All posts tagged: quantum physics

Universe may have 7 dimensions in bombshell theory | Science | News

Universe may have 7 dimensions in bombshell theory | Science | News

Published by Sam Flores

A paradox that stumped scientists for decades has an explanation, as long as the universe has seven dimensions. Stephen Hawking’s theory that black holes eventually evaporate into nothingness presented a contradiction to a fundamental understanding in physics and quantum mechanics. However, a new theory by scientists suggests that black holes never fully disappear and remnants are left behind, as long as there are seven dimensions, three extra to the traditionally accepted four dimensions we have known about for generations. Scientists believe that, as well as length, width, height and time, there are three hidden dimensions in the universe, and they are folded so densely that they cannot be easily perceived. This seems to solve the decades-old ‘information paradox’, as traditionally, the laws of quantum mechanics state that information can never completely disappear or be destroyed, which contradicts Hawking’s theory that back holes eventually evaporate and cease to exist. Senior researcher at the Slovak Academy of Sciences, Richard Pinčák, told the Daily Mail: “Imagine you throw a book into a fire. The book is destroyed, but …

Quantum batteries could be charged by reversing time

Quantum batteries could be charged by reversing time

Published by skeptic

Quantum batteries could harvest energy by reversing time’s arrow da-kuk/Getty Images A method that can reverse the flow of time in quantum systems could one day be used to help charge quantum batteries. For every process we observe in the universe, events appear to happen in only one direction, following an apparent arrow of time. But most physical laws and equations work whether time flows forwards or backwards. Physicists have different explanations for why a discrepancy exists between the observed forward arrow of time and the permitted two-way flow. For example, the second law of thermodynamics says that systems are more likely to become disordered as time goes on, creating a preferred direction of time. In the quantum world, the arrow of time is defined differently. Quantum processes, like classical physical laws, can run in either direction, but we can define an arrow of time by comparing our measurements of a quantum system with our calculations of how a quantum system should change over time. When these line up with a particular statistical pattern, we …

We might finally know the size of the proton

We might finally know the size of the proton

Published by skeptic

A vacuum chamber used to measure electron transitions in atomic hydrogen, from which the proton’s size was inferred Axel Beyer/MPQ At long last, we have pinned down the size of a proton. More than 15 years after an experiment unexpectedly shook the world of particle physics, researchers are regaining their grip on one of this fundamental particle’s most basic properties. Look around you, and everything you see will be filled with protons. The proton is a fundamental building block of our world – and until 2010, we thought we understood it fairly well. We knew its composition – it is made from three quarks – and we knew its size. Then, a measurement based on an exotic hydrogen atom showed that the proton may actually be about 4 per cent smaller than expected. Physicists scrambled, exploring sources of experimental error as well as theories about new physics phenomena that could resolve this “proton radius puzzle”. In 2019, another experiment strengthened the evidence that the proton’s size had long been overestimated. Now, the issue may have …

Quantum entanglement can be measured in solids for the first time

Quantum entanglement can be measured in solids for the first time

Published by skeptic

The behaviour of two distinct particles can be linked by quantum entanglement Science Photo Library / Alamy We finally have a way to measure quantum entanglement of solids, which could lead to advances in both quantum technology and fundamental physics. When it comes to quantum entanglement – an inextricable link between quantum particles that keeps their behaviours correlated, even when they are extremely far apart – researchers have limited experimental tools. They can determine if two particles are entangled by using a procedure called the Bell test, for example, and purposely create entanglement between several objects within quantum computers. But finding out whether a piece of some material is full of entangled particles is more challenging. This is especially important for developing new and better devices for quantum computing and quantum communication, which require entanglement. Allen Scheie at Los Alamos National Laboratory in New Mexico and his colleagues have spent more than half a decade developing a technique to do just that – and now it works. “We’ve established that it works, 100 per cent, …

How a century-long argument over light’s true nature came to an end

How a century-long argument over light’s true nature came to an end

Published by skeptic

Light is both a wave and a particle, and we know it for sure now Anna Bliokh/Getty Images The following is an extract from our Lost in Space-Time newsletter. Each month, we dive into fascinating ideas from around the universe. You can sign up for Lost in Space-Time here. When physicist Clinton Davisson received the Nobel prize in 1937 for discovering that electrons, which had been considered to be particles, could sometimes unexpectedly behave like waves, he made a point of taking a jab at light. He said, “the perfect child of physics [had] been changed into a gnome with two heads”. It was already known to not be one or the other, but both wave-like and particle-like. Physicists used to think that being a particle and being a wave was mutually exclusive, yet here we had, in light and now also electrons, two examples contradicting that. Somewhat baffled, Davisson couldn’t help but reach for a grotesque metaphor. He was in good company – 10 years earlier, Albert Einstein had a famous argument with Niels Bohr over this seeming absurdity. …

