Earth is a sphere, so if you start digging in the Northern Hemisphere, then you’ve got to end up in the Southern Hemisphere. China is far away, but it’s also in the Northern Hemisphere.

With such immense speed, you completely overshoot earth’s center. As you travel through the far end of the hole, gravity is now in the opposite direction and slows you down. You are slowed down to zero speed just as you emerge from the hole on the other side of the world.

The question we had was, what would happen if you dug a hole all the way through the earth(from one side to the other, right through the middle) and dropped an object into the hole? The answer is as follows. So the stone would keep on moving, going straight on up the other side of the hole, towards China.

The deepest hole by far is one on the Kola Peninsula in Russia near Murmansk, referred to as the “Kola well.” It was drilled for research purposes beginning in 1970. After five years, the Kola well had reached 7km (about 23,000ft).

The Kola Superdeep Borehole was just 9 inches in diameter, but at 40,230 feet (12,262 meters) reigns as the deepest hole. It took almost 20 years to reach that 7.5-mile depth—only half the distance or less to the mantle.

Drilling To The Mantle Of The Earth Fifty years ago, scientists attempted to drill deep through ocean crust to the Earth’s mantle, an endeavor called “Project Mohole.” That project failed, but scientists are sharpening their drill bits again.

When the molten outer core cools and becomes solid, a very long time in the future, the Earth’s magnetic field will disappear. When that happens, compasses will stop pointing north, birds will not know where to fly when they migrate, and the Earth’s atmosphere will disappear.

Convergent boundaries

Identification of the oldest preserved pieces of Earth’s crust in southern Greenland has provided evidence of active plate tectonics as early as 3.8 billion years ago, according to a report by an international team of geoscientists in Science magazine.