Cosmic 'barcode' from distant galaxy confirms Nature's constancy November 15, 2016 Please Register or Log in to view the hidden image! Astronomers observed light from a quasar 8.5 billion years after it passed through distant galaxies. Credit: James Josephides and Professor Michael Murphy Astronomers have precisely measured the strength of a fundamental force of Nature in a galaxy seen eight billion years in the past. Researchers from Swinburne University of Technology and the University of Cambridge have confirmed that electromagnetism in a distant galaxy has the same strength as here on Earth. They observed a quasar – a supermassive black hole with enormously bright surroundings – located behind the galaxy. On its journey toward Earth, some of the quasar's light was absorbed by gas in the galaxy eight billion years ago, casting shadows at very specific colours. Read more at: http://phys.org/news/2016-11-cosmic-barcode-distant-galaxy-nature.html#jCp
http://mnras.oxfordjournals.org/content/464/3/3679 High-precision limit on variation in the fine-structure constant from a single quasar absorption system: Abstract The brightest southern quasar above redshift z = 1, HE 0515−4414, with its strong intervening metal absorption line system at zabs = 1.1508, provides a unique opportunity to precisely measure or limit relative variations in the fine-structure constant (Δα/α). A variation of just ∼3 parts per million (ppm) would produce detectable velocity shifts between its many strong metal transitions. Using new and archival observations from the Ultraviolet and Visual Echelle Spectrograph (UVES), we obtain an extremely high signal-to-noise ratio spectrum (peaking at S/N ≈ 250 pix−1). This provides the most precise measurement of Δα/α from a single absorption system to date, Δα/α = −1.42 ± 0.55stat ± 0.65sys ppm, comparable with the precision from previous, large samples of ∼150 absorbers. The largest systematic error in all (but one) previous similar measurements, including the large samples, was long-range distortions in the wavelength calibration. These would add an ∼2 ppm systematic error to our measurement and up to ∼10 ppm to other measurements using Mg and Fe transitions. However, we corrected the UVES spectra using well-calibrated spectra of the same quasar from the High Accuracy Radial velocity Planet Searcher, leaving a residual 0.59 ppm systematic uncertainty, the largest contribution to our total systematic error. A similar approach, using short observations on future well-calibrated spectrographs to correct existing high S/N spectra, would efficiently enable a large sample of reliable Δα/α measurements. The high-S/N UVES spectrum also provides insights into analysis difficulties, detector artefacts and systematic errors likely to arise from 25–40-m telescopes.
Oh, yes! Not a window to the dynamics of the Big Bang (not old enough), but sweet. No 'tired' photons or 'stretching of space' that long ago, in that (or any other) direction. Isotropism almost as fine as the CMBR, since close to forever. Makes sense; if space stretched, energy would not be conserved. Isotropism of time is a requirement to have that. It doesn't get much deeper. For those wo don't remember, the fine structure constant is related to quantum entangled spin flips, which is the fundamental basis of time itself. This is also why for this measurement, variations in the speed of light over billions of years can be ruled out. The linear propagation of light in a vacuum is considerably slower than quantum entangled spin flips, even and especially on scales spanning billions of years.
