Making waves: The power of concentration gradients - Sasha Wright

Prevodilac: Anca Dimovska Lektor: Mile Živković

If you've ever floated on an ocean swell,

Ako ste ikada plutali okeanom,

you'll know that the sea moves constantly.

znate da se more neprestano pomera.

Zoom out, and you'll see the larger picture:

Udaljite se i videćete širu sliku:

our Earth, covered by 71 percent water,

Naša zemlja, je prekrivena vodom 71%,

moving in one enormous current around the planet.

koja se kreće u jednoj ogromnoj struji oko planete.

This intimidating global conveyor belt

Ova zastrašujuća pokretna traka

has many complicated drivers,

ima mnogo komplikovanih pokretača,

but behind it all is a simple pump

ali iza svega toga je jednostavna pumpa

that moves water all over the earth.

koja pomera vodu po čitavoj zemlji.

The process is called thermohaline circulation,

Proces se zove termalinsko strujanje,

and it's driven by a basic concept:

i pokreće ga osnovni koncept -

the concentration gradient.

nivo koncentracije.

Let's leave the ocean for one moment

Hajde da ostavimo okean na trenutak

and imagine we're in an empty room

i zamislimo da smo u praznoj prostoriji

with lots of Roombas sardined together

sa dosta Rumba robota koji su poređani ko sardine

in one corner.

u jednom uglu.

Turn them all on at once

Ako ih sve odjednom uključite

and the machines glide outwards

svi će da klizaju spolja

bumping into and away from each other

i da se sudaraju i udaljavaju

until the room is filled with an evenly spaced distribution.

dok soba nije popunjena jednakom distribucijom.

The machines have moved randomly

Mašine su se nasumice pomerale

towards equilibrium,

ka ekvilibrijumu,

a place where the concentration of a substance

mestu gde je koncentracija supstance

is equally spread out.

jednako raširena.

That's what happens along a concentration gradient,

Ovo se dešava sa nivoom koncentracije,

as substances shift passively from a high,

dok se supstance pasivno pomeraju iz visoke,

or squashed, concentration,

ili zgnječene koncentracije,

to a lower, more comfortable one.

na nižu, prijatniju koncentraciju.

How does this relate to ocean currents and thermohaline circulation?

Kako je ovo povezano sa okeanskim strujama i termalinskim strujanjem?

Thermo means temperature,

Termo znači temperatura,

and haline means salt

i helin znači so

because in the real world scenario of the sea,

jer u realnom scenariju mora,

temperature and salinity drive the shift

temperatura i salinitet se smenjuju

from high to low concentrations.

sa visoke na nisku koncentraciju.

Let's put you back in the ocean

Hajde da vas vratimo u okean

to see how this works.

da vidimo kako ovo radi.

Snap!

Cap!

You're transformed into a molecule of surface water,

Pretvorili ste se u molekul površinske vode,

off the temperate coast of New York

sa umerene obale Njujorka,

surrounded by a zillion rowdy others.

okruženi zilionom drugih larmadžija.

Here, the sun's rays act as an energizer

Ovde, sunčevi zraci deluju kao punjači

that set you and the other water molecules

koji pokreću vas i druge molekule vode

jostling about, bouncing off each other

da se gurate i odudarate jedni od drugih

like the Roombas did.

kao što su to činile Rumbe.

The more you spread out,

Što se više proširite,

the less concentrated the water molecules

manja je koncentracija molekula vode

at the surface become.

na površini.

Through this passive motion,

Kroz ovo pasivno kretanje,

you move from a high to a lower concentration.

pomerate se iz mesta visoke u mesta niske koncentracije.

Let's suspend the laws of physics for a moment,

Hajde da ostavimo zakone fizike na trenutak,

and pretend that your molecular self

i da se pretvaramo da vi kao molekul

can plunge deep down into the water column.

možete da zaronite dublje u vodenu kolonu.

In these colder depths,

U ovim hladnijim dubinama,

the comparative lack of solar warmth

uporediv nedostatak solarne toplote

makes water molecules sluggish,

čini molekule vode sporim,

meaning they can sit quite still at high concentrations.

što znači da mogu sasvim mirni da stoje u visokim koncentracijama.

No jostling here.

Ovde nema guranja.

But seeking relief

Ali u potrazi za olakšanjem od skučenih uslova u kojima su,

from the cramped conditions they're in,

they soon start moving upwards

uskoro počinju da se kreću nagore

towards the roomier situation at the surface.

ka mestu sa više prostora na površini.

This is how temperature

Eto kako temperatura

drives a shift of water molecules

vodi smenu vodenih molekula

from high to low concentrations,

sa visokih na nisku koncentraciju,

towards equilibrium.

ka ekvilibrijumu.

