What If You Fell Through the Center of the Earth?

Imagine a world where you could dig a tunnel straight through the Earth. What would happen if you jumped in? Would you end up on the other side? Would you get stuck? Or would you burst into flames? Let's explore this fascinating thought experiment.

The Impossibility of a Through-Earth Tunnel

First, let's address the elephant in the room: creating a tunnel through the Earth is currently impossible. The deepest hole ever drilled, the Kola Superdeep Borehole, only scratched the surface, reaching a mere 0.3% of the way to the Earth's core. Our planet isn't a solid, uniform mass. It's composed of layers with varying densities, from solid to molten, making tunnel construction incredibly challenging.

The Earth's Layers

• Crust: The Earth's outermost layer.
• Mantle: A hot, dense layer.
• Outer Core: A liquid layer of iron and nickel.
• Inner Core: A solid iron core.

The Perils of the Plunge

Even if we could build this tunnel, jumping into it would be fatal for several reasons:

1. Extreme Heat

Temperatures increase dramatically as you descend. The Kola Superdeep Borehole encountered temperatures of 180 degrees Celsius (356 degrees Fahrenheit) at just 12 kilometers down. By the time you reach the mantle, temperatures soar to 1,000 degrees Celsius (1,800 degrees Fahrenheit) and beyond. Without advanced heat protection, you'd be incinerated long before reaching the center.

2. Crushing Pressure

Air pressure also increases rapidly. At the surface, we experience about 16 psi (pounds per square inch). If the air pressure in the tunnel increased at the same rate, you'd experience pressures exceeding 15,000 psi just 50 kilometers down. That's equivalent to the pressure at the bottom of the ocean.

3. The Coriolis Effect

The Earth's rotation introduces another challenge: the Coriolis effect. The surface of the Earth rotates faster than its deeper sections. As you fall, your trajectory would deviate from the tunnel's path, causing you to collide with the walls at high speed. To avoid this, the tunnel would need to be built along the Earth's axis of rotation (between the North and South Poles).

A Hypothetical Journey

Let's imagine a scenario where we have a stable, temperature-controlled, vacuum-sealed tunnel through the Earth. What would happen then?

Vacuum Advantage

A vacuum tunnel eliminates air resistance, allowing you to accelerate without reaching terminal velocity. You'd plummet towards the core, with your acceleration decreasing as you approach the center.

Speed and Weightlessness

Using calculations based on a spacesuit-clad human, you'd reach the Earth's center at a staggering 28,000 km/h (17,000 mph). At the center, you'd experience weightlessness as the Earth's mass pulls you equally in all directions.

Simple Harmonic Motion

As you pass the center, gravity would begin to pull you back. You'd slow down as you approach the other end of the tunnel, eventually coming to a complete stop at the same distance from the core as your starting point. This motion is known as simple harmonic motion.

Perpetual Oscillation

The journey from the center to the other end would take about 21 minutes, for a total trip time of approximately 42 minutes and 30 seconds. Without a way to stop yourself, you'd then fall back towards the center, oscillating through the Earth indefinitely.

Conclusion

While falling through the center of the Earth is a fascinating thought experiment, the reality is far more complex and dangerous. From extreme temperatures and pressures to the Coriolis effect, numerous obstacles stand in the way of a successful journey. So, for now, let's stick to exploring the Earth's surface.