So maybe you’ve heard this before, but just in case you haven’t, here’s a myth that needs to be debunked. This has been brought to my attention before and I didn’t think anyone would actually believe in it, but apparently some people still do.

So without further ado, maybe you’ve heard of the idea of a billion Chinese people jumping simultaneously and knocking the Earth out of its orbit and causing mass destruction. Or maybe you’ve heard of World Jump Day, designed to get everyone in the world to jump at once and “stop global warming, extend daytime hours and create a more homogeneous climate.” Both ideas are equally ludicrous and can be debunked in the same way. Therefore, we’re going to debunk World Jump Day because there’s more people involved.

Could this be expected to happen?

Let’s try some physics.

First, some very unreasonable and unlikely assumptions:

• Everyone in the world is participating in the jump.
• Everyone is jumping at the same time (in reality, the difference between the fastest clock in the world and the slowest clock in the world is probably large).
• Everyone is jumping in the same region (or else the jump would cancel out).

J’accuse! Mon Jumps are being canceled out by those vile New Zealanders!

 

Now that we’re naturally assuming everyone is jumping correctly and we’re getting the full 6,783,557,000 people in on it, we can try to figure out just what kind of impact they’re going to have.

6,783,557,000 people sure sounds like a lot, but as we’ve investigated before, the Earth is very big. Like 5.9742×10²⁴kg big. Like take the average school bus. Now somehow find a stack of one billion school buses. I’ll wait…

Not entirely relevant, but still freaky to look at.

 

Okay. So how much does one billion school buses weigh? A lot. But the Earth has still got you beat. The Earth weighs 500 billion times more.

So let’s start adding up the force of the world population. Let’s assume an average weight of 70kg, which is probably above average but we don’t know just how much obesity has set in yet. Now given our other estimate for population, and assuming ridiculously that everyone is jumping and everyone is jumping correctly and perfectly simultaneously — we have 474,848,990,000kg in the air.

Let’s go back to the school buses. Get a group of a billion school buses again. Maybe you can reuse your old one. Anyways, how many groups do you need to add up to the mass of people in the air? You actually don’t even need one full group of a billion school buses. You don’t even need half a group. 48% of one group will do. The Earth just pwn’d you with science.

We always knew the Earth was kind of a jerk.

 

But how much distance is the Earth going to move? Even with the Earth being much larger, the massive amount of people must produce some distance, right? Well, the average person jumps about fifty centimeters. That means when they hit the Earth, the Earth is going to move the same distance proportional to its increased mass. Since the Earth is 12 trillion times more massive, the Earth will move 12 trillion times less the distance. That’s a total of .000000000004cm, or 1/750th of an atom’s radius. Which is also known as not much.

So in the end it’s like a flea jumping on your head and excepting you to reach escape velocity. …Not going to happen.

 

But that’s not all!
Even with the fact that the Earth won’t even budge with the combined force of humanity, there’s another portion that we forgot to calculate for. Newton’s Third Law of Motion — for every action, there’s an equal and opposite reaction. The way it works is that when all of humanity jumps up, the Earth is pushed down with an equal force. When humanity hits the Earth on it’s way down, the Earth is pushed up with an equal force. It all turns out to be zero.

Newton… also a jerk.

 

The fundamental problem is that humanity is gravitationally bound to the Earth and is part of it’s mass. Moving the Earth by mass jumping is a lot like mounting a giant fan on a sailboat, pointing the fan at the sail, and expecting the boat to move forwards. You’re not going to go anywhere.

It’s also like bending over, grabbing your shoes and expecting to pull yourself into the air and fly away. It doesn’t work because as you pull up on your shoes, your shoes pull down on you by the same amount. You won’t go flying around, no matter how much you saw Wile E. Coyote do it on TV. You’re fundamentally attached to your shoes, just like we’re attached to the Earth.

It’s not working!