#SummerScienceFriday | The Entropy of Moving Out!


Last week, as calendars were being flipped to August, CWH was busy moving out of our long-time offices in the Metropolitan Water District building and into new (much smaller) spaces. Although we are still settling in, Council for Watershed Health is now calling WeWork offices in Pasadena and DTLA home. For those who haven’t heard, WeWork is a company that provides hip, shared, community-oriented office space to small startups and organizations. CWH is new to this whole concept but we’re very excited to be here and a part of a new community!




Now, you may be wondering, “how is the move announcement related to #SummerScienceFridays?”


The answer is entropy!


Entropy is a term used in chemistry and physics. Put simply, entropy is a measure of disorder in a system, or how energy is distributed in a system. This idea is very important for understanding how our world works, for example, the reason ice melts, tires leak air, and cream disperses in coffee is because of entropy (1)!


Understanding Entropy

All matter is composed of atoms which are connected by chemical bonds that hold energy.  Let’s start by imagining two identical boxes. These boxes are composed of chemical bonds with the same amount of energy, but the energy is distributed differently in each box’s chemical bonds. With different distribution of energy, the boxes have different entropy levels. Energy will typically try to spread out as much as possible, increasing “disorder,” resulting in higher levels of entropy. Therefore, the box with more dispersed energy has higher entropy. Energy is always pushing to become more and more spread out and disordered, with increasing complication.


DeviantArt and Nespresso



Which has higher entropy: a glass of water or a glass of ice? After watching the video below, make an educated guess and then keep reading for the answer!


Entropy: The Reason Time Doesn't Flow Backwards


The concept of entropy can be applied to landscape evolution and in watersheds, too (2). Gravity is the largest force acting upon water in a river, causing water to flow from high elevation to lower elevations. As rivers flow, some gravitational energy is converted to kinetic energy and the water moves downward. The energy of water in the river is striving to become “uniformly distributed” or spread out to reach equilibrium. This tendency influences the path of least resistance that water takes (2). Once at lower elevations and with proper conditions, water can finally spread out and can sometimes result in a landscape feature called an alluvial fan.



Alluvial fans are formed as water spreads, taking many different paths and dispersing on the land. To apply the concept of entropy, an alluvial fan can act as evidence of energy distributing itself, becoming more disorderly and spread out. Watch this video for an illustration of how energy is dispersed in the formation of an alluvial fan!


The Formation of an Alluvial Fan