"The Core" has an interesting premise and a great scene in which an inventor is offered a check for $50 billion to get a craft that can travel to Earth's core built in 3 months. But when the ship runs into a huge crystal-lined "cavern" in the deep mantle, the plausibility meter hits zero.
If you think such a trip is completely impossible, think again. Read about the "modest proposal" of Prof David Stevenson (a kiwi) from Caltech (http://www.geotimes.org/july03/NN_core.html).
