Physics
Researchers have succeeded in embedding nearly perfect semiconductor crystals into a silicon nanowire. They say the new method of producing hybrid nanowires, very fast and multi-functional processing units, can be accommodated on a single chip in the future.
Nano-optoelectronics are considered the cornerstone of future chip technology, but the research faces major challenges: on the one hand, electronic components must be accommodated into smaller and smaller spaces. On the other hand, what are known as compound semiconductors are to be embedded into conventional materials. In contrast…
Earlier this week Science Magazine used the neck down image of a group of transgender women walking in the streets of Jakarta, Indonesia to highlight HIV/AIDS research. There is one good reason this image was offensive, an offense which was compounded by the insensitive remarks of one editor of Science. Someone who felt that the objectification and misogyny directed at these women was OK because they were born as men. Which can be taken to say what he may really think about women on a deep level. This is what is termed trans-misogyny (a primer by Julia…
It is now generally admitted that the BICEP2 Collaboration has not yet produced an evidence for the existence of primordial B-modes in the measured polarization of the cosmic microwave background (CMB) radiation. Contrary to the claim contained in the initial (March 2014) version of their article arXiv:1403.3985v1 and to the strong media coverage that followed this announcement, the Physical Review Letters 112, 241101 version (June 2014) explicitly recognizes that the experimental and phenomenological situation is not so simple. It is by now not excluded that the entire BICEP2 signal be…
A vacuum - empty space - is not as empty as one might think. In fact, empty space is a bubbling soup of various virtual particles popping in and out of existence – a phenomenon called "vacuum fluctuations". Usually, such extremely short-lived particles remain completely unnoticed, but in certain cases vacuum forces can have a measurable effect.
A team of researchers have proposed a method of amplifying these forces by several orders of magnitude using a transmission line, channeling virtual photons.
"Borrowing" Energy, but just for a Little While
If you park your car somewhere and…
Many new particles and other new physics signals claimed in the last twenty years were later proven to be spurious effects, due to background fluctuations or unknown sources of systematic error. The list is long, unfortunately - and longer than the list of particles and effects that were confirmed to be true by subsequent more detailed or more statistically-rich analysis.
Physicists have a strict criterion for claiming discovery of a new effect or signal: since the top quark discovery (which was obtained in 1995 by the CDF and DZERO experiments, following an "evidence" claimed by CDF on the…
As a consumer of science who is not a scientist how can you know if a theory is legitimate or simply crakcpottery. Here are some easy to understand signs that an alternative theory is legitimate science.
A blog about spam by Tommaso Dorigo ( The Spam Of Physicist Mailboxes ) got me thinking about this issue. How can one know if a theory which is less favored or "alternative" to the accepted "standard model(s)" is legitimate science? These points will apply to any area of science, but I know astronomy and astrophysics the best. So, I will use an example from that area…
Ultra-short X-ray flashes have enabled scientists to watch electrons jumping between the fragments of exploding molecules. The study reveals up to what distance a charge transfer between the two molecular fragments can occur, marking the limit of the molecular regime.
The technique used can show the dynamics of charge transfer in a wide range of molecular systems. Such mechanisms play a role in numerous chemical processes, including photosynthesis.
"The charge transfer takes place at up to approximately ten times the normal bond length," says Dr. Benjamin Erk, a DESY scientist working with…
Have physicists conquered the scaling behavior of exotic giant molecules?
When a two-body relation becomes a three-body relation, the behavior of the system changes. The basic physics of two interacting particles is well understood but the mathematical description of a three- or many-body system becomes so difficult that calculating the dynamics can blast the capacities of even modern super computers.
Under certain conditions, the quantum mechanical three-body problem may have a universal scaling solution and physicists from Heidelberg University say they have experimentally confirmed…
The U.S. Department of Energy has given the green light to the LUX-Zeplin (LZ) experiment, which wants to help figure out dark matter, an invisible substance that must make up a lot more of the universe than visible matter does. It is essentially a scientific placeholder because whatever it is should explain a number of important behaviors of the universe, including the structural integrity of galaxies.
LZ's approach posits that dark matter may be composed of Weakly Interacting Massive Particles – known as WIMPs – which pass through ordinary matter virtually undetected. The experiment…
A timely article discussing the hot topic of the production rate of pairs of vector bosons in proton-proton collisions has appeared on the Cornell arxiv yesterday. As you might know, both the ATLAS and CMS collaborations, who study the 8-TeV (and soon 13-TeV) proton-proton collisions delivered by the Large Hadron Collider at CERN, have recently reported an excess of events with two W bosons. The matter is discussed in a recent article here.
Those departures of WW cross sections from theory predictions are not extreme - one could well explain them away as a statistical fluctuation, or the…