How do really tall trees get water all the way up to their leaves? It seems impossible for water to go against gravity like that.

Tall trees manage to transport water all the way up to their leaves primarily through a mechanism called transpiration pull. Water continuously evaporates from the leaves through tiny pores called stomata – this process is transpiration. As water molecules evaporate, they create a "pull" or suction force, similar to drinking through a straw. This pull is transmitted downwards through the continuous column of water in the xylem vessels, drawing more water up from the roots. This column is maintained due to two properties of water: cohesion (water molecules sticking to each other) and adhesion (water molecules sticking to the walls of the xylem vessels). Root pressure also plays a minor role, but transpiration pull is the main driving force against gravity.