Compressing water in liquid form is challenging due to its relatively high bulk modulus, which defines its resistance to compression. While water is compressible, it is less so compared to gases, and its density increases under pressure rather than decreases. The discussion highlights that water at greater depths, like in oceans, is denser due to the weight of the water above it. The conversation also touches on the nature of atomic spacing in liquids and the concept that compression involves forcing atoms closer together, raising questions about the space between them. Ultimately, the consensus is that while water can be compressed, it is not easily done, and its molecular structure plays a significant role in this process.