Back in 1963,Playboy foursome season 1 episode 2 when Stephen Hawking was 21 years old, doctors gave him two to five years to live after he was diagnosed with amyotrophic lateral sclerosis (ALS).

On Sunday, the world's most famous theoretical physicist turned 75 years old.

SEE ALSO: The 'Star Trek' cast and Stephen Hawking team up for the stuff of sci-fi dreams

The man has accomplished a lot in his life: groundbreaking research on black holes, a bestselling book, and continued support for ALS research and awareness.

It's no surprise that organizations like NASA decided to pay tribute to the great scientist.

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Near the Idaho-Oregon border, amateur scientists in a group called Near Space Education and Research (NEAR) launched a balloon into the stratosphere to celebrate Hawking's birthday.

Want some dramatic music to imagine flying through the cosmos? Spotify came up with a Stephen Hawking-themed playlist to mark his special day.

Plenty of other smart people decided to show him some love.

Despite the fact that Hawking is getting deeper into his 70s, he hasn't disappeared from the public eye. In 2014, he was the subject of the movie The Theory of Everything, which was nominated for an Academy Award for Best Picture. Over the last year, he made headlines for stressing the importance of space travel and joking with the Star Trek cast.

Happy birthday, Professor Hawking. You deserve all the praise in the universe.

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