How the three domains of life (Archaea, Bacteria and Eukarya) evolved is still a matter of debate. One hypothesis, namely the domain cell theory (DCT), proposes that each of the three domains of life arose from a pre-existing ancestor. In this scenario each domain represents a unique and independent cellular lineage. Another hypothesis posits that Eukarya arose by a cellular fusion event between a bacterium and an archaeon. In their article published in BioEssays, James Staley and Gustavo Caetano-Anollés challenge this popular cell fusion hypothesis. Instead they propose an Archaea-first model and discuss evidence supporting the co-evolution of early archaeal lineages with emerging Bacteria and Eukarya.
Gamma-ray bursts are some of the highest-energy explosions ever detected, shining brighter than a million trillion times the output of Earth's sun, according to NASA.
A new study, published Aug. 13 in The Astrophysical Journal, has found that high-energy black hole gamma-ray bursts are time-reversed, meaning the brilliant light wave is spit out one way and then sent out again in the opposite order.
It is titled “Smoke and Mirrors,” but a new discovery from College of Charleston astrophysicist Jon Hakkila may be anything but smoke and mirrors.
Hakkila and student researchers have discovered a peculiarity in the light curves of gamma-ray bursts (GRBs) that may provide a breakthrough in understanding the conditions that produce these events. GRBs are the intrinsically brightest explosions known in the universe. They last from seconds to minutes, and originate during the formation of a black hole accompanying a beamed supernova or...
Gamma-rays have been observed emanating from the solar poles at a higher rate than expected.
Gamma-rays are the highest observed energy of electromagnetic radiation and are typically produced in energy transitions in atomic nuclei. Similar to photons of light being emitted as electrons reconfigure in atoms, photons of light are released in the reconfiguration of nuclei in an atomic nucleus, albeit at a much higher energy range!
Our star – the Sun – is a hot rotating ball of plasma continuously emitting radiation at a broad range of energies, from radio to gamma-rays.
Energy generation is greatest in the centre of the Sun, decreasing radially outward.
High energy radiation, such as gamma-rays, are thus thought to be due to the bombardment of the solar atmosphere by high velocity protons – hadronic cosmic rays. However, as the gamma-rays from such an interaction are assumed to be absorbed long before...
We are not living in the first universe. There were other universes, in other eons, before ours, a group of physicists has said. Like ours, these universes were full of black holes. And we can detect traces of those long-dead black holes in the cosmic microwave background (CMB) — the radioactive remnant of our universe's violent birth.
At least, that's the somewhat eccentric view of the group of theorists, including the prominent Oxford University mathematical physicist Roger Penrose (also an important Stephen Hawking collaborator). Penrose and his acolytes argue for a modified version of the Big Bang.
In Penrose and similarly-inclined physicists' history of space and time (which they call conformal cyclic cosmology, or CCC), universes bubble up, expand and die in sequence, with black holes from each leaving traces in the universes that follow. And in a new paper released Aug. 6 in the preprint journal arXiv—apparent...
A paper posted to arXiv last month claims to have achieved superconductivity at room temperature, but other physicists say the data may be incorrect.
When it comes to applied quantum mechanics, there are two “holy grails” in the field.
One is building a large scale quantum computer and the other is achieving superconductivity above the freezing point of water, colloquially known as room temperature superconductivity. Superconductors are materials that have no electrical resistance—meaning that electrons can flow through the object unimpeded—but so far physicists have only been able to achieve superconductivity by bringing the materials to incredibly cold temperatures. If superconductivity could be harnessed at room temperature, it would allow for the free transport of energy, wildly faster computers, and incredibly precise sensors. Indeed, it would fundamentally change the world.
In July, Dev Thapa and Anshu Pandey, two well-regarded chemical physicists from...
The discovery of buckyballs surprised and delighted chemists in the 1980s, nanotubes jazzed physicists in the 1990s, and graphene charged up materials scientists in the 2000s, but one nanoscale carbon structure – a negatively curved surface called a schwarzite – has eluded everyone. Until now.
UC Berkeley chemists have proved that three carbon structures recently created by scientists in South Korea and Japan are in fact the long-sought schwarzites, which researchers predict will have unique electrical and storage properties like those now being discovered in buckminsterfullerenes (buckyballs or fullerenes for short), nanotubes and graphene.
The new structures were built inside the pores of zeolites, crystalline forms of silicon dioxide – sand – more commonly used as water softeners in laundry detergents and to catalytically crack petroleum into gasoline. Called zeolite-templated carbons (ZTC), the structures were being investigated for possible interesting...
The infamous exotic state of matter - Bose Einstein Condensates – that allows scientists to observe the quantum world has now just been created in space!
In the normal world atoms are separate systems with clearly defined boundaries, however at temperatures nearing absolute zero all those boundary conditions come down and the individual atomic systems coalesce into one. This exotic state of matter is known as a Bose Einstein Condensate (BEC) and was named after physicists Satyendra Nath Bose and Albert Einstein whose work on groups of photons and bosonic atoms led to its prediction in 1924.
BECs are extremely interesting, as now you have an agglomeration of atoms coalesced into one entity such that it can be described by a wave function that is normally reserved for the quantum world.
The first realization of this exotic matter came in 1995 by Eric Cornell and Carl Wiemann when a...
Imaging Tool Flags New Proteins, Lipids and DNA to Track Metabolic Changes in Animals
Imaging tools like X-rays and MRI have revolutionized medicine by giving doctors a close up view of the brain and other vital organs in living, breathing people. Now, Columbia University researchers report a new way to zoom in at the tiniest scales to track changes within individual cells.
Described in Nature Communications, the tool combines a widely used chemical tracer, D2O, or heavy water, with a relatively new laser-imaging method called stimulated Raman scattering (SRS). The technique’s potential applications include helping surgeons quickly and precisely remove tumors, to helping to detect head injuries and developmental and metabolic disorders.
“We can use this technology to visualize metabolic activities in a wide range of animals,” said the study’s senior author Wei Min, a chemistry...
There has been a number of recent scientific discoveries about the Great Pyramids of Giza using technologically advanced methods. For instance, a methodology that utilizes measurements in the variation of flux from cosmic muons (heavy cousins of the electron)—called archaeological muography—detected evidence for a possible second entrance and hidden corridor in the Great Pyramid of Giza (the largest of the Pyramids of Giza). As well, thermal imaging have revealed perplexing thermal anomalies in the Great Pyramid. Several explanations were put forward to explain the cause of the anomalies, but one particularly suggestive explanation was that it is due to increased air circulation caused by a hidden corridor or chamber -- corroborating similar findings using muonic radiographic analysis.
General relativity tells us that light will be affected by gravity. This so-called bending of spacetime has now just been observed in the warped light of a star orbiting the Milky Way’s very own super massive black hole (SMBH) - Sagittarius A*.
The bending of light due to the presence of a massive object - where the massive object is blocking its path and refocusing it, like a lens – is known as gravitational lensing. The light will be traveling at a constant speed along curved space – the medium or path has therefore not changed, and so no energy is lost. However, if the photon of electromagnetic radiation moves away from the curved path then energy will be lost, and the wavelength will be increased – this is known as gravitational redshift.
Utilizing infrared observations made at the Very Large Telescope in Chile, astronomers were able to follow a group of high...