Why aren't we drilling for heat from the earth's core to use as an energy source?

In some places they are, sort of. In many places they tap into geothermal hotspots and use it to generate heat and power. But until we oil becomes too expensive (it's not yet) or we get oil men out of the white house then the US is all about oil.

It isn't endless for one thing. The earth's core is slowly cooling down. If we used the heat for energy it will speed up the cooling process causing large problems for the earth possibly even the end of the world.

Can you spell VOLCANO! We do not YET have materials that can take the heat and/or pressure to SAFELY tap the core, nor the mechanical knowledge to drill that deep. We have enough active volcanos NOW without drilling to make more if one gets away due to an error in drilling.

First, it is very difficult, if not impossible, to do so. Think of how deep the earth's core is. The deepest hole does not even exceed the earth's crust. There are several layers (all much thicker than the Earth's crust) beside the earth's crust to dig. Second, it would be very expensive: to start (hiring, planning, designing, etc.), to build(there is several thousand miles of earth to go) and to maintain (rusty pipes at sector 6, replacement needed). Third, we don't have the technology to harness geothermal energy efficiently. Fourth, there is competition. There are many more easy ways of getting energy. Think of how easy it is to cut trees and use them for our fuel needs; than digging miles and miles of earth, building a geothermal generator and deal with its inconveniences. I say , it is impractical.

The cost factor. The cost of recovering is more than the conventional energy sources.

have you watched The Core recently? ha, i think it would be a good idea in theory but in practice its probably ridiculously expensive and dangerous, if you think about it Volcanoes are outputs of the molten core yet no-one has tried to harness the energy from them so to dig down and make a man-made volcano would probably have too many unforeseen consequences. I think the big oil war thats going on is part of the reason as all the major oil companies are fighting hard to make sure they dont go out of business by making it hard for renewable resources to be easily accessed. I think i remember reading about cars that can run on vegetable oil for about 2pence per litre and how there was a big action/coverup by the big oil companies so that this would not become a reality until all their oil was bought and used up for obvious economic reasons.

What a GREAT idea, You are so smart!

ONE SIMPLE ANSWER: 1000€ / meter

Because it is molten...ie way too hot for our modern day technology to handle..there is no way we could capture it (think throwing an ant into a fire...the ant won't come out with bits of fire, it'll die). As well, it is not JUST heat, it is rock and as such, is not endless but makes up our planet (you wouldn't eat your guts when hungry would you?) Finally, burning rock isn't clean...if you have ever seen a volcano exploding, there are thick clouds of smoke sent up which include sulfur and other elements that are not healthy being sent into the environment. I agree we should be looking for clean, nearly endless sources of energy, but using our planet's core is not the answer.