In Jules Verne’s classical science fiction tale Journey to the Center of the Earth, a group of scientists and adventurers descend deep into the interior of Earth. Among the equipment they carry with them is a rugged and carefully calibrated clock. Imagine a 21st-century update of this story in which colleagues on the surface of Earth possess an identical clock and remain in contact with the explorers throughout their descent via ground penetrating EM waves. As the journey unfolds, would the underground travelers notice any change in the rate at which their clock ticked from what they experienced at the start of their trip? What about those monitoring the expedition from Earth’s surface? Would they note any deviation in the rate of ticking of the subterranean clock relative to their own? If so, would the remote clock be seen to be running too slow? Too fast? Explain.