Rubu' Mujayyab (Sine Quadrant)

Kalkulator silam dan Moden

Sekarang sedang berlangsung kursus penggunaan Rubu' Mujayyab anjuran Jabatan Mufti di Kolej Matrikulasi Labuan. Kursus selama 3 hari akan menumpukan kaedah menentukan masa dan masa solat menggunakan Rubu' Mujayyab.

Gambar menunjukkan kedua-dua kalkulator menyelesaikan Sin 30.. sin 30=0.5... rubu' menunjukan sin 30= 30/60.... kalkulator moden dan kalkulator zaman pertengahan.. di saat empayar Islam tengah pesat.. astrolabe yang di cipta oleh orang yunani di gunakan bahkan diperbaiki fungsinya oleh orang Islam.. Rubu' mujayyab (sukuan sinus/ sine quadrant) salah satu alat yang digunakan oleh umat Islam dahulu untuk menyelesaikan persamaan trigonometry.. walaupun alat sekarang dah canggih, kalau kita belajar alatan2 silam, dapat juga kita hargai betapa hebatnya orang dahulu dan betapa untungnya kita

Insya'Allah akan tulis summary macam mana menggunakan rubu' mujayyab akan datang

Lunar Observation June 2013

Object: Moon
Date: 17/06/13
Time: 7:00 pm-7:30pm
Weather: Clear
Telescope: Orion XT4.5 (my friend's telescope)

Clear Sky at last. I cant remember the last time I have a clear sky like this in Labuan. I took this opportunity to do some lunar observation. No matter how busy I am, when there is a clear sky, I will definitely go out and observe the sky.

Moon was 60% full during the observation. There is a lot of interesting formation that can be observe during this phase. The obvious formation was the Apennines mountain. I saw a clear crispy image of Eratosthenes crater near the mountain using XT4.5 telescope.  Vales Alpes was still visible. Through 4.5 inch reflector, Plato looks clear and empty, like there is no secondary crater inside Plato. Of course, that is not true.. I did not take a lot of picture. The observation last about 30 minutes.

During the Observation, I tested my new green laser pointer for Astronomy. Every Astronomer should have one. It is very useful during public observation, or with family.

Below is photograph taken during the observation:

I missed ISS flyby on 4th of June 2013, The next ISS flyby (above Labuan) is on 2nd of July 2013. Let's hope for clear skies. I will write an update before the event.