Physics

Preparing the documents needed for an exam for a career advancement, to a scientist like me, is something like putting order in a messy garage. Leave alone my desk, which is indeed in a horrific messy state - papers stratified and thrown around with absolutely no ordering criterion, mixed with books I forgot I own and important documents I'd rather have reissued rather than searching for them myself. No, I am rather talking about my own scientific production - pubished articles that need to be put in ordered lists, conference talks that I forgot I have given and need to be cited in the…

Earth's magnetic field, a familiar directional indicator over long distances, is routinely probed in applications ranging from geology to archeology, and now it has provided the basis for a technique which could characterize the chemical composition of fluid mixtures in their native environments. Researchers from the Lawrence Berkeley National Laboratory conducted a proof-of-concept nuclear magnetic resonance experiment in which a mixture of hydrocarbons and water was analyzed using a high-sensitivity magnetometer and a magnetic field comparable to that of the Earth. NMR has been in use since…

My post of July 22 « BICEP2 Data, CMB B-modes, Inflation, Alternative Cosmologies... (II) » already discussed the situation after the publication (19 June 2014) of the Physical Review Letters 112, 241101 version of the BICEP2 article « Detection of B-Mode Polarization at Degree Angular Scales by BICEP2 ». It clearly appears that the possible existence of primordial B-modes in the polarization of the cosmic microwave background (CMB) radiation would not by itself be an evidence for cosmic inflation, as alternative cosmologies can also reproduce such an effect. Simultaneously to the BICEP2…

My post of July 22 « BICEP2 Data, CMB B-modes, Inflation, Alternative Cosmologies... (II) » already discussed the situation after the publication of the Physical Review Letters 112, 241101 version of the BICEP2 article « Detection of B-Mode Polarization at Degree Angular Scales by BICEP2 ». It clearly appears that the possible existence of primordial B-modes in the polarization of the cosmic microwave background (CMB) radiation would not by itself be an evidence for cosmic inflation, as alternative cosmologies can reproduce such an effect. Simultaneously to the BICEP2 announcement, a…

Can math be evidence? Not ordinarily, but recent calculations are compelling because they show that particles predicted by the theory of quark-gluon interactions but never observed are being produced in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC), located at Brookhaven National Laboratory. They just need to be detected. These heavy strange baryons, containing at least one strange quark, still cannot be observed directly, but instead are making their presence known by lowering the temperature at which other strange baryons "freeze out" from the quark-gluon plasma (QGP)…

Magnetic resonance imaging (MRI) is the medical application of nuclear magnetic resonance spectroscopy and a powerful diagnostic tool. It works by resonantly exciting hydrogen atoms and measuring the relaxation time -- different materials return to equilibrium at different rates; this is how contrast develops (i.e. between soft and hard tissue). By comparing the measurements to a known spectrum of relaxation times, medical professionals can determine whether the imaged tissue is muscle, bone, or even a cancerous growth. At its heart, MRI operates by quantum principles, and the underlying…

Although now widely accepted as the most natural explanation of the observed features of the universe around us, dark matter remains a highly mysterious entity to this day. There are literally dozens of possible candidates to explain its nature, wide-ranging in size from subnuclear particles all the way to primordial black holes and beyond. To particle physicists, it is of course natural to assume that dark matter IS a particle, which we have not detected yet. We have a hammer, and that looks like a nail. Indeed the searches for dark matter at collider experiments have flourished in recent…

There has been discussion among cosmologists about galileons, a hypothetical class of effective scalar fields which are extremely universal and arise generically in describing the short distance behavior of the new degrees of freedom introduced during the process of modifying gravity, and in describing the dynamics of extra dimensional brane worlds.  They might be able to explain dark matter - no cosmological constant needed. Despite prolific use of the term 'theory', they are math that hopes to become physics. Modified gravity and brane worlds are just some of the ideas that have been…

It is a well-known fact that given the availability of food, we eat far more than what would be healthy for our body. Obesity has become a plague in many countries, and the fact that it correlates very tightly with a decreased life expectancy is not a random chance but the demonstrated result of increased risk of life-threatening conditions connected with excess body fat. Yet we eat, and drink, and eat. We look like self-pleasing monkeys trained to press a button to self-administer a drug. To make matters worse, many of the foods and drinks we consume contain substances purposely added to…

A team of researchers has developed a technique to record the quantum mechanical behavior of an individual electron - contained within a nanoscale defect in diamond. Their technique uses ultrafast pulses of laser light both to control the defect's entire quantum state and observe how that single electron state changes over time.    This research contributes to the emerging science of quantum information processing, which demands that science leave behind the unambiguous universe of traditional binary logic—0 or 1—and embrace the counterintuitive quantum world, where behavior is…