The Demon of Physics Has Existed Since Ancient Times!

Last time, I touched upon the history of unraveling the famous 'Maxwell's Demon' in physics.

In short,
by incorporating information theory into the demon's work, the law of increasing entropy does not statistically collapse,
is the gist of it.

However, this is strictly a 'thought experiment,' and the demon does not exist in reality.

...Or so I thought, until I found an article claiming that Maxwell's Demon had been discovered. I would like to introduce it as a supplement this time.

In short,
the transport organs that mediate substances across cell membranes exhibit the same behavior as Maxwell's Demon,
is the story.

The substance with this transport function is called an 'ABC (ATP-binding cassette) transporter'. To supplement the ATP (adenosine triphosphate) in parentheses, it is like a pump that generates energy for life activities. Because of this role, it is sometimes compared to the 'energy currency of living organisms'.

The main role of ABC transporters is to take in or exclude necessary or unnecessary substances inside and outside the cell.

The diagram in the paper is easy to understand, so I will quote it as is.

Without worrying about the technical terms, let's compare this with the movements of Maxwell's Demon. I will repost the conceptual diagram of the demon's work used last time.

The demon is imagined as being at the boundary, acting maliciously to prevent the small rooms separated by the door from reaching equilibrium.

Similarly, when an ABC transporter finds a specific substance, it opens and closes its door (powered by ATP) to send it through, preventing the inside and outside of the cell membrane from reaching equilibrium (having similar components).

It is a bit detailed, but I will also include a diagram from the original paper that comparatively shows both. (Please ignore the technical terms...)

Surprisingly, it is known that these ABC transporters exist not only in our cell membranes (specifically, eukaryotic cells with nuclei) but also in the membranes of cells (prokaryotic cells without nuclei) that have existed since ancient times (it is estimated that cell-like things were born 1 billion years after the birth of the Earth).

Moreover, it is known that there are various types depending on the type of substance that identifies the opening and closing. To put it in terms of Japanese companies, it's like having various transport companies such as Sagawa Express and Japan Post, not just Yamato Transport.

Although it is still at the hypothesis stage in detail, if we assume it is correct, it is very interesting to get a glimpse of the driving force of our life phenomena.

There is a book called 'What is Life?' by Schrödinger, which is still considered a masterpiece in the world of life science.

It was groundbreaking in that it attempted to grasp life phenomena physically (reductionistically) for the first time, and there is an anecdote that many people were inspired by this to switch from physicists to biologists. (One of the discoverers of the DNA double helix is also from that lineage.)

Within this, there is the famous phrase,
“organisms feed on negative entropy”
.

In our previous discussion on the quest for demons, we understood that the work of generating energy (the demon's job) increases entropy, but looking solely at the results of that work, it truly appears to be an act of “feeding on negative entropy.”

I felt that the mysterious phenomenon of life itself, when broken down to the cellular level, might ultimately boil down to an act of resisting the flow of energy.

Furthermore, the cause that led to this energy reversal might just be the “origin of life” itself.