It's mathematically highly likely that there is life elsewhere in the universe

Travel, no. The universe feels designed to keep us apart.

But where are the signals-light/radio, or do we need new physics to see another communication medium?

Robotic prices or emissaries, maybe.

or maybe what there is likely never makes it past the microbial stage? As we go up the food chain, entropy gets so much higher, with as many things that can go wrong as can go right. Look at the fossil record, most higher life forms either adapt (dinosaurs becoming smaller birds) or die