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  • richardmitnick 10:25 am on September 17, 2021 Permalink | Reply
    Tags: "BNL’s Zhangbu Xu and others prove 87-year-old theories of famous physicists", , Breit and Wheeler suggested that colliding light particles could create pairs of electrons and their antimatter opposites known as positrons., , , This is the first experiment on Earth that demonstrates experimentally that polarization affects the interactions of light with the magnetic field in a vacuum., Vacuum birefringence   

    From DOE’s Brookhaven National Laboratory (US) : “BNL’s Zhangbu Xu and others prove 87-year-old theories of famous physicists” 

    From DOE’s Brookhaven National Laboratory (US)

    August 21, 2021
    Daniel Dunaief

    Zhangbu Xu at the STAR detector.

    Zhangbu Xu in front of the time-of-flight detector, which is important for identifying the electrons and positrons the STAR Collaboration measured. Photo from BNL.

    Gregory Breit and John Wheeler were right in the 1930s and Werner Heisenberg and Hans Heinrich Euler in 1936 and John Toll in the 1950s were also right.

    Breit, who was born in Russia and came to the United States in 1915, and Wheeler, who was the first American involved in the theoretical development of the atomic bomb, wrote a paper that offered theoretical ideas about how to produce mass from energy.

    Breit and Wheeler suggested that colliding light particles could create pairs of electrons and their antimatter opposites known as positrons. This idea was an extension of one of Albert Einstein’s most famous equations, E=mc2, converting pure energy into matter in its simplest form.

    Working at the Relativistic Heavy Ion Collider (RHIC)[below] at Brookhaven National Laboratory, a team of scientists in the STAR Collaboration [below] has provided experimental proof that the ideas of some of these earlier physicists were correct.

    “To create the conditions which the theory predicted, even that process is quite exhausting, but actually quite exciting,” said Zhangbu Xu, a senior scientist at BNL in the physics department.

    The researchers published their results recently in Physics Review Letters, which provides a connection to Breit and Wheeler, who published their original work in a predecessor periodical called Physics Review.

    While Breit and Wheeler wrote that the probability of two gamma rays colliding was “hopeless,” they suggested that accelerated heavy ions could be an alternative, which is exactly what the researchers at RHIC did.

    The STAR team, for Solenoidal Tracker at RHIC, also proved another theory proposed decades ago by physicists Heisenberg, who also described the Heisenberg Uncertainty Principle, and Hans Heinrich Euler in 1936 and John Toll, who would later become the second president at Stony Brook University (US), in the 1950s.

    These physicists predicted that a powerful magnetic field could polarize a vacuum of empty space. This polarized vacuum should deflect the paths of photons depending on photon polarization.

    Researchers had never seen this polarization-dependent deflection, called birefringence, in a vacuum on Earth until this set of experiments.

    Creating mass from energy

    Xu and others started with a gold ion. Without its electrons, the 79 protons in the gold ion have a positive charge, which, when projected at high speeds, triggers a magnetic field that spirals around the particle as it travels.

    Once the ion reaches a high enough speed, the strength of the magnetic field equals the strength of the perpendicular electric field. This creates a photon that hovers around the ion.

    The speeds necessary for this experiment is even closer to the speed of light, at 99.995%, than ivory soap is to being pure, at 99.44%.

    When the ions move past each other without colliding, the photon fields interact. The researchers studied the angular distribution patterns of each electron and its partner positron.

    “We also measured all the energy, mass distribution, and quantum numbers of the system,” Daniel Brandenburg, a Goldhaber Fellow at BNL who analyzed the STAR data, said in a statement.

    Even in 1934, Xu said, the researchers realized the cross section for the photons to interact was so small that it was almost impossible to create conditions necessary for such an experiment.

    “Only in the last 10 years, with the new angular distribution of e-plus [positrons] and e-minus [electrons] can we say, ‘Hey, this is from the photon/ photon creation,’” Xu said.

    Bending light in a vacuum

    Heisenberg and Euler in 1936 and Toll in the 1950’s theorized that a powerful magnetic field could polarize a vacuum, which should deflect the paths of photons. Toll calculated in theory how the light scatters off strong magnetic fields and how that connects to the creation of the electron and positron pair, Xu explained. “That is exactly what we did almost 70 years later,” he said.

    This is the first experiment on Earth that demonstrates experimentally that polarization affects the interactions of light with the magnetic field in a vacuum.

