Top 15 Paul Davies Quotes

[I]f you have a Maxwell demon or something like a Szilard engine in , could you use it, as Maxwell envisaged, to use information to extract energy from De Sitter space and... do... useful work? ...[Perhaps] only if you can create a region of the De Sitter space that is screened out from that horizon... from that thermal nature. If you put a reflective barrier around the demon, you then have De Sitter space, but with the horizon screened out. ...[T]hat's a problem I'm working on now ...

[P]article detectors in De Sitter space respond as if they are immersed in a bath of thermal radiation. However, the stress energy momentum tensor in De Sitter space is not that of thermal radiation. It's just a renormalization of the cosmological constant. So there's something a bit funny about the thermal nature of De Sitter space, and I've been interested in whether you can mine that thermal stuff...

I know of no theorem that tells you... the maximum amount of change that agency can achieve in the universe, and what interests me... is agency at the end of the universe. If you end up in , which has a temperature and a horizon entropy, can you do anything with... those thermal fluctuations? Can you mine them... to extract energy?

[C]osmological limits of agency... [W]hat's the best that the universe can do? There's about... 10¹⁰⁰k bits of free energy out there. What could be achieved? ... [Egyptian pyramids have] been achieved... Maybe... astro-engineering... [T]ake a galaxy that's rotating clockwise and make it rotate anti-clockwise? ...I suspect ...maybe yes. ...[T]urn the expanding universe into a contracting universe? ...I'm sure the answer is no.

We want to know the transition zone between this demonic cut... from just <nowiki>[</nowiki>Shannon] bits of information... to this more complex form of global, or contextual, or functional information. ...[H]azarding some guesses ...it might be a transition that would be measured by the integrated information, or... pathway complexity that Lee Cronin toyed with, or the breakdown of unitarity, if you think that this is associated in some way with the quantum classical transition.

[T]here is... not just [some] new physical law, but a new kind of physical law. ...[W]hat kind of physical law? ...[O]ne idea that Sarah Walker and I have flirted with is state-dependent laws of information. ...[T]ake chess as an analogy ...If you had a modified game of chess in which the rules ...could be updated according to the state of play ...this opens the way to new forms of complexity and new forms of configuration.

If ever you want an example of going from physics to biology, it's the origin of the .

[A]t what point does information, in the physics of matter, cease to just be a thermodynamic issue, and become much more of a control issue? ...[O]ne place ...is the . ...[H]ow did this come into existence?

I'm using this term demonic cut by analogy with the Cartesian cut...

[T]his is something that can't be defined locally. It's got to be defined globally, in the context of the system as a whole. ...[T]hat's a very difficult thing for physicists to cope with because we're used to formulating all our laws of physics as local laws, and not as global laws.

[A] is a set of instructions for ribosome to make a protein. If you look at the DNA sequence that codes for a gene, there's nothing that can tell you, at the sequence level, that if you look at a particular , that this is a bit of functional or coding or contextual information, and it's not just junk.

Information in life... amounts to much more than just playing the margins of the , and gaining some... energy advantage. ...I'm calling this a demonic cut. It's much more than just Shannon s at the thermodynamic level. Biological information is... contextual, or functional, or semantic. It depends upon the overall system.

It's now commonplace to have an informational term entering into the fundamental laws of physics as a source of free energy.

s are the way in which... you are thinking and paying attention, because the signals that travel between neurons, down the s, are controlled by the flow of s across the membranes of the axons... [T]hey are, in effect, little demons that sense the incoming signal and open and close the gates; and the ions flow. ...[T]his is so incredibly energy efficient that ...your brain, which is like a megawatt supercomputer, operates with the energy equivalent of a small light bulb.

Life was onto this... billions of years ago. Life uses many many nano-molecules... in effect, Maxwell demons. Our bodies are full of [them]... doing the business of life. ...not quite perfect ...but they're coming pretty close to the theoretical limit, in terms of energy expenditure.