The magic of Fibonacci numbers | Arthur Benjamin | TED

5,673,991 views ・ 2013-11-08

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Translator: Petra Zajc Reviewer: Nika Kotnik
00:12
So why do we learn mathematics?
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Torej, zakaj se učimo matematike?
00:15
Essentially, for three reasons:
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V glavnem imamo tri razloge:
00:18
calculation,
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računanje
00:19
application,
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uporaba
00:21
and last, and unfortunately least
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in na koncu še razlog, ki je žal daleč zadaj,
00:24
in terms of the time we give it,
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kar se tiče časa, ki mu ga namenimo,
00:26
inspiration.
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navdih.
00:28
Mathematics is the science of patterns,
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Matematika je znanost vzorcev
00:30
and we study it to learn how to think logically,
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in učimo se je, da se naučimo razmišljati logično,
00:34
critically and creatively,
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kritično in ustvarjalno.
00:36
but too much of the mathematics that we learn in school
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Ampak prevečkrat za matematiko, ki jo učijo v šoli,
00:39
is not effectively motivated,
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ni učinkovite motivacije
00:41
and when our students ask,
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in ko nas učenci vprašajo:
00:43
"Why are we learning this?"
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"Zakaj se to učimo?"
00:44
then they often hear that they'll need it
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pogosto slišijo, da bodo znanje potrebovali
00:46
in an upcoming math class or on a future test.
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pri pouku matematike ali pri naslednjem testu.
00:50
But wouldn't it be great
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Ampak, ali ne bi bilo krasno,
00:51
if every once in a while we did mathematics
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če bi kdaj pa kdaj uporabljali matematiko
00:54
simply because it was fun or beautiful
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preprosto zato, ker je zabavna ali lepa
00:57
or because it excited the mind?
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ali pa ker spodbuja razmišljanje?
00:59
Now, I know many people have not
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Veliko ljudi ni imelo priložnosti,
01:01
had the opportunity to see how this can happen,
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da bi videli, kako se to lahko zgodi,
01:03
so let me give you a quick example
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zato vam bom na hitro pokazal primer
01:05
with my favorite collection of numbers,
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s svojo najljubšo zbirko številk,
01:07
the Fibonacci numbers. (Applause)
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Fibonaccijevimi števili. (Aplavz)
01:10
Yeah! I already have Fibonacci fans here.
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To! Tu je nekaj Fibonaccijevih oboževalcev.
01:12
That's great.
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Odlično.
01:13
Now these numbers can be appreciated
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Torej, ta števila so krasna
01:15
in many different ways.
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na veliko različnih načinov.
01:17
From the standpoint of calculation,
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Z vidika računanja
01:20
they're as easy to understand
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so tako lahko razumljiva
01:22
as one plus one, which is two.
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kot ena plus ena, kar je dva.
01:24
Then one plus two is three,
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Potem imamo ena plus dva je tri,
01:26
two plus three is five, three plus five is eight,
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dva plus tri je pet, tri plus pet je osem
01:29
and so on.
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in tako naprej.
01:31
Indeed, the person we call Fibonacci
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V resnici se je oseba, ki ji pravimo Fibonacci,
01:33
was actually named Leonardo of Pisa,
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imenovala Leonardo Pisano
01:36
and these numbers appear in his book "Liber Abaci,"
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in ta števila so zapisana v njegovi knjigi "Liber Abaci",
01:39
which taught the Western world
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ki je zahodni svet naučila
01:41
the methods of arithmetic that we use today.
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aritmetičnih metod, ki jih uporabljamo danes.
01:44
In terms of applications,
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Kar se tiče uporabe,
01:45
Fibonacci numbers appear in nature
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se Fibonaccijeva števila v naravi pojavljajo
01:48
surprisingly often.
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presenetljivo pogosto.
01:49
The number of petals on a flower
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Število cvetnih listov na roži
01:51
is typically a Fibonacci number,
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je ponavadi Fibonaccijevo število,
01:53
or the number of spirals on a sunflower
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pa tudi število spiral na sončnici
01:56
or a pineapple
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ali ananasu
01:57
tends to be a Fibonacci number as well.
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je pogosto Fibonaccijevo število.
02:00
In fact, there are many more applications of Fibonacci numbers,
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Pravzaprav je možnosti uporabe Fibonaccijevih števil veliko več,
02:03
but what I find most inspirational about them
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a sam mislim, da so pri njih najbolj navdušujoči
02:06
are the beautiful number patterns they display.
