Tuesday, December 21, 2010

Usin Brunei

One Dollar
Five Dollars
Five Dollars

Ten Dollars
Ten Dollars
Fifty Dollars
One Hundred Dollars
Five Hundred Dollars
One Thousand Dollars
Ten Thousand Dollars
Syiling

The Truth of The Life of This World

There are some phrases commonly used by people regarding the shortness of this life: "Make the most of your life while it lasts", "life is short", "one does not live forever" are phrases always referred to indefinition of the nature of this world. Yet, these phrases contain an implicit attachment to this life rather than the next. They reflect the general attitude of people to life and death. Having such a strong affection for life, conversations about death are always interrupted with jokes or by raising other subjects thus attempting to alleviate the seriousness of the matter. These interruptions are always on purpose, a deliberate effort to reduce such an important subject to insignificance.
Mortality is surely a grave topic to ponder. Until this moment in his life, it may well be that the person is unaware of the significance of this reality. Yet, now that he has the chance to grasp its importance, he must reconsider his life and his expectations. It is never too late to repent to God, and to reorient all one's deeds and the conduct of one's life in submission to the will of God.
Life is short; the human soul is eternal. During this short period, one should not allow temporary passions to control one. A person
should resist temptation and keep himself away from everything that will strengthen his bonds to this world. It is surely unwise to neglect the next world just for the sake of the temporary joys of this one.
Nevertheless, disbelievers who cannot comprehend this fact spend their lives in vain being forgetful of God. Moreover, they know that it is impossible to attain these desires. Such people always feel a deep dissatisfaction and want even more of what they currently possess. They have endless wishes and desires. Yet, the world is not an appropriate arena in which to satisfy these desires.
An endless search for the new and better, attaching no value to something once it has been achieved, deprecation of the old and
placing all hopes in something new: these are the vicious circles that people have everywhere experienced throughout history. Yet an
intelligent person should stop and ask himself for a moment: why is he chasing after temporary ambitions and has he ever gained any benefit from such pursuit? Finally, he should draw the conclusion that "there is a radical problem with this viewpoint." Yet people, lacking this kind of reasoning, continue to chase after dreams they are unlikely to achieve.
Nobody, however, knows what will happen even in the next few hours: at any time one may have an accident, be severely injured, or
become disabled. Furthermore, time flies in the countdown to one's own death. Every day brings that predestined day closer. Death surely eradicates all ambitions, greed and desires for this world. Under the soil, neither possessions nor status prevail. Every possession with which we are being stingy, including the body, will also vanish and decay in the earth. Whether one is poor or wealthy, beautiful or ugly, one will be wrapped in a simple shroud one day.
take from The Complete Works of Harun Yahya

Eclipses

Introduction to eclipse

  • "Eclipse" is an astronomical event in which heavenly bodies (stars, planets, satellites, asteroids, comets, etc) are positioned such that one either heavenly body falls in the region of the shadow of another heavenly body, thereby making it invisible temporarily, or one heavenly body comes in between two heavenly bodies such that one is invisible to the other temporarily.
  • The term "eclipse" is derived from the Greek word ékleipsis, which means "to cease to exist".
  • An eclipse can be a complete eclipse or a partial eclipse. In the former, the heavenly body is hidden completely from view, whereas in the latter, the heavenly body is hidden from view partially.
  • Eclipses can occur on any heavenly body like the sun, moon, earth, planets, etc.
  • From earth we are able to observe two types of eclipses, the solar eclipses (i.e., the eclipses of the sun) and the lunar eclipses (i.e., the eclipses of the moon).

Solar Eclispe

 Introduction
A solar eclipse is an astronomical event in which observers at particular regions of the earth are unable to view the complete sphere of the sun due to the shadow of the moon falling on those regions of the earth. To the solar eclipse observers, the sun appears hidden from view partially or completely by the moon.

