What kinds of cosmological questions produce antinomies in the Critique of Pure Reason?

In his Critique of Pure Reason, Immanuel Kant identified four cosmological antinomies—contradictions where reason appears equally justified in supporting both a thesis and its antithesis. These arise when pure reason attempts to grasp the unconditioned regarding the following questions:

• The limits of the universe: Whether the universe has a beginning in time and is of finite spatial extent, or is infinite in both time and space.1
• The composition of matter: Whether every complex substance is composed of simple, indivisible parts, or whether nothing is simple and everything is infinitely divisible.1
• Causality and freedom: Whether there is freedom in the universe (i.e., not every event has a sufficient natural cause), or whether everything is determined solely by natural necessity.1
• The existence of a necessary being: Whether there exists a necessary being as part of the world or as its cause, or whether no such being exists anywhere.1

Kant used these contradictions to argue that human knowledge is limited to phenomena, while the noumena (things in themselves) remain beyond our reach.1