    Xu explained that one of the reasons this principle hasn’t been observed often is that the effect is small without a “huge magnetic field. That’s why it was predicted many decades ago, but we didn’t observe it.”

    Scientists who were a part of this work appreciated the connection to theories their famous and successful predecessors had proposed decades earlier.

    “Both of these findings build on predictions made by some of the great physicists in the early 20th century,” Frank Geurts, a professor at Rice University (US), said in a statement.

    The work on bending light through a vacuum is a relatively new part of the research effort.

    Three years ago, the scientists realized they could study this, which was a surprising moment, Xu said.

    “Many of our collaborators (myself included) did not know what vacuum birefringence was a few years ago,” he said. “This is why scientific discovery is exciting. You don’t know what nature has prepared for you. Sometimes you stumble on something exciting. Sometimes, there is a null set (empty hand) in your endeavor.

    Xu lives in East Setauket. His son Kevin is earning his bachelor’s degree at The University of Pennsylvania (US), where he is studying science and engineering. His daughter Isabel is a junior at Ward Melville High School.

    As for the recent work, Xu, who earned his PhD and completed two years of postdoctoral research at Yale Unversity (US) before coming to BNL, said he is pleased with the results.

    “I’ve been working on this project for 20 years,” he said. “I have witnessed and participated in quite a few exciting discoveries RHIC has produced. These are very high on my list.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    One of ten national laboratories overseen and primarily funded by the DOE(US) Office of Science, DOE’s Brookhaven National Laboratory (US) conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University(US), the largest academic user of Laboratory facilities, and Battelle(US), a nonprofit, applied science and technology organization.

    Research at BNL specializes in nuclear and high energy physics, energy science and technology, environmental and bioscience, nanoscience and national security. The 5,300 acre campus contains several large research facilities, including the Relativistic Heavy Ion Collider [below] and National Synchrotron Light Source II [below]. Seven Nobel prizes have been awarded for work conducted at Brookhaven lab.

    BNL is staffed by approximately 2,750 scientists, engineers, technicians, and support personnel, and hosts 4,000 guest investigators every year. The laboratory has its own police station, fire department, and ZIP code (11973). In total, the lab spans a 5,265-acre (21 km^2) area that is mostly coterminous with the hamlet of Upton, New York. BNL is served by a rail spur operated as-needed by the New York and Atlantic Railway. Co-located with the laboratory is the Upton, New York, forecast office of the National Weather Service.

    Major programs

    Although originally conceived as a nuclear research facility, Brookhaven Lab’s mission has greatly expanded. Its foci are now:

    Nuclear and high-energy physics
    Physics and chemistry of materials
    Environmental and climate research
    Energy research
    Structural biology
    Accelerator physics


    Brookhaven National Lab was originally owned by the Atomic Energy Commission(US) and is now owned by that agency’s successor, the United States Department of Energy (DOE). DOE subcontracts the research and operation to universities and research organizations. It is currently operated by Brookhaven Science Associates LLC, which is an equal partnership of Stony Brook University(US) and Battelle Memorial Institute(US). From 1947 to 1998, it was operated by Associated Universities, Inc. (AUI) (US), but AUI lost its contract in the wake of two incidents: a 1994 fire at the facility’s high-beam flux reactor that exposed several workers to radiation and reports in 1997 of a tritium leak into the groundwater of the Long Island Central Pine Barrens on which the facility sits.


    Following World War II, the US Atomic Energy Commission was created to support government-sponsored peacetime research on atomic energy. The effort to build a nuclear reactor in the American northeast was fostered largely by physicists Isidor Isaac Rabi and Norman Foster Ramsey Jr., who during the war witnessed many of their colleagues at Columbia University leave for new remote research sites following the departure of the Manhattan Project from its campus. Their effort to house this reactor near New York City was rivalled by a similar effort at the Massachusetts Institute of Technology (US) to have a facility near Boston, Massachusettes(US). Involvement was quickly solicited from representatives of northeastern universities to the south and west of New York City such that this city would be at their geographic center. In March 1946 a nonprofit corporation was established that consisted of representatives from nine major research universities — Columbia University(US), Cornell University(US), Harvard University(US), Johns Hopkins University(US), Massachusetts Institute of Technology(US), Princeton University(US), University of Pennsylvania(US), University of Rochester(US), and Yale University(US).

