Psience Quest

Does new physics lurk inside living matter?

Paul Davies

Quote:The link between information and physics has been implicit since James Clerk Maxwell introduced his famous demon. Information is now emerging as a key concept to bridge physics and biology.

Quote:Maxwell conceived of his demon as a thought experiment, but advances in nanotechnology now permit experimental realizations of the basic idea (see the box). Yet life has been making and using varieties of demons for billions of years. Our bodies are replete with them.5 Molecular machines that copy DNA, transport cargo along fibers, or pump protons through cell membranes operate very close to the ideal thermodynamic limit. They play the margins of the second law to gain an energy advantage.6,7 The human brain uses in its wiring a type of demon—voltage-gated ion channels—to propagate electrical signals. Those ion channels enable the brain to run on the energy equivalent of a dim light bulb even though it has the power of a megawatt supercomputer.8

Quote:Amazingly, if those monsters are in turn chopped in two, they do not revert to the normal phenotype. Rather, the two-headed worms make more two-headed worms, and likewise with two-tailed worms. Despite all having identical DNA, the worms look like different species. The system’s morphological information must be getting stored in a distributed way in the truncated tissue and guiding the appropriate regeneration at the gene level. But how does that happen? Does an encrypted electrical code operate alongside the genetic code?

Quote:Life on the quantum edge

If biology deploys new physics, such as state-dependent dynamical rules, then at what point between simple molecules and living cells does it emerge? CA models may be instructive, but they are cartoons, not physics; they tell us nothing about where to look for new emergent phenomena. As it happens, standard physics already contains a familiar example of state-dependent dynamics: quantum mechanics...

I'd be curious what Davies means when he argues Information is physical....what does he mean by "physical"....

Quantum teleportation is even weirder than you think

Phillip Ball

Quote:A write-up of the work in Discover reports that the scientists “have successfully transmitted quantum entangled particles” — only to clarify, confusingly, that “unlike science fiction teleportation devices, nothing physical is being transported”.

But wait: didn’t someone once say information is physical? That was physicist Rolf Landauer3, a pioneer of information theory. So if you send nothing physical, how can you transmit anything at all from A to B?

This is one of the deep issues that quantum physicists and philosophers still argue about. We can debate whether ‘quantum teleportation’ as a term is a catchy way of conveying a scientific idea, or a misleading bit of hype. But the real question — what, exactly, is transmitted during quantum teleportation, and how — touches on issues much more profound.