The detection of gravitational waves (GW) has been a remarkable breakthrough for many reasons, among them, the possibility of discarding or testing different theories describing gravity. Some of these new theories require the existence of additional dimensions to the standard 3D+1 of general relativity (GR). These extra dimensions are mainly required to give an alternative route to the dark matter and energy hypothesis, since gravity would leak into these additional dimensions, diminishing the amplitude of the GW signal observed. This would give an error in the inferred distance to the gravitational wave source predicted by GR. If true, it could account for the yet undetectable dark matter and energy, at the cost of challenging GR theory, since the existence of dark matter and dark energy results from assuming that GR is valid at all scales and distances.
The collision of two...
Why are some planets rocky and some gaseous? We may just be nearer to finding an answer through a new planet discovered by master’s student Merrin Peterson.
Have you ever wondered why the Earth is rocky and solid and planets like Jupiter and Neptune are gaseous? To add to the intrigue there are brown dwarfs which are neither planet or star, read more on brown dwarfs here.
So, what is it that classifies something as a planet and differentiates between rocky planets and gaseous planets?
Planets and stars are theorized to have formed in the collapsing dust of a nebulae, with the star forming in the centre of rotation and the planets forming in the corresponding disk. Obviously at the centre of rotation the angular momentum will be the greatest and the star will be experiencing significant energy production and emitting vast quantities of visible light. This is not the case for...
An experiment has confirmed that quantum mechanics allows events to occur with no definite causal order. The work has been carried out by Jacqui Romero, Fabio Costa and colleagues at the University of Queensland in Australia, who say that gaining a better understanding of this indefinite causal order could offer a route towards a theory that combines Einstein’s general theory of relativity with quantum mechanics
In classical physics – and everyday life – there is a strict causal relationship between consecutive events. If a second event (B) happens after a first event (A), for example, then Bcannot affect the outcome of A. This relationship, however, breaks down in quantum mechanics because the temporal spread of a particles’s wave function can be greater than the separation in time between A and B. This means that the causal order...
The seemingly random digits known as prime numbers are not nearly as scattershot as previously thought. A new analysis by Princeton University researchers has uncovered patterns in primes that are similar to those found in the positions of atoms inside certain crystal-like materials.
The researchers found a surprising similarity between the sequence of primes over long stretches of the number line and the pattern that results from shining X-rays on a material to reveal the inner arrangement of its atoms. The analysis could lead to predicting primes with high accuracy, said the researchers. The study was published Sept. 5 in the Journal of Statistical Mechanics: Theory and Experiment.
“There is much more order in prime numbers than ever previously discovered,” said Salvatore Torquato, Princeton’s Lewis Bernard Professor of Natural Sciences, professor of chemistry and the Princeton Institute...
That the human brain contains magnetite is well established; however, its spatial distribution in the brain has remained unknown. A new study shows that the reproducible magnetization patterns of magnetite is preferentially partitioned in the human brain, specifically in the cerebellum and brain stem.
In 1992 researchers identified the presence of magnetite—a permanently magnetic form of iron oxide—in human brain tissue. Iron in the body was no surprise. It is commonly found in ferritin, an intracellular protein common to several organisms, and the magnetite was thought to have formed biogenically, with some possibly originating in ferritin. But the presence of magnetite in the brain could be more than incidental. Various studies have shown that brain cells respond to external magnetic fields. There’s also a disturbing link to neurodegenerative disease: Evidence exists of elevated levels...
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...