Lifeboat Foundation

An accelerator known as a muon collider could revolutionize particle physics—if it can be built.

The renowned scientist won the Nobel Prize for Physics in 2013.

Last week, at the annual Rencontres de Moriond conference, the CMS collaboration presented a measurement of the effective leptonic electroweak mixing angle. The result is the most precise measurement performed at a hadron collider to date and is in good agreement with the prediction from the Standard Model.

The Standard Model of particle physics is the most precise description to date of particles and their interactions. Precise measurements of its parameters, combined with precise theoretical calculations, yield spectacular predictive power that allows phenomena to be determined even before they are directly observed.

In this way, the model successfully constrained the masses of the W and Z bosons (discovered at CERN in 1983), of the top quark (discovered at Fermilab in 1995) and, most recently, of the Higgs boson (discovered at CERN in 2012). Once these particles had been discovered, these predictions became consistency checks for the model, allowing physicists to explore the limits of the theory’s validity.

First of all, they have to have survived the impact. Laboratory tests have shown that frozen specimens of the Hypsibius dujardini species travelling at 3,000 km/h in a vacuum were fatally damaged when they smashed into sand. However, they survived impacts of 2,600 km/h or less – and their “hard landing” on the Moon, unwanted or not, was far slower.

The Moon’s surface is not protected from solar particles and cosmic rays, particularly gamma rays, but here too, the tardigrades would be able to resist. In fact, Robert Wimmer-Schweingruber, professor at the University of Kiel in Germany, and his team have shown that the doses of gamma rays hitting the lunar surface were permanent but low compared with the doses mentioned above – 10 years’ exposure to Lunar gamma rays would correspond to a total dose of around 1 Gy.

But then there’s the question of “life” on the Moon. The tardigrades would have to withstand a lack of water as well as temperatures ranging from −170 to −190°C during the lunar night and 100 to 120°C during the day. A lunar day or night lasts a long time, just under 15 Earth days. The probe itself wasn’t designed to withstand such extremes and even if it hadn’t crashed, it would have ceased all activity after just a few Earth days.

New technique measures the gravitational pull on a micron-scale levitating magnetic particle.

That is, until we drop an egg, spill our coffee, or an expensive vase falls off a shelf in our homes, reminding us that even the weakest of the four fundamental interactions known to physics, while hidden in plain sight, still exerts a significant influence on everything around us.

Some 10²⁹ times weaker than the appropriately named weak force, which governs the radioactive decay of atoms, gravity is so subtle that it has virtually no effect at the subatomic level. Yet at the scale where interactions between objects are observable to us, gravity is the force that literally commands the motions of planets, as well as that of stars and galaxies. Even light, which universal laws govern to be the fastest thing in existence, cannot escape the influence of gravity.

Despite its ubiquity, gravity also remains one of the great mysteries of modern physics. While there remains no complete or perfect theory as to how gravity works, the best description of it remains the one Einstein gave us in 1915 with the publication of his general theory of relativity. To Einstein, gravity can be thought of not so much as a force acting on objects, but instead as a way to observe the curvature of spacetime itself that results from variances in the distribution of mass throughout the universe.

Ever since its discovery in 2004, graphene has been revolutionizing the field of materials science and beyond. Graphene comprises two-dimensional sheets of carbon atoms, bonded into a thin hexagonal shape with a thickness of one atom layer. This gives it remarkable physical and chemical properties.

Operating at CERN’s Large Hadron Collider (LHC) since 2022, the FASER experiment is designed to search for extremely weakly interacting particles. Such particles are predicted by many theories beyond the Standard Model that are attempting to solve outstanding problems in physics such as the nature of dark matter and the matter-antimatter imbalance in the universe.

University of Copenhagen team contributes to an Antarctic large-scale experiment striving to find out if gravity also exists at the quantum level; An extraordinary particle able to travel undisturbed through space seems to hold the answer.

Several thousand sensors distributed over a square kilometer near the South Pole are tasked with answering one of the large outstanding questions in physics: does quantum gravity exist? The sensors monitor neutrinos – particles with no electrical charge and almost without mass – arriving at the Earth from outer space. A team from the Niels Bohr Institute (NBI), University of Copenhagen, has contributed to developing the method that exploits neutrino data to reveal if quantum gravity exists.

“If as we believe, quantum gravity does indeed exist, this will contribute to unite the current two worlds in physics. Today, classical physics describes the phenomena in our normal surroundings such as gravity, while the atomic world can only be described using quantum mechanics. The unification of quantum theory and gravitation remains one of the most outstanding challenges in fundamental physics. It would be very satisfying if we could contribute to that end,” says Tom Stuttard, Assistant Professor at NBI.