The world we experience is governed by classical physics. How we move, where we are, and how fast we’re going are all determined by the classical assumption that we can only exist in one place at any one moment in time.
But in the quantum world, the behavior of individual atoms is governed by the eerie principle that a particle’s location is a probability. An atom, for instance, has a certain chance of being in one location and another chance of being at another location, at the same exact time.
When particles interact, purely as a consequence of these quantum effects, a host of odd phenomena should ensue. But observing such purely quantum mechanical behavior of interacting particles amid the overwhelming noise of the classical world is a tricky undertaking.
Scientists have come closer than ever before to creating a laboratory-scale imitation of a black hole that emits Hawking radiation, the particles predicted to escape black holes due to quantum mechanical effects.
The black hole analogue, reported in Nature Physics1, was created by trapping sound waves using an ultra cold fluid. Such objects could one day help resolve the so-called black hole ‘information paradox’ — the question of whether information that falls into a black hole disappears forever.
The physicist Stephen Hawking stunned cosmologists 40 years ago when he announced that black holes are not totally black, calculating that a tiny amount of radiation would be able to escape the pull of a black hole2. This raised the tantalising question of whether information might escape too, encoded within the radiation.
The fundamental forces of physics govern the matter comprising the Universe, yet exactly how these forces work together is still not fully understood. The existence of Hawking radiation — the particle emission from near black holes — indicates that general relativity and quantum mechanics must cooperate. But directly observing Hawking radiation from a black hole is nearly impossible due to the background noise of the Universe, so how can researchers study it to better understand how the forces interact and how they integrate into a “Theory of Everything”?
According to Haruna Katayama, a doctoral student in Hiroshima University’s Graduate School of Advanced Science and Engineering, since researchers cannot go to the Hawking radiation, Hawking radiation must be brought to the researchers. She has proposed a quantum circuit that acts as a black hole laser, providing a lab-bench black hole equivalent with advantages over previously proposed versions. The proposal was published on Sept. 27 Scientific Reports.
“In this study, we devised a quantum-circuit laser theory using an analogue black hole and a white hole as a resonator,” Katayama said.
The universe is governed by two sets of seemingly incompatible laws of physics – there’s the classical physics we’re used to on our scale, and the spooky world of quantum physics on the atomic scale. MIT physicists have now observed the moment atoms switch from one to the other, as they form intriguing “quantum tornadoes.”
Things that seem impossible to our everyday understanding of the world are perfectly possible in quantum physics. Particles can essentially exist in multiple places at once, for instance, or tunnel through barriers, or share information across vast distances instantly.
These and other odd phenomena can arise as particles interact with each other, but frustratingly the overarching world of classical physics can interfere and make it hard to study these fragile interactions. One way to amplify quantum effects is to cool atoms right down to a fraction above absolute zero, creating a state of matter called a Bose-Einstein condensate (BEC) that can exhibit quantum properties on a larger, visible scale.
For a few brief moments, the high-powered lasers generated 1.3 megajoules of fusion energy.
A breakthrough experiment last month at Lawrence Livermore National Laboratory’s (LLNL) National Ignition Facility (NIF) in California has turned up a whopping 1.3 megajoules of energy, or about three percent of the energy contained in one kilogram of crude oil. The work, as outlined in the journal Physical Review E, puts physicists “at the threshold of fusion ignition,” according to the lab’s press release.
Nuclear fusion, in the simplest terms, is a reaction in which atoms are smashed together to generate an abundance of energy. In some ways, it’s less dangerous than nuclear fission —a process that involves splitting heavy, unstable atoms into two lighter ones—and has the potential to create a lot more energy.
All of today’s functional nuclear power plants currently use nuclear fission, and scientists have long been on the hunt for a way to make nuclear fusion a reality; consider it a kind of holy grail of clean energy.
The uncertainty principle, first introduced by Werner Heisenberg in the late 1920’s, is a fundamental concept of quantum mechanics. In the quantum world, particles like the electrons that power all electrical product can also behave like waves. As a result, particles cannot have a well-defined position and momentum simultaneously. For instance, measuring the momentum of a particle leads to a disturbance of position, and therefore the position cannot be precisely defined.
Roughly 13.8 billion years ago, our Universe was born in a massive explosion that gave rise to the first subatomic particles and the laws of physics as we know them.
About 370,000 years later, hydrogen had formed, the building block of stars, which fuse hydrogen and helium in their interiors to create all the heavier elements. While hydrogen remains the most pervasive element in the Universe, it can be difficult to detect individual clouds of hydrogen gas in the interstellar medium (ISM).
This makes it difficult to research the early phases of star formation, which would offer clues about the evolution of galaxies and the cosmos.
Invisibility devices may soon no longer be the stuff of science fiction. A new study published in the De Gruyter journal Nanophotonics by lead authors Huanyang Chen at Xiamen University, China, and Qiaoliang Bao, suggests the use of the material Molybdenum Trioxide (a-MoO3) to replace expensive and difficult to produce metamaterials in the emerging technology of novel optical devices.
The idea of an invisibility cloak may sound more like magic than science, but researchers are currently hard at work producing devices that can scatter and bend light in such a way that it creates the effect of invisibility.
Thus far these devices have relied on metamaterials – a material that has been specially engineered to possess novel properties not found in naturally occurring substances or in the individual particles of that material – but the study by Chen and co-authors suggests the use of a-MoO3 to create these invisibility devices.