In information theory, Landauer's principle argues that energy has to be expended to erase information. This principle was put forward in the 1960s by German-born American physicist Rolf Landauer.
Landauer’s principle, said another way, argues that in order to erase one bit of information, we need to increase the entropy of the environment by at least as much. In other words we need to dissipate at least one bit of heat into the environment (which is just equal to the bit of entropy times the temperature of the environment). [2]
In 1961, through some demonstrations, Landauer argued that when information is lost in an “irreversible circuit”, i.e. a circuit whose inputs cannot be reconstructed from its outputs, the information becomes entropy and an associated amount of energy is dissipated as heat.
Some have reasoned that this principle links thermodynamics with information theory. [1]
A 2011 paper by Vlatko Vedral argues that in quantum physics or quantum mechanics, one can, in fact, erase information and cool the environment at the same time and that this, in some way, “flout the second law”, owing to a relation between entanglement and negative entropy. [2]
References
1. Daintith, John. (2005). Oxford Dictionary of Science (5th ed.). Oxford: Oxford University Press.
2. Vedral, Vlatko. (2011). “Does Quantum Mechanics Flout the Laws of Thermodynamics”, Scientific American, Guest Blog, Jun 01.
Further reading
● Thims, Libb. (2012). “Thermodynamics ≠ Information Theory: Science’s Greatest Sokal Affair” (url), Journal of Human Thermodynamics, 8(1): 1-120, Dec 19.
External links
● Landauer’s principle – Wikipedia.
