Chapter 1: The Hypothetical Fall Through Earth

Have you ever wondered how long it would take to fall straight through the Earth? If you could disregard certain pesky physics and geological realities, such as temperature and pressure, the journey would take approximately 42 minutes and 12 seconds to reach the opposite side. This calculation assumes that you would survive the experience and avoid being crushed by the immense pressure at Earth's core, which is around 3.6 million atmospheres, and the scorching temperature that reaches about 10,800 degrees Fahrenheit (6,000 degrees Celsius)—similar to the surface of the sun.

Imagine this: as you descend, you would generate friction with the air, but this would only be a concern until the hole eventually collapsed under the extreme conditions. However, if we could magically eliminate these obstacles, the experience would be quite exhilarating.

Section 1.1: The Mechanics of Falling

As you dropped into the hole, you would initially accelerate. As you neared the center of the Earth, your acceleration would gradually decrease until you reached a state of weightlessness while traveling at around 17,700 miles per hour (28,485 kilometers per hour).

Once you passed the center, you would begin to decelerate as you approached the exit on the other side. Without a method to halt your journey, you would find yourself bouncing back through the hole, akin to a mass on a spring due to gravitational pull, following Hooke’s Law. The entire round trip would take approximately 84.5 minutes.

Subsection 1.1.1: The Challenges of the Descent

However, there are additional complexities to consider in this thought experiment. Your momentum would cause you to rebound off the sides of the hole, resulting in rapid oscillations. To avoid being crushed against the walls, you'd need to be exceptionally elastic while traversing this imaginary tunnel.

As you continued on this wild journey, the oscillations would intensify in frequency, and upon exiting, you would be propelled at an astonishing speed of 930 meters per second or Mach 2.7. Now that would be a thrilling ride!

Chapter 2: The Deepest Human Endeavor

In the quest to understand our planet, scientists have attempted to dig deeper than ever before. The Soviet Union’s ambitious project to drill into the Earth's crust lasted 24 years, achieving a depth unmatched in history.

For those eager to learn more intriguing facts about Earth's depths, check out Knowledge Stew’s Fact World on Medium.