by the constraints of time, as it is itself part of his own creation. The Ismaili thinker Nasir Khusraw (d. after 1070) expands on his colleague’s work. He writes that these days refer to cycles of creation demarcated by the arrival of God’s messengers (ṣāḥibān-i adwār), culminating in the arrival of the Lord of the Resurrection (Qāʾim al-Qiyāma), when the world will come out of darkness and ignorance and “into the light of her Lord” (Quran 39:69). His era, unlike that of the enunciators of divine revelation (nāṭiqs) before him, is not one where God prescribes the people to work. Rather, his is an era of reward for those “who laboured in fulfilment of (the Prophets') command and with knowledge”. Galaxy observation The Arab astronomer Alhazen (965–1037) made the first attempt at observing and measuring the Milky Way's parallax, and he thus "determined that because the Milky Way had no parallax, it was very remote from the earth and did not belong to the atmosphere." The Persian astronomer Abū Rayhān al-Bīrūnī (973–1048) proposed the Milky Way galaxy to be "a collection of countless fragments of the nature of nebulous stars." The Andalusian astronomer Ibn Bajjah ("Avempace", d. 1138) proposed that the Milky Way was made up of many stars which almost touched one another and appeared to be a continuous image due to the effect of refraction from sublunary material, citing his observation of the conjunction of Jupiter and Mars on 500 AH (1106/1107 AD) as evidence. Ibn Qayyim Al-Jawziyya (1292–1350) proposed the Milky Way galaxy to be "a myriad of tiny stars packed together in the sphere of the fixed stars". In the 10th century, the Persian astronomer Abd al-Rahman al-Sufi (known in the West as Azophi) made the earliest recorded observation of the Andromeda Galaxy, describing it as a "small cloud". Al-Sufi also identified the Large Magellanic Cloud, which is visible from Yemen, though not from Isfahan; it was not seen by Europeans until Magellan's voyage in the 16th century. These were the first galaxies other than the Milky Way to be observed from Earth. Al-Sufi published his findings in his Book of Fixed Stars in 964. Possible worlds Al-Ghazali, in The Incoherence of the Philosophers, defends the Ash'ari doctrine of a created universe that is temporally finite, against the Aristotelian doctrine of an eternal universe. In doing so, he proposed the modal theory of possible worlds, arguing