If Gas is the only state of matter where you can change the density with pressure, how can you pressurise liquids like water?

Question

I know that solids and liquids can’t change density without changing their molecular structure, so how do things like oil pressure and water pressure exist?

In: Physics

Answer 1

Think of the molecular forces like springs. Gas is a soft spring, water is a stiff spring, steel is a really stiff spring. 10 lbs of force is 10 lbs regardless which spring, the difference is just how much they move. Similar with pressure, if you put a liquid and gas and steel block in a tank and pressurize the gas, all 3 will be at roughly the same pressure, but the gas will change volume a lot, the liquid a little, and the steel the least, but they all do compress and they all “feel” the same pressure