Artículos con la etiqueta ‘General Physics (physics.gen-ph)’

Life Before Earth

Por • 26 dic, 2013 • Category: Ciencia y tecnología

An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide. The genetic complexity, roughly measured by the number of non-redundant functional nucleotides, is expected to have grown exponentially due to several positive feedback factors: gene cooperation, duplication of genes with their subsequent specialization, and emergence of novel functional niches associated with existing genes. Linear regression of genetic complexity on a log scale extrapolated back to just one base pair suggests the time of the origin of life 9.7 billion years ago. This cosmic time scale for the evolution of life has important consequences: life took ca. 5 billion years to reach the complexity of bacteria; the environments in which life originated and evolved to the prokaryote stage may have been quite different from those envisaged on Earth; there was no intelligent life in our universe prior to the origin of Earth, thus Earth could not have been deliberately seeded with life by intelligent aliens; Earth was seeded by panspermia; experimental replication of the origin of life from scratch may have to emulate many cumulative rare events; and the Drake equation for guesstimating the number of civilizations in the universe is likely wrong, as intelligent life has just begun appearing in our universe.

The quantum vacuum as the origin of the speed of light

Por • 3 mar, 2013 • Category: Crítica

We show that the vacuum permeability and permittivity may originate from the magnetization and the polarization of continuously appearing and disappearing fermion pairs. We then show that if we simply model the propagation of the photon in vacuum as a series of transient captures within these ephemeral pairs, we can derive a finite photon velocity. Requiring that this velocity is equal to the speed of light constrains our model of vacuum. Within this approach, the propagation of a photon is a statistical process at scales much larger than the Planck scale. Therefore we expect its time of flight to fluctuate. We propose an experimental test of this prediction.

The ontology of General Relativity

Por • 2 feb, 2013 • Category: Filosofía

I discuss the ontological assumptions and implications of General Relativity. I maintain that General Relativity is a theory about gravitational fields, not about space-time. The latter is a more basic ontological category, that emerges from physical relations among all existents. I also argue that there are no physical singularities in space-time. Singular space-time models do not belong to the ontology of the world: they are not things but concepts, i.e. defective solutions of Einstein’s field equations. I briefly discuss the actual implication of the so-called singularity theorems in General Relativity and some problems related to ontological assumptions of Quantum Gravity.

Quantum motor and future

Por • 23 ene, 2013 • Category: Ambiente

In a popular language, the possibilities of the Casimir expulsion effect are presented, which can be the basis of quantum motors. Such motors can be in the form of a special multilayer thin film with periodic and complex nanosized structures. Quantum motors of the type of the Casimir platforms can be the base of transportation, energy and many other systems in the future.

Adversus singularitates: The ontology of space-time singularities

Por • 10 oct, 2012 • Category: Filosofía

I argue that there are no physical singularities in space-time. Singular space-time models do not belong to the ontology of the world, because of a simple reason: they are concepts, defective solutions of Einstein’s field equations. I discuss the actual implication of the so-called singularity theorems. In remarking the confusion and fog that emerge from the reification of singularities I hope to contribute to a better understanding of the possibilities and limits of the theory of General Relativity.

A physical universe from the universe of codes

Por • 10 jun, 2012 • Category: Educacion

We investigate the most general phase space of configurations, consisting of the collection of all possible ways of assigning elementary attributes, «energies», to elementary positions, «cells». We discuss how this space defines a «universe» with a structure that can be approximately described by a quantum-relativistic physical scenario in three space dimensions. In particular, we discuss how the Heisenberg’s Uncertainty and the bound on the speed of light arise, and what kind of mechanics rules on this space.

The Missing Memristor: Novel Nanotechnology or rather new Case Study for the Philosophy and Sociology of Science?

Por • 30 may, 2012 • Category: Educacion

In 2008, it was widely announced that the missing memristor, a basic two-terminal electrical circuit element, had finally been discovered. The memristor is the fourth and last such circuit element and thus completes circuit theory. Predicted already in 1971, the eventual discovery of something seemingly so basic needed almost 40 years. However, this discovery is doubted. The predicted memristor has no material memory and is based on magnetic flux, but the discovered devices constitute analogue memory storage that do not involve magnetism. The person who originally proposed the memristor did not reject the discovery but instead changed his mind about what a memristor is. We briefly introduce the history and then carefully memristance and the memristor as such. We discuss its status as a model rather than a device. We discuss the discovered devices, their stability, and how stability relates to the consistency of the theoretical entities. A thought experiment assumes a world without magnetism. Inductors cannot exist there, but memory resistors could still be constructed. On the same grounds as the memristor was historically predicted, an «inductor» could then be predicted. Likely, somebody would also ‘discover’ one. A tentative sociological analysis compares to the flawed detection of gravitational waves but comes to very different conclusions.