Did you know?

Gravitational waves, like light waves, get more and more feeble the further away we are from the source. Experiments like LIGO and VIRGO that detected the first gravitational waves have an incredible precision. In fact they can observe displacements as small as 10⁻¹⁸ meters.

Gravitational waves are waves of the spacetime so their passage make object moves with respect to each other and we can measure that displacement. 10⁻¹⁸ is an incredibly small number: To comparison the size of an atom is around 10⁻¹⁵, so the displacement they can measure is 1000 times smaller than the size of an atom.

... was the detection of proton decay, incidentally has provided important information on neutrino oscillation and the collaboration won a Nobel Prize for it!

Now the observation of proton decay is not anymore the main purpose for which these experiments are built, and these experiments are realized to study the properties of neutrinos.

The name Grand Unified Theories has been chosen because its initials make up the word GUTs.

Trying to unify all the fundamental interactions was a very ambitious project and it took some “guts” to do so. The first paper in which this name appeared was by D. Nanopoulos in 1978!

The history of the Standard Model is older than a century! The first particle to be discovered was the electron, back in 1897, by Joseph John Thomson at the Cavendish Laboratory in Cambridge. At that time, not only the Standard Model but even Quantum Mechanics, the physical theory at the basis of it, had not been formulated yet. The Higgs boson is the last particle that was discovered in 2012 at the LHC, CERN.

Not everyone in the scientific community is convinced of the existence of Dark Matter. An active research field is the so-called MOdified Newtonian Dynamics (MOND). The main idea is that the laws describing gravity must be modified in such a way that they can explain astrophysical observations without the need for additional matter. While this option is not completely ruled out, it seems harder and harder for these theories to explain the current evidence.

The original equations of General Relativity, describing the interaction between matter and gravity, predicted an expanding Universe. Einstein was not satisfied with this result and included a constant term in the equations, the so-called Cosmological Constant, in such a way that the solution allowed for a static Universe. However, soon after the development of his theory, astrophysical observations showed that the Universe is expanding! Einstein defined the Cosmological Constant as the greatest blunder of his career. However, in 1998, two groups of astrophysicists showed that the expansion of the Universe is accelerating, and this can be explained by reintroducing the Cosmological Constant. This term is interpreted today as a parametrization of Dark Energy.

Bees are not able to perceive red light, but they can perceive colours other than purple to which we humans are not sensitive! This is useful for them in better distinguishing certain flowers from others and understanding which ones to pollinate, which is of little use to us.

The GPS uses a system of satellites orbiting the earth to map the position on earth. Since it is essential to know exactly when the position request was made, effects due to relativity must be taken into account for time dilation! If this were not the case, after just one day the accumulated error would already amount to few kilometers!

Technologies using the quantum phenomenon of superposition already exist! So-called “quantum computers” (but not only!) are able to use it to speed up certain calculations exponentially! What could take a traditional computer a millennium to calculate can be done in a few minutes.