Maryam Saeedi, an assistant professor of economics at Carnegie Mellon, is effectively trapped inside the US.

Under Trump’s immigration ban, which, among other things, restricts immigrants and visa holders from seven Muslim-majority countries from entering the US for 90 days, she and her husband — both Iranian academics and green card holders — have learned they may not be able to reenter the US if they leave.

“We’ve been living [here] for years,” she told Vox. “We are a productive part of this community — and now we’re banned. They just consider us to be terrorists.”

As rumors began to circulate last week that the immigration ban targeting Muslims might be coming down, Saeedi and a handful of Iranian colleagues started to mobilize. For researchers like them, who attend many international scientific conferences a year, restrictions on travel will take a heavy toll on crucial collaborations with other scientists from around the world, not to mention their personal lives.

The online petition they launched on Friday, where their peers in academia can voice their opposition to the ban, now has more than 7,000 names, including 40 Nobel laureates. It calls the executive order discriminatory and unduly burdensome for the people affected — but it also describes how much it will hurt “American leadership in higher education and research.”

It’s just one place researchers are pointing out the chilling effect the ban will have on the US economy — making recruitment and international research collaborations more difficult, barring highly-skilled workers and scholars from entering the country, and leaving those who are already here in limbo.

“This executive order will disrupt scientific research in America, plain and simple,” said Brittany Ulrich, a graduate student studying neurodegenerative diseases at UCLA. “The scientific community [here] thrives because of immigrants who want to be educated and work in American laboratories, and the field has always welcomed them.”

Ulrich has colleagues from the seven countries affected who she says are frightened, and she’s waiting to find out what this will mean for the new hires they were planning to make this year. “This ban is actively preventing cures for cancer, or Alzheimer's, all of these diseases that destroy lives,” she added.

Foreign researchers in limbo

With the executive order, Trump suspended all refugee admissions to the US for 120 days and Syrian refugee admissions program indefinitely. He also blocked immigrants and visa holders from Iraq, Iran, Syria, Libya, Yemen, Somalia, and Sudan from entering America for 90 days.

This left researchers who were in transit and those with visas permitting them to come and work in America in limbo — or worse. Dr. Seyed Saravi, an Iranian who was headed to Harvard for a cardiovascular pharmacology fellowship, told Vox he’s been stranded in Iran since last week. Going to Harvard has been a “childhood dream,” he said. But the US visa he had is now suspended for three months, and he has no idea what’ll happen next.

I was pretty excited to join @soumya_boston's lab but denied boarding due to my Iranian nationality. Feeling safer? — Samira Asgari (@samsam_86) January 28, 2017

There were many other examples of researchers who say their work or their labs has been thrown into chaos by Trump’s sudden ruling. Samira Asgari, a 30-year-old Iranian woman, was stopped in Switzerland just before boarding a flight to Boston for a post-doctoral fellowship in genomics at the Harvard-affiliated Brigham and Women’s Hospital. “A gentleman stopped me from boarding the plane,” she told Vox’s Sarah Kliff. “He told me he was a consulate of the American government in Frankfurt and not allowing anybody with a number of nationalities to board planes to the United States. They had already unloaded my luggage and everything.” For now, her US research plans are on hold.

Iranian postdoc with my group / @Princeton is at conference abroad; likely to be denied re-entry despite green card. Help? Please RT @Penn — Joshua B. Plotkin (@jplotkin) January 28, 2017

Because of uncertainties surrounding the immigration ban, the scientific conference circuit has also been thrown into disarray. Mehrdad Hariri, a Canadian-Iranian and president of the Canadian Science Policy Center, was planning to go to attend the American Association for the Advancement of Science meeting in Boston in February, as he’s done every year for the past nine years. But now he’s not sure if he’ll be allowed to enter because of his dual citizenship.

“The exchange of ideas, collaboration, networking between scientists of different countries is essential and vital for the advancement of science,” Hariri said. “When this is banned or diminished, it has a really drastic effect on scientific research. It’s a bad day for science in the US and globally.”

Abe Alahmad, a Syrian-French researcher and green-card holder at Texas Tech University, also had plans to attend a conference in Germany in April for his work on finding cures for stroke injuries. “I have been [in the US] for seven years. I have a spouse, children, and a mortgage. And I have an academic job here. So what will happen if I get rejected [to return to the US]?”

He’s also facing hugely difficult decisions in his personal life. “I have my parents in France and what happens if one of them die? If I cannot attend the funeral or be next to them on their [death] bed? Should I stay here or not have a chance to say goodbye to them if that happens?” For now, he has more questions than answers and he says he’s anxiously waiting news of what will happen next.

Other researchers told us they are considering cancelling conferences that were scheduled for the US: If attendees from the Muslim-majority countries affected by the ban won’t be able to come, they’ll need to find new venues. Or they’re dropping out of US-based conferences to stand in solidarity with the scientists who are now barred from entering America.

Immigration ban will have terrible consequences for US scientific meetings. Speakers unaffected by ban are dropping out in solidarity — Russ Poldrack (@russpoldrack) January 29, 2017

“I am reviewing my involvement with US conferences and US government agencies,” said Malcolm Macleod, a professor of neurology at the University of Edinburgh. “I feel very sympathetic towards my immediate US collaborators, but I would not wish to do anything to support what I think is a deeply immoral administration.”

The ban will make the US a less attractive destination for science

Trump’s policies are also making the US a less attractive place to do science, and driving talented researchers elsewhere, said Neo Mohsenvand, an Iranian PhD student at MIT. Like Saeedi and Alahmad, he and his colleagues from the affected countries feel stuck in the US until further notice. He said he has friends from Iran who were on track to get their work visas — and now they don’t know what to expect for their future.

So Mohsenvand and his peers are already looking for jobs in other countries — and exploring the possibility of returning home for good. “Even with all the problems that we have there, it is still more desirable than the US because we don’t know what else can happen here,” he said.

Saeedi, the petition organizer, has been having similar thoughts. While she’s hoping that the government will remove the immigration ban, she and her husband are also considering leaving the US. Her mother-in-law has cancer, and they had planned on bringing her to the US for treatment. But that doesn’t seem possible anymore and Saeedi doesn’t know when she’ll be able to visit Iran. “We cannot tell her, ‘We’ll see you in four or eight years when there’s a new president,’” she said.

“We don’t want to but if we are going to be under so much persecution for anything we do or don’t do — we will not be staying here. At some point you will think that you need to have your dignity you cannot be just continuing take more and more of [our rights].”

If you’re a researcher/doctor with a story about how your work has been affected by Trump’s sudden policy changes, email me at julia.belluz@vox.com