Theory that challenges Einstein's physics could soon be put to the test November 25, 2016 by Hayley Dunning Scientists behind a theory that the speed of light is variable - and not constant as Einstein suggested - have made a prediction that could be tested. Einstein observed that the speed of light remains the same in any situation, and this meant that space and time could be different in different situations. The assumption that the speed of light is constant, and always has been, underpins many theories in physics, such as Einstein's theory of general relativity. In particular, it plays a role in models of what happened in the very early universe, seconds after the Big Bang. But some researchers have suggested that the speed of light could have been much higher in this early universe. Now, one of this theory's originators, Professor João Magueijo from Imperial College London, working with Dr Niayesh Afshordi at the Perimeter Institute in Canada, has made a prediction that could be used to test the theory's validity. Structures in the universe, for example galaxies, all formed from fluctuations in the early universe – tiny differences in density from one region to another. A record of these early fluctuations is imprinted on the cosmic microwave background – a map of the oldest light in the universe – in the form of a 'spectral index'. Working with their theory that the fluctuations were influenced by a varying speed of light in the early universe, Professor Magueijo and Dr Afshordi have now used a model to put an exact figure on the spectral index. The predicted figure and the model it is based on are published in the journal Physical Review D. Read more at: http://phys.org/news/2016-11-theory-einstein-physics.html#jCp
http://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.101301 Critical geometry of a thermal big bang: ABSTRACT: We explore the space of scalar-tensor theories containing two nonconformal metrics, and find a discontinuity pointing to a “critical” cosmological solution. Due to the different maximal speeds of propagation for matter and gravity, the cosmological fluctuations start off inside the horizon even without inflation, and will more naturally have a thermal origin (since there is never vacuum domination). The critical model makes an unambiguous, nontuned prediction for the spectral index of the scalar fluctuations: nS=0.96478(64). Considering also that no gravitational waves are produced, we have unveiled the most predictive model on offer. The model has a simple geometrical interpretation as a probe 3-brane embedded in an EAdS2×E3geometry. Received 10 March 2016
Nice article, but my money is that nothing new will come to fruition. Please Register or Log in to view the hidden image!
I have confidence that the research, rigour, observational verification, and predictive powers, will hold true for Einsteins theories. I don't believe I have ever doubted that.
They certainly do hold up under research, rigour, predictive power and observational verification. This however doesn't mean they are necessarily a complete description of nature; only a self-consistent and useful one. No theory before or since has ever achieved the level of scientific certainty relativity has for over 100 years and a decade. It correctly predicted the existence of gravity waves beyond that, even if it failed to predict what magnitude to expect from specific events. And it has a real pleasure watching these events unfold with you.
While no one has said its a complete description of nature, perhaps the question should be asked, if there is any complete description of nature? We have no way of knowing that any QGT will even be a complete description of nature...... Couldn't agree more, on all counts!
No complete description of nature exists other than that provided by nature herself, the only both complete and self-consistent description of anything. No symbols are necessary for nature to pare down her descriptions to make it possible for finite minds to grasp the essentials about what she does or how to reason about them. This is the missing corollary to Gödel's incompleteness theorems which as far as I know, has never been explicitly stated anywhere, other than where you have just read it. Those individuals disposed to treating mathematics as something superior to nature should re-read it as many times as it takes for its importance to sink in. It applies to anything that can be expressed symbolically, used by any mind that is the product of evolution, including reasoning engines constructed by them which operate by means of symbolic logic. It saves an awful lot of wasted effort trying in vain to implement machinery that reasons in our own image. To reason otherwise is tantamount to idolatry because a symbol is inferior to nature, as is any idea(s) derived of them. Godel alone tells us why. Einstein evidently understood this. Of course, this idea would belong in philosophy, not science.
