APOD: The Starry Night of Alamut (2010 Jun 25)

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Expand view Topic review: APOD: The Starry Night of Alamut (2010 Jun 25)

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by DavidLeodis » Sat Jun 26, 2010 10:33 am

It's a superb image. Due to light pollution where I am it is a goodnight if I can readily see just some of the brightest stars!

As a non-photographer I am though amazed that so much detail can be obtained in just a 50 seconds tracked exposure, particularly as there does seem to be a fair amount of light pollution on the right.

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by hstarbuck » Sat Jun 26, 2010 2:17 am

Babak wrote:This is a non-composite image. It's made using Canon 5Di modified camera and 15mm lens, at f2.8 and ISO1600 and 50 seconds tracked exposure. The deep blue color in the sky is the beginning of morning twilight. The light on the rock comes from the nearby village.
Regards
Babak Tafreshi
http://www.twanight.org/tafreshi
Great work. I think the staircase gives scale that may be missed otherwise and agree that is satisfying to know that this is not a composite.

Tusi

by neufer » Fri Jun 25, 2010 10:18 pm

http://en.wikipedia.org/wiki/Nasir_al-Din_al-Tusi wrote:
<<Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī (born 18 February 1201 in Ṭūs, Khorasan – 26 June 1274 in al-Kāżimiyyah, Baghdad), better known as Naṣīr al-Dīn al-Ṭūsī or simply Tusi in the West, was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed.

As the armies of Genghis Khan swept his homeland, he fled to join the Ismailis and made his most important contributions in science during this time when he was moving from one stronghold to another. He finally joined Hulagu Khan's ranks, after the invasion of the Alamut castle by the Mongol forces. Tusi convinced Hulegu Khan to construct an observatory for establishing accurate astronomical tables for better astrological predictions. Beginning in 1259, the Rasad Khaneh observatory was constructed in Azarbaijan, west of Maragheh, the capital of the Ilkhanate Empire.
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Based on the observations in this for the time being most advanced observatory, Tusi made very accurate tables of planetary movements as depicted in his book Zij-i ilkhani (Ilkhanic Tables). This book contains astronomical tables for calculating the positions of the planets and the names of the stars. His model for the planetary system is believed to be the most advanced of his time, and was used extensively until the development of the heliocentric model in the time of Nicolaus Copernicus. He also calculated the value for the annual precession of the equinoxes and contributed to the construction and usage of some astronomical instruments including the astrolabe. Tusi was the first to present empirical observational evidence of the Earth's rotation, using the location of comets relevant to the Earth as evidence, which Ali al-Qushji elaborated on with further empirical observations. The arguments of Tusi were similar to the arguments later used by Copernicus in 1543 to explain the Earth's rotation.
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Biology

Tusi wrote extensively on biology and is one of the early pioneers of biological evolution in scientific thought. He begins his theory of evolution with the universe once consisting of equal and similar elements. According to Tusi, internal contradictions began appearing, and as a result, some substances began developing faster and differently from other substances. He then explains how the elements evolved into minerals, then plants, then animals, and then humans. Tusi then goes on to explain how hereditary variability was an important factor for biological evolution of living things: "The organisms that can gain the new features faster are more variable. As a result, they gain advantages over other creatures. [...] The bodies are changing as a result of the internal and external interactions."
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Chemistry and Physics

In chemistry and physics, Tusi stated a version of the law of conservation of mass. He wrote that a body of matter is able to change, but is not able to disappear: "A body of matter cannot disappear completely. It only changes its form, condition, composition, colour and other properties and turns into a different complex or elementary matter."
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Mathematics

In his On the Sector Figure, he formulated the famous law of sines for plane triangles, which was one of his main mathematical contributions. He also stated the law of sines for spherical triangles, discovered the law of tangents for spherical triangles, and provided proofs for these laws.

