If we can't tunnel through the Earth, how do we know what's at its center?

Answer 1

First, scientists are pretty sure the Earth's core is about 80 percent iron. How they know that is a series of educated guesses.

For starters, they can be reasonably sure of the planet's mass based on its gravitational pull. The material on the surface isn't dense enough to match up with that mass, so the rest of the Earth has to be much denser.

Iron, meanwhile, is one of the most prevalent elements in the universe, but it isn't all that evident in the Earth's crust. Since scientists would expect more iron to be in our planet and it's a fairly dense element, that leads to the conclusion that the Earth's core is mostly iron. They theorize that it was pulled to the core over millions of years. By examining different seismic waves, they know that the inner part of the core is solid and the outer core is molten.

It's a lot more scientific than I've made it sound, but hopefully that gets at the gist of it.

Answer 2

First, scientists are pretty sure the Earth's core is about 80 percent iron. How they know that is a series of educated guesses.

For starters, they can be reasonably sure of the planet's mass based on its gravitational pull. The material on the surface isn't dense enough to match up with that mass, so the rest of the Earth has to be much denser.

Iron, meanwhile, is one of the most prevalent elements in the universe, but it isn't all that evident in the Earth's crust. Since scientists would expect more iron to be in our planet and it's a fairly dense element, that leads to the conclusion that the Earth's core is mostly iron. They theorize that it was pulled to the core over millions of years. By examining different seismic waves, they know that the inner part of the core is solid and the outer core is molten.

It's a lot more scientific than I've made it sound, but hopefully that gets at the gist of it.

Answer 3

its mainly extremely hot solid iron. the reason it is solid because of the immense pressure of everything on top of it and since liquid iron takes up more volume than solid it gets squished down. the reason we think it is mostly iron is bc it is a dense element and as were taught when young things that are more dense sink

Answer 4

A tunnel, dug from one side of the Earth to the other would be, on average, 12,742 km. So it's a shorter trip, sure, but that's not the best part.

If you jumped into the tunnel, you'd fall down towards the center of the Earth, accelerating constantly, thanks to gravity. By the time you reached the halfway point, after falling for 21 minutes, you'd be traveling at 28,000 kilometers per hour.

Answer 5

Through a lot of guessing theories and volvcanic activity we are pretty sure about the layers of the earth though it doesn't neccessarilly have to be 100% accurate cause it is mostly based of of theories. and yes of course volcanic and tectonic activity too did help us define the leayers

Answer 6

What would happen if you fell through a tunnel through the earth?

If you jumped into the tunnel, you'd fall down towards the center of the Earth, accelerating constantly, thanks to gravity. By the time you reached the halfway point, after falling for 21 minutes, you'd be traveling at 28,000 kilometers per hour.

Answer 7

Due to the physical signs earth gives off for one such as our magnetic field is due to liquid iron rotation at our core. Also g.p.r. ( ground penetrating radar ) is used to determine what something is made of. Not to mention gravity has a tendency to draw heavier material down towards the center of the earth. Thats also a reason people think the moon is hollow. Due to the density being far different than earths. Although its only different than most of earth. So when the earth was forming and it pulled all the heavier elements towards its center a collision happened and the material that was ejected and collected to form the moon was the outer layer of earth which is less dense than the center of earth or most of the other layers of earth. Also if you jumped in a hole that went through to the other side of earth which by the way is impossible due to the liquid core but if we could you would end up plastered on the side of the wall due to the different speeds at which the different layers of earth spin like a running track, the outside lanes are longest which needs to move faster than the inside lanes. But if you drilled the hole from pole to pole you wouldn't have that problem. You wouldn't make it to the other side though unless both sides where equal length from surface to center due to gravity pulling you down towards the center after passing the midpoint of the earth. So even if the hole was one mile deeper opposite the side you jumped you wouldn't make it to the other side. That and other factors such as heat and pressure and friction getting thicker the closer you get to the center.

Answer 8

It is a subtle reading of P, S& T waves that pass through the Earth, when there is say an earthquake.

Answer 9

For the same reasons we know if we flew into the sun we would burn up and die way before we got there.

Answer 10

Nobody knows perfectly but scientists have got a clue from the modern instruments they use to pass some radiations below earth