She calls fine-tuning of the universe for life “anthropic selection”:
The general argument against the success of anthropic selection is that all evidence for the finetuning of our theories explores only a tiny space of all possible combinations of parameters. A typical argument for finetuning goes like this: If parameter X was only a tiny bit larger or smaller than the observed value, then atoms couldn’t exist or all stars would collapse or something similarly detrimental to the formation of large molecules. Hence, parameter X must have a certain value to high precision. However, these arguments for finetuning – of which there exist many – don’t take into account simultaneous changes in several parameters and are therefore inconclusive.
Importantly, besides this general argument there also exist explicit counterexamples. In the 2006 paper A Universe Without Weak Interactions, Harnik, Kribs, and Perez discussed a universe that seems capable of complex chemistry and yet has fundamental particles entirely different from our own. More recently, Abraham Loeb from Harvard argued that primitive forms of life might have been possible already in the early universe under circumstances very different from today’s. And a recent paper (ht Jacob Aron) adds another example:
Sabine Hossenfelder, “Sorry, the universe wasn’t made for you” at BackRe(Action) (September 6, 2016)
She has tweeted on this and written a paper as well.
From Miller and Meyer:
Hossenfelder’s arguments represent common errors committed by critics, so they deserve special attention. Her weakest argument is that the assumption of fine-tuning has led to inaccurate predictions related to the discovery of new fundamental particles. This assertion is without merit since a few inaccurate predictions related to one set of parameters in no way challenge the generally accepted evidence of fine-tuning for a completely different set. Another weak argument is that the analyses of individual parameters, such as the mass of an electron, “don’t take into account simultaneous changes in several parameters and are therefore inconclusive.” This criticism completely overlooks Luke Barnes’s careful studies of the effect of altering multiple parameters at the same time. His results only reinforce the fine-tuning conclusion.
A more substantive argument is that some details of the universe might be less restrictive than originally assumed. Hossenfelder cites a paper by Harnik, Kribs, and Perez that asserts that a universe without a weak force could still support life. Yet such claims have not withstood careful scrutiny. For instance, a paper by Louis Clavelli and Raymond White demonstrates that the authors of the initial paper only considered some of the consequences of removing the weak force. They ignored other consequences that would likely have precluded any possibility of the universe hosting complex life.
Brian Miller, Stephen C. Meyer, “Physicist Sabine Hossenfelder Challenges the Evidence for Cosmological Fine-Tuning” at Evolution News and Science Today
Fine-tuning of the universe is one of those concepts that can pass every possible evidence test and still be rejected because it is just not supposed to be true. No matter how foolish the arguments against it are, they will always appear preferable. If the situation results in confusion, well, confusion is clarity.
See also: What becomes of science when the evidence does not matter?