Spread across two tables, this intricate series of marble physics tricks is the culmination of weeks of work by chain reaction YouTuber Kaplamino. Blue Marble 3 is based on their Blue Marble video from 2018, but levels up the complexity with a rotating track, a suspenseful slide, more magnets, rubber bands, a tape measure, lots of string work, a water trick, a fire catapult, and two air tricks powered by balloons. From the video notes:
The air loop is very fun. The two main challenges were first to inflate the balloon with exactly the amount of air it takes to make 3 turns of the loop, and then to push a plug into the balloon (a small magnet with exactly the right size by coincidence) with exactly the right strength to hold it well but not too much :p You can see big magnets everywhere to recover the plug and prevent it from blocking a track, it was pretty unpredictable to know where it was going to jump. I couldn’t put a large magnet too close because it could stop the two small magnets from getting closer or tear the cap off too soon.
File under: patience and practice. Also from Kaplamino: Blue Marble 2.