#18 Un post muy largo para decir "magufo".
Lo de la velocidad dependiendo de la frecuencia es un experimento que ya se hizo. No hay variación. Esto lo veo totalmente correcto. Cualquier hipótesis capaz de plantear una predicción medible es una buena hipótesis, aunque resulte luego ser falsa. Cayó, pero cayó como se debe caer.
Si has llegado hasta aquí no te costará nada leer el original en inglés:
Why Lee Smolin is an immoral double-faced fraudster and liar
August 23, 2009
Every competent high-energy physicist who knows Lee Smolin may confirm that Smolin is the ultimate symbol of the complete absence of the scientific integrity and, indeed, the very basic human ethical values.
David Gross discusses some experience with a double-faced Lee Smolin - concerning AdS/CFT and background independence - in their discussion with journalist George Johnson. It was the very first public video from which the laymen could learn that the top physicists consider Lee Smolin to be a crackpot - a fact that would be completely hidden if the information only depended on the journalists.
More worrisome and persistent stories are often told by A.S., A.V., R.B., and many other big shots.
But what he's doing and saying after the Fermi collaborations have proved that all the "theories" he has ever invented about quantum gravity were rubbish simply exceeds all the limits that could be tolerable for a person who should be allowed to freely walk on the street.
After many years when he was boasting about his "falsifiable predictions" of loop quantum gravity (Lee has even become a template for Leslie Winkle in an award-winning sitcom) that were moreover completely "generic", and when he was using these "predictions" to sling mud on the top research in high-energy physics, namely string theory, he has turned his coat.
Quite suddenly, everything is different. There have never been any predictions, he says. Let's compare what he said about loop quantum gravity e.g. for edge.org and what he's writing these days. Edge.org:
When we first worked out the predictions for these smallest units of area and volume, we had no idea that they would be observable in real experiments in our lifetime. However, a number of people—beginning with Rodolfo Gambini, of the University of the Republic in Montevideo, and Jorge Pullin, then at Penn State—showed that there are indeed observable consequences. At about the same time, Amelino-Camelia and others were pointing out that if there were such effects, they would be detectable in experiments involving cosmic rays and gamma-ray bursts. These effects are caused by light scattering off the discrete structure of the quantum geometry, analogous to diffraction and refraction from light scattering off the molecules of the air or liquid it passes through. The quantum gravity effect is tiny—many orders of magnitude smaller than that due to matter. However, we observe light from gamma-ray bursts—huge explosions, possibly caused by mergers of binary neutron stars or black holes—that has traveled across the universe for some 10 billion light-years. Over such long distances, the small effects amplify to the point where they can be observed. Because elementary particles travel as waves in quantum theory, the same thing happens to such particles—protons and neutrinos, for example. It is possible that these effects may be responsible for the surprises I mentioned in the observations of very-high-energy cosmic rays.
Now, here is the really interesting part: Some of the effects predicted by the theory appear to be in conflict with one of the principles of Einstein's special theory of relativity, the theory that says that the speed of light is a universal constant. It's the same for all photons, and it is independent of the motion of the sender or observer.
How is this possible, if that theory is itself based on the principles of relativity? The principle of the constancy of the speed of light is part of special relativity, but we quantized Einstein's general theory of relativity. Because Einstein's special theory is only a kind of approximation to his general theory, we can implement the principles of the latter but find modifications to the former. And this is what seems to be happening!
So Gambini, Pullin, and others calculated how light travels in a quantum geometry and found that the theory predicts that the speed of light has a small dependence on energy. Photons of higher energy travel slightly slower than low-energy photons. The effect is very small, but it amplifies over time. Two photons produced by a gamma-ray burst 10 billion years ago, one redder and one bluer, should arrive on Earth at slightly different times. The time delay predicted by the theory is large enough to be detectable by a new gamma-ray observatory called GLAST (for Gamma-ray Large Area Space Telescope), which is scheduled for launch into orbit in 2006. We very much look forward to the announcement of the results, as they will be testing a prediction of a quantum theory of gravity.