Lifeboat Foundation

Circa 2014 o.o!

When someone mentions “different dimensions,” we tend to think of things like parallel universes – alternate realities that exist parallel to our own, but where things work or happened differently. However, the reality of dimensions and how they play a role in the ordering of our Universe is really quite different from this popular characterization.

To break it down, dimensions are simply the different facets of what we perceive to be reality. We are immediately aware of the three dimensions that surround us on a daily basis – those that define the length, width, and depth of all objects in our universes (the x, y, and z axes, respectively).

Continue reading “A universe of 10 dimensions” »

The development of experimental platforms that advance the field of quantum science and technology (QIST) comes with a unique set of advantages and challenges common to any emergent technology. Researchers at Stony Brook University, led by Dominik Schneble, PhD, report the formation of matter-wave polaritons in an optical lattice, an experimental discovery that permits studies of a central QIST paradigm through direct quantum simulation using ultracold atoms. The scientists project that their novel quasiparticles, which mimic strongly interacting photons in materials and devices but circumvent some of the inherent challenges, will benefit the further development of QIST platforms that are poised to revolutionize computing and communication technology.

The research findings are detailed in a paper published in the journal Nature Physics.

The study sheds light on fundamental polariton properties and related many-body phenomena, and it opens up novel possibilities for studies of polaritonic quantum matter.

The physics of the microrealm involves two famous and bizarre concepts: The first is that prior to observation, it is impossible to know with certainty the outcome of a measurement on a particle; rather the particle exists in a “superposition” encompassing multiple mutually exclusive states. So a particle can be in two or more places at the same time, and you can only calculate the probability of finding it in a certain location when you look. The second involves “entanglement,” the spooky link that can unite two objects, no matter how far they are separated. Both superposition and entanglement are described mathematically by quantum theory. But many physicists believe that the ultimate theory of reality may lie beyond quantum theory. Now, a team of physicists and mathematicians has discovered a new connection between these two weird properties that does not assume that quantum theory is correct. Their study appears in Physical Review Letters.

“We were really excited to find this new connection that goes beyond quantum theory because the connection will be valid even for more exotic theories that are yet to be discovered,” says Ludovico Lami, a member of the physics think-tank, the Foundational Questions Institute, FQXi, and a physicist at the University of Ulm, in Germany. “This is also important because it is independent of the mathematical formalism of quantum theory and uses only notions with an immediate operational interpretation,” he adds. Lami co-authored the study with Guillaume Aubrun of Claude Bernard University Lyon 1, in France, Carlos Palazuelos, of the Complutense University of Madrid, in Spain, and Martin Plávala, of Siegen University, in Germany.

While quantum theory has proven to be supremely successful since its development a century ago, physicists have struggled to unify it with gravity to create one overarching “theory of everything.” This suggests that quantum theory may not be the final word on describing reality, inspiring physicists to hunt for a more fundamental framework. But any such ultimate theory must still incorporate superposition, entanglement, and the probabilistic nature of reality, since these features have been confirmed time and again in lab tests. The interpretation of these experiments does not depend on quantum theory being correct, notes Lami.

We consider dark matter production during the inflaton oscillation epoch. It is conceivable that renormalizable interactions between dark matter and inflaton may be negligible. In this case, the leading role is played by higher dimensional operators generated by gravity and thus suppressed by the Planck scale. We focus on dim-6 operators and study the corresponding particle production in perturbative and non-perturbative regimes. We find that the dark matter production rate is dominated by non-derivative operators involving higher powers of the inflaton field. Even if they appear with small Wilson coefficients, such operators can readily account for the correct dark matter abundance.

Abstract: Spin-two particles appear in the spectra of both open and closed string theories. We studied a graviton and massive symmetric rank-two tensor in string theory, both of which carry spin two. A graviton is a massless spin-two particle in closed string theory while a symmetric rank-two tensor is a massive particle with spin two in open string theory. Using Polyakov’s string path integral formulation of string scattering amplitudes, we calculated cubic interactions of both spin-two particles explicitly, including $\ap$-corrections (string corrections). We observed that the cubic interactions of the massive spin-two particle differed from those of the graviton. The massive symmetric rank-two tensor in open string theory becomes massless in the high energy limit where $\ap \rightarrow \infty$ and $\ap$-correction terms, containing higher derivatives, dominate: In this limit the local cubic action of the symmetric rank-two tensor of open string theory coincides with that of the graviton in closed string theory.

From: Taejin Lee [view email].

Nobody can explain why this ‘sinuous discrete aurora’ happened.

While scientists have detected discrete auroras above certain patches of the Red Planet before, never have they seen one on such a “massive scale,” the team said. The solar storm that propelled charged particles into the Martian atmosphere at a faster and more turbulent pace than usual is likely a key factor in this type of long, sinuous aurora, the researchers added.

Solar storm occurrences are predicted to increase over the next several years as the sun approaches its solar maximum — the period of greatest activity in the sun’s 11-year cycle — in 2025. The EMM’s Hope orbiter will continue watching for these newly discovered auroras in the meantime, while scientists dig into archival data collected by NASA and the European Space Agency to hunt for more examples of the snake-like streaks over Mars.

An experiment conducted on hybrid matter-antimatter atoms has defied researchers’ expectations.

In the pre-industrial age, people only needed to measure years and months to a fair amount of accuracy. The position of the sun in the sky was good enough to break up the day. Timing at the level of fractions of a second was simply not needed.

Eventually, modern industry arose. Fast-moving machines came to dominate human activity, and clocks required hands that could measure seconds. In the current era of digital technology, the timing of electronic circuitry means that millionths or billionths of a second actually matter. None of the high-tech stuff we need, from our phones to our cars, can be controlled or manipulated if we cannot keep close track of it. To make technology work, we need clocks that are faster than the timing of the machines we need to control. For today’s technology, that means we must be able to measure seconds, milliseconds, or even nanoseconds with astonishing accuracy.

Every timekeeping device works via a version of a pendulum. Something must swing back and forth to beat out a basic unit of time. Mechanical clocks used gears and springs. But metal changes shape as it heats or cools, and friction wears down mechanical parts. All of this limits the accuracy of these timekeeping machines. As the speed of human culture climbed higher, it demanded a kind of hyper-fast pendulum that would never wear down.