In 1265, Tusi wrote a manuscript regarding the calculation for nth roots of an integer. Moreover, he revealed the coefficients of the expansion of a binomial to any power giving the binomial formula and the Pascal triangle relations between binomial coefficients. He also wrote a famous work on theory of colour, based on mixtures of black and white, and included sections on jewels and perfumes.
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Image
A 60-km diameter lunar crater located on the southern hemisphere of the moon is named after him as "Nasireddin". A minor planet 10269 Tusi discovered by Soviet astronomer Nikolai Stepanovich Chernykh in 1979 is named after him. The K. N. Toosi University of Technology in Iran and Observatory of Shamakhy in the Republic of Azerbaijan are also named after him.>>

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by Babak » Fri Jun 25, 2010 9:51 pm

This is a non-composite image. It's made using Canon 5Di modified camera and 15mm lens, at f2.8 and ISO1600 and 50 seconds tracked exposure. The deep blue color in the sky is the beginning of morning twilight. The light on the rock comes from the nearby village.
Regards
Babak Tafreshi
http://www.twanight.org/tafreshi

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by neufer » Fri Jun 25, 2010 6:53 pm

http://en.wikipedia.org/wiki/Ismailism wrote:
<<The Hashashin: Surrounded by the Abbasids and other hostile powers, and low in numbers, Hassan-i-Sabbah derived a way to attack the Ismāʿīlī enemies with a small loss and number. Using the method of assassination, from which the English word is derived from Hashashin, he ordered the killing of Sunni scholars and politicians that threatened the Ismāʿīlīs. Knives and daggers were used. Sometimes, in warning, a knife would be put into the pillow of the enemy and often they understood the message. However, when an assassination was actually made the Hashashin would not be allowed to run away, but rather to strike further fear in the enemy by showing no emotion, they would stand there. This further increased the reputation of the Hashashin in the Sunni world.>>
Which might explain the curious ambivalence of the Times Square Bomber.
http://en.wikipedia.org/wiki/Alamut wrote:
<<Alamūt (Persian: الموت "Eagle taught" or "Eagle's Nest") was a mountain fortress located in the central Alborz Mountains south of the Caspian Sea close to Gazor Khan near Qazvin, about 100 km from Tehran in Iran. Only ruins remain of this fortress today. According to Hamdollah Mostowfi, the first fortress was built in 840 at an elevation of 2,100 m. It was built in a way that had only one passable artificial entrance that wound its way around the cliff face (the one natural approach, a steep gravel slope, was too dangerous to use); thus making conquering the fortress extremely difficult. The top was extremely narrow and long — perhaps 400 meters long, and no more than 30 meters wide in any place and usually less. Archaeological excavations revealed rooms for food storage as well as water reservoirs built into the fort. Hamideh Choubak, head of the Alamut Research Center, said, "the site's largest water reservoir is 11.45m long, 4m wide and about 4m deep." She continued that the residents collected rain and snow water in big cisterns and used it during summer.

Image
Hashshashin fortress of Alamut.

In 1090 the fortress was infiltrated and occupied by Hassan-i Sabbah the founder of powerful Hashshashins, a faction of Nizāri Ismā‘ilī Shī‘a Islam known to the West as "the Assassins", and was then fabled for its gardens and libraries. The fortress was destroyed on December 15, 1256 by Hulagu Khan as part of the Mongol offensive on Islamic southwest Asia. The fortress itself was impregnable, but Ruknud-Dīn Khurshāh surrendered it without a real fight, in the vain hope that Hulagu would be merciful.>>

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by Chris Peterson » Fri Jun 25, 2010 4:45 pm

John MDM wrote:It annoys me when composite pictures are presented as real photos!
While it isn't clear if this image is or is not a composite, it's rubbish to suggest a composite isn't a "real photo". Virtually every astronomical image is a composite. There is no imaging technology capable of capturing the dynamic range of astronomical objects in a single exposure.

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by John MDM » Fri Jun 25, 2010 4:32 pm

It annoys me when composite pictures are presented as real photos!

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by moonstruck » Fri Jun 25, 2010 2:15 pm

That is one beatuiful starry, starry night. About half way up the mountain it looks like steps going up to an open door. Looks like they left the light on for us. :|

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by León » Fri Jun 25, 2010 1:20 pm

Fortress of Alamut. From it a political and religious leader, Hasan Ibn Saba, indoctrinating and training a group of fanatical Fedayeen of the sect of the hashashins, to fight a holy war against the Turks in 1092, are masters of an empire. Promised paradise, and the elect, enables them to visit him before going into battle. "
Marco Polo in The Travels of Marco Polo claimed to have visited Alamut and meet the Old Man of the Mountain. The Venetian traveler in Europe introduced the legend that has brought fame to Alamut: that he had hidden gardens imitating paradise.
Ralata the fall of the castle in addition to Alan, lord of the Tartars.

