LHC Experiments for finding parallel universes? I watched this video featuring Michio Kaku explaining parallel universes. In the last two minutes he said that experiments in the LHC could reveal that there might be parallel universes and then he stops. What experiment was he talking about? And how would that be possible? 
 A: The LHC is a discovery machine, and a lot of phenomenologists have worked hard to make predictions from various models , some of them using mainstream theories, some of them not.
Searching on the net I found this preprint which proposes checking the data for such signatures:

The existence of the dark matter with amount about five times the ordinary matter is now well established experimentally. There are now many candidates for this dark matter. However, dark matter could be just like the ordinary matter in a parallel universe. If both universes are described by a non-abelian gauge symmetries, then there will be no kinetic mixing between the ordinary photon and the dark photon, and the dark proton, dark electron and the corresponding dark nuclei, belonging to the parallel universe, will be stable. If the strong coupling constant, (αs)dark in the parallel universe is five times that of αs, then the dark proton will be about five time heavier, explaining why the dark matter is five times the ordinary matter. However, the two sectors will still interact via the Higgs boson of the two sectors. This will lead to the existence of a second light Higss boson, just like the Standard Model Higgs boson. This gives rise to the invisible decay modes of the Higgs boson which can be tested at the LHC, and the proposed ILC. 

They have put bounds from their model using available LHC data. Note that they are talking of two parallel universes, not infinite. So the video you watched probably has no connection to this, but I submit it to show how one can search for signatures of the invisible in the LHC data.
