All posts tagged: physics

The Leap Second Is No More

The Leap Second Is No More

Published by Miika Tikkanen

“There are continuing problems with positive leap seconds even after 50 years, and the concern was that the negative leap second would be much more serious because its effects had never been tested,” Levine says. BIPM time department director Patrizia Tavella confirmed those concerns in an email to WIRED. “The probability of a negative leap second convinced us [to] set the application date in 2027,” she wrote, adding that there was added urgency following tests by an industry standards group that “showed several failures with a negative leap.” Tavella says the group is waiting until May 20 2027 to implement it because it’s the anniversary of 1875 signing of the Metre Convention, creating BIPM, as well as Metrology Day. In other words, it’s the perfect time to mark the passing of time—or more accurately, the lack thereof. The death of the leap second makes life easier for everyone now. “The nice fact is that we have nothing to do!” Tavella says. “Just continue to accumulate second[s] and ‘normal’ minutes of 60 seconds.” Levine concurs, writing …

Norman McCubbin obituary

Norman McCubbin obituary

Published by Miika Tikkanen

My brother Norman McCubbin, who has died aged 77, was a scientist who worked at the forefront of experimental particle physics. A leading light in experiments that took place on the Large Hadron Collider, the world’s biggest and most powerful particle accelerator at the European Organization for Nuclear Research (Cern) in Switzerland, he spent the last five years of his working life as director of the particle physics department at the Rutherford Appleton Laboratory (RAL) in Oxfordshire, until his retirement in 2012. Afterwards he became a tutor to undergraduates at St Anne’s College, Oxford, and was still in that role at his death. Norman was born in Pinner, Middlesex, the first child of Hugh, an accountant, and his wife, Pat (nee Rosenberg). The family moved to Leicester, where his brothers, Richard and I, were born, and then in 1958 to Kenya for Hugh to take up a post as finance director of the Kenya Farmers’ Association . When Hugh joined the UN’s World Food Programme, the family moved to Lesotho and later, Taiwan, while Norman …

Precision physics and the measurements that can change a theory

Precision physics and the measurements that can change a theory

Published by Miika Tikkanen

A more precise result can expose a new problem or resolve an apparent discrepancy. Muons, particle masses and optical clocks show why progress depends on the relationship between measurement, calculation and independent comparison. An extra decimal place can change a scientific argument. It can make an apparent disagreement harder to ignore, reveal a previously hidden instrumental effect or show that a prediction works better than expected. The result matters because of the question it resolves, rather than because the number is unusually precise. This is the common thread connecting several active areas of physics. A particle circulating in a magnetic field, a short lived boson reconstructed from its decay products and an atom used to keep time seem far apart. Each becomes useful when researchers can explain exactly what was measured and how far the result can be trusted. For research leaders and technology developers, the comparison also changes where investment appears most valuable. More data may help, but so may a better calculation, an improved reference instrument or a second method that responds differently …

Nobel physics prize awarded for discovery of ‘ghostly messengers’ from the cosmos

Nobel physics prize awarded for discovery of ‘ghostly messengers’ from the cosmos

Published by Miika Tikkanen

The 2026 Nobel prize for physics has been awarded to US-based researcher Francis Halzen for his discovery of high energy neutrino particles from space. The Nobel committee said Halzen has made “decisive contributions” to the discovery of “neutrinos of astrophysical origin” with IceCube, an experiment installed under ice at the South Pole. Ellen Moons, secretary general of the Royal Swedish Academy of Sciences, described these neutrinos as “ghostly messengers”. This references the fact the particles have nearly no mass and pass through solid objects with hardly any interaction. In fact, billions of neutrinos pass through any given person on Earth every second. Most of these neutrinos are emitted by the Sun. However, high energy neutrinos coming from elsewhere in the cosmos also reach our planet. These neutrinos are about a billion times rarer than those that stream out from the Sun. They originate from diverse sources, such as black holes located at the hearts of distant galaxies that accelerate particles to extreme energies. The idea for the IceCube experiment was to use the ice at …

How much can we stretch the proton and the neutron?

How much can we stretch the proton and the neutron?

Published by Miika Tikkanen

How does a nucleon respond to an electromagnetic field? Professors Haiyan Gao and Calvin Howell of Duke University outline the Experimental Programme using Photons to Stretch the Nucleon More than 99% of visible matter in the Universe is from atomic nuclei with building blocks of protons and neutrons, known together as nucleons. Atomic nuclei are interesting laboratories that nature provides in which all four fundamental forces are present. They include the strong nuclear force that binds nucleons into the nucleus, nuclear beta decay driven by the weak force, electromagnetic force between the nucleons associated with charge and magnetic dipole moments, and the gravitational force between any two nucleons. While the theory of strong force, quantum chromodynamics (QCD), has been well established for more than half a century, our understanding of how the theory works is rather limited, especially in the energy region where ordinary matter exists. As such, the study of the nucleon structure that started in the 1950s continues to be a vibrant field due to the richness and internal dynamics of the nucleon …