    Out of 17 considered sites in the Boston-Washington corridor, Camp Upton on Long Island was eventually chosen as the most suitable in consideration of space, transportation, and availability. The camp had been a training center from the US Army during both World War I and World War II. After the latter war, Camp Upton was deemed no longer necessary and became available for reuse. A plan was conceived to convert the military camp into a research facility.

    On March 21, 1947, the Camp Upton site was officially transferred from the U.S. War Department to the new U.S. Atomic Energy Commission (AEC), predecessor to the U.S. Department of Energy (DOE).

    Research and facilities

    Reactor history

    In 1947 construction began on the first nuclear reactor at Brookhaven, the Brookhaven Graphite Research Reactor. This reactor, which opened in 1950, was the first reactor to be constructed in the United States after World War II. The High Flux Beam Reactor operated from 1965 to 1999. In 1959 Brookhaven built the first US reactor specifically tailored to medical research, the Brookhaven Medical Research Reactor, which operated until 2000.

    Accelerator history

    In 1952 Brookhaven began using its first particle accelerator, the Cosmotron. At the time the Cosmotron was the world’s highest energy accelerator, being the first to impart more than 1 GeV of energy to a particle.

    The Cosmotron was retired in 1966, after it was superseded in 1960 by the new Alternating Gradient Synchrotron (AGS).

    The AGS was used in research that resulted in 3 Nobel prizes, including the discovery of the muon neutrino, the charm quark, and CP violation.

    In 1970 in BNL started the ISABELLE project to develop and build two proton intersecting storage rings.

    The groundbreaking for the project was in October 1978. In 1981, with the tunnel for the accelerator already excavated, problems with the superconducting magnets needed for the ISABELLE accelerator brought the project to a halt, and the project was eventually cancelled in 1983.

    The National Synchrotron Light Source (US) operated from 1982 to 2014 and was involved with two Nobel Prize-winning discoveries. It has since been replaced by the National Synchrotron Light Source II (US) [below].

    After ISABELLE’S cancellation, physicist at BNL proposed that the excavated tunnel and parts of the magnet assembly be used in another accelerator. In 1984 the first proposal for the accelerator now known as the Relativistic Heavy Ion Collider (RHIC)[below] was put forward. The construction got funded in 1991 and RHIC has been operational since 2000. One of the world’s only two operating heavy-ion colliders, RHIC is as of 2010 the second-highest-energy collider after the Large Hadron Collider(CH). RHIC is housed in a tunnel 2.4 miles (3.9 km) long and is visible from space.

    On January 9, 2020, It was announced by Paul Dabbar, undersecretary of the US Department of Energy Office of Science, that the BNL eRHIC design has been selected over the conceptual design put forward by DOE’s Thomas Jefferson National Accelerator Facility [Jlab] (US) as the future Electron–ion collider (EIC) in the United States.

    In addition to the site selection, it was announced that the BNL EIC had acquired CD-0 (mission need) from the Department of Energy. BNL’s eRHIC design proposes upgrading the existing Relativistic Heavy Ion Collider, which collides beams light to heavy ions including polarized protons, with a polarized electron facility, to be housed in the same tunnel.

    Other discoveries

    In 1958, Brookhaven scientists created one of the world’s first video games, Tennis for Two. In 1968 Brookhaven scientists patented Maglev, a transportation technology that utilizes magnetic levitation.

    Major facilities

    Relativistic Heavy Ion Collider (RHIC), which was designed to research quark–gluon plasma and the sources of proton spin. Until 2009 it was the world’s most powerful heavy ion collider. It is the only collider of spin-polarized protons.
    Center for Functional Nanomaterials (CFN), used for the study of nanoscale materials.
    BNL National Synchrotron Light Source II(US), Brookhaven’s newest user facility, opened in 2015 to replace the National Synchrotron Light Source (NSLS), which had operated for 30 years.[19] NSLS was involved in the work that won the 2003 and 2009 Nobel Prize in Chemistry.
    Alternating Gradient Synchrotron, a particle accelerator that was used in three of the lab’s Nobel prizes.
    Accelerator Test Facility, generates, accelerates and monitors particle beams.
    Tandem Van de Graaff, once the world’s largest electrostatic accelerator.
    Computational Science resources, including access to a massively parallel Blue Gene series supercomputer that is among the fastest in the world for scientific research, run jointly by Brookhaven National Laboratory and Stony Brook University.
    Interdisciplinary Science Building, with unique laboratories for studying high-temperature superconductors and other materials important for addressing energy challenges.
    NASA Space Radiation Laboratory, where scientists use beams of ions to simulate cosmic rays and assess the risks of space radiation to human space travelers and equipment.

