Reasons for the seasons - Rebecca Kaplan

Transcriber: Andrea McDonough Reviewer: Jessica Ruby

Translator: Hygna Husada Reviewer: Reno Kanti Riananda

When I was a kid,

Ketika aku kecil, pemahamanku terhadap musim adalah:

my understanding of the seasons

was that December and January were cold

Desember dan Januari musim yang dingin

and covered with snow,

dan tertutup salju;

April and May were bursting with flowers,

April dan Mei bertabur bunga;

July and August were hot and sunshiny,

Juli dan Agustus panas dan cerah;

and September and October were a kaleidoscope of colorful leaves.

serta September dan Oktober serupa kaleidoskop daun warna warni.

It was just the way the world worked,

Itulah cara dunia bekerja, dan rasanya ajaib.

and it was magical.

If you had told me back then

Jika dulu kamu memberitahuku

that one-third of Earth's population

bahwa sepertiga populasi di bumi

had never seen snow

tidak pernah melihat salju

or that July 4th was most definitely not a beach day,

atau tanggal 4 Juli tidak selalu hari yang cerah,

I would have thought you were crazy.

aku mungkin menganggap kamu gila.

But in reality, seasonal change with four distinct seasons

Faktanya, perubahan musim dengan empat musim yang berbeda

only happens in two regions on the planet.

hanya terjadi di dua wilayah di bumi.

Selain itu,

And, even in those two,

the seasons are reversed.

waktunya pun berkebalikan.

But why?

Mengapa?

A lot of people have heard of an astronomer

Banyak orang mengenal astronom bernama Johannes Kepler

called Johannes Kepler

and how he proved that planetary orbits are elliptical

yang membuktikan bahwa orbit planet berbentuk elips

and that the sun is not at the center of the orbit.

dan matahari tidak terletak tepat di tengahnya.

It was a big deal when he figured this out

Hal ini sangat penting saat ia membuktikannya ratusan tahun yang lalu.

several hundred years ago.

His discovery solved a lot of mathematical problems

Penemuannya memecahkan banyak masalah matematika

that astronomers were having

yang dihadapi oleh astronom

with planetary orbit measurements.

saat melakukan pengukuran orbit.

While it's true that our orbit's not perfectly circular,

Meskipun orbit kita tidak berbentuk lingkaran sempurna,

those pictures in our science books,

gambaran dalam buku sains, TV, dan film

on TV, and in the movies

give an exaggerated impression

memberi kesan yang berlebihan

of how elongated our orbit is.

tentang seberapa panjangnya orbit kita.

In fact, Earth's orbit is very nearly a perfect circle.

Kenyataanya, orbit bumi hampir menyerupai lingkaran sempurna.

However, because Earth's orbit is technically an ellipse,

Namun, karena orbit bumi secara teknis berbentuk elips,

even though it doesn't look like one,

meskipun tidak terlihat seperti itu,

and the sun isn't quite exactly at the center,

dan matahari tidak tepat terletak di tengahnya,

it means that our distance from the sun

jarak kita ke matahari berubah-ubah sepanjang tahun.

does change through the year.

Ah-ha!

Nah! Jadi, musim dingin terjadi ketika bumi menjauhi matahari.

So, winter happens when the Earth is further away from the sun!

Well, no, not so fast.

Yah, tidak sesederhana itu juga sih.

The Earth is actually closer to the sun

Bumi lebih dekat jaraknya ke matahari pada bulan Januari daripada bulan Juli—

in January than we are in July

by 5 million kilometers.

dengan perbedaan sekitar 5 juta kilometer.

January is smack-dab in the middle

Bulan Januari tepat di tengah

of the coldest season of the year

musim terdingin sepanjang tahun

for those of us up north.

bagi belahan utara bumi.

Still not convinced?

Masih belum yakin?

How about this:

Bagaimana dengan ini:

Summer and winter occur simultaneously

musim panas dan dingin terjadi bersamaan

on the surface of our planet.

di permukaan planet kita.

When it's winter in Connecticut,

Saat di Connecticut musim salju, di New Zealand sedang musim panas.

it's summer in New Zealand.

So, if it's not the distance from the sun,

Jika bukan karena jarak dari Matahari, apa penyebabnya?

what else could it be?

Well, we need to also need to know

Nah, kita harus menyadari bahwa posisi bumi tidak tegak lurus.

that the Earth doesn't sit straight up.

It actually tilts.

Bumi itu miring.

And that axial tilt of the Earth

Sumbu kemiringan bumi adalah salah satu alasan utama terjadinya musim.

is one of the main reasons for the seasons.

The Earth spins on an axis

Bumi berputar pada sumbu

that's tilted 23.5 degrees from vertical.

dengen kemiringan 23,5 derajat dari sumbu vertikal.

At the same time, the Earth revolves around the sun

Di saat yang sama, bumi mengelilingi matahari

with the axis always pointing in the same direction in space.

dan sumbunya selalu menunjuk ke arah yang sama di ruang angkasa.

Together with the tilt,

Bersama kemiringan ini, rotasi dan revolusi bumi menyebabkan

the spinning and revolving causes the number

of hours of daylight in a region to change

waktu siang di suatu wilayah berubah setiap tahunnya:

as the year goes by,

with more hours in summer

lebih panjang saat musim panas dan lebih singkat saat musim dingin.

and fewer in winter.

So, when the sun is shining on the Earth, it warms up.

Jadi, ketika matahari menyinari bumi, bumi menjadi hangat.

