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Co-stars, science leaders and fans pay tribute to "Star Trek's" Leonard Nimoy

Nimoy, best known for his role as Mr. Spock, died Friday at 83

CNN  — 

Since Friday, social media debates such as #thedress were silenced.

There was more sobering news. Leonard Nimoy, “Star Trek’s” beloved Mr. Spock, had died.

His co-stars, fellow celebrities and fans reacted with heartfelt tributes from around the world and all the way to space, where astronaut Terry W. Wirts flashed a Vulcan salute aboard the International Space Station.

As the weekend went on, billboards from the company Outfront Media (formerly CBS, owners of “Star Trek”) showed up around Atlanta.

Longtime friend and co-star William Shatner remembered Nimoy “like a brother.”

George Takei wrote, “Today, the world lost a great man, and I lost a great friend. We return you now to the stars, Leonard.”

And Zachary Quinto, who played Spock in the recent “Star Trek” movie reboots, said, “my heart is broken.”

The hashtag #LLAP, which stands for “Live long and prosper” and which Nimoy used to sign his tweets, was trending across several social media platforms after the news of his death.

The outpouring on Twitter and elsewhere left no doubt about Nimoy’s indelible mark on pop culture.

Nimoy’s career also inspired some of the most brilliant minds in space and science. NASA posted a 1979 photo of Nimoy and the “Star Trek” cast – some sporting ’70s leisure suits – visiting the space shuttle Enterprise.

And then there were the ordinary fans – Trekkies, aspiring actors and science geeks who related to Nimoy’s brainy Spock character – who posted personal messages and remembrances.

Nimoy in 2010: “I feel very fulfilled” with my work

Paul Roth, 39, chief information officer at Chesapeake Systems in Baltimore, posted a teary-eyed photo using the #LLAP hashtag.

“Leonard Nimoy showed a young, nerdy, bullied me that not only could science be important and valued, but it could literally save entire ships, planets, and galaxies of lives,” he said. “As I grew up, he taught me that reason could be tempered with humor. That learned adults still had more to learn. That feminism and opposing prejudice was vital. And that there is no age too late to reinvent yourself.”

Neil Macdonald from Widnes in the United Kingdom wrote on Instagram: “I have been and always shall be your friend.”

And, Molly Desormeaux, an acting student in Montreal, Quebec, said: “Leonard Nemoy is one of the reasons why I still believe that acting can change peoples’ lives.”

Nimoy: “Fringe” cast impressed me the most

We’ll give Nimoy himself the last word. The actor, filmmaker and author, who was an active user of Twitter up until his death, shared a final thought Monday that exemplifies the fleetingness and beauty of life.

CNN’s Daphne Sashin and Christina Zdanowicz contributed to this story.