    Off-site contributions

    It is a contributing partner to ATLAS experiment, one of the four detectors located at the Large Hadron Collider (LHC).

    It is currently operating at CERN near Geneva, Switzerland.

    Brookhaven was also responsible for the design of the SNS accumulator ring in partnership with Spallation Neutron Source at DOE’s Oak Ridge National Laboratory (US), Tennessee.

    Brookhaven plays a role in a range of neutrino research projects around the world, including the Daya Bay Neutrino Experiment (CN) nuclear power plant, approximately 52 kilometers northeast of Hong Kong and 45 kilometers east of Shenzhen, China.

    Brookhaven Campus.

  • richardmitnick 11:08 am on July 20, 2019 Permalink | Reply
    Tags: "Yes Virtual Particles Can Have Real Observable Effects", A neutron star despite being mostly made of neutral particles produces the strongest magnetic fields in the Universe., As particle-antiparticle pairs pop in-and-out of existence they can interact with real particles, , , , , In 2016 scientists were able to locate a neutron star that was close enough and possessed a strong enough magnetic field to make these observations possible., On scales of both the very large and the very small we do far better by applying our best scientific theories extracting physical predictions and then observing and measuring the critical phenomena., , Real particles like electrons or photons leaving signatures imprinted on the real particles that are potentially observable., The light around RX J1856.5–3754 is just perfect., The nature of our quantum Universe is puzzling counterintuitive and testable. The results don’t lie., Vacuum birefringence, When you apply a strong magnetic field particles and antiparticles have opposite charges from one another., When you have particle/antiparticle pairs present in empty space you might think they simply pop into existence live for a little while and then re-annihilate and go back into nothingness.   

    From Ethan Siegel: “Yes, Virtual Particles Can Have Real, Observable Effects” 

    From Ethan Siegel
    July 19, 2019

    As electromagnetic waves propagate away from a source that’s surrounded by a strong magnetic field, the polarization direction will be affected due to the magnetic field’s effect on the vacuum of empty space: vacuum birefringence. By measuring the wavelength-dependent effects of polarization around neutron stars with the right properties, we can confirm the predictions of virtual particles in the quantum vacuum. (N. J. SHAVIV / SCIENCEBITS)

    The nature of our quantum Universe is puzzling, counterintuitive, and testable. The results don’t lie.

    Although our intuition is an incredibly useful tool for navigating daily life, developed from a lifetime of experience in our own bodies on Earth, it’s often horrid for providing guidance outside of that realm. On scales of both the very large and the very small, we do far better by applying our best scientific theories, extracting physical predictions, and then observing and measuring the critical phenomena.

    Without this approach, we never would have come to understood the basic building blocks of matter, the relativistic behavior of matter and energy, or the fundamental nature of space and time themselves. But nothing matches the counterintuitive nature of quantum vacuum. Empty space isn’t completely empty, but consists of an indeterminate state of fluctuating fields and particles. It’s not science fiction; it’s a theoretical framework with testable, observable predictions. 80 years after Heisenberg first postulated an observational test, humanity has confirmed it. Here’s what we’ve learned.

    An illustration between the inherent uncertainty between position and momentum at the quantum level. There is a limit to how well you can measure these two quantities simultaneously, and uncertainty shows up in places where people often least expect it. (E. SIEGEL / WIKIMEDIA COMMONS USER MASCHEN)

    Discovering that our Universe was quantum in nature brought with it a lot of unintuitive consequences. The better you measured a particle’s position, the more fundamentally indeterminate its momentum was. The shorter an unstable particle lived, the less well-known its mass fundamentally was. Material objects that appear to be solid on macroscopic scales can exhibit wave-like properties under the right experimental conditions.

    But empty space holds perhaps the top spot when it comes to a phenomenon that defies our intuition. Even if you remove all the particles and radiation from a region of space — i.e., all the sources of quantum fields — space still won’t be empty. It will consist of virtual pairs of particles and antiparticles, whose existence and energy spectra can be calculated. Sending the right physical signal through that empty space should have consequences that are observable.

    An illustration of the early Universe as consisting of quantum foam, where quantum fluctuations are large, varied, and important on the smallest of scales. (NASA/CXC/M.WEISS)

    The particles that temporarily exist in the quantum vacuum themselves might be virtual, but their effect on matter or radiation is very real. When you have a region of space that particles pass through, the properties of that space can very much have real, physical effects that be predicted and tested.

