What is the rarest color in nature? - Victoria Hwang

1,170,653 views ・ 2022-06-09

TED-Ed


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Prevoditelj: Maja Kovacevic Recezent: Petra Lauš
00:07
Every color you see in front of you can be found in nature.
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Svaku boju koju vidite ispred sebe možete pronaći u prirodi.
00:11
Some plant, animal, or mineral bears almost every hue imaginable.
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Biljke, životinje i minerali imaju gotovo svaku moguću nijansu.
00:15
But which of these colors are you least likely to see in the natural world?
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Ali koje od ovih boja su najrjeđe u prirodi?
00:20
There are two factors that drive the rarity of color in nature:
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Dva faktora utječu na učestalost boja u prirodi:
00:24
physics and evolution.
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fizika i evolucija.
00:27
Let’s start with physics.
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Započnimo s fizikom.
00:29
Colors are generated when wavelengths of light interact with objects,
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Boje nastaju kada dođe do međudjelovanja valne duljine svjetlosti s predmetima,
00:33
and most of the colors you’ve seen outside a screen
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i većina boja koje vidite izvan ekrana
00:36
were produced in one of two ways.
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nastale su na jedan od dva načina.
00:38
In absorption-based colors,
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U bojama temeljenim na apsorpciji,
00:40
certain wavelengths are absorbed by an object, while others are not.
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određene valne duljine predmet apsorbira, a druge ne.
00:44
The result is a matte final color generated by these leftover light waves.
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Rezultat je završna mat boja nastala od preostalih svjetlosnih valova.
00:49
Most naturally occurring colors fall into this category,
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Većina prirodnih boja spada u ovu kategoriju,
00:52
including those of many fruits and flowers.
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uključujući one mnogih vrsta voća i cvijeća.
00:55
Plants are full of compounds called pigments that absorb light waves
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Biljke sadrže spojeve zvane pigmenti koji apsorbiraju svjetlosne valove
00:58
as part of photosynthesis,
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u sklopu fotosinteze,
01:00
the process by which they convert sunlight into energy.
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procesa putem kojeg pretvaraju sunčevu svjetlost u energiju.
01:03
While different plants have evolved different pigments
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Dok su različite biljke razvile različite pigmente
01:06
that result in different colors,
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koji rezultiraju različitim bojama,
01:08
higher energy wavelengths are more easily absorbed than lower energy ones.
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valne duljine veće frekvencije lakše se apsorbiraju od onih manje frekvencije.
01:13
And blue light has some of the highest energy wavelengths
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A plava boja ima jednu od najvećih frekvencija
01:15
in the visible spectrum.
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u vidljivom spektru.
01:17
Numerous pigments have evolved to absorb blue light,
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Razvili su se brojni pigmenti koji upijaju plavu svjetlost,
01:20
including chlorophyll, which absorbs blue and red wavelengths
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npr. klorofil, koji upija plavu i crvenu valnu duljinu
01:23
to produce nature’s trademark green.
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kako bi proizveo prirodnu zelenu boju.
01:26
However, green light is still fairly energetic,
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Međutim, zeleno svjetlo je još uvijek prilično energično,
01:29
and the most common class of pigments evolved to absorb these wavelengths
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i najčešća vrsta pigmenta koja upija te valne duljine
01:33
as well.
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isto tako.
01:34
There are over 1,100 types of carotenoids,
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Postoji preko 1100 vrsta karotenoida,
01:38
pigments which absorb high energy blue and green light,
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pigmenata koji upijaju plavo i zeleno svjetlo visoke frekvencije,
01:42
while leaving behind the lower energy red and yellow light.
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dok u pozadini ostavljaju crveno i žuto svjetlo niske frekvencije.
01:46
While carotenoids are present in most green plants,
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Dok su karotenoidi prisutni u većini zelenih biljaka,
01:49
they only become visible each fall when chlorophyll gets broken down
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oni postanu vidljivi tek u jesen kada se klorofil počinje raspadati
01:53
to save energy for the winter.
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radi čuvanja energije za zimu.
01:55
But whether they’re working alone or side by side,
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Bez obzira na to rade li sami ili skupa,
01:58
these pigments absorb blue light in virtually all plants.
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ti pigmenti apsorbiraju plavo svjetlo u gotovo svim biljkama.
02:02
Even fruits and flowers that appear blue
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Čak i plavo voće i cvijeće
02:05
actually have pigments that are red or purple,
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zapravo ima pigmente koji su crveni ili ljubičasti,
02:07
and only truly turn blue under specific chemical conditions.
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a tek pod posebnim kemijskim uvjetima. zaista postanu plavi.
02:12
So, is blue the rarest color in nature?
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Stoga, je li plava najrjeđa boja u prirodi?
02:16
Not quite.
