Entropic force

In other words, thermal fluctuations tend to bring a system toward its macroscopic state of maximum entropy.

[5][7] The entropic force by a freely jointed chain has a clear mechanical origin and can be computed using constrained Lagrangian dynamics.

[8] With regards to biological polymers, there appears to be an intricate link between the entropic force and function.

Another related and counter-intuitive example of entropic force is protein folding, which is a spontaneous process and where hydrophobic effect also plays a role.

[11] Structures of water-soluble proteins typically have a core in which hydrophobic side chains are buried from water, which stabilizes the folded state.

[12] Charged and polar side chains are situated on the solvent-exposed surface where they interact with surrounding water molecules.

If the regions of reduced polymer density around two colloids overlap with one another, by means of the colloids approaching one another, the polymers in the system gain an additional free volume that is equal to the volume of the intersection of the reduced density regions.

The additional free volume causes an increase in the entropy of the polymers, and drives them to form locally dense-packed aggregates.

A similar effect occurs in sufficiently dense colloidal systems without polymers, where osmotic pressure also drives the local dense packing[17] of colloids into a diverse array of structures [18] that can be rationally designed by modifying the shape of the particles.

Matt Visser, professor of mathematics at Victoria University of Wellington, NZ in "Conservative Entropic Forces"[25] criticizes selected approaches but generally concludes: There is no reasonable doubt concerning the physical reality of entropic forces, and no reasonable doubt that classical (and semi-classical) general relativity is closely related to thermodynamics.

Based on the work of Jacobson, Thanu Padmanabhan, and others, there are also good reasons to suspect a thermodynamic interpretation of the fully relativistic Einstein equations might be possible.In 2009, Erik Verlinde argued that gravity can be explained as an entropic force.

[4] It claimed (similar to Jacobson's result) that gravity is a consequence of the "information associated with the positions of material bodies".

[4] In the wake of the discussion started by Verlinde, entropic explanations for other fundamental forces have been suggested,[25] including Coulomb's law.

[28] It was argued that causal entropic forces lead to spontaneous emergence of tool use and social cooperation.

A formal simultaneous connection between the mathematical structure of the discovered laws of nature, intelligence and the entropy-like measures of complexity was previously noted in 2000 by Andrei Soklakov[32][33] in the context of Occam's razor principle.