Position of the earth, moon and sun during a solar eclipse

A solar eclipse occurs only on a new moon day. The earth, sun and moon lie in the same straight line on a new moon day, with the moon in between the earth and the sun. Since sun is a luminous body, the moon's shadow is cast on the earth on a new moon day when the moon is close enough to the earth. Since the moon is smaller than the earth, the moon's shadow only falls on a small region on the earth, where the sun becomes hidden for the observers.
Position of the earth, sun and moon during a solar eclipse

Partial and total solar eclipse

A partial solar eclipse is one in which the sun is not completely hidden from view by the moon. A total solar eclipse is one in which the sun is completely hidden from view by the moon.
There are two regions of the shadow of the moon falling on the earth during a solar eclipse. One is the Umbra, which is the region of complete darkness, and the other is the Penumbra, which is the region of semi-darkness.
Thus, during a solar eclipse, the region of the earth under the Umbra views a total solar eclipse, whereas the region of the earth under the penumbra views a partial solar eclipse.

Lunar Eclipse

Position of the earth, sun and moon during a lunar eclipse

Lunar eclipse introduction

A lunar eclipse is an astronomical event in which the moon is partially or completely hidden from view of the observers on the earth due to the shadow of the earth falling on the moon. A lunar eclipse occurs only on a full moon night, since relative position of the earth sun and moon are ideal for a lunar eclipse during a full moon night.

Position of the earth, sun and moon during a lunar eclipse

The earth, sun and moon are positioned in the same straight line during a lunar eclipse, with the earth in between the sun and the moon. A lunar eclipse takes place only when the shadow of the earth falls on the moon which causes the moon to be hidden from view as it is a non-luminous body, and can only be seen when it reflects the light of the sun.
A Lunar eclipse occurs when on a full moon night, the moon is close enough to the earth for the earth's shadow to fall on it. Furthermore, the moon has to be positioned in one of the nodes of its orbit around the earth for the shadow of the earth to fall on it.

Partial and total lunar eclipse

During a lunar eclipse, the moon passes into the region of the earth's shadow in space, and is thus rendered invisible for the time until it comes out of the earth's shadow as it orbits around the earth.
Thus, when the moon is completely inside the earth's shadow, it is completely hidden from view and forms a total lunar eclipse, whereas when it is partially hidden by the earth's shadow, it is said to be a partial lunar eclipse.

Gerhana Matahari dan Gerhana Bulan

Beragam mithos tentang gerhana di berbagai tempat di muka bumi menarik untuk disimak sebagai pelestarian kekayaan khasanah budaya manusia di masa lalu. Raksasa Betara Kala atau Rahu menelan matahari karena dendamnya pada Sang Surya (matahari), menyebabkan terjadinya gerhana. Di belahan bumi lain muncul pula cerita tentang Naga Langit yang menelan matahari atau bulan saat gerhana berlangsung. Tidak kalah menariknya beragam aktivitas makhluk hidup dilakukan mulai dari perilaku yang "kurang wajar" oleh sekelompok orang di pedesaan seperti memukul-mukul kentongan, bersembunyi di rumahnya dengan menutup rapat-rapat semua pintu dan jendela rumah, menutup sumur dan tempayan, menyelam di sungai, memukul-mukul pohon kelapa, perempuan hamil bersembuni di bawah tempat tidur dsb, sebagai cerminan rasa ketakutan psikologis akibat kepercayaan terhadap pengaruh mithos gerhana, maupun perilaku binatang malam yang keluar dari sarangnya di siang hari, sampai penelitian ilmiah modern pun dilakukan oleh manusia.

Dalam kamus Ilmu Pengetahuan Alam, sebenarnya gerhana merupakan gejala alam biasa yang berulang akibat perulangan gerak bulan dan bumi mengedari matahari. Gerhana merupakan gejala saling menutupi antar benda langit. Bulan bergerak di antara kedua belahan langit, utara dan selatan di sepanjang daerah zodiak. Pada suatu waktu bulan lewat di depan matahari dan menghalanginya sehingga terjadi gerhana matahari yang dapat terjadi pada saat fase bulan mati atau posisi konjungsi. Gerhana matahari dapat berupa gerhana matahari total, gerhana matahari cincin (anular) atau gerhana matahari sebagian.

Pada saat lain, yaitu ketika bulan sedang beroposisi terhadap matahari atau penampakan fase purnama, bulan dapat melewati bayangan bumi, sehingga terjadi gerhana bulan. Gerhana ini dapat berupa gerhana bulan total, gehana bulan sebagian atau gerhana penumbra (samar).

