## Friday, August 12, 2005 ... //

### Josephson disproving the landscape?

I feel that in order to compensate the revelation that Prof. Josephson believes ESP - and tries to unify Mind, Matter, and Music into his own version of M-theory :-) - we should write something nice and hot related to him.

The cosmological constant is surprisingly small. The zero point fluctuations associated with various fields are examples of terms that are expected to contribute much more; a currently fashionable explanation of the smallness is that the contributions cancel by chance and this chance is justified and "explained" by the required existence of life (or galaxies). However, one may imagine that there is an ultraviolet frequency cutoff that simply removes the high frequencies. I was writing about these issues when the concept of fat gravitons was discussed together with the rumors about the observed deviations from the Newton's law. Incidentally, the newest rumors (via A.S. of Stanford) say that the anomaly has disappeared once again.

Back and Mackey argued that the required frequency is about 1700 GHz; above this frequency, the vacuum fluctuations could disappear if a "natural" explanation of the dark energy operates in our Universe. If Back and Mackey are right (which is a very non-trivial "if", as argued later), such a disappearance could be measured using the Josephson junction that plays an important role for superconductivity; in fact, the critical frequency lies just behind the corner and should be accessible to our technology in the very near future.

Today, Paul Frampton - whom I send greetings - argues why such an unexpected cutoff would have dramatic consequences. For example, it could nuke out the landscape. As Frampton points out in a provocative but legitimate way, if the landscape is an inevitable mechanism implied by string theory, the observed cutoff would falsify not only the landscape but also string theory.

Would not it be fun if an obscure condensed matter phenomenon that was once believed to lead to a new generation of computers - but whose author eventually became an advocate of telekinesis and ghosts - would serve as a tool to show that the smallness of dark energy has a rational, non-religious explanation? Unfortunately, nature does not necessarily choose scenarios that maximize fun. What's the problem? The main problem is probably the statement by Jetzer and Straumann that the noise measurements of the Josephson junctions cannot determine the vacuum energy contributions; their line of argument is obvious. In any non-gravitational experiment (such as those proposed by Back and Mackey), only the energy differences matter.