What is the easiest things we can do with numbers? Count them. But we can't count to infinity. We would need an infinite amount of time. Heck even manipulating infinity itself is hard. We have a proof (which is considered wrong by some, me included) that the sum of positive numbers (ie. 1,2,3,4,5,6....) is -1/12.
In many ways, the concept of infinity is a scientific enigma. The fact of the matter is that infinity cannot be proven real or unreal at this point. It's a concept that has never been realized, but it has been theorized. With that in mind, infinity is an enigma that we may very well be able to prove or disprove one day.
Infinity is a scientific enigma. It is large and mysterious and most people don't know if it actually exists and can be used right, or if it just too as much of our knowledge right now. We have no way of going all the way out into new universes so we don't know.
Although it is possible to use current knowledge of scientific and mathematic principles to form hypotheses about infinity, it's impossible to actually fully understand infinity because it cannot be tested. Infinity is something so large that it is immeasurable. It is not possible to understand or control all of its component in an experiment.
No, infinity is not a scientific enigma, because it is a sound and real principle. Infinity exists as a practical matter, for example in space. Infinity exists in a serious of numbers, for example a number divided by nine has an infinite number of decimals as its answer. Infinity is a proven concept that is well-represented in mathematical concepts.
I do not believe infinity is a scientific enigma. I believe an enigma is something obscure or that can not easily be understood or explained. Infinity simply means it goes on forever, without stopping. I think it is simple to explain what infinity means and I think many people can grasp the idea, as well.