Playlist: Do We Live in a Simulated Reality?
The Quantum World of Digital Physics: Can a virtual reality be real?
“Quantum physics requires us to abandon the distinction between information and reality.” Anton Zeilinger.
Part 1. Information and Simulated Reality.
At school you may have been taught that helium was a noble gas because it was totally unreactive.
But, new research suggests it might not be as virtuous as we first thought.
An international team of scientists has created a stable helium compound which is composed of both helium and sodium atoms, and say their discovery marks a ‘new frontier of chemistry.’
Interesting read for those interested in inorganic protein (NP) states from a solid to a liquid as the research proves inorganic NPs are in a ‘glassy’ state while transitioning from a solid to a liquid form.
Molecular dynamics simulations of ubiquitin in water/glycerol solutions are used to test the suggestion by Karplus and coworkers that proteins in their biologically active state should exhibit a dynamics similar to ‘surface-melted’ inorganic nanoparticles (NPs). Motivated by recent studies indicating that surface-melted inorganic NPs are in a ‘glassy’ state that is an intermediate dynamical state between a solid and liquid, we probe the validity and significance of this proposed analogy. In particular, atomistic simulations of ubiquitin in solution based on CHARMM36 force field and pre-melted Ni NPs (Voter-Chen Embedded Atom Method potential) indicate a common dynamic heterogeneity, along with other features of glass-forming (GF) liquids such as collective atomic motion in the form of string -like atomic displacements, potential energy fluctuations and particle displacements with long range correlations (‘colored’ or ‘pink’ noise), and particle displacement events having a power law scaling in magnitude, as found in earthquakes. On the other hand, we find the dynamics of ubiquitin to be even more like a polycrystalline material in which the α-helix and β-sheet regions of the protein are similar to crystal grains so that the string -like collective atomic motion is concentrated in regions between the α-helix and β-sheet domains.
Nice read & video illustration.
Quantum entanglement may appear to be closer to science fiction than anything in our physical reality. But according to the laws of quantum mechanics — a branch of physics that describes the world at the scale of atoms and subatomic particles — quantum entanglement, which Einstein once skeptically viewed as “spooky action at a distance,” is, in fact, real.
Quantum’s natural selection explored.
There might be no getting around what Albert Einstein called “spooky action at a distance.” With an experiment described today in Physical Review Letters — a feat that involved harnessing starlight to control measurements of particles shot between buildings in Vienna — some of the world’s leading cosmologists and quantum physicists are closing the door on an intriguing alternative to “quantum entanglement.”
“Technically, this experiment is truly impressive,” said Nicolas Gisin, a quantum physicist at the University of Geneva who has studied this loophole around entanglement.
According to standard quantum theory, particles have no definite states, only relative probabilities of being one thing or another — at least, until they are measured, when they seem to suddenly roll the dice and jump into formation. Stranger still, when two particles interact, they can become “entangled,” shedding their individual probabilities and becoming components of a more complicated probability function that describes both particles together. This function might specify that two entangled photons are polarized in perpendicular directions, with some probability that photon A is vertically polarized and photon B is horizontally polarized, and some chance of the opposite. The two photons can travel light-years apart, but they remain linked: Measure photon A to be vertically polarized, and photon B instantaneously becomes horizontally polarized, even though B’s state was unspecified a moment earlier and no signal has had time to travel between them.
When light shines on certain materials, it causes them to emit electrons. This is called “photoemission” and it was discovered by Albert Einstein in 1905, winning him the Nobel Prize. But only in the last few years, with advancements in laser technology, have scientists been able to approach the incredibly short timescales of photoemission. Researchers at EPFL have now determined a delay of one billionth of one billionth of a second in photoemission by measuring the spin of photoemitted electrons without the need of ultrashort laser pulses. The discovery is published in Physical Review Letters.
Photoemission
Photoemission has proven to be an important phenomenon, forming a platform for cutting-edge spectroscopy techniques that allow scientists to study the properties of electrons in a solid. One such property is spin, an intrinsic quantum property of particles that makes them look like as if they were rotating around their axis. The degree to which this axis is aligned towards a particular direction is referred to as spin polarization, which is what gives some materials, like iron, magnetic properties.
Surprised it took this long for this article to surface.
Quantum and travel.
Written by Arjun Walia
One of the strangest phenomena you’re likely to come across in all of science is quantum entanglement — where two particles interact in such a way that they become deeply linked, and essentially ‘share’ an existence, even if they’re light-years apart.
Einstein famously couldn’t get on board with this idea, and ultimately decided that it was just too weird to be true. But a new experiment has just made the strongest case yet for the reality of quantum entanglement, so it looks like our Universe is just as bizarre as we suspected.
“The real estate left over for the skeptics of quantum mechanics has shrunk considerably,” one of the team, David Kaiser from MIT, told Jennifer Chu at Phys.org.
IBM researchers have established experimental proof of a previously difficult-to-prove law of physics, and in so doing may have pointed to a way to overcome many of the heat management issues faced in today’s electronics. Researchers at IBM Zurich have been able to take measurements of the thermal conductance of metallic quantum point contacts made of gold. No big deal, you say? They conducted measurements at the single-atom level, at room temperature—the first time that’s ever been done.
These measurements confirm the Wiedemann–Franz law, which predicts that the smallest amount of heat that can be carried across a metallic junction — a single quantum of heat — is directly proportional to the quantum of electrical conductance through the same junction. By experimentally confirming this law, it can now be used with confidence to predict and to explore nanoscale thermal and electrical phenomena affecting materials down to the size of few atoms or a single molecule.
“Although the Wiedemann–Franz law is predicted, and should be valid for certain metals, it has turned out to be difficult to prove it when you go to the nanoscale,” explained Bernd Gotsmann, an IBM scientist and one of the lead researchers on this work, in an e-mail interview with IEEE Spectrum. “We think the difficulty is mainly a sign of the challenges related to the measurement of thermal transport on small scales.”
Published today, using a technique which looks like trampoline, IBM scientists have measured the thermal conductance of metallic quantum point contacts made of gold down to the single-atom level at room temperature for the first time.
As everything scales to the nanoscale, heat – more precisely, the loss of it – becomes an issue in device reliability. To address this, last year, IBM scientists in Zurich and students from ETH Zurich published and patented a technique to measure the temperature of these nano-sized objects at and below 10 nanometer – a remarkable achievement. They called the novel technique scanning probe thermometry (video) and it provided engineers, for the first time, with the ability to map heat loss across a chip, and, more importantly, map heat loss down to the single device level and to map temperature distributions.
