How do sciencists know what's inside of the Earth?

Answer 1

They don't know, but they can conclude it by making observations. They observe how the seismic waves change when they get to the center of the Earth, leading them to infer what the inside of the Earth looks like. For a more detailed explanation, go to [related links].

Answer 2

There is debate on exactly what it looks like and what it is made up of. Most are based on physical science theories and what we know of geology.

Imagine this. If we were to dig down far enough we would stop digging through rock and have reached molten lava. Lava near the surface is in veins like rivers and come out many places, like volcanoes. However below the solid rock we stand on there are whole lakes of lava. Below that are whole oceans of lava, until you go down far enough to the point were there is nothing but lava, now called Magma.

On average the solid crust of our planet is about 3 miles (in oceans) to 110 miles (mountains) thick and it floats on this magma like a boat on water. Below that is over 4000 miles of hot molten rock that acts like water (very thick hot water to be sure) to our crust.

We stand on solid rock that is just a shell that is only 1/40 of distance to center of the world. Picture a balloon. The skin is the ground you walk on and the air inside the Magma!

Gravity holds all this together. It was once thought that at the core was a super dense Solid Iron core. This may be true but strangely enough gravity would not form this (I.e., heavy iron sinking to core of planet. Our planet is very massive so on the surface it pulls you towards the core.

BUT at the core what happens is that all that mass that was pulling you down is NOW over your head pulling you UP! But it's all around you so now it is pulling you in every single direction. If you place a balloon at the center it would stay a perfect sphere. And if popped it would coat the inside like a pond in every direction you looked.

Considering just gravity then the center of the planet would have to be a hollow sphere. The size determined by the balance of the pull up and the pull down of all that mass.

However, because of heat and other factors there is a lot of pressure exerted (like when you go underwater the pressure increases). Is there enough pressure to overcome the gravity and collapse the hollow sphere I just described? Probably, so we are back to a solid core, but it is nowhere near as dense as first thought. And is probably made of layers of heavy and light elements that find balance somewhere between the core and the surface. Or at least is in the process of doing this.

Anyone - including you - can do this for any problem you come up with. It is the basis of scientific thinking. Scientists know more about the reasons why they accept one idea and reject others. But they too have to use "Thought Experiments" in order to find out what they do not know so they can devise other experiments that will tell them the answers.

Answer 3

Scientists have determined what the interior of the Earth is like through analyzing "seismic waves" caused by earthquakes.

Answer 4

Scientists use sound waves to detect what is inside earth. By sending waves down we can study not only the earths structure but also weather its liquid or solid

Answer 5

scientists dont know but they make observations , by the scismic waves changing .