[CharlesWayneCT]

Something off my usual political focus; thought this was a cool technological breakthrough.

[CharlesWayneCT]

In college (which for me was back in the late 1970s), the hardest problem I remember having to work was a final exam question about wave propagation through solid rock.

So this has always fascinated me; I wish I could think of cool ideas like this, or Facebook. Using magnetic waves to communicate through solid rock.

Here's another link with only slightly more information: Emergency Communication System Reaches Mines

[null and void]

Good. This should be more reliable.