By way of Slash and the Beeb, someone over at CalTech has imagined to explore deeply into the Earth’s crust and mantel by embedding a robot probe in jacket of several million tonnes of molten iron. This iron would then be dropped into a fissure opened a nuclear weapon. Telemetry with the probe would be conducted by seismic waves. The researcher doesn’t really think the idea will work but wanted to spur others to think about novel ways to accomplish this. This is really neat!
Maybe, assuming the blob of iron idea doesn’t work, we could use a china syndrome effect. We could create this blob of radioactive materials at critical mass surrounding or leading a blob of molten iron. We’d have to figure out some way of continuously feeding radioactives into the critical mass to keep it from diffusing away from critical mass as it bleeds through the rock. We’d also have to keep feeding iron into the mixture to replace that which wears away. It’s a been a long time since, I’ve been a physics student but this idea really intrigues me.