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Baš i nije.
02:18
Absorption is just one of the two main ways light generates color.
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Apsorpcija je samo jedan od dva glavna načina kako svjetlost stvara boju.
02:23
In the second method, some wavelengths are scattered and amplified—
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Prema drugom načinu, neke valne duljine su raspršene i pojačane
02:27
overpowering the others to determine an object's final color.
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te nadjačaju ostale i tako određuju konačnu boju nekog predmeta.
02:31
These structural colors occur
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Te strukturne boje nastaju
02:33
because some objects around us are made of microscopic particles
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zato što su predmeti oko nas napravljeni od mikroskopskih čestica
02:37
which can form nanostructures that interfere with visible light.
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koje tvore nanostrukture koje interferiraju s vidljivom svjetlosti.
02:42
For example, this feather has no blue pigments in it.
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Na primjer, ovo pero nema plavih pigmenata u sebi.
02:46
But when light strikes it, the electrons within its nanostructure
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Ali kada ga obasja svjetlost, elektroni unutar njegove nanostrukture
02:50
vibrate at the same frequency as the weight.
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vibriraju istom frekvencijom kao i težina.
02:53
This makes the particles send out a new wave with the same frequency,
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Zbog toga čestice šalju novi val iste frekvencije,
02:57
starting a chain reaction that amplifies and scatters blue light.
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što započinje lančanu reakciju koja pojačava i raspršuje plavu svjetlost.
03:03
Nanostructures of various shapes and sizes scatter different wavelengths,
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Nanostrukture različitih oblika i veličina raspršuju različite valne duljine,
03:07
but they typically scatter high-energy wavelengths most easily—
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ali obično najlakše raspršuju valne duljine visoke frekvencije
03:11
making blue the most common structural color.
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čineći plavu najčešćom strukturnom bojom.
03:16
Meanwhile, low-energy wavelengths like red are only weakly scattered.
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Dok se valne duljine niske frekvencije poput crvene, jako malo raspršuju.
03:20
Even when something evolves specific nanostructures
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Čak i kada nešto razvije specifične nanostrukture
03:23
that strongly scatter red light
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koje snažno raspršuju crveno svjetlo
03:25
they still resonate with other wavelengths,
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oni i dalje rezoniraju s ostalim valnim duljinama,
03:27
only appearing red at some angles of illumination and observation.
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pod nekim kutevima iluminacije i opservacije.
03:32
This gives us two contenders for nature’s rarest color:
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To nam daje dva natjecatelja za titulu najrjeđe boje u prirodi:
03:36
absorption-based matte blues and structural iridescent reds.
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mat plavu boju temeljenu na apsorpciji i strukturnu prštavu crvenu boju.
03:41
Between these two, structural reds are much rarer.
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Među njima dvjema, strukturna crvena puno je rjeđa.
03:45
Only a handful of animals and rocks scatter red light
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Samo nekoliko životinja i stijena raspršuje crveno svjetlo
03:48
and none of them scatter red light exclusively.
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i nijedno ne raspršuje isključivo crveno svjetlo.
03:51
But since red and blue are rare in one way and common in another,
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Ali obzirom na to da crvena i plava i jesu i nisu rijetke boje,
03:55
we actually end up seeing both colors quite often.
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u konačnici ih zapravo često vidimo.
03:59
So what color is least likely to be generated
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Stoga, koja boja je najrjeđa
04:02
in structural and absorption-based forms?
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u strukturnim i apsorpcijski temeljenim oblicima?
04:06
The answer is violet.
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Odgovor je: ljubičasta.
04:08
Not to be confused with purple, which is just a combination of red and blue light,
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Koja nije ista kao i purpurna, koja je kombinacija crvene i plave svjetlosti
04:13
violet occupies a small portion of the visible light spectrum.
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ljubičasta zauzima malen dio vidljivog spektra svjetlosti.
04:17
There are only a few nanostructures precise enough
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Samo neke nanostrukture imaju dovoljnu preciznost
04:20
to exclusively scatter violet light.
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raspršivanja isključivo ljubičaste svjetlosti.
04:23
And violet wavelengths are even more energetic than blue ones,
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A ljubičaste valne duljine su energičnije čak i od plavih,
04:27
making them likely to be absorbed by pigment.
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zbog čega ih pigment može lako apsorbirati.
04:30
So if you ever stumble onto the iridescent violet wings
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Stoga, ako ikada nabasate na krila prštave ljubičaste boje
04:34
of a purple emperor butterfly,
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velike modre preljevice,
04:37
take a second to appreciate one of nature’s rarest spectacles.
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zastanite na sekundu i divite se jednom od najrjeđih spektakla prirode.
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