    One of those effects is this: when light propagates through a vacuum, if space is perfectly empty, it should move through that space unimpeded: without bending, slowing, or breaking into multiple wavelengths. Applying an external magnetic field doesn’t change this, as photons, with their oscillatory electric and magnetic fields, don’t bend in a magnetic field. Even when your space is filled with particle/antiparticle pairs, this effect doesn’t change. But if you apply a strong magnetic field to a space filled with particle/antiparticle pairs, suddenly a real, observable effect arises.

    Visualization of a quantum field theory calculation showing virtual particles in the quantum vacuum. (Specifically, for the strong interactions.) Even in empty space, this vacuum energy is non-zero. As particle-antiparticle pairs pop in-and-out of existence, they can interact with real particles like electrons or photons, leaving signatures imprinted on the real particles that are potentially observable. (DEREK LEINWEBER)

    When you have particle/antiparticle pairs present in empty space, you might think they simply pop into existence, live for a little while, and then re-annihilate and go back into nothingness. In empty space with no external fields, this is true: Heisenberg’s energy-time uncertainty principle applies, and so long as all the relevant conservation laws are still obeyed, this is all that happens.

    But when you apply a strong magnetic field, particles and antiparticles have opposite charges from one another. Particles with the same velocities but opposite charges will bend in opposite directions in the presence of a magnetic field, and light that passes through a region of space with charged particles that move in this particular fashion should exhibit an effect: it should get polarized. If the magnetic field is strong enough, this should lead to an observably large polarization, by an amount that’s dependent on the strength of the magnetic field.

    There have been many attempts to measure the effect of vacuum birefringence in a laboratory setting, such as with a direct laser pulse setup as shown here. However, they have been unsuccessful so far, as the effects have been too small to be seen with terrestrial magnetic fields, even with gamma rays at the GeV scale.(YOSHIHIDE NAKAMIYA, KENSUKE HOMMA, TOSEO MORITAKA, AND KEITA SETO, VIA ARXIV.ORG/ABS/1512.00636)

    This effect is known as vacuum birefringence, occurring when charged particles get yanked in opposite directions by strong magnetic field lines. Even in the absence of particles, the magnetic field will induce this effect on the quantum vacuum (i.e., empty space) alone. The effect of this vacuum birefringence gets stronger very quickly as the magnetic field strength increases: as the square of the field strength. Even though the effect is small, we have places in the Universe where the magnetic field strengths get large enough to make these effects relevant.

    Earth’s natural magnetic field might only be ~100 microtesla, and the strongest human-made fields are still only about 100 T. But neutron stars give us the opportunity for particularly extreme conditions, giving us large volumes of space where the field strength exceeds 10⁸ (100 million) T, ideal conditions for measuring vacuum birefringence.

    A neutron star, despite being mostly made of neutral particles, produces the strongest magnetic fields in the Universe, a quadrillion times stronger than the fields at the surface of Earth. When neutron stars merge, they should produce both gravitational waves and also electromagnetic signatures, and when they cross a threshold of about 2.5 to 3 solar masses (depending on spin), they can become black holes in under a second. (NASA / CASEY REED — PENN STATE UNIVERSITY)

    How do neutron stars make such large magnetic fields? The answer may not be what you think. Although it might be tempting to take the name ‘neutron star’ quite literally, it isn’t made exclusively out of neutrons. The outer 10% of a neutron star consists mostly of protons, light nuclei, and electrons, which can stably exist without being crushed at the neutron star’s surface.

    Neutron stars rotate extremely rapidly, frequently in excess of 10% the speed of light, meaning that these charged particles on the outskirts of the neutron star are always in motion, which necessitated the production of both electric currents and induced magnetic fields. These are the fields we should be looking for if we want to observe vacuum birefringence, and its effect on the polarization of light.

    Light coming from the surface of a neutron star can be polarized by the strong magnetic field it passes through, thanks to the phenomenon of vacuum birefringence. Detectors here on Earth can measure the effective rotation of the polarized light. (ESO/L. CALÇADA)

    It’s a challenge to measure the light from neutron stars: although they’re quite hot, hotter even than normal stars, they’re tiny, with diameters of just a few dozen kilometers. A neutron star is like a glowing Sun-like star, at perhaps two or three times the temperature of the Sun, compressed into a volume the size of Washington, D.C.

