The cost of forgetting the past

Post date: Aug 15, 2014 2:52:0 PM

Today I was interested in knowing what is the amount of energy required to forget our past.

This is connected to the amount of information the brain is able to store, which is roughly 2.5 petabytes, and the Landauer's principle, which says that the cost of erasing one bit is given exactly by E=k T ln(2).

A rough calculation shows that, at the temperature of the brain (circa 334 Kelvin), the energy needed to erase your brain is 4 10^{-20} Joules of energy per bit.

A petabyte is a million gigabytes, which is more or less 10^{16} bits. This implies that you need more or less a millijoule to erase your brain efficiently.