How do we know what's at the center of the earth?

Question

....If we've never been there?

Answer 1

Scientists "shoot" sound waves into the earth, by measuring the time it takes to get back, and where it slows down and speeds up, we can accurately predict the viscosity of the material in the center of the earth. Based on theories about how the earth formed and clues we have found in the earths crust we can guess that the earths core is probably molten metals under allot of pressure. Plate tectonics, volcanoes, and earthquakes also support this claim.

Answer 2

Seismic waves define the properties the material must have. meteorites tell us the common compositions of planetary materials. Iron-nickel meteorites are common yet have known observed equivalent. The properties of iron-nickel minerals are consistent with the properties identified at great depth, suggesting that the core is iron-nickel. Finally, the earth's magnetic field requires a dynamo for its production, and the characteristics of the field are consistent with its production from an iron-nickel core with a solid interior and liquid exterior. There are other reasons too, but they are more complicated to explain.

Answer 3

We know things like how waves travel through solids, liquids and gases. Also how waves travels through different densities of material differently. We also know the weight of the earth.
The connections are chapter long explanations so I suggest you read about earthquakes and how they give information about substances in the earth.

Answer 4

We have been there or very close, too close in
my opinion.

As you excavate to each lower level, there is a definite change in soil composition and temperature, and hot and cold.

This is how scientists can tell what has transpired over the earth's history.

On one job I was on, we excavated down to the glauconite layer (sp?). It was an old shark bed, in Nacogdoches, TX. It hasn't been underwater in a while....

Answer 5

I don't think we know. There is a book about the center of the earth.

Answer 6

seismic waves are used to study the composition of the earth's interior. the behavior of these waves during earthquakes indicate that the earth's center is composed of solid iron.

Answer 7

Brigit B is right there is evidence but a small and almost unusable amount unless you are a hyper genius. I am a nomal genius yet I cannot answer your question without guessing

Answer 8

Recordings of seismic waves from earthquakes gave the first clue. Seismic waves will bend and reflect at the interfaces between different materials.... (you can read more below)

Answer 9

Evidence, my friend! First there is volcanoes! They go very far down into the earth. Also the Theory of Techtonic Plates and Pangea and all that nonsense, supports what is in our earth's core.

Answer 10

Many tools are used to study it. No, we haven't been there because you'd disintegrate way before you got there, like going down an erupting volcano. Here's info. for you on it:
http://geology.about.com/od/core/a/about_the_core.htm
http://news.nationalgeographic.com/news/2005/08/0825_050825_earthcore.html
http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html