    Neutron stars are very faint, but they do emit light from all across the spectrum, including all the way down into the radio part of the spectrum. Depending on where we choose to look, we can observe the wavelength-dependent effects that the effect of vacuum birefringence has on the light’s polarization.

    VLT image of the area around the very faint neutron star RX J1856.5–3754. The blue circle, added by E. Siegel, shows the location of the neutron star. Note that despite appearing very faint and red in this image, there is enough light reaching our detectors for us, with the proper instrumentation, to search for this vacuum birefringence effect. (ESO)

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    Glistening against the awesome backdrop of the night sky above ESO_s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT, a major asset of the Adaptive Optics system

    All of the light that’s emitted must pass through the strong magnetic field around the neutron star on its way to our eyes, telescopes, and detectors. If the magnetized space that it passes through exhibits the expected vacuum birefringence effect, that light should all be polarized, with a common direction of polarization for all the photons.

    In 2016, scientists were able to locate a neutron star that was close enough and possessed a strong enough magnetic field to make these observations possible. Working with the Very Large Telescope (VLT) in Chile, which can take fantastic optical and infrared observations, including polarization, a team led by Roberto Mignani was able to measure the polarization effect from the neutron star RX J1856.5–3754.

    A contour plot of the phase-averaged linear polarization degree in two models (left and right): for an isotropic blackbody and for a model with a gaseous atmosphere. At top, you can see the observational data, while at the bottom, you can see what you get if you subtract out the theoretical effect of vacuum birefringence from the data. The effects match partically perfectly. (R.P. MIGNANI ET AL., MNRAS 465, 492 (2016))

    The authors were able to extract, from the data, a large effect: a polarization degree of around 15%. They also calculated what the theoretical effect from vacuum birefringence ought to be, and subtracted it out from the actual, measured data. What they found was spectacular: the theoretical effect of vacuum birefringence accounted for practically all of the observed polarization. In other words, the data and the predictions matched almost perfectly.

    You might think that a closer, younger pulsar (like the one in the Crab Nebula) might be better suited to making such a measurement, but there’s a reason that RX J1856.5–3754 is special: its surface is not obscured by a dense, plasma-filled magnetosphere.

    If you watch a pulsar like the one in the Crab Nebula, you can see the effects of opacity in the region surrounding it; it’s simply not transparent to the light we’d want to measure.

    Supernova remnant Crab nebula. NASA/ESA Hubble

    But the light around RX J1856.5–3754 is just perfect. With the polarization measurements in this portion of the electromagnetic spectrum from this pulsar, we have confirmation that light is, in fact, polarized in the same direction as the predictions arising from vacuum birefringence in quantum electrodynamics. This is the confirmation of an effect predicted so long ago — in 1936 — by Werner Heisenberg and Hans Euler that, decades after the death of both men, we can now add “theoretical astrophysicist” to each of their resumes.

    The future X-ray observatory by the ESA, Athena, will include the capability of measuring the polarization of X-ray light from space, something that none of our leading observatories today, such as Chandra and XMM-Newton, can do. (ESA / ATHENA COLLABORATION)

    NASA/Chandra X-ray Telescope

    ESA/XMM Newton

    Now that the effect of vacuum birefringence has been observed — and by association, the physical impact of the virtual particles in the quantum vacuum — we can attempt to confirm it even further with more precise quantitative measurements. The way to do that is to measure RX J1856.5–3754 in the X-rays, and measuring the polarization of X-ray light.

    While we don’t have a space telescope capable of measuring X-ray polarization right now, one of them is in the works: the ESA’s Athena mission. Unlike the ~15% polarization observed by the VLT in the wavelengths it probes, X-rays should be fully polarized, displaying right around an 100% effect. Athena is currently slated for launch in 2028, and could deliver this confirmation for not just one but many neutron stars. It’s another victory for the unintuitive, but undeniably fascinating, quantum Universe.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    “Starts With A Bang! is a blog/video blog about cosmology, physics, astronomy, and anything else I find interesting enough to write about. I am a firm believer that the highest good in life is learning, and the greatest evil is willful ignorance. The goal of everything on this site is to help inform you about our world, how we came to be here, and to understand how it all works. As I write these pages for you, I hope to not only explain to you what we know, think, and believe, but how we know it, and why we draw the conclusions we do. It is my hope that you find this interesting, informative, and accessible,” says Ethan

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