Thread: Tunnel throgh the core of the Earth

hello, i had an idea wheather it could be possible to build a tunnel through the core of our planet from surface to surface. maybe its silly but maybe this topic would provoke you to think a bit over this even if its impossible

so the biggest problem is that what would withstand 6000°C and 350GPa pressure , the cooling of the tunnel, the tectonic movements and the mass flow in the inner of our planet...
the best refractory material i know is Ta4HfC5 with melting point 4215°C(and i think it raises with raising pressure), the strongest pressure withstanding material is probably carbon fibre(i dont know how thick should be the wall of the tunnel from carbon fibre at given internal diameter - if someone knows statics please calculate it)
cooling could be done in cascade, the central part of it could be cooled with some boiling metal, for example iron, at higher levels the condensing metal or any other material would heat up the next stage cooling medium, and this will cool also the wall of the tunnel, etc..., the cooling medium would be placed between an outer
frame tube and inner tube which will be the transportation shaft...

so before i am going to think about it further i need to have positive answer about the statics of the outer frame bearing the pressure

dont think if there is enuogh tantallum and hafnium on the earth for this, just think if it is possible anyhow with mankinds nowadays knowledge...

thank you for answers my mad friends

Getting through the crust alone would be a hell of a task. I think both America and Russia tried to dig down to the mantle at one stage. America got part of the way, wasted billions of dollars and then had to abandon it. Russia got a bit further, but they had to abandon the endeavour as well. I don't know whether newer technology would be any better, but I doubt it.

dont think about dollars, i know very well that a few kilometers are problem, think just about mankinds knowledge and materials available in the universe, dont think the economic side of the problem

Originally Posted by Incoming Dessert

Getting through the crust alone would be a hell of a task. I think both America and Russia tried to dig down to the mantle at one stage. America got part of the way, wasted billions of dollars and then had to abandon it. .

This is not strictly accurate. (In fact it's wrong.) Rather than wasting billions of dollars they spent a few million dollars confirming the feasibility of deep water drilling and coring. They retrieved the first samples of deep ocean floor below the surface sediments, establishing its basaltic composition, and they were technically ready to proceed with the next phase of the project when congress refused the funding. Other drilling continued and the subsequent programs that grew out of Project Moho have contributed enormously to Earth science over almost five decades.

do someone know how to calculate the g value inside the earth in different depth?

Originally Posted by dexterrius

do someone know how to calculate the g value inside the earth in different depth?

The gravitational field in side a sphere with density that is radially symmetric is just the field that goes with the material inside the sphere with radius corresponding to the point in question (i.e. you can ignore the material outside the radius in question). In particular the gravitational field at the center is 0.

what is the density of the middle of the core?

Originally Posted by John Galt

Originally Posted by Incoming Dessert

Getting through the crust alone would be a hell of a task. I think both America and Russia tried to dig down to the mantle at one stage. America got part of the way, wasted billions of dollars and then had to abandon it. .

This is not strictly accurate. (In fact it's wrong.) Rather than wasting billions of dollars they spent a few million dollars confirming the feasibility of deep water drilling and coring. They retrieved the first samples of deep ocean floor below the surface sediments, establishing its basaltic composition, and they were technically ready to proceed with the next phase of the project when congress refused the funding. Other drilling continued and the subsequent programs that grew out of Project Moho have contributed enormously to Earth science over almost five decades.

But the point still stands, they didn't reach the mantle