The word uncertainty is used a lot in quantum mechanics. One school of thought is that this means there’s something out there in the world that we are uncertain about. But most physicists believe nature itself is uncertain.
In 1924, French physicist Louis de Broglie proposed that photons – the subatomic particle that constitutes light – behave as both a particle and a wave. Known as “particle-wave duality”, this property has been tested and shown to apply with other subatomic particles (electrons and neutrons) as well as larger, more complex molecules.
Everything you see around you is made up of elementary particles called quarks and leptons, which can combine to form bigger particles such as protons or atoms. But that doesn’t make them boring – these subatomic particles can also combine in exotic ways we’ve never spotted. Now CERN’s LHCb collaboration has announced the discovery of a clutch of new particles dubbed “pentaquarks”. The results can help unveil many mysteries of the theory of quarks, a key part of the standard model of particle physics.
In February of 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) made history by announcing the first-ever detection of gravitational waves (GWs). These ripples in the very fabric of the Universe, which are caused by black hole mergers or white dwarfs colliding, were first predicted by Einstein’s Theory of General Relativity roughly a century ago.
The idea of one day traveling to another star system and seeing what is there has been the fevered dream of people long before the first rockets and astronauts were sent to space. But despite all the progress we have made since the beginning of the Space Age, interstellar travel remains just that – a fevered dream. While theoretical concepts have been proposed, the issues of cost, travel time and fuel remain highly problematic.
Quantum simulation gives a sneak peek into the possibilities of time reversal. An international team of scientists led by Argonne explored the concept of reversing time in a first-of-its-kind experiment, managing to return a computer briefly to the past. The results present new possibilities for quantum computer program testing and error correction.
Physicists aren’t often reprimanded for using risqué humour in their academic writings, but in 1991 that is exactly what happened to the cosmologist Andrei Linde at Stanford University. He had submitted a draft article entitled ‘Hard Art of the Universe Creation’ to the journal Nuclear Physics B. In it, he outlined the possibility of creating a universe in a laboratory: a whole new cosmos that might one day evolve its own stars, planets and intelligent life.
Number of proton-neutron pairs determine how fast the particles move, results suggest.
The Large Hadron Collider (LHC) at CERN is the most powerful particle accelerator in the world. During its ten years of operations it has led to remarkable discoveries, including the long sought-after Higgs boson. On January 15, an international team of physicists unveiled the concept design for a new particle accelerator that would dwarf the LHC.