I don’t know if there’s a definitive “scientific” answer to your good question, but let me posit a catechism paragraph that may be informative:*CCC#395 The power of Satan is, nonetheless, not infinite. He is only a creature, powerful from the fact that he is pure spirit, but still a creature. He cannot prevent the building up of God’s reign. Although Satan may act in the world out of hatred for God and his kingdom in Christ Jesus, and although his action may cause grave injuries - of a spiritual nature and, indirectly, even of a physical nature- to each man and to society, the action is permitted by divine providence which with strength and gentleness guides human and cosmic history. It is a great mystery that providence should permit diabolical activity, but “we know that in everything God works for good with those who love him.”*This tells us that God “allows” the devil to permeate this world apparently from his position in hell. We also see this in Scripture in the opening verses of the book of Job. In a similar way, we can imagine the activity of the holy angels, who always bear the face of God (Matt. 18:10), yet can act in this world without “leaving” heaven, so to speak. Eventually, those in heaven and hell (sheep and goats; cf. Matt 25), will be forever separated at the Second Coming.