Final answer:
Without additional context, the correct altitude to fly if communication was lost after crossing OALDY cannot be determined. Standard lost communication procedures would apply. For the celestial pole altitude change, as one travels south, the altitude of the celestial pole in the sky would decrease.
Step-by-step explanation:
The question about what altitudes to fly if communication was lost after crossing OALDY appears to pertain to an aviation scenario, specifically about Instrument Flight Rules (IFR) and lost communication procedures.
However, there is insufficient context to provide an accurate altitude, as it depends on the airplane's flight plan, the assigned route, and the lost communication procedures outlined in the Aeronautical Information Manual (AIM) and Federal Aviation Regulations (FARs).
Usually, under lost communication procedures, a pilot follows the route and altitudes as assigned in the last clearance, the expected routing in case of radio failure, or the filed flight plan. If the scenario in this question is based on a real flight plan, the pilot should refer to their specific emergency procedures, IFR charts, and clearance to determine the correct course of action.
Concerning the second question about celestial pole altitude changes, as you drive south from your current location, the altitude of the celestial pole in the sky would decrease. The celestial pole appears to be at the zenith of the Earth's pole and lowers as one moves towards the equator, where it lies on the horizon.