A YouTuber visits Mark Robert, a famous American YouTuber with 26 million subscribers, in his secret lair in San Francisco. Mark has worked at NASA and holds several Guinness records, including the largest gelatin pool and Nerf gun. The visitor tries out some of Mark's incredible inventions, such as a self-playing piano, a secret door hidden behind a soda machine, a flamethrower, a giant air bazooka, and a tennis ball cannon. Mark's office is filled with 3D printers, and his team is constantly working on new projects. The visitor also meets Mark's team and sees the museum of his past projects, including the glitter bomb. At the end, Mark shows the visitor previews of his upcoming videos, and the visitor encourages his own viewers to subscribe to Mark's channel.
Here are the key facts extracted from the text:
1. Mark Robert is an American YouTuber who worked at NASA.
2. Mark Robert has 26 million subscribers.
3. Mark Robert's videos have hundreds of millions of views.
4. Mark Robert made the largest gelatin pool in the world.
5. Mark Robert holds the Guinness record for making the largest Nerf gun in the world.
6. Mark Robert also holds the Guinness record for making the largest elephant pasta explosion in the world.
7. Mark Robert has a secret lair in San Francisco.
8. Mark Robert's office has a secret door that requires a specific code to enter.
9. Mark Robert has created a piano that can play by itself and even speak.
10. Mark Robert has a giant arcade machine with a secret hiding place.
11. Mark Robert has a fireman's piston that allows people to slide down from the second floor.
12. Mark Robert has a giant air bazooka that shoots smoke.
13. Mark Robert has a tennis ball cannon with a target and a briefcase with $10,000.
14. Mark Robert has a museum of his most important products, including fake boxes with glitter bombs.
15. Mark Robert has a Guinness record for making the tallest fountain of elephant pasta in the world.
16. Mark Robert has a Guinness record for making a domino effect with 6141 domino pieces stacked in one hour by a robot.
17. Mark Robert has a dartboard with a strange mechanism that makes darts automatically fall on the red dot.
18. Mark Robert has a foam pool with wheels that can be moved wherever you want.
19. Mark Robert's office has 20 3D printers working at the same time.
20. Mark Robert's bathroom has a magnetic contact switch that locks the door if the toilet seat is raised.