But sea water is made up of more than just H2O.

Ali morsku vodu čini više nego H20.

There are a great deal of salt ions in it as well.

Ima i dosta jona soli.

And like you, these guys have a similar desire

I kao i vi, ovi momci imaju sličnu želju

for spacious real estate.

za prostranom nekretninom.

As the sun warms the sea,

Kako sunce greje more,

some of your fellow water molecules

neki od njegovih vodenih molekula

evaporate from the surface,

isparavaju,

increasing the ration of salt to H2O.

pojačavajući količinu soli u odnosu na H20.

The crowded salt ions left behind

Zbijeni joni soli koji ostaju

notice that lower down,

primećuju da niže

salt molecules seem to be enjoying more space.

molekuli soli uživaju više prostora

And so an invasion begins,

I tako invazija počinje,

as they too move downwards in the water column.

kako se oni pomeraju niže u vodenu kolonu.

In the polar regions,

U polarnim oblastima,

we see how this small local process

vidimo kako ovaj mali lokalni proces

effects global movement.

utiče na globalno kretanje.

In the arctic and antarctic,

Na Arktiku i Antarktiku,

where ice slabs decorate the water's surface,

gde ledene kape ukrašavaju vodenu površinu

there's little temperature difference

postoji mala razlika u temperaturi

between surface and deeper waters.

između površine i vode u dubini.

It's all pretty cold.

Svuda je prilično hladno.

But salinity differs,

Ali se salinitet razlikuje

and in this scenario,

i u ovom scenariju

that's what triggers the action.

to je ono što pokreće akciju.

Here, the sun's rays melt surface ice,

Ovde, sunčevi zraci tope led na površini,

depositing a new load of water molecules

ostavljajući novu količinu vodenih molekula

into the sea.

u moru.

That not only increases the proximity

To ne samo da smanjuje udaljenost

between you and other water molecules,

između vas i drugih vodenih molekula,

leaving you vying for space again,

ostavljajući vas da se ponovo takmičite oko prostora

but it also conversely dilutes

ali takođe razblažava

the concentration of salt ions.

koncentraciju jona soli.

So, down you go,

I sada opet idete niže

riding along the concentration gradient

sa gradijentom koncentracije

towards more comfortable conditions.

ka udobnijim uslovima.

For salt ions, however,

A za jone soli,

their lower concentration at the surface,

njihova niža koncentracija na površini

acts like an advertisement

je kao oglas

to the clamoring masses of salt molecules below

za bučnu masu molekula soli ispod

who begin their assent.

koja daje svoj glas.

In both temperate and polar regions,

I u umerenim i u polarnim oblastima

this passive motion along a concentration gradient,

pasivno kretanje sa gradijentom koncentracije

can get a current going.

može da pokrene morsku struju.

And that is the starting point

I to je početna tačka

of the global conveyor

globalne pokretne trake

called thermohaline circulation.

koja se zove termalinska cirkulacija.

This is how a simple concept

Ovako jedan jednostavan koncept

becomes the mechanism underlying

postaje mehanizam iza

one of the largest

jednog od najvećih

and most important systems on our planet.

i najbitnijih sistema na našoj planeti.

And if you look around,

I ako pogledate oko sebe,

you'll see it happening everywhere.

videćete da se to svuda dešava

Turn on a light, and it's there.

Upalite sveto, i eto ga

Concentration gradients govern

Gradijenti koncentracije vode

the flow of electricity,

tok elektriciteta,

allowing electrons squashed together in one space

dopuštajući elektronima zbijenim u jednom prostoru

to travel to an area of lower concentration

da putuju do mesta s nižom koncentracijom

when a channel is opened,

kada je kanal otvoren,

which you do by flipping a switch.

što činite kad pritisnete prekidač.

Right now, in fact, there's some gradient action going on

Upravo sada se u stvari, dešava akcija sa gradijentom

inside you as you breath air into your lungs

u vama dok udišete vazduh

letting the concentrated oxygen in that air

puštajući zasićeni kiseonik u taj vazduh

move passively out of your lungs

koji se pasivno kreće iz vaših pluća

and into your blood stream.

u vaš krvotok.

We know that the world is filled

Znamo da je svet pun

with complex physical problems,

složenih fizičkih problema,

but sometimes the first step

ali nekad prvi korak

towards understanding them can be simple.

prema njihovom razumevanju može biti jednostavan.

So when you confront the magnitude

Kada se suočite sa veličinom struja okeana,

of the ocean's currents,

or have to figure out how electricity works,

ili morate da razumete kako elektricitet funkcioniše,

remember not to panic.

setite se da ne paničite.

Understanding can be as simple as flipping a switch.

Shvatanje može da bude jednostavno kao pritiskanje prekidača.