AI makes its first meaningful breakthrough in theoretical physics

AI makes its first meaningful breakthrough in theoretical physics

Published by Jenni Sidey

One of the greatest challenges — and perhaps the most important challenge of all — for any theoretical physicist is to connect something you can predictively calculate to something you can go out and measure experimentally or observationally. This is the key not just to testing your current best understanding of reality, but to discovering any anomalies that could pave the way forward to the next revolution in our conception of the Universe. Most of the great revolutions in physics history have arisen where theory and observation/experiment have failed to match, including: the mismatch in Uranus’s predicted orbit from Kepler’s laws leading to the discovery of Netpune, the extra precession observed over what Newton predicted for Mercury’s orbit leading to general relativity, and the failure of classical physics to predict the short-wavelength behavior of a radiating blackbody leading to the start of the quantum revolution. Over the past few generations, quantum field theory is how we arrive at the most precise physical predictions ever made. The act of testing those predictions against particle physics experiments …

With a Better Understanding of Physics, We Could Predict Volcanic Eruptions

With a Better Understanding of Physics, We Could Predict Volcanic Eruptions

Published by Miika Tikkanen

As part of this work, hundreds of seismometers, as well as networks of fiber-optic cables, will be used to record even the tiniest of earthquakes during periods of tranquility and unrest. This monitoring effort will be aided by machine learning programs that will be taught to identify minute shifts in the seismic soundtrack of these volcanoes. In recent years, these programs have been used to process a huge volume of data far more proficiently and efficiently than scientists can manage alone. This work has already revealed myriad previously hidden magmatic pathways beneath volcanoes while also permitting scientists to track, almost in real time, magma barreling through the crust. The idea of Ex-X is to gain unprecedented detail on how tiny changes in the behavior or position of magma can lead to eruptions. Those insights can, in turn, illuminate some of the underlying physics. All these Caribbean volcanoes, diverse though they may be, could have a shared set of fluid dynamics equations. However, seismology won’t be enough by itself. “We lack the physical understanding of what …

Is It Even Possible to Understand Quantum Mechanics?

Is It Even Possible to Understand Quantum Mechanics?

Published by Miika Tikkanen

That’s just silly, right? It’s crazy that the act of measurement changes the outcome. Does this mean that physics experiments can change reality? Maybe. What About That Zombie Cat? I mentioned Erwin Schrödinger above. He was one of the pioneers of quantum theory, but he couldn’t bring himself to accept this idea of superposition. Using his macro-world common sense, he insisted there must be a flaw in the model, and that a complete theory of quantum mechanics would eventually be deterministic like classical physics. When scientists don’t like something, they make up absurd scenarios to invite mockery of its proponents. So Schrödinger created a famous thought experiment you may have heard of. It’s called Schrödinger’s Cat, and it goes like this: There is a cat in a box. This box also contains a radioactive atom, a detector, and a vial of poison. If the atom decays and produces radiation, the detector will open the vial and the cat will die. But if the box is closed, the atom is in a superposition state, being both …

Future Circular Collider positrons produced for first time at PSI

Future Circular Collider positrons produced for first time at PSI

Published by Miika Tikkanen

Researchers at the Paul Scherrer Institute (PSI) in Switzerland have successfully produced the first positrons using a prototype source designed for CERN’s proposed Future Circular Collider (FCC). The test system, installed at the SwissFEL X-ray free-electron laser facility, combines high-temperature superconducting magnets with new beam-control technologies to generate and capture positrons at high efficiency. The milestone is significant because producing sufficient positrons and forming them into a usable beam is one of the major technical challenges facing the proposed collider. PSI researchers have spent around five years developing the new source, which is intended to address limitations in existing positron-production technology. Initial results indicate that the system could capture enough positrons to meet the demanding requirements of the FCC. The successful first production demonstrates that the prototype’s key components can operate together and provides a foundation for further work to increase beam intensity and optimise performance. The positron challenge facing the Future Circular Collider The Future Circular Collider is being studied by CERN as a potential successor to the Large Hadron Collider (LHC). The proposed …

What Is Entropy, Really?

What Is Entropy, Really?

Published by Miika Tikkanen

Entropy is one of the most maligned and misunderstood concepts in science. Maybe you’ve heard it defined as the “amount of disorder” in a system. And the second law of thermodynamics says the entropy of a closed system always increases over time. So you might think, why should you clean up your office if it will only get messier? That might be true, but you can’t blame it on entropy. The messy-room metaphor is often used to introduce the idea (it’s usually a teenager’s bedroom—can you relate?), but it’s misleading. See, disorder doesn’t mean messiness or chaos; it refers to the number of ways the parts of a system can be arranged without changing the overall state of the system. For example, say your “system” is just a box full of air. Inside, at the microscopic level, the gas molecules are bouncing around like bumper cars. Now, imagine you could map the location and velocity of each particle at a given instant. That would be one possible arrangement, or microstate, but there are an infinitude …