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by orin stepanek » Fri Jun 25, 2010 12:04 pm

I liked today's picture but also liked the fortress on the mountain top. :) http://en.wikipedia.org/wiki/File:Alamut2.jpg Is that a hole near the side of the structure?

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by Chris Peterson » Fri Jun 25, 2010 7:23 am

alter-ego wrote:At first I thought the curved meteor trail was special, but I think it's the artifact of the near-matching image field curvature visible in the Milky Way. Comments?
Meteor trails are usually curved in images. You are mapping a line on a sphere onto a plane. The wider the FOV of the lens, the more curved meteor trails are likely to be (depending on where they are in the field). An extreme case is a fisheye lens pointed at the zenith and a meteor traveling in a straight line parallel to the horizon.
Denver fireball, 2010 May 16
Denver fireball, 2010 May 16
20100516_215553_005.jpg (11.35 KiB) Viewed 4457 times

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by Ann » Fri Jun 25, 2010 7:04 am

bright white stars Deneb (in Cygnus), Vega
In the picture, Vega is the brightest individual star, a white point of light surrounded by a very obvious blue halo.

I have shown Vega through a telescope to several people (to strangers who don't know anything about my color obsession, I might add) and I have asked them what color they think it is. They have all answered that it looks blue.

So Vega looks blue through a telescope. It looks blue in this picture. It is much bluer than the Sun, so if we could just for a moment replace our Sun with Vega (in such a way that we got the same amount of visible light from Vega as we get from the Sun) the daylight around us would take on an intensely blue cast.

So Vega is blue any way you look at it, except - and this I will admit - when you look at it with the naked eye. Then it is not obviously blue. Then again, if the North America Nebula had looked strikingly reddish in this image (which it doesn't) we would undoubtedly have been asked to note the red North America Nebula, even though it will never look red either to the naked eye or through a telescope. We are told over and over that emission nebulae are red even though we can never see it even with a telescope, but we are told about stars whose blue color can indeed be seen through a telescope that they are nevertheless white just because they have been defined as white. I hate it!

Nice picture in any case.

Ann

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by alter-ego » Fri Jun 25, 2010 5:12 am

At first I thought the curved meteor trail was special, but I think it's the artifact of the near-matching image field curvature visible in the Milky Way. Comments?

Re: APOD: The Starry Night of Alamut (2010 Jun 25)

by BeeJay » Fri Jun 25, 2010 5:01 am

Home of the legendary Assassins featured in the adventure movie Prince of Persia,
Just as a point of note, in the movie Prince of Persia, Alamut is a sacred holy city and the site of the titular Sands of Time. The villainous "Hassassins" (sp?) come from some other fortress as the people of Alamut are peaceful and "..have no forges.". However, in the game Assassin's Creed, the Assassins come from a very similar mountain top sanctuary but this is not named Alamut.

Sources
  • Personal Experience
  • Wikipedia entry for Alamut(which you link to in your article)

APOD: The Starry Night of Alamut (2010 Jun 25)

by APOD Robot » Fri Jun 25, 2010 4:04 am

Image The Starry Night of Alamut

Explanation: A meteor's streak and the arc of the Milky Way hang over the imposing mountain fortress of Alamut in this starry scene. Found in the central Alborz Mountains of Iran, Alamut Castle was built into the rock in the 9th century. The name means Eagle's Nest. Home of the legendary Assassins featured in the adventure movie Prince of Persia, Alamut was also historically a center for libraries and education. For a time, it was the residence of important 13th century Persian scholar and astronomer Nasir al-Din al-Tusi. To identify the stars in a night sky Tusi certainly pondered, just slide your cursor over the image. Highlights include bright white stars Deneb (in Cygnus), Vega, and Altair, nebulae near the Galactic Center, and the dark obscuring dust clouds of the Milky Way also known as the Great Rift. Lights at the lower right are from small villages and the capital Tehran, over 100 kilometers away to the southwest.

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