If a mathematician wants to explore infinity, there are many options - for example by calculating π , or the square root of 2, or dividing any number by 0.
For philosophers, the concept of infinity is fraught with enigmas :
Such questions (and others) are on record as having been considered for at least 2,000 years - without, as yet, any general agreement.
Further reading with examples The Internet Encyclopedia of Philosophy (IEP), University of Tennessee.
Also see : 'Beyond Infinty' Australian Academy of Science.