If everyone on the plane jumped at the same time the plane would dip slightly and then return to normal flight. When everyone starts to jump they will push down on the plane to jump into the air. That extra downward force would push the aircraft down ever so slightly.
Herein, what would happen if everyone was the same?
If everyone was equal in every way, everyone would have the same thoughts, bodies, movements, tastes, preferences and so on. Any such thoughts would fade away with the onset of a mental interruption and they would return to the blissful ignorance of living in complete equality.
Subsequently, question is, does the earth move when we jump?
Even the hardest bedrock is somewhat elastic. This means that when you jump, you don't actually exert a force on the entire earth at once. Being elastic, the entire earth does not accelerate all at once away from you when you jump. Instead, you just deform a tiny bit of earth right under your feet.
What would happen if everyone on earth sneezed at the same time?
You may hear a tiny sound coming from the very loud sneezers. In large areas that echo, like malls or stadiums, you might hear a momentary loud sneezing sound. In stadiums, since many people are facing in the same direction there may be a small invisible cloud of particulates that would rapidly spread out and disperse.
What if Earth stopped spinning?
If the Earth stopped spinning suddenly, the atmosphere would still be in motion with the Earth's original 1100 mile per hour rotation speed at the equator. This means rocks, topsoil, trees, buildings, your pet dog, and so on, would be swept away into the atmosphere.