Technical Director Erhard Huttel, from Germany, in the inner storage ring of the SESAME facility. (Dean Calma/International Atomic Energy Agency)

They’ve built a machine in the desert in the heart of the Middle East. Israelis will use it — and so will Iranians, Jordanians, Turks, Pakistanis and many others. Scientists from countries recently at war or without diplomatic relations will work side by side — Muslims, Jews, Christians and atheists sharing the pursuit of knowledge.

This may seem an impossible dream, and indeed the project took decades to materialize and often came close to disintegration. As the saying goes: The difficult we do immediately;the impossible takes longer.

The project is called SESAME — as in “Open, Sesame!” — and it is an acronym for Synchrotron-light for Experimental Science and Applications in the Middle East.

The machine functions a bit like an X-ray. About 50 of these “light sources” exist around the world, and they are prized among researchers for their versatility. They can reveal the atomic structure of matter, making them useful for everything from biology to chemistry to archaeology.

The new machine is in Jordan, about a 45-minute drive from the capital of Amman. The leaders of the project and many dignitaries will formally dedicate the facility in a ceremony on Tuesday, with Jordan’s King Abdullah II presiding.

“It’s a beacon, one lighthouse, in this era where there is killing, beheadings, gassing. We are showing a different way,” said Eliezer Rabinovici, 70, a physics professor at Hebrew University of Jerusalem and one of the founders of the endeavor.

The project has been raked by political and financial crosswinds. The internationalism at the core of SESAME had to overcome fierce nationalistic passions. Security remains a concern.

But SESAME shows the centripetal force of the global scientific enterprise. Scientists speak the common language of mathematics, and they search for truths that are almost invariably universal, and not defined by political or cultural boundaries. Science is ­arguably the most international human endeavor; the only thing that comes close is the Olympic Games, which happen for a couple of weeks every two years and are centered on competition rather than collaboration.

That is one reason the scientific community in the United States was so outraged by President Trump’s proposed travel ban affecting a number of Muslim-majority countries.

Scientists depend increasingly on elaborate machines, such as particle accelerators, supercomputers and space telescopes — shared tools on a colossal scale. The premier example of this is CERN, the research facility outside Geneva where physicists used a particle accelerator to search for theoretical Higgs boson (found!).CERN is run by 28 member or associate states.

But science is not immune to political turmoil.

SESAME was roiled in 2010 when two Iranian scientists with connections to the project were killed in separate incidents. This was part of several attacks on Iranian scientists perceived to have connections to Iran’s nuclear program. The government in Tehran accused Israel and the United States of involvement in the attacks, which both countries denied. The SESAME council later issued a condemnation of the assassinations.

Tensions also flared at a meeting held in 2010 shortly after ­Israeli commandos attacked a Turkish-owned ship carrying aid to Palestinians in the Gaza Strip, recalled Khaled Toukan, chairman of the Jordan Atomic Energy Commission.

“We were on the verge of withering away,” he said. “It has not been easy. But we made it.”

Rabinovici said the council resolved not to discuss politics or issue political statements. He said in an email that scientists also never discuss their religious faith.

In an article on the project, Rabinovici noted that there continue to be some “bitter” feelings from things that have happened over the years. Asked to elaborate, he replied, “Let’s concentrate on the good feelings.”

Money has been and continues to be in short supply for SESAME. And the world’s richest country, the United States, has not given money directly to the project.

SESAME traces its origin to an optimistic period in the mid-1990s after the signing of the Oslo accords. One day at CERN, the laboratory in Geneva, an esteemed Italian physicist named Sergio Fubini approached Rabinovici, the Israeli physics professor, in a corridor and said it was time to test Rabinovici’s ideals about Arab-Israeli collaboration.

They decided to join forces with others to found an organization called the Middle Eastern Science Committee.

Rabinovici and Fubini traveled to Egypt and enlisted the support of that country’s minister for scientific research, Venice Kamel Gouda, and she helped organize an international meeting in November 1995 in the Red Sea resort of Dahab.

That was only a few weeks after Israeli Prime Minister Yitzhak Rabin had been assassinated. Gouda asked all the scientists present — Arabs and Israelis alike — to stand for a moment of silence in memory of the slain Rabin.

“I will carry that moment of silence with me for as long as I live,” Rabinovici says.

Then came a powerful earthquake on Mount Sinai — magnitude 6.9.

“We thus got clear signs from above that something is happening here.”

The next major advance was serendipitous, spurred by something happening in Germany. The Germans had a synchrotron-light source, and wanted to build a new and more powerful one.

