dark energy

At Horizons EU we are told, “New efforts to figure out just how fast the universe has expanded since the Big Bang, a speed known as the Hubble constant, could upend current theories of physics , according to some scientists. If current theories were upended, who would know. Consider these stories from this month alone: Discover: Even the best dark matter theories “are crumbling” Is there a crisis in the physics of our time? The cat is back: Is quantum theory dead, alive, AND contradicting itself? “Perhaps physics has slipped into a post-empirical era…” That’s a lot of fundamental uncertainty, as opposed to the endless quibbles of any scholarly discipline. Ultimately, more accurate measurements would establish the correct value of Read More ›

That’s dark energy.topic The most mysterious phenomenon in cosmology – dark energy – may not exist at all, according to Professor Subir Sarkar, head of the particle theory group at the University of Oxford in the UK. In the late 1990s, astronomers found evidence from supernovae that the universe has been expanding faster and faster as it gets older. Having no explanation for what was driving it, they dubbed this accelerating expansion ‘dark energy’. What did you think about these findings at the time? ‘I was sceptical from the beginning. I’m unusual in the cosmology community in that I’ve had experience working in experiments as well as theory, and I didn’t think the astronomers were taking full account of the Read More ›

Dark energy. Even the name is intriguing. Isn’t it a line of cosmetics already? But the evidence base is getting murkier all the time. The conjecture, if true, would mean the density of dark energy in our universe cannot be constant, but must instead take a form called “quintessence” — an energy source that will gradually diminish over tens of billions of years. Several telescope experiments are underway now to more precisely probe whether the universe is expanding with a constant rate of acceleration, which would mean that as new space is created, a proportionate amount of new dark energy arises with it, or whether the cosmic acceleration is gradually changing, as in quintessence models. A discovery of quintessence would Read More ›

From ScienceDaily: One of the candidates for ‘dark energy’ is the symmetron field. Researchers have developed an experiment capable of measuring extremely small forces with the help of neutrons. The measurements could have provided pointers to the mysterious symmetrons, but the particles didn’t show up. This excludes the possibility of symmetrons in a broad parameter range. ‘Dark energy’ is going to have to be explained differently. One thing is certain: there’s something out there we don’t yet know. For years now scientists have been looking for “dark matter” or “dark energy” — with our current inventory of particles and forces in nature we just can’t explain major cosmological phenomena, such as why the universe is expanding at an ever faster Read More ›