A so-called “jumping gene” that researchers long considered either genetic junk or a pernicious parasite is actually a critical regulator of the first stages of embryonic development, according to a new study in mice led by UC San Francisco scientists and published June 21, 2018 in Cell.
Only about 1 percent of the human genome encodes proteins, and researchers have long debated what the other 99 percent is good for. Many of these non–protein coding regions are known to contain important regulatory elements that orchestrate gene activity, but others are thought to be evolutionary garbage that is just too much trouble for the genome to clean up.
For example, fully half of our DNA is made up of “transposable elements,” or “transposons,” virus-like genetic material that has the special ability of duplicating and reinserting itself in different locations in the genome, which has led researchers to dub them genetic parasites. Over the course...
Experiments by Sam Dillavou and Shmuel Rubinstein at Harvard University have, for the first time, revealed that the friction between two surfaces has a “memory”. This means that the force can depend not only on the present state of the interface but also on how the interface has reached its current state.
This new insight could have a bearing on how physicists characterize friction in materials such as rock, metals and paper and apply to a wide range of physical systems from micromachines to earthquakes.
The amount of friction generated by two surfaces is directly related to their contact area. Microscopic irregularities in the surfaces are gradually flattened as time progresses, increasing the contact area and therefore increasing friction.
Under these conditions, the contact area, and thus friction, increases logarithmically with time in a process known as ageing. “The observed behaviour is...
The latest supernovae survey reveals the crucial importance in furthering our understanding of supernovae and reaching confident conclusions as soon as possible.
The standard theory of stellar evolution results in an explosion and is revealed in a rare and beautiful astronomical event. Astronomers search for these events in the hope that they will provide greater insight into our understanding of stellar evolution. Although each supernovae event is different, specific stars will yield certain characteristics. One type of Supernovae event that is of particular interest is the type associated with a binary star system in which one of the components is a white dwarf – this is known as a Type 1a supernova. White dwarfs are extremely dense stars that have exhausted all their hydrogen and their extreme density is thus a result of them not being able to support the inward pull of gravity...
The scientific collaborations LIGO and Virgo have detected gravitational waves from the fusion of two black holes, inaugurating a new era in the study of the cosmos. But what if those ripples of space-time were not produced by black holes, but by other exotic objects? A team of European physicists suggest an alternative—wormholes that can be traversed to appear in another universe.
Scientists have deduced the existence of black holes from a multitude of experiments, theoretical models and indirect observations such as the recent LIGO detections, which are believed to originate from the collision of two of these dark gravitational monsters.
But there is a problem with black holes—they present an edge, called an event horizon, from which nothing can escape. This is in conflict with quantum mechanics, whose postulates ensure that information is always preserved, not lost.
One of the theoretical ways to deal with this conflict...
The rotation speed – spin rate – of Saturn was previously found through observations of its magnetic field. Now, scientists have determined the spin rate through ripples in its rings!
NASA's twin voyager probes, launched over 40 years ago, observed the swirling magnetic field of Saturn, from which it was able to deduce a rotation period for the magnetic field and conclude a spin rate of 10 hours and 40 minutes. During this mission, in the 1980’s, the ring system was observed in great detail revealing the gravitational effects of Saturn’s moons on the rock and ice particles in the rings. When the particles and moons orbit at simple ratios of each other, the particles are periodically kicked by the moons. These kicks, known as orbital resonance, can launch waves that propagate away from the planet – with some anomalous “backwards” waves.
Detailed observations of these waves have been made, since 2000,...
The "Back to the Future" time machine runs on an imaginary flux capacitor but could the movie invention become reality?
In the popular movie franchise Back to the Future, an eccentric scientist creates a time machine that runs on a flux capacitor.
Now a group of actual physicists from Australia (RMIT University, University of Queensland) and Switzerland (ETH Zurich) have proposed a similar device that can break time-reversal symmetry.
While their flux capacitor doesn’t enable time travel, it’s a critical step in future technologies like the quantum computer and could lead to better electronics for mobile phones and wifi.
The research, published in Physical Review Letters, proposes a new generation of electronic circulators - devices that control the direction in which microwave signals move.
RMIT’s Professor Jared Cole said the device proposed in the research was built from a superconductor, in which electricity can flow without electrical...
For decades physicist Nassim Haramein has been expounding a controversial idea in astrophysics—that structures from elementary particles to galaxies and the universe itself are the result of infinitely curved spacetime geometries, popularly known as black holes. In essence, this means that all the stuff we think of as material, physical objects in fact only appear substantive because of the geometry and torque of spacetime in these regions. As Charles Misner and John Wheeler stated it:
There is nothing in the world except empty curved space. Matter, charge, electromagnetism, and other fields are only manifestations of the bending of space. Physics is...
The largest particle detector of its kind has failed to turn up any hints of dark matter, despite searching for about a year.
Known as XENON1T, the experiment is designed to detect elusive dark matter particles, which are thought to make up most of the matter in the cosmos. Physicists don’t know what dark matter is. One of the most popular explanations is a particle called a WIMP, short for weakly interacting massive particle. XENON1T searches for WIMPs crashing into atomic nuclei in 1,300 kilograms of chilled liquid xenon. But XENON1T saw no such collisions. The particles’ absence further winnowed down their possible hiding places by placing new limits on how frequently WIMPs can interact with nuclei depending on their mass.
Researchers describe the results May 28 in two talks, one at Gran Sasso National Laboratory in Italy, where XENON1T is located, and the other at the European particle physics lab CERN in Geneva. XENON1T...
Charge – that is the degree to which an entity is affected by an external force – comes in all shapes in sizes. Now for the first-time scientists have been able to determine the weak charge of the proton.
The weak force is one of the four fundamental forces of nature and is significant in radioactivity – the spontaneous emission of energy and/or subatomic particles i.e. an unstable nucleus will decompose spontaneously (decay) into a more stable configuration. Note, this is done by emitting specific particles and/or specific amounts/forms of energy. For example, radioactive beta decay transforms a neutron into a proton, an electron, and an electron anti-neutrino.
The standard model describes these forces in terms of the exchange of virtual force carriers. In this model the weak force is thought to interact thorough the exchange of the massive (~ 100 x mass of a proton)...
The biggest map of our galaxy just got revealed and it confirms the intriguing discrepancy in the value of the Hubble constant, further questioning our understanding of the expanding Universe.
Hubble’s constant – which is essentially a measure of the speed of the expanding universe – is determined by two different methods. One method looks at the early universe through the observation of the Cosmic Microwave Background (CMB) and the other method looks at the local universe through the light emitted by Cepheid variables.
In a recent news post, we described how Nobel laureate Adam Reiss and his team at the Space Telescope Science Institute determined a value for the Hubble constant 9% higher than that found by the CMB method. This value was found to an improved accuracy compared to previous studies and thus brings into question the reason for such a discrepancy.
Now with the help of Gaia, the...