Deverebond

Fair to say that ,if a global boundary was ever discovered it would be perhaps the most revolutionary discovery in science? The equivalent of the ability to look at ourselves "from the outside" -something which I would count as a self contradictory concept. Raider5678's PhotoRaider5678 I personally look at it like the game of risk. We can only see a part of the map until we explore past it. If there is a boundary, just by finding what we think is a boundary and look past it we redefine the boundary. If the big bang theory is correct and as is theorised the speed of moving apart of galaxies is getting greater then there must be an edge of the universe but there must be something further than that to move into. I think that the question should be, what is outside the universe

My question is, is light heavy. Ive tried asking in other forums but don't get any good answers. I've been told photons are massless but have momentum (a product of mass and velocity) so that doesn't make sense. Matter is transformed into energy so if there is light in the universe is it getting less massive. If yes what runs out first energy or matter?