The usual hype machine is at work this week, with the usual mechanism:<\/p>\n
Normally I try to defend the journalists involved, feeling that the most irresponsible behavior is coming from the scientists themselves. In this case, Hertog has a lot to answer for, but it’s not Hawking’s fault since he’s dead. Any semi-competent journalist should have realized that this is not news: the same stories had already been written and published a month ago, and then conclusively debunked in many places (see here<\/a>, here<\/a> and here<\/a> for instance).<\/p>\n This is rather depressing, making one feel that there’s no way to fight this kind of bad science, in the face of determined efforts to promote fake physics to the public. It’s one thing for journalists to be misled by a new variant on an old debunked story, but that they’re getting misled again by exactly the same story is a new development.<\/p>\n Update<\/strong>: More hype from Hertog, this time from Scientific American, which tells us that his work is based on<\/p>\n string theory, one of the most dominant emerging paradigms in 21st-century physics.<\/p><\/blockquote>\n Hertog is asked about the undeniable fact that his work predicts nothing:<\/p>\n How do you counter critics of string theory, who argue it cannot be tested?<\/strong><\/p>\n I don\u2019t agree with this statement; it is not my intuition that string theory can\u2019t be tested. We may already have observations based on studies of the universe\u2019s large-scale structure and evolution that are telling us something about the nature of quantum gravity. Of course, further theoretical work will be needed to arrive at a mathematically rigorous, fully predictive framework for cosmology.<\/p>\n So, your paper\u2019s key predictions depend on the reality and nature of inflation. Will that be testable?<\/strong><\/p>\n There are the obvious observables, yes. Just as it amplified tiny quantum fluctuations in the early universe, inflation should have amplified gravitational waves in the early universe, too. Gravitational waves are ripples in spacetime, first predicted by Einstein, that were finally observed just a few years ago\u2014but the ones we have observed come from black holes and other stellar remnants in neighboring galaxies, not from the primordial universe. These amplified gravitational waves would leave their imprint on the polarization of the cosmic microwave background. Astronomers are actively trying to detect this polarization pattern.<\/p>\n So you are optimistic they will succeed?<\/strong><\/p>\n Well, our theory certainly predicts that primordial gravitational waves should be there at some level.<\/p><\/blockquote>\n As Sabine Hossenfelder points out<\/a>, saying “at some level”, without even an order of magnitude estimate, is not a prediction at all. In addition, this non-prediction is exactly the same non-prediction of the theory (eternal inflation) that Hertog is claiming his work challenges.<\/p>\n","protected":false},"excerpt":{"rendered":" The usual hype machine is at work this week, with the usual mechanism: University press offices and grant agencies put out irresponsible hype about the work of one their faculty or grantees. In this case, it’s Taming the multiverse: Stephen … Continue reading