He basically argues that there are no forces to be discovered which could have a measurable effect on our day-to-day functioning. For example, so far, we have not discovered any dark matter particles. This does not rule out that we will discover them, but for us humans (consisting of protons, neutrons and electrons) it will not have any effect. Because if it would, we already would have discovered them. The existence of other particles, like neutrino's, which zip through our bodies by the billions every day, also have no effect. We are of course effected by photons in some energy spectrums. In view of this, I think it is very unlickly that we discover any new physics which would allow us to communicate with aliens.

You mean room-temperature superconductors?