Synchrotron radiation is a kind of side-effect of high-energy physics experiments that send particles spinning around a ring. These particle accelerators give off light in various wavelengths that “comes off like mud off a spinning tire,” says Herman Winick, a physicist at Stanford University and a pioneer in developing light sources. Mirrors and other devices can focus that light into a beam that can be used as a probe of matter.

(International Atomic Energy Agency)

Winick recalls asking German colleagues in 1997, “What are you going to do with the old machine?” The answer: “We’re going to call in a junkyard dealer and sell it for scrap.”

Winick says he persuaded the Germans to offer the machine, named Bessy, to scientists in the Middle East.

SESAME began to take shape as an organization. The project initially had nine full members: Israel, Iran, Jordan, Egypt, Turkey, Pakistan, Bahrain, Cyprus and the Palestinian Authority (Bahrain stopped paying dues and has dropped out). The United States, the European Union and a number of other countries became “observers,” without membership.

The project’s leaders decided in 2000 to put the facility in Jordan. (“It’s obvious that most of the people involved would not come to Israel,” Rabinovici said.) The next challenge would be persuading scientists in the region
that this would be a world-class ­facility.

“When I had first heard about it, I didn’t believe that it would work and I didn’t want to be involved in it,” Zehra Sayers, a Turkish scientist, said in an email to The Washington Post. “This was an old machine donated by Germany, probably it would not work properly when assembled in Jordan, and who was going to use it? Nobody in the Middle East even knew what a synchrotron meant.”

But the backers of the project assured her that the key elements would be rebuilt and modernized — they were — and she became a supporter. She’s now the chair of the scientific advisory committee, and intends to use the light source for a project to study how a protein in a bacterium latches on toiron.

More troubles lay ahead. The roof fell in during a snowstorm. Egypt’s support withered after the revolution of the Arab Spring. Rabinovici feared that the project was collapsing and went to the Finance Ministry of the Israeli government asking for a new infusion of money. The government pledged $5 million if other countries matched it. Turkey, Jordan and Iran then pledged the same amount each, although Iran so far has given only a fraction of its pledge, leaders of the project say.

The E.U. has also provided funds. Conspicuously, the United States has not, to the frustration of project leaders.

They suspect that one reason is the involvement of Iran. The scientists say that synchrotron technology has nothing to do with nuclear weapons.

In Congress, two physicists, Reps. Rush D. Holt (D-N.J.) and Bill Foster (D-Ill.), pushed for ­authorization of money for ­SESAME, but got nowhere.

“It’s a shame, an embarrassment, that the United States has not put, as far as I know, a dime into the SESAME project,” said Holt, who is now the chief executive of the American Association for the Advancement of Science.

“The suspicion is that, because Iran is a member, that’s a third rail that nobody wants to touch,” Winick said. “I am disappointed and embarrassed.”

SESAME is not quite ready for experimental research. The most essential hardware is in place, but the two beam lines of the light source won’t be ready for research efforts for another few months.

SESAME magnets spin particles and radiation “comes off like mud off a spinning tire.” (Dean Calma/International Atomic Energy Agency)

Gihan Kamel, an infrared beam line scientist from Egypt, works in a SESAME lab. (Dean Calma/International Atomic Energy Agency)

There ought to be many more beam lines for researchers, project leaders say. And among the immediate logistical challenges is the need for on-site lodging.

But the backers of SESAME are exultant.

Among those traveling to ­Jordan for the dedication ceremony this week will be Edward Witten, an acclaimed mathematician at the Institute for Advanced Study in Princeton — Albert Einstein’s old haunt. Witten says of ­SESAME, “It’s like news from another world in which there is peace in the Middle East.”

A thousand years ago, during Europe’s Dark Ages, the Islamic world was home to many of the greatest scientists on the planet. Today, many young scientists in the Middle East and in developing countries generally will go abroad, to the United States, ­Europe or Japan, to get advanced degrees, and many never return. SESAME could reverse that brain drain, the promoters hope.

Rabinovici said the key to ­SESAME’s existence is the persistence of the people who believed in it. He notes that mathematicians have a concept known as “an existence proof.” It’s a hypothesis proved to be true by the construction, and irrefutable existence, of the thing being hypothesized.

“I’m very persistent,” Rabinovici said. “It’s not always good in research. Sometimes in research you have to let go. Sometimes your old ideas, which you love, are wrong. But I am persistent, and I thought it was a very important thing — to show that such a thing is possible.”