After the sun sets, it has time to cool down.

Setelah matahari terbenam, saatnya untuk pendinginan.

So, in the summer,

Saat musim panas, tempat mana pun yang berada 40 derajat di utara ekuator,

any location that's about 40 degrees north of the equator,

like Hartford, Connecticut,

seperti Hartford, Connecticut,

will get 15 hours of daylight each day

mendapat cahaya matahari 15 jam per hari, dan 9 jam kegelapan.

and 9 hours of darkness.

It warms up for longer than it cools.

Pemanasan lebih lama daripada pendinginan.

This happens day after day,

Hal ini terjadi hari demi hari,

so there is an overall warming effect.

sehingga ada efek pemanasan secara keseluruhan.

Remember this fact for later!

Ingatlah fakta ini!

In the winter, the opposite happens.

Ketika musim dingin, terjadi kebalikannya.

There are many more hours of cooling time

Waktu pendinginan lebih panjang dibandingkan pemanasan,

than warming time,

and day after day, this results in a cooling effect.

dan hari demi hari, menghasilkan efek pendinginan.

The interesting thing is, as you move north,

Hal yang menarik adalah, ketika kamu bergerak ke utara,

the number of daylight hours in summer increases.

waktu siang di musim dingin lebih panjang.

So, Juneau, Alaska would get about 19 hours of daylight

Juneau, Alaska, mendapat cahaya matahari selama 19 jam,

on the same summer day that Tallahassee, Florida gets about 14.

sementara Tallahassee, Florida, mengalami siang hari selama 14 jam.

In fact, in the summertime at the North Pole,

Bahkan, saat musim panas di Kutub Utara,

the sun never sets.

matahari tak pernah terbenam.

OK, then, it's all about daylight hours, I've got it!

Oke, berarti ini tentang jam siang hari, aku paham!

Well, no, there's another important piece to this puzzle.

Tidak juga. Ada kepingan penting lain dalam teka-teki ini.

If daylight hours were the only thing

Jika jam siang hari adalah satu-satunya yang memengaruhi suhu rata-rata,

that determined average temperature,

wouldn't the North Pole be the hottest place

bukankah Kutub Utara akan menjadi tempat terpanas saat musim panas

on Earth in northern summer

because it receives 24 hours of daylight

karena menerima cahaya matahari selama 24 jam

in the months surrounding the summer solstice?

pada bulan-bulan dengan siang yang panjang?

But it's the North Pole.

Namun, itu kan Kutub Utara.

There's still icebergs in the water

Masih ada gunung es di air dan salju di daratannya.

and snow on the ground.

So, what's going on?

Jadi, ada apa gerangan?

The Earth is a sphere

Bumi berbentuk bulat, sehingga jumlah energi matahari yang diterima

and so the amount of solar energy an area receives

changes based on how high the sun is in the sky,

berubah tergantung tingginya matahari di langit,

which, as you know, changes during the day

yang berubah sepanjang hari dari matahari terbit hingga tenggelam.

between sunrise and sunset.

But, the maximum height also changes during the year,

Namun, tinggi maksimumnya berubah sepanjang tahun.

with the greatest solar height during the summer months

Puncak ketinggian matahari saat musim panas

and highest of all at noon on the summer solstice,

di siang hari saat titik balik matahari musim panas

which is June 21st in the northern hemisphere

jatuh di tanggal 21 Juni di belahan bumi utara

and December 21st in the southern hemisphere.

dan tanggal 21 Desember di belahan bumi selatan.

This is because as the Earth revolves,

Saat bumi berputar,

the northern hemisphere ends up tilted away

belahan bumi utara bergerak miring menjauhi matahari di musim dingin

from the sun in the winter

and toward the sun in summer,

menghadap matahari musim panas,

which puts the sun more directly overhead

membuat matahari tepat di atas kepala untuk jangka waktu yang lebih lama.

for longer amounts of time.

Remember those increased summer time daylight hours?

Ingat waktu siang hari di musim panas yang bertambah?

And solar energy per square kilometer increases

Energi matahari meningkat per kilometer persegi

as the sun gets higher in the sky.

seiring posisinya yang semakin tinggi di angkasa.

So, when the sun's at an angle,

Saat matahari ada di sudut tertentu, jumlah energi yang dikirimkan

the amount of energy delivered

to each square of the sunlit area is less.

untuk setiap meter area yang terkena sinar lebih sedikit.

Therefore, even though the North Pole is getting 24 hours

Meskipun Kutub Utara selama 24 jam

of daylight to warm up,

menerima cahaya matahari,

the sunlight it receives is very spread out

cahaya tersebut menyebar luas,

and delivers less energy than a place further south,

menghantarkan lebih sedikit energi dibandingkan di selatan,

where the sun is higher in the sky

saat posisi matahari lebih tinggi

because it's more tilted toward the sun.

karena posisinya miring ke arah matahari.

Besides, the North Pole has a lot to make up for.

Lagipula, Kutub Utara mendapat banyak kompensasi.

It was cooling down without any sunlight at all

Cuacanya dingin tanpa sinar matahari selama kurun waktu 6 bulan.

for 6 months straight.

So, as the seasons change, wherever you are,

Jadi, ketika musim berubah, di mana pun kamu berada,

you can now appreciate not just the beauty of each new season

kamu tak hanya dapat mengapresiasi keindahan setiap musimnya,

but the astronomical complexity

tetapi juga kompleksitas astronominya.

that brings them to you.