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lepi številski vzorci, ki jih ustvarjajo.
02:08
Let me show you one of my favorites.
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Pokazal vam bom enega od svojih najljubših.
02:11
Suppose you like to square numbers,
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Recimo, da radi kvadrirate števila,
02:13
and frankly, who doesn't? (Laughter)
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konec koncev, kdo jih pa ne? (Smeh)
02:16
Let's look at the squares
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Poglejmo kvadrate
02:18
of the first few Fibonacci numbers.
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prvih nekaj Fibonaccijevih števil.
02:20
So one squared is one,
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Torej, ena na kvadrat je ena,
02:22
two squared is four, three squared is nine,
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dva na kvadrat je štiri, tri na kvadrat je devet,
02:24
five squared is 25, and so on.
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pet na kvadrat je 25 in tako naprej.
02:27
Now, it's no surprise
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No, ni prav presenetljivo,
02:29
that when you add consecutive Fibonacci numbers,
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da, ko seštejemo zaporedna Fibonaccijeva števila,
02:32
you get the next Fibonacci number. Right?
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dobimo naslednje Fibonaccijevo število. Drži?
02:34
That's how they're created.
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Tako nastanejo.
02:35
But you wouldn't expect anything special
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Ne bi pa pričakovali, da se zgodi
02:37
to happen when you add the squares together.
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kaj posebnega, ko seštejemo njihove kvadrate.
02:40
But check this out.
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Pa poglejte zdaj tole.
02:42
One plus one gives us two,
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Ena plus ena je dva
02:44
and one plus four gives us five.
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in ena plus štiri je pet.
02:46
And four plus nine is 13,
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In štiri plus devet je 13,
02:48
nine plus 25 is 34,
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devet plus 25 je 34,
02:52
and yes, the pattern continues.
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in ja, vzorec se nadaljuje.
02:54
In fact, here's another one.
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V bistvu imamo še en vzorec.
02:56
Suppose you wanted to look at
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Recimo, da bi hoteli pogledati
02:58
adding the squares of the first few Fibonacci numbers.
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seštevek kvadratov prvih nekaj Fibonaccijevih števil.
03:00
Let's see what we get there.
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Pa poglejmo, kaj dobimo.
03:02
So one plus one plus four is six.
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Torej, ena plus ena plus štiri je šest.
03:04
Add nine to that, we get 15.
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Dodajmo še devet in dobimo 15.
03:07
Add 25, we get 40.
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Dodamo 25 in dobimo 40.
03:09
Add 64, we get 104.
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Dodamo 64, dobimo 104.
03:12
Now look at those numbers.
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Zdaj pa poglejmo ta števila.
03:14
Those are not Fibonacci numbers,
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To niso Fibonaccijeva števila,
03:16
but if you look at them closely,
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ampak, če jih pogledate od blizu,
03:18
you'll see the Fibonacci numbers
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boste videli, da se Fibonaccijeva števila
03:20
buried inside of them.
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skrivajo v njih.
03:22
Do you see it? I'll show it to you.
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Jih vidite? Vam bom pokazal.
03:24
Six is two times three, 15 is three times five,
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Šest je dva krat tri, 15 je tri krat pet,
03:28
40 is five times eight,
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40 je pet krat osem,
03:30
two, three, five, eight, who do we appreciate?
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dva, tri, pet, osem, koga občudujemo?
03:33
(Laughter)
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(Smeh)
03:34
Fibonacci! Of course.
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Fibonaccija! Jasno.
03:36
Now, as much fun as it is to discover these patterns,
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Zelo zabavno je odkrivati vzorce,
03:40
it's even more satisfying to understand
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a v še večje zadovoljstvo je razumeti
03:42
why they are true.
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zakaj držijo.
03:44
Let's look at that last equation.
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Poglejmo zadnjo enačbo.
03:46
Why should the squares of one, one, two, three, five and eight
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Zakaj mora seštevek kvadratov od ena, ena, dva, tri, pet in osem
03:50
add up to eight times 13?
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znašati osem krat 13?
03:53
I'll show you by drawing a simple picture.
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To vam bom pokazal s preprosto sliko.
03:56
We'll start with a one-by-one square
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Začeli bomo s kvadratom ena krat ena
03:58
and next to that put another one-by-one square.
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in zraven njega narisali še en kvadrat ena krat ena.
04:02
Together, they form a one-by-two rectangle.
