For as long as I can remember, the concept of infinity has mesmerized me. Georg Cantor's diagonality proof that some infinities are bigger than others completely transformed my way of thinking. The idea that something truly infinite exists in nature underlines what physicists search for every day, to explore the never ending infinity no matter how deep and profound. Physics works with two strands; the infinitely big and the infinitely tiny. Einstein's Relativity governing the infinitely big and Quantum Mechanics governing the infinitely tiny. As hard as we all try, combining and marrying the two has proven fruitless through the years.
By infinitely big, I mean that space can have intimate mass, volume and that time can tick forever. By infinitely tiny I mean that even the tiniest patches of space can still have an infinate amount of particles and varying masses which can change simultaneously.
So where does this leave us? If the universe is infinite, there are infinite possibilities. There is another infinite amount of copies of you reading this right now in an infinite universe. In theory, this means that measuring almost anything about the universe itself is impossible given the infinite amount of space and time there is in existence.
Some physicists actually campaign to retire the notion of infinity. Mathematics points to the universe being infinite but how can infinity be measured? Just because humans can't see the end doesn't make it infinite. More like an unknown end.
I read an article recently by Max Tegmark who agrees that infinity is a beautiful concept, it is ruining physics. Ironically the concept of infinity severely limits what can be discovered if the assumption of infinity is always used when speaking of visibly impossible distances outside the observable universe.
Consider this, if the universe is expanding constantly will it eventually snap? Assuming this is easy here on Earth with no actual matter similar to the fabric of space and time. It is too difficult to say providing the other side of the universe can't be observed neither the point to which it actually started.
At one point the speed of light was considered as infinite. When this notion changed the speed of light in a vacuum was clocked at 300,000km/s. Particles interact with the Higgs Field which is everywhere, the more a particle interacts the slower it will travel. Without any interaction particles can only travel at one speed, as fast as it is possible to go.
Moreover, to keep the speed of light infinite, we would need an infinite amount of mass to generate an infinite amount of energy to keep the speed of light as infinite. When the notion of infinity goes, more possibilities seem to appear. As difficult as this may be; something has to give.