Inside the cases are models of ancient scientific instruments from the Muslim world. The exhibits range from compasses to clocks to astrolabes for determining the altitude of stars in the night sky.
Sezgin is the white-haired, genteel octogenarian explaining the exhibits to visitors. As he does, he easily switches between Turkish, Arabic, German, and English.
The professor is one of the world's leading authorities on Islam's Golden Age of Science, which he says extended from the 8th to the 16th centuries. He is also one of that period's most prolific chroniclers.
As he tells RFE/RL, he has just published three new installments in his ever-growing 13-volume history of Arabic-Islamic science. The new books detail the accomplishments of the Muslim world's cartographers and, he says, thus fill in important gaps in the history of cartography as it is usually taught.
"I have written in these three volumes the history of mathematical geography for the first time, generally. Until now, it was impossible to write the [full] history of mathematical geography because [scholars] did not know the mathematical geography in Islam," Sezgin says.
Sezgin says it has long been recognized that Muslim navigators undertook sea voyages over vast distances, which gave them a more complete view of geography than the ancient Greeks and Romans.
But he says he believes he is the first to compile a comprehensive collection of evidence showing how Muslim cartographers combined the navigators' information with studies of astronomy and mathematics to compile maps of astonishing precision for their day.
Sezgin says one of his greatest successes was tracking down a copy of a particularly famous map that Western scholars knew existed from Arab histories but which was generally assumed to be lost. That is the map of the world that Caliph al-Ma'mum, who reigned in Baghdad from 813 to 833 AD, commissioned from a large group of astronomers and geographers.
"Many geographers, many astronomers, many mathematics scholars made this map. Historians of geography knew of this map, but by its name only. I [finally] found this map in an encyclopedia in Topkapi Sarai [Museum in Istanbul]," Sezgin says.
The map shows large parts of the Eurasian and African continents with recognizable coastlines and major seas. It depicts the world as it was known to the captains of the Arab sailing dhows which, with planks secured by palm-fiber ropes rather than nails, used the monsoon wind cycles to trade over vast distances. Western historians recognize that by the 9th century, Arab sea traders had reached Canton, in China.
Sezgin says the Caliph al-Ma'mum map illustrates how far the Muslim cartographers departed from earlier world views. The maps of the Greeks and Romans reveal a good knowledge of closed seas like the Mediterranean but little understanding of the vast ocean expanses beyond.
"This map [shows] the Muslims knew the continents are islands, not like the Greeks' thinking that the seas are closed seas," Sezgin says.
But if Sezgin has devoted his life to understanding Islam's Golden Age of Science -- he has spent 55 years writing about it -- he is far from having chauvinistic views. He says Muslim scientists were able to make such advances because they were ready to build on the work of earlier scholars -- Muslim or otherwise. The professor says this "receptiveness" enabled Muslim science to become the world's dominant scientific tradition within 200 years of the beginnings of the Arab conquests.
"The Arabs, the Muslims, had taken from Christians, from Jews, from [Persia] without complexes. The Muslims were tolerant. The Muslims had accepted these Christians and Jews as teachers. That's very important, because the period of the reception of science was [thus just] 200 years," Sezgin says.
Islam's Golden Age of Science finally ended as the stability and wealth of the Muslim world was shaken by rival powers. European states controlled the Mediterranean trade routes by the 14th century, and the Mongol invasions of the 13th to 15th centuries disrupted trade with China. State patronage of science gave way to military affairs.
Still, Muslim science never disappeared. Instead, it reemerged as part of the new body of science developing in Europe as scholars there -- in their turn -- borrowed liberally from Muslim scholars before them.
Sezgin says Portuguese and Spanish navigators used the knowledge they gained from Muslim cartographers while Iberia was under Arab domination to launch their own voyages of discovery.
Those great sea journeys, including the circumnavigation of the world and the discovery of the Americas, helped lead to a modern view of Earth as a globe containing all of the major continents.
Sezgin, who mostly writes in German, says the first volume of his book on the Muslim cartographers has just been translated into English and will be published next month. He hopes the translation will help his work reach a broader audience, both in the West and the Muslim world.
In the meantime, he remains busy revising five more books he has written on other areas of Muslim science. Asked if he has new works planned for the future, he smiles and answers yes. Then he offers this note of caution: "You know, my age, I am 80 years old. I should be very happy if I see these five volumes, which are just at the moment in manuscript [form], are printed."
Sezgin has no plans to retire and is much in demand at the fair among journalists and visiting officials from the 22 countries of the Arab world, which is the fair's special focus this year.