, and come out with an integer, whereas if you tried say p=5, (2^4)/5 isn't an integer. Because you can rewrite the conjecture 2^(p-1) = 1, it needs to come out with an integer, to be a Wieferich Prime, hope that sort of helped with understanding it
@EbbeTheGuitarist
@EbbeTheGuitarist 11 жыл бұрын
That's because the circumference can't really be written as fraction because it's made up by 2*pi*radius, and pi is irrational. In schoolmath you always get simplifications like circumference = 10, but it's really an irrational consepts. In real life applications we round it up, but it's rally just an irrational numer * rational numer = a new irrational numer. If you use like 50 desimals of pi, then you could messure the circumference of the universe by only the lenght of a hydrogen atom wrong!
@dwarduk2
@dwarduk2 11 жыл бұрын
Take pi for example. a0 is the integer part of that, so 3. Now take the reciprocal of the fractional part. a1 is the integer part of that, so a1 = 7, giving a geometric mean so far of 4.58. Take the reciprocal of the fractional part of what you currently have, and a2 is the integer part of that (15), and so on. I'm going to reply to this comment with some actual data on this as it applies to pi.
@burk314
@burk314 11 жыл бұрын
I agree. Khinchin's constant assumes that the aliens would have even invented continued fractions in the first place. While I do find them interesting, continued fractions are kind of a niche concept in number theory and aren't really important to a lot of mathematics. Then Khinchin's constant is a non-obvious derivation from that which doesn't work for common numbers. Compared to pi which pops up in many different areas of mathematics, Khinchin's constant is not that important.
@burk314
@burk314 11 жыл бұрын
With the composite numbers vs the primes you'd be comparing two countably infinite sets. You need another way to compare the sets, say natural density in which the primes have density zero. So in that sense, yes the composite numbers are the vast majority. You are correct in that we need to be careful about our definitions and "vast majority" is vague, but the phrase 'almost every' in mathematics, oddly enough, has a very precise definition which has little to do with topological density.
@modus_ponens
@modus_ponens 11 жыл бұрын
So a₁ a₂ a₃ ... are just numbers that fit to construct that number in that specific way? It should be said in clearer way that this applies only for irrational numbers. But according to wikipedia √19 repeats with a perioid of 6. So ...hmmmphh... ((2*1*3*1*2*8)¹⁰⁰⁰)⁽¹⁻⁶⁰⁰⁰⁾ ... (sorry no up index slash with sift+^ + /)... =2,14... so this did get somewhat close, but it's no near 2.69... It is maybe just my computers calculator or this is one of the numbers that doesn't fit.
@ExtremeMagneticPower
@ExtremeMagneticPower 11 жыл бұрын
A continued fraction expansion is basically a decimal turned into a sequence, and any digit is turned into an integer. Let's take pi as an example. 3 is the first digit, so that will be the first number in the expansion sequence: a0. 1 is the first decimal: a1 4 is the second: a2 The sequence would be: {3,1,4,1,5,9, ... } In the above sequence, if I was to take a0 + 1 / a1, it would give me 3.1 If I was to take a0 + 1/ (a1 + 1 / a2), it would give me 3.14 Make sense now?
@Boomshicleafaunda
@Boomshicleafaunda 11 жыл бұрын
Uh, better example. Think back to 1st Grade when you learned Place Value. The 2 in the TENS place means 2 tens, or 20. In base 8, a 7 in the EIGHTS place means 7 eights, or 56. And where we have the 100th Place, or 10^2, in base eight the second place would be 64th, or 8^2. Thus replacing the 1,000th Place, or 10^3, with 512th Place, or 8^3. Example: 123 [10] = 123; 123 [8] = 83; 123 [5] = 38. As your example stated, numbers in base [b] go from 0 to b-1, and after 9 we tend to use letters.
@ehhorvath13
@ehhorvath13 11 жыл бұрын
in a nut shell, a base is how you describe the place holder. we generally use base 10, so each place holder is a power of 10: one's place, 10's place, 100's place...or in other words 10^0 place, 10^1 place, 10^2 place. If I want base 5, each place holder would be a power of 5. 5^0, 5^1, 5^2 ect. so if I want to write the number "six" in base 5, I would write 11. meaning, one set of 5^1=5 and one set of 5^0=1 ==> 5+1=6.
@zelda12346
@zelda12346 11 жыл бұрын
People can rattle off the first few digits of Pi and e, but most people define Pi as the ratio between the diameter of a circle and its circumference...which requires you to measure exactly since in order to calculate one of those things, you need Pi. However, there are other ways to exactly calculate Pi and e via the sum of an infinite series. I would like to see the proof as to why these work
@a.gorlovicha9169
@a.gorlovicha9169 7 жыл бұрын
Isn't 3 a Wieferich prime? Because 3^2=9 and 9 divides by 3 (2^3-1)-1
@ThorHC11
@ThorHC11 7 жыл бұрын
Видео от A.Gorlovich'a You've got it backwards. it's that p² divides 2^(p-1)-1, not divides by it. for three to work, 3 would have to divide by 9, and it doesn't, because 1/3 is not whole.