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Skupaj sestavljata pravokotnik ena krat dva.
04:06
Beneath that, I'll put a two-by-two square,
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Pod njega bom narisal kvadrat dva krat dva,
04:08
and next to that, a three-by-three square,
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zraven njega pa kvadrat tri krat tri,
04:11
beneath that, a five-by-five square,
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pod njega kvadrat pet krat pet
04:13
and then an eight-by-eight square,
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in nato kvadrat osem krat osem,
04:15
creating one giant rectangle, right?
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in tako sem sestavil ogromen pravokotnik.
04:18
Now let me ask you a simple question:
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Zdaj vam bom postavil preprosto vprašanje:
04:20
what is the area of the rectangle?
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Kolikšna je ploščina pravokotnika?
04:23
Well, on the one hand,
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No, po svoje
04:25
it's the sum of the areas
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je vsota ploščin
04:28
of the squares inside it, right?
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vseh kvadratov v njem, drži?
04:30
Just as we created it.
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Kot smo ga naredili.
04:31
It's one squared plus one squared
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Ena na kvadrat plus ena na kvadrat
04:33
plus two squared plus three squared
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plus dva na kvadrat plus tri na kvadrat
04:35
plus five squared plus eight squared. Right?
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plus pet na kvadrat plus osem na kvadrat.
04:38
That's the area.
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To je ploščina.
04:40
On the other hand, because it's a rectangle,
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Po drugi strani pa, ker je pravokotnik,
04:42
the area is equal to its height times its base,
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je ploščina enaka višini krat širini
04:46
and the height is clearly eight,
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in višina je očitno osem,
04:48
and the base is five plus eight,
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širina pa pet plus osem,
04:51
which is the next Fibonacci number, 13. Right?
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kar je naslednje Fibonaccijevo število, 13. Je tako?
04:55
So the area is also eight times 13.
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Tako imamo ploščino osem krat 13.
04:58
Since we've correctly calculated the area
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Ker smo pravilno izračunali ploščino
05:00
two different ways,
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na dva različna načina,
05:02
they have to be the same number,
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moramo dobiti enako številko
05:04
and that's why the squares of one, one, two, three, five and eight
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in zato je seštevek kvadratov od ena, ena, dva, tri, pet in osem
05:08
add up to eight times 13.
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skupaj osem krat 13.
05:10
Now, if we continue this process,
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Če nadaljujemo s tem postopkom,
05:12
we'll generate rectangles of the form 13 by 21,
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bomo ustvarili pravokotnike s stranicami 13 krat 21,
05:16
21 by 34, and so on.
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21 krat 34 in tako naprej.
05:19
Now check this out.
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Zdaj pa poglejte tole.
05:20
If you divide 13 by eight,
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Če 13 delimo z osem,
05:22
you get 1.625.
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dobimo 1,625.
05:24
And if you divide the larger number by the smaller number,
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In če delimo večje število z manjšim številom,
05:28
then these ratios get closer and closer
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se razmerje vedno bolj približuje
05:31
to about 1.618,
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okoli 1,618,
05:33
known to many people as the Golden Ratio,
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kar veliko ljudi pozna kot zlati rez,
05:37
a number which has fascinated mathematicians,
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število, ki je stoletja navduševalo
05:39
scientists and artists for centuries.
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matematike, znanstvenike in umetnike.
05:42
Now, I show all this to you because,
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To vam kažem, ker,
05:45
like so much of mathematics,
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kot toliko matematike,
05:47
there's a beautiful side to it
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v sebi skriva nekaj lepega,
05:49
that I fear does not get enough attention
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čemur mislim, da v naših šolah žal
05:51
in our schools.
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ne posvečamo dovolj pozornosti.
05:52
We spend lots of time learning about calculation,
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Veliko časa se učimo o računanju,
05:55
but let's not forget about application,
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ampak ne smemo pozabiti na uporabo,
05:58
including, perhaps, the most important application of all,
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vključno z morda najpomembnejšo uporabo,
06:01
learning how to think.
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da se naučimo, kako razmišljati.
06:03
If I could summarize this in one sentence,
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Če bi lahko to zajel v enem stavku,
06:05
it would be this:
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bi rekel tole:
06:07
Mathematics is not just solving for x,
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Matematika ni samo iskanje x-a,
06:10
it's also figuring out why.
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ampak tudi smisla.
06:13
Thank you very much.
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Najlepša hvala.
06:15
(Applause)
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(Aplavz)
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