Bulan dan bumi membentuk kerucut bayangan akibat disinari oleh matahari. Pada bayangan itu terdapat daerah gelap (umbra) dan bagian samar (penumbra). Ketika terjadi gerhana matahari, bayangan bulan jatuh ke permukaan bumi dan bergerak sepanjang daerah tertentu yang disebut daerah lintasan gerhana. Daerah ini terdiri atas daerah gerhana total dan daerah gerhana sebagian. Daerah gerhana matahari total dilalui oleh bayangan umbra bulan dan daerah gerhana matahari sebagian hanya dilalui oleh bayangan penumbranya. Tempat yang mengalami gerhana berbeda dari satu kejadian ke kejadian berikutnya, akibat dari sistem peredaran bumi terhadap matahari dan peredaran bulan sebagai satelit bumi.

Gerhana matahari total merupakan peristiwa yang mempunyai arti lebih penting dibandingkan dengan gerhana matahari lainnya maupun gerhana bulan, oleh karena kita dapat menyelidiki sifat-sifat matahari dan juga gejala-gejala terestrial.

Aspek-aspek yang dapat dipelajari pada saat gerhana matahari total, antara lain penampakan korona matahari, prominensa dan lapisan khromosfer. Terjadinya gerhana disertai pula oleh peristiwa pasang laut maksimum antara letak matahari, bulan dan bumi yang segaris. Fenomena lainnya pada saat terjadi gerhana matahari total yang menarik untuk diteliti: perubahan cuaca secara mendadak, perilaku makhluk hidup yang ada di bumi termasuk kegiatan manusianya sendiri, semua itu merupakan kegiatan penelitian fisika, biologi ataupun sosial. Durasi gerhana matahari total relatif singkat, yang terlama hanya sekitar 7 menit.

Gerhana matahari cincin terjadi apabila puncak kerucut bayangan umbra bulan tidak mencapai permukaan bumi. Hal itu bisa terjadi karena jarak bumi-bulan berubah-ubah, sesuai dengan lintasan peredaran bulan yang berbentuk ellips. Pada saat gerhana matahari cincin ini bulatan bulan tampak lebih kecil dari ukuran piringan matahari.

Gerhana bulan juga menarik untuk diamati dan dipelajari, misalnya untuk menguji ketepatan perhitungan ephemeris (koordinat benda langit). Pada saat itu posisi bulan, bumi dam matahari tepat satu garis. Jika bulan bergerak di dalam daerah bayangan penumba bumi, tanda-tanda gerhana tak tampak, oleh karena itu yang bisa kita amati ialah pada saat bulan memasuki daerah bayangan umbra bumi. Gerhana bulan terlihat oleh hampir setengah muka bumi, bisa berlangsung sampai lebih dari 3 jam.

Fase bulan berulang rata-rata dalam 29,5 hari yang disebut satu bulan sinodis. Tidak setiap bulan mati terjadi gerhana matahari, begitu pula tidak setiap bulan purnama terjadi gerhana bulan. Hal ini disebabkan oleh orbit bulan membentuk bidang miring sebesar 5 derajat terhadap bidang ekliptika. Perpotongan dua bidang tersebut membentuk garis nodal yang berputar ke arah barat dalam periode 18,6 tahun, yang disebut periode nutasi bulan. Kedudukan matahari dekat sebuah titik nodal disebut musim gerhana, yang berulang pada setiap 173,3 hari. Perpaduan periode putaran garis nodal dan periode fase bulan menyebabkan gerhana serupa akan berulang setiap 18 tahun 11,3 hari, yang disebut periode saros. Setiap perulangan periode saros, wilayah lintasan gerhana di bumi akan bergeser pada tempatnya, akibat harga periode saros tidak bulat. Jika musim gerhana pertama jatuh pada bulan januari, gerhana matahari dapat terjadi sebanyak 5 kali dalam satu tahun. Jumlah maksimum seluruh jenis gerhana baik gerhana matahari dan gerhana bulan dalam satu tahun dapat terjadi sampai 7 kali.

Saat-saat terjadinya gerhana matahari maupun gerhana bulan dapat diperhitungkan jauh-jauh sebelumnya, karena sistem pergerakan bumi mengitari matahari dan bulan mengelilingi bumi telah diketahui dengan sangat teliti.