We’re solving the fundamental mystery of how reality is glued together

We’re solving the fundamental mystery of how reality is glued together

Published by skeptic

As you read this, every atom in your body is desperately trying to tear itself apart. In fact, that goes for every atom, everywhere, since the beginning of time. Thankfully, those efforts have failed. These self-destructive tendencies relate to the nucleus, a tiny knot of matter at the centre of every atom. Inside, protons are packed shoulder to shoulder, each one bristling with positive charge and frantic to get away from its companions. If atoms obeyed only electricity and magnetism, the universe would have been a brief, bright firework. Instead, something else intervenes, a force so strong it makes electromagnetism look feeble. This maintains the solid furniture of reality by keeping the building blocks of atoms glued together. But the deeper physicists have probed this force, the stranger it has seemed. The equations that describe it look disarmingly simple, yet follow them through and something puzzling happens: a theory built from weightless ingredients somehow produces particles that are unmistakably heavy. Sweeping away this inconsistency wouldn’t just tidy up our understanding of the force that binds …

How Anthony Leggett pushed the boundaries of quantum physics

How Anthony Leggett pushed the boundaries of quantum physics

Published by skeptic

Sir Anthony Leggett was a giant in the field of quantum physics University of Illinois Urbana-Champaign/L. Brian Stauffer In my first year of graduate school, I briefly shared an office with a quiet, older graduate student. When we finally managed some chit-chat, I learned that he was “working on theory of glasses with Tony.” Two things became clear: cracking the physics of glasses was difficult, and I really ought to have known who Tony was. I met him soon enough. A polite British man in his 70s, he spoke with the cadence of a life-long teacher and an incontrovertible twinkle in his eyes. His full name was Anthony James Leggett: a Nobel laureate, a knight of the British Empire, winner of countless prizes, an expert on the ultracold denizens of the quantum world, and a theorist who co-developed an influential test for probing just where that world might end, a question he pursued for decades. He passed away on 8 March, survived not only by his family but by countless inspired researchers to whom he …

Temperature gets a new definition using a quantum device

Temperature gets a new definition using a quantum device

Published by skeptic

The main part of the new set-up for cooling and trapping rubidium atoms Tomasz Kawalec CC BY-SA 4.0 A better, more reliable definition of temperature could come from a quantum device full of giant atoms. While some countries measure temperatures in Celsius and others use Fahrenheit, physicists everywhere use a unit called kelvin. Zero kelvin denotes the absolute coldest temperature allowed by the known laws of physics, so kelvin is said to measure “absolute temperature”. In practice, however, making sure that when you measure a single kelvin, it really is a single kelvin is a laborious process. “If you want to make an absolute temperature measurement, you buy a commercial temperature sensor, which was calibrated by another commercial temperature sensor, which was calibrated by another commercial temperature sensor, and so on. And one of those sensors was, at some point, sent to the National Institute of Standards [and Technology],” says Noah Schlossberger at NIST in Colorado. He and his colleagues have now built a device that uses quantum effects to measure kelvin, which researchers could …

Physicists build a quantum Newton’s cradle where energy flows without resistance

Physicists build a quantum Newton’s cradle where energy flows without resistance

Published by Jenni Sidey

In most materials, motion eventually fades. Electric current weakens as electrons scatter inside a wire. Heat spreads through a solid until temperature differences vanish. Fluids moving through pipes lose energy to friction along the walls. Collisions, defects, and random motion steadily break down organized flow. Yet in a laboratory experiment in Austria, physicists built a system where that familiar slowdown almost disappears. Working with an ultracold gas of rubidium atoms, researchers at TU Wien observed a form of transport in which mass and energy keep moving without degrading. Even after many collisions between atoms, the flow remained intact rather than dispersing. The result, reported in Science, offers a rare glimpse of nearly perfect transport in a controlled quantum system. Schematic of the experimental protocol. An atom chip creates a tight transverse confinement (along the x and y axes), confining a gas of ultracold bosons to one dimension. (CREDIT: Science) Two Ways Motion Usually Spreads Physicists generally describe transport in two basic ways. One is ballistic motion. In this regime, particles travel freely with little interruption. …

A crisis in cosmology may mean hidden dimensions really exist

A crisis in cosmology may mean hidden dimensions really exist

Published by skeptic

DAVID PARKER/SCIENCE PHOTO LIBRARY Last year, cosmologists working on the Dark Energy Spectroscopic Instrument (DESI) reported hints that the mysterious dark energy thought to be driving the expansion of the universe may be weakening over time. If these startling findings prove correct, then dark energy cannot be a cosmological constant – a fixed term in our equations that represents the energy of empty space – after all. When this bombshell hit, most of the buzz focused on what that means for the standard model of cosmology, known as lambda-CDM, our best attempt to explain the evolution of universe. If the results firm up, we may finally have the clues required to build a better theory. Already, researchers are busy trying to rethink dark energy, and possibly dark matter and gravity, too. But if the strength of dark energy really does diminish over cosmic time, the implications could run far wider and deeper. Wider, in the sense that it could provide fresh impetus for proponents of alternative cosmologies that change our understanding of the fate of …