The physics of surfing - Nick Pizzo

Prevoditelj: Neda Vrkic Recezent: Sanda L

Whether or not you realize it,

Bez obzira shvaćate li to ili ne,

as a surfer you’re a master of complicated physics.

kao surfer majstor ste složene fizike.

The science of surfing begins

Znanost surfanja počinje

as soon as you and your board first hit the water.

čim vi i vaša daska dotaknete površinu mora.

The board’s size and light construction help it displace a lot of water.

Veličina i lagana konstrukcija daske pomaže joj da istisne dosta vode.

In turn, a buoyant force

Zauzvrat, sila uzgona

equal to the weight of the displaced water pushes up,

jednaka težini istisnute količine vode gura prema gore,

counteracting you and your board’s weight.

suprotstavljajući se vama i težini vaše daske.

This lets you stay afloat while you wait to paddle for a wave.

To vam omogućuje da ostanete na površini dok veslajući čekate val.

And what exactly are you waiting for?

I što točno čekate?

The perfect wave, of course.

Savršen val, naravno.

Like other waves in physics, ocean waves represent a transfer of energy.

Kao i drugi valovi u fizici, oceanski valovi predstavljaju prijenos energije.

Wind blowing across the ocean accelerates water particles near the surface,

Vjetar koji puše preko oceana ubrzava čestice vode blizu površine,

leading to the growth of ripples that become waves.

što dovodi do rasta mreškanja koje se pretvara u valove.

These deviations from the flat surface are acted upon by gravity,

Ova odstupanja od ravne površine nastaju zbog gravitacije,

which tries to restore the surface to its original flat state.

koja pokušava vratiti površinu u izvorno ravno stanje.

As the waves then move through the water,

Dok se valovi tako kreću,

particles push and pull on their neighbors through the wave induced pressure,

čestice guraju i povlače svoje susjede kroz pritisak pobuđen valom,

and this motion propagates energy through the water in unison with the wave motion.

i ovo kretanje širi energiju u skladu s gibanjem vala.

The motion of these particles

Kretanje ovih čestica

is much more limited than the overall motion of the waves.

mnogo više je ograničeno od sveukupnog kretanja valova.

Near the shore,

Blizu obale,

the shallower seafloor constrains the motion of the waves

plitko morsko dno ograničava kretanje valova

to occur in a more limited region than out at sea,

koje se događa u ograničenijem prostoru nego na otvorenom moru,

concentrating the wave energy near the surface.

koncentrirajući energiju vala blizu površine.

If the topography of the shoreline is even and smooth,

Ako je topografija obale ujednačena i glatka,

this will refract the waves to become more

to će lomiti valove tako da postanu

parallel to the shore as they approach.

paralelniji s obalom kako se približavaju.

This is the crucial moment.

Ovo je ključni trenutak.

As the wave gets near,

Kako se val približava,

you quickly pivot your board in the same direction as the wave

brzo okrenete dasku u smjeru vala

and paddle to match its speed.

i veslate da se uskladite s njegovom brzinom.

Your board forms an angle with the water,

Vaša daska oblikuje kut s vodom

and this creates a dynamic pressure on the bottom of it,

i to stvara dinamički pritisak na njenom dnu,

forcing you and your board out of the water,

istiskujući vas i vašu dasku iz mora

to skim along the surface.

da klizite po površini.

At the same time,

U isto vrijeme,

your increased forward momentum makes you more stable,

vaša povećana brzina kretanja vas čini stabilnijima,

allowing you to stand up and surf along the wave.

što vam omogućava da ustanete i surfate uz val.

Now you’ve caught the wave,

Sada ste uhvatili val

and are riding along its front face parallel to the shoreline.

i jašete uz njegovu prednju stranu paralelno s obalom.

Fins on the surfboard allow you to alter your speed and direction

Peraje na dasci za surfanje omogućuju vam mijenjanje vaše brzine i smjera

by repositioning your weight.

premještanjem težine.

Above you is the wave’s crest,

Iznad vas je greben vala,

where the water particles are undergoing their greatest acceleration.

gdje vodene čestice dobivaju svoje najveće ubrzanje.

That forces them to move faster than the underlying wave,

To ih prisiljava da se kreću brže od vala ispod

so they shoot ahead before falling under gravity’s influence.

pa se brzo kreću prema naprijed prije nego što padnu pod utjecaj gravitacije.

This forms the waves’ characteristic curls, or jets,

To oblikuje karakteristične vrtloge ili mlazove valova,

as they break along the shore.

dok se lome duž obale.

Sometimes, the curl might completely enclose part of the wave,

Ponekad vrtlog može potpuno obuhvatiti dio vala,

forming a moving tube of water known as the barrel.

oblikujući pokretnu cijev vode poznatu kao "bačva".

Because of irregularities in the seafloor and the swell itself,

Zbog nepravilnosti na morskom dnu i samog mrtvog mora,

few barrels last as long as the legendary 27-second ride off the coast of Namibia.

nekoliko "bačvi" traje koliko i legendarna vožnja od 27 sekundi uz obalu Namibije.

But many who manage to get barreled

Ali mnogi koji su uspjeli ući u "bačvu"

have said they feel time passing differently inside,

rekli su da imaju osjećaj da vrijeme unutra drugačije prolazi,

making it one of the most magical experiences a surfer can have.

čineći ga jednim od najčarobnijih iskustava koje surfer može imati.

Of course,

Naravno,

not all beaches are created equal.

nisu sve plaže stvorene jednakima.

Offshore underwater canyons or rock formations

Podmorski kanjoni ili formacije stijena

in certain locations like Nazare, Portugal or Mavericks, California

na određenim lokacijama, poput Nazare u Portugalu ili Mavericksa u Kaliforniji,

refract the incoming wave energy into a single spot,

lome nadolazeću energiju vala u jednom mjestu,

creating massive waves sought by surfers worldwide.

stvarajući masivne valove koji su traženi od surfera širom svijeta.

And some of these waves travel for more than a week,

I neki od tih valova putuju više od tjedan dana,

with swells originating more than 10,000 kilometers away from shore.

s mrtvim morem koje nastaje na više od 10,000 kilometara udaljenosti od obale.

Waves surfed in sunny California

Valovi na kojim se surfa u sunčanoj Kaliforniji

may have originated in the stormy seas near New Zealand.

možda su nastali na olujnim morima blizu Novog Zelanda.

So while you may not be thinking about weather patterns in the South Pacific,

Pa dok možda ne razmišljate o vremenskim obrascima u Južnom Tihom oceanu,

tectonic geology, or fluid mechanics,

tektonskoj geologiji ili mehanici fluida,

the art of catching the perfect wave relies on all these things and more.

umjetnost hvatanja savršenog vala oslanja se na sve ove stvari i više.

And the waves we surf, created by wind,

I valovi na kojima surfamo, stvoreni vjetrom,

are just one visible part of the continuous oscillation of energy

samo su jedan dio neprekidne oscilacije energije

that has shaped our universe since its very beginning.

koja je oblikovala naš svemir od samog početka.