Wally and Osborne aren’t morons, just a bit naive. It’s actually about 7,926 miles from the south pole to the north pole. If they could average five feet an hour they could be there in about 955 years. This is of course based on them maintaining that digging speed going through rock and metal as well as being burned up from the heat of the earth’s core (Actually little is known about the earth’s core but scientists speculate that it is made up of iron and nickel and reaches temperatures over 9000°F).