@razzamattazz
@razzamattazz 11 жыл бұрын
If it began with 0 then I'm pretty sure it would have to just be an infinite sequence of zeros. 0, 0, 0, 0, 0, 0, etc. How many times does 1 appear in the sequence? Well, the 1st term is 0 so it has to appear 0 times. How many times does 2 appear in the sequence? Well, the 2nd term is 0 so it appears 0 times, and so on and so forth
@anticorncob6
@anticorncob6 11 жыл бұрын
Of course pi can be written as a fraction, ALL numbers can. Irrational numbers cannot be written as a fraction where BOTH NUMBERS ARE INTEGERS. This means it is impossible for there to exist a circle in plane space where the diameter and circumference are both integer lengths, no matter what unit you use.
@joebunny3807
@joebunny3807 11 жыл бұрын
It's not intuitive, so let's take a series that depends on the number of digital rays of the forelimbs that some animal species on some planet *happened* to have when inventing their number system. That's not how you capture the spirit of that "universality" that Khintchine's constant is all about. So Elliott couldn't have said it better: it was exactly the wrong choice.
@MultiPaulinator
@MultiPaulinator 11 жыл бұрын
Actually, those are just the powers of 2. A perfect number is a number whose entries in its divisor list -- including 1 but not the number itself -- add up to the number in question. Finding them goes something like this: Iff(sic) 2^(p-1) is prime -- which is only possible, though not guaranteed, when p is prime -- then 2^(p-1)*(2^p-1) is perfect.
@christophersam1989
@christophersam1989 11 жыл бұрын
Here he means 'almost all' in the measure theoretic sense, rather than cardinality. Just as the interval [0,1] contains 'almost none' of the numbers in the Cantor set, despite being an uncountable subset. Essentially if you picked a number at random there is probability 1 that it gives Khinchin's constant and probability 0 that it lies in the Cantor set.
@Sharaton
@Sharaton 11 жыл бұрын
You've also missed that there are n factors in the product. If they all were equal to x the product would be x^n and the exponents would cancel out. When you take limits you have to take the limit of the entire expression, not just parts. (Furthermore, the limit would be of the type infinity^0 which is undefined)
@TeamDragofied
@TeamDragofied 7 жыл бұрын
does khinchin's constant work with -1/12?
@Cernoise
@Cernoise 6 жыл бұрын
The Meem no, because that's a rational number and it doesn't work with rational numbers.
@TeamDragofied
@TeamDragofied 6 жыл бұрын
Angela Brett it was a joke just look up “negative one twelfth”
@Cernoise
@Cernoise 6 жыл бұрын
I have seen the videos about -1/12, but didn't really see why it would be funny to mention it here so I thought you might actually think it was a special case or something.
@TeamDragofied
@TeamDragofied 6 жыл бұрын
Angela Brett I guess it’s just kind of a meme here because there’s so many videos with a mention of it
@Cernoise
@Cernoise 6 жыл бұрын
I guess it's like the Parker Square of numbers, then.
@redfayl
@redfayl 11 жыл бұрын
It's pretty difficult to do with any number because it does not work with rational numbers. It might seem that is not the case because he says it works for almost all numbers, but the fact remains that there are infinitely more irrational and trascendental numbers than rational ones.
@redfayl
@redfayl 11 жыл бұрын
It doesn't work for rational numbers. So x being 3 does not work since a0 would just be 3. Divides into just means it is a factor of. Or in more mathematical terms, n divides x if x is congruent to 0 mod n (leaves no residue once you do the division algorithm.
@anticorncob6
@anticorncob6 11 жыл бұрын
I used to debate religious people a lot, don't do it anymore unless they bring it up first. And yes, I do know shockofgod and the Hovinds, but not the other people you mentioned. You're right, they are religious nuts, and probably bigger than factsvs science.
@doug65536
@doug65536 11 жыл бұрын
I notice some complaints that this video has more advanced content than usual - and that's ok! I'm seeing similar comments in the network stack video in the computerphile channel. Please, let some videos be more advanced, so more advanced viewers can have some enjoyable content too.
@einsteiner900
@einsteiner900 11 жыл бұрын
Read the Wikipedia article on continued fractions. All rational numbers have terminating (non-infinite) continued fraction representations. Therefore the geometric mean of their terms does not "approach" anything, it just is a fixed value, which will not be the same as Kinschine's constant.
@Beer_Dad1975
@Beer_Dad1975 11 жыл бұрын
I agree, I had to watch it a couple of times, do a google search and work through on a piece of paper myself to understand the first two at all - that's the first time that has happened ever with a video on this channel. Admittedly I'm not the brightest stump in the forest, but I'm no idiot either.
@burk314
@burk314 11 жыл бұрын
In that video, James is talking about natural density in the integers which is a different concept than the measure theory definition of 'almost every'. (In fact James shouldn't have used 'almost every' in that video as natural density is not really a measure)
@rkubiniec
@rkubiniec 11 жыл бұрын
Giving that constant to aliens not only assumes they understand whatever numeric system for transmitting the data we use, but it also assumes that they do math the same way as us, have found the constant, and/or would be able to derive it once we've given it to them. That seems really unlikely.
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