Why does light have a speed? Why does Gravity (Gravitons) have a speed? There is nothing to slow them down... (Or is there!?) E.g. Sounds in water have a speed because of the matter they travel through. Light traveling through different materials will be effected on how fast it can travel through the material. (Sometimes faster). Just like when you drive your car, if there was no resistance (air) you would be able to travel much faster. That is why I believe light has a resistance to a substance ("stuff") we cannot detect. Is that what dark matter is btw?.... My theory on this is, no vacuum is empty. It is impossible to have "empty" space. We simply cannot detect "what" is there because of the state of existence. Anything there would not be effected by time from what I guess. (Not sure on this yet). This "stuff" that occupies this empty space effects the speed of light and possibly gravity. Unless there is some connection between light/gravity & time. Maybe it's a loop where light and gravity travel at instant speeds but we only see the maximum and they are cut at the maximum time would allow, maybe not stopped but put back through time (re-injected into the beginning) where the loop of time begins. Gravity plays a big role in time. Without it we would not exist. Maybe that's how the 2nd time frame gets it's light and gravity except it's all backwards and ours is forward. One example I've tried to come up with. Lets say you had 2 stars in "space". (And nothing else, no universe). 1. How far apart would these 2 stars be? (My theory on this is, if there is nothing in space then the distance would equal the most outer part of the star, they would be beside each other). There is no way for these 2 stars to be further apart unless there was some kind of "stuff" occupying the space in between them. Now lets say for argument sake you say "Sure" they can be further apart and there is nothingness in between them. (let's put them 1000 light years apart) How long would it take gravity to travel from one star to another? My answer would be instant. If there was "nothingness in space". Maybe then the gravitons occupy the space and effect the speed of light, then distance would be 1000 light years. But I don't think that's possible. This stuff that occupies the spaces we cannot detect i believe is in some way related to other states of existence and "time". As our universe is in a state of existence there are possibilities of other universes existing in the same "space" as us but in another state. Similar to how we cannot see certain spectrums of light we cannot see this universe. Hawking says there's 11 different dimensions and 2 different time frames, I'm still trying to figure that one out. Why 11?