Falling through the Earth

2. The scientific study of the nature and properties of matter and energy.
6. To swing back and forth with a steady, uninterrupted rhythm.
8. The measure how condensed an object is, found by dividing the mass by the volume.
9. In geology, Earth’s innermost layer. Or, a long, tube-like sample drilled down into ice, soil or rock.
10. The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.

1. The resistance that one surface or object encounters when moving over or through another material (such as a fluid or a gas).
3. Firm and stable in shape; not liquid or gaseous.
4. A celestial object that orbits a star, is big enough for gravity to have squashed it into a roundish ball and it must have cleared other objects out of the way in its orbital neighborhood.
5. The speed of something in a given direction.
7. A possible (or likely) sequence of events and how they might play out.
8. A slowing force exerted by air or other fluid surrounding a moving object.