How do people know what is the inner core of earth , when they have never been there ?

Question

How do scientists know what is inside the earths core. They say, its a hot bowl of lava, but how do they know when they have never been able to go there, because even metal ships or drills melt at that high temperature.

Answer 1

Seismic waves.

Sir Harold Jeffreys discovered the outer core was liquid when he saw that S-waves stopped and P-waves changed velocity at a certain point/boundary.

Inge Lehmann discovered that the inner core was solid when she saw that P-waves changed velocity once again at another boundary.

We can't go the the centre of the Earth but seismic waves can and we can measure those.

I solid inner core remains solid because the pressure is so intense it raised the melting point of iron dramatically.

Answer 2

Well, we know the earth is liquid rock underneath the crust due to the processes of plate tectonics, and you can see it happening where ever you see a volcano. Deeper into the earth, though we've never been there, physical laws show that the core of the earth is under such extreme temperatures and pressure that the "rocky" liquid is forced into a solid, simply because the pressure is too great for it to expand into a liquid, despite the temperature being so great. When you can't get instruments to where you want to go, you have to fall back on math and physics.

Answer 3

Earthquakes make waves, and the different layers of the earth speed up or slow down the waves based upon their density. Seismic stations can measure the speed of those waves, and we can see how they refract and reflect around the interior of the earth.

Some waves can't travel through liquid for example, so if you have an earthquake here in the USA, China wouldn't be able to pick up the waves from it since the liquid outer core of the earth blocks those waves from reaching the other side.

Answer 4

the seismic evidence, magnetic field behavior, and earth mass-density requirements (gravity imposed constraints) are complemented by meteor evidence. One of the major meteor types consists of iron-nickel minerals, so it is suspected that the earth consists in part of iron-nickel (other meteors match the components of crust and mantle). Density-temperature considerations require this part of the earth to be near its center (that is, experimental evidence and thermodynamic considerations are consistent with a metallic core).

Can't prove it without going there, of course, but not many alternatives make sense in light of all of the evidence.

Answer 5

the earths core make up is inferred from the magnetic field it generates.

Answer 6

thats because of joining the different thories and discoveries about earth's interior....

Answer 7

It's called SCIENCE,child.

Answer 8

we know about it's densities by radar, and things like that